Buriganga river

View with images and charts WATER QUALITY OF THE BURIGANGA RIVER AND ITS IMPACT ON SURROUNDINGS AREA 1.1Introduction Water is an important element for all living beings on this planet. It is needed not only for drinking, for growing food, for washing, but it is also important for many of the pleasant recreational aspects of life (Reeve, 2002). Water is one of the prime necessities of life. We can hardly live for a few days without water (Kudesia, 1990). It has become an essential commodity for the development of industries and agriculture (Kudesia, 1990). All life forms of earth depend upon water. Each human being needs to consume several litres of water daily to sustain his or her life (Baird, 1999). No life can exist without water since water is as essential for life as air is. Water is absolutely essential not only for survival of human beings, but also for animals, plants and all other living things (Raj, 1997).

Generally water contains iron, calcium, magnesium, manganese, silica, fluride, nitrate, phosphates, sulphates and chlorides (Kudesia, 1990). When the quantity of these parts increase then they affect the body system and cause destruction of health (Kudesia, 1990).

Arsenic salts can create cancer, cadmium affects kidney while barium carbonates has bad effects on veins, nerves and hearts. If the quantity of iron exceeds 30 mg/l then vomiting starts. Silver containing water causes liver and lung diseases (Kudesia, 1990). Excess of fluoride affects teeth and causes a disease called ‘Fluorosis’. The presence of manganese in water causes loss of memory, impotence and eye diseases. Vanadium spoils the fertility of the soil and creates cancer in the body while beryllium gives inflammation of pulmonary tissue (Kudesia, 1990).

When man and other higher animals began their life on this earth, there was absolutely no sign of pollution. There was perfect balance in various natural processes. The air and water was pure and soil was fertile. The problem of pollution arose with the very civilization of man. As soon as man learned to use fire, the air pollution began. As human pollution increased, there was increased in our working sphere and with this also increased the pollution (Trivedi, 1992). To day, the cry of “Pollution” is heard from all the nooks and corners of the globe, and pollution has become a major threat to the very existence of mankind on this earth (Trivedi, 1992).

Pollution of water may be by different sources, soil erosion in the catchments of rivers, streams and ponds leads to excessive sediments load thus polluting the water system (Trivedi, 1992). Streams and other water systems are also polluted by municipal waste and industrial effluent, particularly the responsibilities for maintaining civil amenities like water supply, drainage, slum, clearance, open and streets in the rests with our municipal bodies.

Unfortunately there has been a dismal failure on the part of our municipal bodies to keep the cities and near by streams clean (Trivedi, 1992).

Man has fried to cope with this scenario and has rapidly advanced his efforts to counteract this malady. In past few decades natural and polluted water have been studied in detail all over the world and considerable data are available on most kinds of pollutant and their effects on ecosystems as well as on organisms but when one look to the observation of sewage water qualities which includes the sludges, one finds that is essential to have a regular monitoring

of the qualities of the river water which becomes the basin of sewage water. The defilement of water as a result of human activities is a phenomenon as old as the increasing industrialization, urbanization and development activities and consequent pollution of water has brought a veritable water crisis. Today most of the rivers of world receive millions of litre of sewage, domestic waste, industrial and agricultural effluents containing substances varying in characteristics from simple nutrients to highly toxic substances (Trivedi, 1992).

We have still to recognize that good environment is the fundamental right of every citizen as it is essential for his physical, moral and social health. The problem of pollution continues to pose as serious a challenge as the threat of nuclear war (Kudesia, 1990).

Many fresh water resources are contaminate through human activities. Many millions more suffer from frequent and debilitating water-borne illness. About half of the inhabitants of developing countries do not access to safe drinking water and 75% have no sanitation, some of their wastes eventually contaminating their drinking supply. As well as causing much suffering, water-borne diseases also result in great economic loss (Mason, 1996). Water pollution has proven to be a very serious and very visible form of environmental contamination (Francis, 1994). Now a days river are used indiscriminately as dumps. The River Buriganga which is choked with industrial effluent and untreated sewage through numerous outfalls (Khan, 1199). Only one half of the urban population has access to reasonably safe waters; the remaining half depends on contaminated traditional sources. As a World Bank report of 1996 notes, the quantity of water produced per capita in the Greater Dhaka City has not kept pace with the rapid population growth (Khan 1999).

Untreated and waste waters generated in urban centres, industrial establishments etc. advertently or inadvertently are deposed of into the surface bodies which pollute them to such an extent that they become unfit for the designated use (Agrawal, 1994). Such waste water, if processed, can be recycled for use in low grade designated we like flushing of toilets, horticulture, cooling water requirement etc (Agrawal, 1994).

The need for wastewater treatment in developing countries can be seen in the numerous instances where raw sewage is diverted into streams or oceans, thus contaminating water that could be used for human consumption, industrial needs, land irrigation, fish production or recreation (Canter et. al., 1982). However only a small percentage of the population in most developing countries is served by waste water treatment processes, the lake of qualified personnel to operate and maintain sophisticated treatment processes, and the low priority generally assigned to waste water treatment relative to other national needs (Canter et. al., 1982).On the above discussions, all should be concerned about the polluted water of the Buriganga River. The authorities will have to chalk out for treating the water of Buriganga River. Not only the authorities but also all peoples have to be careful about the river.

1.2 Rational of the Study Safe environment is the precondition of safe life. But now our environment is being polluted with alarming rate. The scientists all over the world are searching the causes of water pollution, sources of water pollution and trying to find out the ways to prevent the environment from pollution.

There are some elements of our environment which are important for a safe environment.

Water is one of important elements of our environment. It is also equally important for our

life. Without fresh water life can not survive even a single moment. Not only for human life but also for agricultural, industrial, domestic and commercial uses, quality water is needed.

Now a day, to conserve environmental balance people from the different corner of the earth are very conscious, scientists are trying to find out the causes of environmental pollution, trying to find out the intensity of pollution and trying to find out the preventive measures.

There was held a seminar headlined “Bangladesh Environmental Management” at Bangladesh University of Engineering and Technology (BUET) in 1989 and drew some directions. Raising awareness of common people for realizing the effect of polluted environment was the main direction of that seminar on that day. So, to protect the environment degradation, first of all people’s awareness is needed. It is hopeful that the present research headlined “Water pollution of Buriganga River and its impact on surroundings” will help to raise awareness and will help to be careful about our environment.

A survey conducted in 1998 by the Department of Environment (DoE) showed that the river flowing by the capital’s western flank had been boxed in by at least 244 establishments, most of which are makeshift homes, small factories, dockyards, boat making workshops etc. The survey revealed that approximately 50 acres of Buriganga land have been encroached upon by those occupants. It is strongly desired that the present research will convey much information’s about encroachments which will help to understand pollution.

Water of the Buriganga River turned septic under the huge burden of effluents flowing into it, mostly coming from the sewerage system and caring chromium-rich leftovers from the tanneries at the city’s Hazaribag area. The river with black and stinking water, is constantly receiving industrial and other toxics and poisonous wastes of Dhaka city and oil and grease spill from riverine vessels. Its water is no Langer clean and transparent. Today, the living organisms in the river from Mirpur to Bangladesh-China Friendship Bridge point are all dead, according to a Department of Environment (DoE) survey. The dissolved oxygen in water near the Hazaribag point, according to the survey, reached at a low of 2 mg/litre during JanuaryMay period (Chowdhury, 1999). From above statement it is cleared about the quality of water of Buriganga River. For these reason, by taking consideration on water quality of Buriganga River, the selected research topics is logical and time worthy. The present research will help with a great extent to investigate the deteriorating quality of Buriganga River.

Though a few researches were conducted by various organizations, but the present research will provide further data and information to realize the present condition of water quality which was ignored in previous researches.

1.3 Objectives of the Study River is an important resource for mankind. Today’s industries dump all their waste whether solid or liquid into water (Sharma, 1994). The industry does it because it is the cheapest way to dispose off their unwanted waste. This is in spite of the fact that the law prohibits such dumping. The water of Buriganga River is being polluted through many ways. Polluted water contains many kinds of chemicals and other harmful products spoil the soil, plants and aquatic life and through various sources they enter into man’s body causing number of disorders in various parts and even cancer (Kudsia, 1990). Therefore, in order to ensure the sufficient quantity of good quality water for the peoples of adjoining area, all should be known to the water of the Buriganga River. To meet up the necessary requirements several specific objectives has been taken which are as follows: 1. To observe the changing scenario of various parameters of water in Buriganga River; 2. To find out the sources and extent of pollution;

3. To determine the impact of sewage and other waste waters on Buriganga River; 4. To improve water quality by setting standards for water treatment; and 5. To assess the effect of polluted water on its adjoining area.

1.4 Literature Review Andrews (1972) examined on environmental pollution. The study was designed to increase awareness of environmental problems and full comprehension of the cause and effects of environmental pollution. This study is very relevant to my research.

Reid (1982) reveals appropriate methods of treating water and waste water in developing countries. Here, he explained the importance of water and waste treatment to development of the second and third worlds.

Sarwar (1987) examined some aspect of pollution of drinking water in Dhaka city. He worked to find out the existing situation of water supply of Dhaka city and problems of pollution relating to it.

Stumm (1987) emphasized on chemical processes occurring at the interfaces of water with natural occurring solids. The processes discussed and the concepts presented are applicable to all natural waters (oceans and fresh waters as well as soil water systems and sediment water systems) and to the surfaces of natural solids such as minerals, soils, sediments, biota and humus.

Shamsuddin and Alam (1988) examined on significant variation in water properties between the non-industrial and the industrial sections of the Sitalakhya River and they found significant differences between the industrial and the non industrial stretches in both dry and wet seasons and hence, provide an indication of the extent of pollution in the industrial section.

Siddiqui (1989) examined about fresh water pollution and he categorized the use of fresh water such as i) Irrigation ii) Industry, and iii) Public use etc. As a result the earth’s resources continue to be severely taxed, resulting serious degradation of water quality.

Kudesia (1990) explained sources and nature of various types of industrial effluents and their constituents which are discharged by the industries. He revealed the various techniques involved in collection, preservation and tabulation of industrial samples. He further examined on water pollution principles of disinfection of drinking water, sanitary technology in environmental conditions of our subcontinent. It reveals a comprehensive account of the mechanisms involved in purification of drinking water with various oxidizing disinfectants. It also explains the possible measures to be adopted for controlling the problem of water pollution.

Hasbam (1990) has examined on river pollution. He tried to reveal the awareness of its damaging effects to the rivers and the life they contain, to the seas to which the river flow and on the people drinking the water, is spreading.

Kudesia (1990) worked on pollution and revealed that, various types of pollution occurring in man’s life due to interference with nature. These various sources of pollution have caused mental order, skin ailments, stomach, diseases, blindness and genetic changes; he also

explained the techniques for the detection of pollutants have been described in very lucid style so that a common man may understand them.

Trivedy (1990) examined on river water pollution. He revealed that pollution of a river first affects its chemical quality and them systematically destroys the community the delicate food web Diverse use of the river are seriously impaired due to pollution and even the polluters like industry suffer due to increased pollution of the river.

Trivedi (1992) reveals various problems related to the deterioration of man’s natural environment are through industrialization and urbanization of his mode of life including the danger of genetic degeneration of making himself.

Swarup (1992) studied on water pollution nature and Importance, of water pollution, municipal sewage treatment, Industrial waste etc.

Hossain and Saha (1993) revealed that during dry season (starting from December to March), most of leaves started to shed while a few vegetative buds unfolded. Flowering and fruiting of jackfruit trees start from november and continue up to mid April. Because of the temporary deciduous nature of the angiospermic parasites, they apparently looked to be almost dead by the end of March. By mid April they started a new life by producing numerous vegetative buds and unfolding young leaves, which continued up to the end of May. The growing period and shining yellowish-green color luxuriance persisted up to the end of July. Vegetative growth of the parasites began to cease by mid-August and during this time, older leaves lost their shining color, started to become a bit blackish and ultimately fell off from the plant body. Flower buds appeared in great numbers. Flowering, pollination (by bird) and fruiting were also recorded in some of the parasites during November to December, particularly in macrosolen cochinensis.

Socolow (1994) revealed a wide-ranging exploration of this approach to environmental problems. With contributions from a broad range of disciplines-environmental science technology assessment, economics, policy studies, the book lays out the range of concerns encompassed by industrial ecology.

Agrawal (1994) studied on 29 Indian rivers which reveals, all river water is unfit for human from human settlements account for four times as much as industrial effluents.

Sharma (1994) examined water pollution and pollution control acts, regulations. He has further discussed on pollution problem areas, pollution auditing of a plant global environmental essays etc.

Wahiduzzaman (1994) revealed an impact of textile to pollute the water of Sitalakhya. River various pollutants were discussed here to reach at the objectives.

BBS (1994) survived by agriculture census project. It’s running works in 1889 and its aim on internal fish cultivation identification. Finally it was three types that are fish cultivation, reject and under cultivation.

Bhuiya, et. al. (1994) investigated the sample eco map of Dhaka city surface water bodies.

Fifty water samples from different water bodies were drawn for parametric tests and measurements revealing physical and chemical characteristics of water quality or pollution vector. Parametric values have been obtained for the determinants of water quality of pollution viz. Temperature, hardness, turbidity, CO2, pH, DO and BOD. The physical and

chemical characteristics of water samples are determined by the methods of American Public Health Association.

Hounslow (1995) interrelated water analysis or a group of analyses with major applications on ground water pollution or contaminant transport.

Hounslow (1995) examined on water quality data to help bridge the gap between “Standard” geology and geochemistry and the present job requirements of hydrologists in their evaluation of various water-pollution scenarios.

Manivasakham (1995) examined to fulfill the need for a simple and concise manual on the computed physical & chemical examination of water, sewage and industrial effluents. Every effort has been made to present the material as simply and clearly as possible. Each and every determination are provided with chemical equations on which the colorimetric /titrimetric procedure is bases. The section “Interpretation of the result “enables him to know the limits, effects and other aspects regarding each constituent present in water and waste water.

Billah, et. al. (1995) compared the status of trace elements in drinking water of Jahangirnagar University Campus with water standard quality as per WHO specifications. The implication of the results is also discussed. The concentration of the trace elements in drinking water supplies in JU Campus is found lower than the maximum permissible level except those for Pb and Cd. The high concentrations of Pb and Cd may be due to geomorphological differences between JU Campus and Dhaka which is about 30 km away. These toxic elements may be removed from drinking water by standard procedures.

Schnoor (1996) examined on environmental modeling. The objective of his attempt is to demonstrate, how to develop and solve mathematical models for a wide variety of chemical pollutants. The emphasis is on natural water.

Khan, et .al. (1996) studied on sewage pollution in Chittagong Metropoliton Area. They found that all the parameters of the sewage discharged in the canals such as Chemical Oxygen Demand (COD), Biological Oxygen Demand (BoD) etc. fluctuated substantially.

Dissolved oxygen (Do) was always remarkably low.

Rahman (1996) examined on the perception of water quality in Khulna. He worked to demonstrate people’s ability to identify and to perceive the quality of water that they generally use for livelihood. To find this he surveys a questionnaire survey in the Khulna city.

Chnabra (1996) examined on soil salinity and water quality. He deals with the emerging issues of environmental degradation, especially the methodologies to put to productive uses urban and industrial waste waters.

Schnoor (1996) has examined environmental modeling, the objective of the study is to demonstrate how to develop and solve mathematical models for a wide variety of chemical pollutants. The emphasis is natural water.

Alam, et. al. (1997) investigated the effects of pollutants of Zia Fertilizer Factory discharged into the river water of the Meghna. They found that the values, however, are well within the allowable values both in the dry season and rainy season and rainy season.

Pavel, et. al. (1997) reveals that the soil was clay to loamy and was composed of 29.425% sand, 38.075% clay and 32.50% silt. The CEC was recorded as 13.74 meq/100g. Different physico-chemical properties of soil i.e., pH, OC, avail-N, avail-P and Exg-Ca were determined and were found to vary from 6.3 to 7.2, 0.52 to 0.78%, 9.5 to 13.00 ppm, 6.25 to 18.50 ppm and 65.85 to 95.35 mg/100g of soil respectively. The observation of the study indicates that the experimental pond was in a favorable condition for fish culture.

Farmer (1997) revealed a “Classic” media-bases approach to examining pollution issues, i.e. by undertaking a separate consideration of air, freshwater, marine and radioactive substances.

This approach is in effect, bucking the trend of integrating pollution management.

Giriappa (1997) has studied on rational water use that is gaining increasing importance during recent years in the management of modern agriculture. As irrigation is prerequisite for the use and achieving optimum results from the modern farm inputs, the study on water management in this context gains importance.

In the study “Dhaka City Storm Water Quality Assessment”, Khan and Chowdhury (1998) described that the deterioration of storm water quality in Dhaka has become a matter of concern in the recent years. Identified as one of the most densely populated cities in the world, Dhaka is unable to provide urban quality of living to its over 6 million inhabitants.

Much of this inability has resulted from failure to maintain the required water environment of the city.

Rahman, et. al. (2000) studied to investigate the effects of pollutants of the Jamuna Fertilizer Company Limited (JFCL) discharged into the river water of the Jamuna. The study shows that the pollutants in general had little effects on the river water.

Sultana and others (2000) investigated the water quality of Dhaka city lakes. They worked in the residential areas of Dhaka City there is a scarcity of open spaces but all four planned major residential areas are endowed with water bodies/lakes. Presence of lakes in the residential areas is an advantage as it enhances the beauty of the area, influences the microclimate with its cooling effect at night while the banks of the lakes are utilize for recreational purposes.

A project taken by Dhaka Water and Sewerage Authority (DWASA)(2000) on “Rehabilitation of Dholai Khal” described in its report that before 1947, storm water of Dhaka city drained out through different natural canals. But thereafter, the city developed spontaneously without any master plan causing depletion of natural drains. Henceforth water logging became a problem for the city. In 1964, Dholi khal was filled in for carrying out development works without taking any necessary steps to drain out the water of surrounding area and thus water logging turned out as a great problem.

Tareq and Rahman (2001) investigated the chemical and microbiological quality of potable water. The analytical results obtained indicated that there are considerable variations among the examined samples with respect to their chemical constituents which only occasionally fell above the maximum permissible levels of BSTI drinking water standards. Off all the water classes (DTW, HTW, TW) studied, the locally stored consumer level water showed the highest mean concentration for the ammonium (2.80-5.42 mg/l) and coliforms (210-890 cfu/100 ml). However the quality of water is satisfactory at their origin (i.e., DTW and HPTW), but at the consumers level (i.e., tap water; TW) is highly polluted with faecal coli forms, which may be attributed to the lack of proper management of water supply system.

A study named “Flood Management and Vulnerability of Dhaka City” done by Huq, et. al. in 2001. In their study “effect of urbanization on storm runoff characteristics of Dhaka City” investigated the impact of land use changes due to urbanization on storm runoff characteristics in the eastern part of Dhaka City. They found that the volume of peak rate runoff increases with growth in urbanization. Most of the low lying lands, which once acted as retarding basin, have been filled up. Computed results show that runoff volume is increasing with increase in built-up area in Dhaka City.

Reeve (2002) examined on environmental analysis. It is an introduction into how, sometimes familiar, at other times less familiar, chemical analytical techniques are applied to the environment.

Downs (2002) studied on monitoring ecological impacts it reveals the logic and ways may make strong inferences that lie behind the design of effective monitoring programs – those that allow detecting and assessing, with some confidence whether specified human activities are causing unacceptable changes to the environment.

Hussain (2003) identified the transformation of urban fringe wet lands eastern Dhaka City.

She also studied the nature and process of urban fringe wetland transformation and its consequential effects. She observed that wetland at eastern part of Dhaka city has been transformed and drastic changes have been occurred in the permanent and seasonal wetland during at last ten years.

Alam (2003) described that after implementation of the flood control project in the Dhaka West, unplanned and uncontrolled expansion of urban area stretched rapidly toward the lowlying areas adjacent to the flood protection embankment. These are deeply flooded floodplain areas close to the river. The residents of the houses in these lowlands suffer from inundation due to accumulation of rainwater after heavy rainfall. Land development through land filling processes in the low-lying areas is causing a drastic reduction in water storage areas.

Construction of embankments through low-lying areas without providing adequate drainage facilities has caused internal flooding adversely affecting the residents in those areas.

Ansari (2004) revealed there has been a changing trend in the land use feature over years hail hoar in the human ecological factors. This is happening mostly in the recent decades. The ecological hail hoar is disturbing. Loss at water bodies, water pollution, and introducing exotic species well as pest attract is losing biodiversity in the study area.

But at present it seems that the beauty spots of the residential areas have undergone drastic change, instead of being a healthy habitat for the residents the lakes have turned into highly polluted water bodies endangering the environment and the health of the residents. They compared with the water quality with the Bangladesh standard.

DOE had analyzed the suspended data of the Dhaka city different lakes, utilizing the data of 1990-2007. According their analysis the water quality of Dhaka city lakes clearly identified (DOE, 2007).

From the above discussion it can be said, there is a lot of works on the water pollution but there is no works on water pollution and its impact in selected study area. For this reason, this research is conducted and tried to investigate some objectives.

1.5 Organization of the Study In first chapter there is discussed an introductory discussion on water pollution and its importance. There are also discussed on the significance of the present study and was set

some objectives. Literature review was constructed in this chapter. The scope and limitations were discussed also in this chapter.

In the second chapter research methodology is discussed by which the present study is explored. Here it is discussed how to gather primary and secondary data which is related with the present study and various chemical regents are discussed also to find out the state of the water.

Chapter three is constructed on study area of the present research. There are discussed physiographic and geologic characteristics, soil characteristics, climatic characteristics and land uses of the study area.

Water pollution and pollutants are discussed in the chapter four. Sources of pollution and various pollutants which are mainly accused of water pollution are discussed in this chapter.

In chapter five various sources are discussed from where wastes are coming and mixing up with the water of the Buriganga River. The solid wastes are classified in to several types which are shown in this chapter.

Chapter six is reveals about the state of the water of the Buriganga River. Parameters of the water were collected from the Department of Environment is represented in this chapter.

Collected samples were examined in the laboratory also represented here.

In chapter seven, collected information’s by questionnaire survey are analyzed. Three locations were selected for survey where 200 questionnaires were used to gather various information which are represented in this chapter, and in chapter eight findings, discussion and recommendation were made.

1.7 Scope and Limitations of the Study The present study is constructed on water quality of Buriganga River and its impact on surroundings area. It’s on analytical representation and bases on secondary data specially. To analyze water quality some of parameters is selected and the present research is constructed after based on these parameters. Water pollution, various pollutants, sources of pollutants, prevention of pollutants, probable remedy of pollution, impacts of pollution on surrounding are of Buriganga river are included in the present study. At the same time to assess environmental condition, for there examination on geological condition, soil condition, drainage system, uses of river water etc are discussed in the present study.

Water of Buriganga River is a dependable source of water to the people of Dhaka city. But the present study will bring a preliminary conception about various sources of pollution existing in the study area. In spite of above advantages there are some limitations also. One of the major problems is data collection. Data collection is very difficult and expensive. To collect related data and sample test needs huge amount of money. So scarcity of money and scarcity of times limits the research scope. The present study is based on secondary data though primary data was collected. But the matter of fact all parameters could not obtain as it is very costly.

Besides all of these barriers the present study is very much informative and all selected objective was fulfilled. The present study will also be helpful to them who desire to further study in this sector.

2.1 Introduction To extract real phenomena, research is most easiest and traditional systems. Several procedures are needed to complete any research. The ultimate result of a research depends on overall procedures. So adjustment between objective and procedures is an important issue.

Generally research can be considered as a scientific process to get vast knowledge about a certain thing.

Accurate and dependable information’s are needed for obtaining true knowledge about something. Data collection is the most important part to perform a research. For this reason in various researches, many types of data are colleted to meet up objectives.

There is a vast scope in geography and environment as a discipline, in geographical research man, nature; environment and spatial discrimination are priority full. In geographic research, research methodology is constructed after based on physical, social and economic situation of a certain area. For this reason different methodology are made for different places.

“Water pollution of Buriganga River and its impact on surrounding” is a title of present research which is conducted based on field data and secondary data. To perform the present research the following procedures were followed: 2.2 Data Sources The research is based on both primary and secondary data. Primary data were collected through field work and on laboratory work and secondary data were colleted from various sources as detailed below (Table 2.1): Table 2.1: Sources of data.

Primary data 1. Field work 2. Laboratory 3. Analysis of water samples

Secondary data Department of Environmental, Dhaka Dhaka Municipal corporation Various published and unpublished materials.

2.2.1 Map Collection After selection of a study area maps and maps related information were collected. Maps were collected from various institutions such as Department of Environmental, RJUK, and the Department of Geography and Environmental of Jahanagirnagar University.

2.2.2 Book Review Related information both published and unpublished, related with the present research were collected.

2.2.3Primary Data To capture primary data direct field survey was made and to determine the pollution of the Buriganga River water sample was collected and a questionnaire survey was prepared at survey area.

2.2.4 Secondary data Collection To fulfill the aims and objectives of the present study, the importance of secondary data are very essential. In this research secondary data were used which are generally published by various institutions and researchers. Various published and unpublished information’s, file, research paper and data were also used here. Moreover river water pollution and its impact related many books, published unpublished journal, the daily news paper were explored thoroughly. Major sources of secondary data from where secondary data were collected mostly are Department of Environment, Dhaka Municipal Corporation, Department of Geography and Environmental, Jahangirnagar University, Department of Environmental Science, Jahangirnagar University, Central library of Jahangirnagar University, Bangladesh water Development Board, Bangladesh University of Engineering and Technology are especially mentionable.

2.3 Analysis of primary Data Samples were collected from the various point of the Buriganga River. These sample points were selected randomly.

Water samples were collected in about 1000 ml bottles and temperature of the water was taken on the spot. Collected samples were analyzed by the Department of Environmental Science, Jahangirnagar University and the Department of Chemistry, Jahangirnagar University. The seven parameters by which analysis was done were selected in accordance with water quality standard in Bangladesh as well as with the international standard. These standards refer to drinking, fishing, industrial uses, agricultural uses and recreational uses.

2.3.1 Numerical Presentation Numeral presentations were made to represent the collected data because it helps to realize the main idea.

2.3.2 Graphical Presentation The result was presented by graphical diagram. That helps to realize the result of the study which is presented with vertical graph and circular graph.

The methodology developed to perform selected objectives which are given below as a flow chart (Flow chart 2.1):

Flow Chart 2.1: Methodology of the present research.

Introduction

Data sources

Various Departments Published unpublished Secondary data

Primary data

material Field work Laboratory test Analysis of water test

Analysis of Primary data

Analysis of Secondary data

Numerical presentation Graphical Presentation

Result Analysis

Conclusion & Recommendations

2.4 Water Quality Measurement Three primary factors are necessary to determine the water quality. These are sampling techniques, analytical procedures, and units of expression. Misunderstanding and misinterpretation of data is feasible when these factors are not clearly understood. Two of these are discussed as follows: 2.4.1 Sampling Techniques

To analyze the water quality of the Buriganga River samples were collected. Experiments were carried on the collected water sample to determine the physical, chemical and the biological aspects of the water. Physical examination was conducted to find out the color, conductivity, temperature and odor. Chemical examination revealed the total solids/dissolved solids in the water and the pH component of the water. Biological examination determined the dissolved oxygen of the water.

2.4.2 Analytical Procedures pH of the water samples were measured at field by using digital pH meter ( SCOTTOH GERATE, Gmh, CG 818). Dissolved Solids & suspended solids were determined gravimetrically according to procedures given by USPA and vesilind in the Laboratory and following instruments were used in the laboratory (Table2.2).

Table 2.2: Instruments used in the laboratory.

Parameters

Instruments

pH

Microprocessor pH meter, Model No- 211, Hanna instrument Conductivity meter, Model No- HI 8633, Hanna instrument

Specific Electric Conductivity Salinity

Conductivity meter, Model No- HI 8633, Hanna instrument

Dissolved Oxygen

Dissolved Oxygen Instrument

TDS (Total Dissolved solid)

Total Dissolved Solid meter, Model No- HI 8734, Hanna Instrument

Turbidity

Microprocessor Turbidity Meter. Model No- HI93703, Hanna Instrument

Meter,

Model

No-9143, Hanna

2.4.3 Determination of Water Temperature The temperature was taken by a mercury thermometer graduated 0ยบC to 100ยบC. From the water sample was taken in a clean beaker and bulb of the thermometer was dipped into the water for one minute. The mercury of the bulb was gradually raised through the uniform bore of the stem and become stationary at a certain point. A fine remark was put on the stem of the thermometer at the position where top of the mercury become stationary. The value was noted and repeated the procedure three times in the sample. The mean value was the water temperature.

2.4.4 pH Determination The pH of water sample was determined by using a glass electrode pH meter (Griffin pH meter, model No.40). The pH meter was calibrated with two known buffer solutions (pH 4.0 and 9.2). Then the electrode was rinsed thoroughly by using distilled water and wiped by

using tissue paper. The electrode was dipped into the sample water and was kept until the stable reading was observed. The final reading was recorded.

2.4.5 Dissolved Oxygen Dissolved oxygen is probably the single most important chemical parameter that is required to ensure the ecological health of receiving water. It is frequently the key substance in determining the extent of kinds of life in a water body. Dissolved oxygen content of sample water was determined by using DO meter (HANNA INSTRUMENTS: HI9143, Dissolved Oxygen Meter, Portugal). The sample bottle (250 ml.) was completely filled up with water to avoid the existence of air and DO was measured just after the sample collection.

2.4.6 Biochemical Oxygen Demand (BOD) Biological Oxygen Demand refers to the quantity of oxygen required by bacteria and other microorganisms in biochemical degradation and transformation of organic matter under aerobic conditions. This quantity of oxygen is proportional to the degradable organic substances present and therefore it is possible to estimate from the BOD 5 value the degree of water pollution. High BOD5 values indicate water pollution. BOD5 is an empirical, semiquantitative method, based on oxidation of organic matter by suitable microorganisms during 5-day period. The basic principal underlying BOD determination is the measurement of the DO of sample that is utilized by suitable microorganisms during 5-day period.

The following reaction takes place, Microorganism CH2O + O2 CO2 + H 2O i) Procedure The collected sample was taken in a suitable bottle (250ml). The dissolved oxygen (DO) content of water (D1) was measured by using DO meter (HANNA INSTRUMENTS: HI9143.

Dissolved oxygen meter, Portugal) before incubation. Then the bottle was sealed and incubated the dissolved oxygen (DO) of eater was measured by using DO meter. ii) Calculation The following formula was used to calculated the biological oxygen demand (BOD 5) of water, BOD5 (mg/l) = D1 - D2 Where, D1 = Dissolved oxygen (DO) content water sample before incubation.

D2 = Dissolved oxygen (DO) content of water sample after incubation.

2.4.7 Determination of Chlorine Concentration The best-known reaction for chloride determination is based on the formation of nearly insoluble silver salts.

Cl¯ + AgNO3 → AgCl (white spongy ppt) AgNO3 in the presence of the indicator K2CrO4, is used for precipitating chloride.

NaCl + AgNO3 → AgCl +NaNO3 K2CrO4 +2AgNO3 Ag2CrO4 + 2KNO3 First of all, the most stable salt (AgCl) is formed and then the excessive AgNO 3 reacts with K2CrO4, forming a reddish brown of AgCrO4, which indicate the end point of the reaction.

i) Apparatus Burette, Pipette, Conical flask, Porcelain dish and shaking machine. ii) Reagents 1. Potassium cromate indicator: 5%aqueous solution of pure K2CrO4.

2. 0.02N AgNO3 solution: Dissolved 3.4g of AgNO3 in double distilled water & make up to 1 liter. Standardize this solution against a standard NaCl solution and store in amber colored bottle away from light. iii) Procedure 1. Take 5ml of filter water sample.

2. Add 5/6drops of K2CrO4 indicator and titrate the solution with 0.02N AgNO3 solution (with stirring) till the first reddish brown tinge appear. The volume of AgNO 3 (titre blue) required refers to the amount of chloride present. iv) Calculation 1 ml of 0.049 N AgNO3 = 1 mg of Cl¯ A × N ×1000 Therefore, Chloride (mg/l) = 0.049 × V A = ml of the AgNO3 required.

N = Normality of the silver nitrate solution.

V = ml of the sample taken.

2.4.8 Determination Total Hardness A compleximetric titration using EDTA is a classical method for determining Ca and Mg simultaneously or individually. Analytical success is based on eliminating possible interfering ions, achieving the required pH and employing the approximate indicator. i) Reagents 1. Buffer solution of pH 10 (NH4Cl-NH4OH buffer).

2. Standard EDTA solution (0.02N): Primary standard disodium EDTA was used.

3. NH2OH.HCl solution: Dissolved in five gm of NH2OH.HCl in 100ml of distilled water.

4. K4Fe(CN6)solution: Dissolve 4gm of reagent grade potassium ferocyanide trihydrate {K4Fe(CN)6.3H2O}in 100ml of distilled water.

5. TEA reagent grade.

6. EBT indicator: Dissolved 02gm of EBT in 50ml of methanol. Prepare a fresh solution.

7. Calcon indicator: Dissolve 20ml of calcon in 50ml of methanol. Prepare a fresh a solution.

8. NaOH 10% solution: Dissolved 10gm of reagent grade NaOH in 90ml of distilled water. ii) Procedure 1. Place 5ml of sample water and add 5ml buffer solution.

2. Add 10 drops of NH2OH,HCL, K2Fe(CN)6 respectively.

3. Add 5 drops of TEA. 4. Bring the solution to pH 10 by adding 15ml or larger quantities if needed, of the buffer solution. Heat the solution to near boiling for several minutes to speed the reaction.

5. When the solution has cooled, add 10drops of EBT indicator and titrate it from a blue to a red permanent color with the standard Ca solution. iii) Calculation 1ml of 0.01M EDTA= 1mg CaCO3 Therefore, A × M × 100000 Total hardness (mg CaCO3/l) = V A = ml of required Mg EDTA in titration.

M = Morality of the EDTA titrantion.

V = ml of the sample.

2.4.9 Determination Total Alkalinity Hydroxide, Carbonate and Bicarbonate Alkalinity titremetric method (APHA, 1976) was used for determining total alkalinity. The estimation is based on the simple acidimetric titration. in the presence of phenolphthalein for CO3 (pH >8.5) and then in the presence of methyl orange for HCO3 (pH < 6.0).

When a mixture of carbonate and bicarbonate is titrated with standard H2SO4, the following reactions occursNaCO3 +H2SO4 → NaHSO4 + NaHCO3 2NaHCO3 + H2SO4 → Na2SO4 + 2CO2 +2H2O Phenolphthalein gives color so long as CO3 remains. It will discharged as soon as all the CO3 is converted into HCO3 . HCO3 can be titrated to neutrality with methyl orange as indicator. In the titration with methyl orange, the original HCO 3 , together with the HCO 3 found from the titration of CO3 , is neutralized by the standard acid. i) Apparatus 1. Burette 2. Pipette 3. Conical flask 4. Porcelain disk 5. Shaking machine. ii) Reagents 1. Phenolphthalein indicator: 0.25% solution in 60% ethyl alcohol.

2. Methyl orange indicator: 0.5% solution in 95% alcohol.

3. Standard H2SO4 (0.0925N). iii) Procedure 10ml water sample was taken in a conical flask. Two drops of Phenolphthalein indicator was added to it. No pink color was formed which indicated the absence of hydroxide and carbonate alkalinity.

3.1 Introduction Buriganga River is a tidal-influenced river passing through western and southern part of Dhaka city. In ancient times one course of the Ganges used to reach the Bay of Bengal through Dhaleshwari River. This course gradually shifted and ultimately lost its link with the main channel of the Ganges and was renamed as the Buriganga. The Buriganga River originated from the Dhaleshwari River. Its average width and depth are 400m and 10 m respectively. This river is only 27 km long (Banglapedia). The Turag has met with the Buriganga at Kamrangirchar of Dhaka city. However, the main flow of the Buriganga River comes from the Turag and it meets with the Dhaleshwari River at Munsiganj. The present head of the Buriganga near Chhaglakandi has silted up and opens only during floods, but the lower part is still open throughout the year. The Buriganga River has a great economic importance. It is used as an important water route through which people may go anywhere of Bangladesh by launch by boats etc. This river has been selected as study area (Fig.3.1) and the present study is performed from Mirpur Bridge to Pagla in this river (Fig.3.2).

3.2 Physiography and Geology The Buriganga is being polluted day by day. For measuring the state of water quality of the river some objectives has been taken. To meet up that objectives extensive measurement is must. Physiographic and geology are very important to the present research. For finding out the result vast measurement has been conducted on physiographic and geology of study area.

There has been a short description on these matters as follows: 3.2.1 Location The Buriganga is located within 23°35′ north latitude to 23°48′ north latitude and 90°18′ east longitude to 90°25′ east longitude (Fig.3.3). Dhaka Metropolitan city is on the bank of northern side of the Buriganga River.

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3.2.2 Physiographic Divisions The Buriganga River is flowing through its flood plain containing both old and new alluvium.

From Kalmar char to choto char it passes through the southern most part of the Madhupur tract which extends up to the northern extremity of the Buriganga basin. The southern bank and the flood plain is composed of newer alluvium of the Ganges and the Jamuna, carried to the Buriganga floodplain through the Dhaleswari.

Topographically the Madhupur tract is more elevated than the adjoining floodplain although floods might at times inundate the fringe of the terrace. Probably their higher relief is due not only to the more resistant nature of the materials to weathering and denudation but also due to the gradient uplift which the region has undergone. It has an elevation of about 20 feet on the east rising to about 100 feet on the west. On the south it dips gradually beneath the recent floodplain of the Buriganga and the Dhaleswari but on the east it forms an escarpment with a low angle (Khondaker, 1977).

The Buriganga basin may be classified into the following physiographic units (Fig. 3.4).

Closely dissected terrace Mixed terrace outliers and floodplain Active flood plain and Old meander floodplain.

Closely dissected terrace: closely dissected terrace is composed of mixed red. Non-friable clays and loam to grey loams, mainly shallow and imperfectly drained with light grey silt clay loams in ralleys. They comprise level or rounded small chalas up to about quarter mile broad, usually rising abruptly 10 to 20 feet above broad valleys. The terrace has undergone human interferences as the city of Dhaka stands on it. Closely dissected terrace in the Buriganga basin in about 8 square miles (Khondaker, 1977).

Mixed terrace outliers and floodplain: Mixed terrace outliers and floodplain are the continuation of materials of the Madhupur terrace and recent floodplains. Closely dissected terrace stands on the west of the mixed terrace outliers and floodplain. Mixed terrace is composed of mixed red, non-friable clays, and loam to grey loams, and deep friable mettled soils, mainly yellow brown and grey, imperfectly to poorly drain. The comparatively low lying baids of the terrace have been filled up with the upland soils by erosion. The pagla, Fatulla and Syampur Khals are the principle seasonal streams which drain the terrace in the rainy season. The total area of the terrace is about 12 square miles.

Active floodplain: The active floodplain is the most widespread and elongated hypsographic unit of the Buriganga basin. The floodplain lies along the southern bank of the Buriganga.

This area is annually inundated by flood water and the sand deposit on it is about 4 inches every year. In the upstream the sandy and silt clay loam of the Jamuna system is found while in the south and south-east the Ganges silt clay loam predominates. The total area of this unit is about 33 square miles. The topography of the floodplain is characterized by back swamps, channel bars, natural levees etc and other floodplain features (Khondakar, 1977).

Old meander flood plain: Old meander floodplain has been formed by the Buriganga, the Turag and their tributaries with in the study area. These tributary channels, when in flood, eventually breakout into the adjoining low lying lands to form new channels, subsequently laying down new deposits over the former basin deposits; and all times, following the mean during course of the tributaries. Near and around the confluence of the Buriganga and the Turag Kalmarchar, pitachaka and the Ghata char form part of the old meander floodplains.

The total area of this unit is about 24 square miles (Khondaker, 1977).

3.2.3 Geology The area in and around Dhaka, is physiographic ally located in the southern part of the Madhupur tract, which is one of the May or Pleistocene units of Bangladesh. Tectonically the area situated into the folded flank of the Bengal fore deep (Baktine). The geological formations delineated in the area are Pleistocene Madhupur clay and recent alluvium (Fig. 3.5) (Khondaker, 1977).

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3.2.4 Soil The soil of Buriganga River varies place to place. Closely dissected terrace is composed of mixed red, non friable clays and loam to grey loam, mainly shallow and imperfectly drained with light grey silt clay loam in valleys. Mixed terrace is composed of mixed red, non-friable clays and loam to grey loams, and deep friable mottled soils, mainly yellow brown and grey.

In the upstream the sandy and silt clay loam of the Jamuna system is found while in the south and south-east the Ganges silt clay loam predominates. (Khondaker, 1977).

3.2.5 Buriganga River System The river system of Buriganga River is spreaded in Dhaka city and in neighboring area of Dhaka City. Hydro logically, the river is not separated. Many rivers are interlinked with this river such as Balu River, Dhaleswari River, Kaliganga River, Sitalakhya River, Tongi khal and Turag River (Fig. 2.6). These rivers are also tributaries and brances of the Ganga, the Jumana and the Brahmaputra. Moreover, Dhanmondi Lake and Gulsan Lake also linked with the Burigangla River through Tejgaon, Mohakhali and Beghunbari khal. Most of the pollutants of savar, Dhaka Metropoliton area and Keranigonj area falling into the Buriganga river system. For this reason severe complexity is found in the hydrologic characteristics of Buriganga River. Major tributaries of the Buriganga River are dhulai khal, Shampur khal, Pagla khal and major branches are Jalokhali khal and painer khal (Nahar, 2000

3.2.6 Water Flow The drainage area of the Buriganga from kolmar char to char Kamrongi is highly disrupted.

The low lying areas to the north of Kalmar char upto Ghata char remaine under water from 6 to 8 months every year. (Khondakar, 1977). Then the river Buriganga is flowing through a strait channel from char Kamrangi to Fatulla and it then takes a sharp turn to the south to join the Dhaleswari (Khondakar, 1977). In this river, less influence of ebbs and tides is found in rainy season (June-October) and influence of ebbs and tides is high in winter season (November- May). If back water effect is exist in rainy season the river can also be changed into tidal river. But the tidal range of this river is not much high. In 1993 the tidal range was highest 0.75 metre, it varies year to year but its range is normally very low (Nahar, 2000).

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3.2.7 Climate Laying with the humid tropical zone the Buriganga basin is governed by the tropical monsoon type of climate. The general characteristics of this type of climate are heavy rainfall, high temperature, often excessive humidity and fairly marked seasonal variation.

The basin area receives concentrated rainfall from April to October which averages 90 inches annually, the Madhupur tract in the north receiving comparatively more. The area is also

affected by tropical cyclones, northwesters, associated with tornado which causes heavy rainfall. Annual mean temperature varies from 70F to 85째F having mean July temperature 82째F and mean January temperature 65째F (Khondaker, 1977).

3.3 Land Use Mixed type land uses are found on the bank of the Buriganga River Basically the development of the south tremendously. After the construction of china-Bangladesh Maitri satu-1 (China-Bangladesh Friendship bridge-1) in 1989 the land use pattern has been changed massively. So in the northern part of this urban land uses are prominent at the same time in the southern part rural land uses are prominent. But at present in the southern part mixed type of land uses such as urban-rural land uses are being found. The prominent types of land use on the bank of the Buriganga River as following.

3.3.1 Settlement Dhaka-Narayangonj town stands of the northern bank of the Buriganga river where highly populated settlements is found. Old Dhaka, which is also a best example of unplanned land use practice adjoining river Major parts of Hazarbagh, Rayer bazar, Mohammadpur, Lalbagh, Sutrapur, Gandaria, Kamrangir char etc. are also being used as residential area. Moreover there are slums area across the Dhaka-Narayangonj Flood control Dam and In Islampur, Babubazar there are also found slums those are polluting the water of the Buriganga River (Nahar, 2000).

3.3.2 Industry In Hazaribag area, there are about 277 tannery industries. The area is very close to the Buriganga River. Moreover there are 15 dying, 31 brick filed in savar and Aminbazar area.

There are also is Aluminum Industry, 3 salt industry, 1 pharmaceutical industry, 1 soap factory, 2 match factory and 2 lead-zinc industry along the banks of the Buriganga river.

Further more there are 2 hardboard mills, 1 cold storage, and 2 ship repairing industry are located between china-Bangladesh Friendship Bridges 1 to Babubazar area. The pollutants materials are being yield by these industrial and being disposed in the water of Buriganga River. These are hampering the natural flow of the river and polluting the water massively (Nahar, 2000).

3.3.3 Trade and Commerce Many kinds of business has bee flourished beside the old Dhaka city. Most of the business institutes are located at Babubazar, Chalkbazar, Sadarghat, Kamrangir char, Jinjira etc.

Various items of goods are sold there such fruits, vegetables, fishes etc. About 40-50 new garments industry was established as a branch of old Dhaka wholesale garment industry between kaligonj to Asadnagar in 1988. So a great portion of bank of the Buriganga River is engaged with business related activities (Nahar, 2000).

3.3.4 Agricultural Land Use Most of the land of Bangladesh is being used as agricultural land. But agricultural lands are decreasing while increasing urban land use. Dhaleshwari is very fertile. So the area was used

as agricultural land massively. Now the patterns are being changed even in southern part of Buriganga River (Nahar, 2000).

3.4. Uses of Water Buriganga River is only route of Dhaka city to communicate with southern area of Bangladesh. So the largest river port was flourished on the north bank of the river. Therefore a large part of the bank is being used by the people which also a reason of pollution. Most of the water of Buriganga River is being used by the resident of Dhaka city. The water is also being used in many ways as follows: a) Dhaka WASA collects water from the Chadnighat and purifies it and serves it through the city.

Every day people take their bath, wash their cloths and wash their household utensils in the river.

The water of Buriganga River is being used for agricultural cultivation purposes.

Most of the Industry collects their necessary water from this river and this is the only source of water.

The water course is being used as a route for boat, Stimmer, Lauch etc.

The river is also a source of recreation for the people.

Besides these uses, the water of Buriganga River is used for many other purposes. For these reason we can say the river has a great significance to the inhabitants of Dhaka city also to the people of surrounding area.

4.1 Introduction Comprising over 70% of the Earthâ&#x20AC;&#x2122;s surface, water is undoubtedly the most precious natural resources that exist on our planet. Without the seemingly invaluable compound comprised of hydrogen and oxygen, life on Earth would be non-existent. Though it is well known to us but we disregard this fact by polluting our rivers, lakes and oceans. As a result various organisms are dying at a very alarming rate, where we are mostly accused of polluting water. In addition to innocent organisms dying off, our drinking water has become greatly affected. Sewage, detergents, pesticides, and other chemical residues have changed sparkling rivers into foulsmelling sewers and clear blue lakes, rivers etc have become polluted, which is unfit for most human needs (Andrew, 1972).

4.2 Pollution The word pollution has been taken from the Latin word pollutioem, meaning defilement from pollure, to soil or defile (make dirty). Oxford English Dictionary used the word pollute with reference to physical contamination of terrestrial or aquatic environments in nineteenth century. In 20th century the word pollution was used with reference to contamination of water, soil and air (Kudesia, 1990). According to general thinking of people, pollution means the introduction into natural waters of anything that to them appears to be foreign. But this idea neither includes the concept of measurable change in the receiving water nor the concept of reduction in the value of that water for any use by man.

4.3 Water Pollution

There are a number of definitions of water pollution. In 1952, Coulson and Forbes defined water pollution as the addition of something to water which changes its natural qualities so that the riparian properties does not get the natural water of the stream transmitted to him. As well in 1966, national research committee on pollution gave a report in which water pollution is defined as a undesirable change in the physical, chemical or biological characteristics of water that may or will harmfully affect human life or that of over desirably species, our industrial processes, living conditions and cultural assets or that may or will waste or deteriorate our raw materials resources. Water pollution means direct or indirect introduction as a result of human activity of substances, heat into the water which may be harmful to human health or the quality of the environment, result in damage to material property, or impair or interfere with amenities and other legitimate uses of the environment (Farmer, 1997).

From the above discussions it may be defined the general definition as follows: â&#x20AC;&#x153;When some excess substance mixes up with water and change its natural characteristics such as if changes physical, chemical and biological characteristics of water and if it affects on the surroundings greatly at that time it can be considered as water pollution.â&#x20AC;?

4.4 Water Pollution: Sources and Distribution Process There are two conventional ways of describing water pollution sources. One is based on the activity that produces the pollutant, and the other is based on the way the pollution is discharged into the environment. The latter uses only two categories, generally called point sources and non-point sources.

4.4.1 Point Sources Point source pollution is that from a specific source, and is released at a known discharge point or outfall, usually a pipe or ditch. The main point sources are municipal sewer systems, industry, and power plants. While point source pollutants are very important, the majority of stream pollution comes from non-point sources.

4.4.2 Point Source Pollution Non-point source pollution represents spatially dispersed usually nonspecific, sources that are released in various ways at many points in the environment. Storm water in both rural and urban areas is the principle source of non-point pollution. It is generated from various land uses over large areas and is discharged into streams, lakes, and other water features at countless places along channels and shores. In most countries, agriculture is the chief contributor of non-point source pollution and sediment is the main contaminate.

In general, non-point water pollution can be characterized as a there past systems consisting of on-site production followed by removal from the production site and ending with delivery to a stream, lake or wetland. Production represents the amounts and types of contaminants generated by a land use. For example on streets and highways cars and trucks are the principle contaminant producers (e.g., oil, gasoline, and tire particles) and the rate of output is directly tied to traffic levels (Margh & Grossa, 2002).Export or removal is accomplished mainly by runoff. Delivery entails routing the storm water in a pipe or ditch from the road edge to a stream or water body.

4.4.3 Main Sources of Pollution There are many sources of water pollution, polluting our rivers, ponds, lakes and other water bodies. In following the major sources of water pollution are discussed:

4.4.3.1 Water Pollution by Urban Activity In a sense, the existence of human beings itself is a source of water pollution. In primitive ages, the purifying capacity of nature was much greater than the rate of water pollution caused by human living. But as time passed, men began to settle near water areas for the conveniences of living, and then they developed various industries which provided them with the foundation of civilized life. The emergence of various industries coupled with the developed of waste water containing pollutants. On the other hand, the increasing concentration of the population has also invited the concentration of pollution sources. As a result the rate of environmental pollution has exceeded the rate of natural purification if all the urban activities of human beings related with water pollution are viewed as a metabolic system; it can be outlined as follows (Table 4.1): Table 4.1: Water pollution by urban activities.

Water Substances Energies

Urban community Human waste and Municipal waste Waste gas and waste heat.

Municipal waste such as waste water, human waste, household waste, waste gas and west heat are the causes of water pollution.

Although water pollution is an age old problem but in this modern age, the problems like population increase sewage disposal, industrial waste, radioactive waste etc. have polluted our water resources so much so that about 70% rivers and streams contain polluted water.

There is discussed some important sources of water pollution along with the constituents which pollutes the rivers, streams and fields.

A. Domestic Sewage It is very serious pollutants of wells and rivers which are important sources of our drinking water. These rivers and wells are polluted with our own excreta besides that of animals and birds. The drinking water from these sources contains high amounts of nitrite, nitrate, B.O.D, C.O.D, chloride, sulphates and total dissolved solids. These elements in high concentrations are toxic and destroy fish and plant life ((Kudesia, 1990).

B. Industrial Waste The trade waste and effluents (flowing out from sewage tanks) of industries play a significant role in pollution of water (Kudesia, 1990). The industrial pollution has spoiled the three wealth of life-water, air and soil. The effluents have caused havoc for all. The following types of materials are discharged by them: 1. Acids: Various acid manufacture industries discharge acidic effluents into the nearby river or water body or land. It makes our land in fertile and makes the water acidic.

2. Alkalis: There are alkali manufacture or textile industries which discharge alkaline effluents causing infertility of the soil and render the water useless for human beings. They destroy the flora and fauna of the vicinity (Kudesia, 1990).

3. Pesticides: There thousand of pesticides in the market. They either contaminate the water by phosphate or chloride along with increase of BOD, COD, sulphates and nitrates. The dangerous pesticides such as DDT, aldrin, dieldrin, heptachlor, benzene etc., are harmful for the aquatic life and human beings.

4. Chemical Industries: The chemical industries discharge various toxic chemicals in the fields causing destruction of vegetation, soil and water.

5. Fluoride Industries: These industries discharge lot of fluorides in the fields without any treatment due to which people suffer from mental and stomach ailments. Fluoride also reduces production in fields (Kudesia, 1990).

6. Metal Industries: These industries discharge various metals, metallic oxides, other slay causing metallic pollution in the air, water and soil. The toxic metals percolate in the ground water slowly and slowly and cause eristic diseases and mental disorders (Kudesia, 1990).

7. Fertilizer Manufacture Industries: These industries either discharge sulphur dioxide or nitrogen dioxide in the air and both cause acid rain or destroy the growth of trees, fruits, vegetables and even grasses. The effluent of these industries is also harmful and must be discharged after proper treatment (Kudesia, 1990).

8. Oil Industries: This kind of industries discharge oil directly into nearby water bodies which pollutes the water heavily. This pollution is harmful for aquatic leaves and organisms.

4.4.3.2 Water Pollution by Agriculture Water pollution caused by agriculture is mainly on outcome of fertilizer and agricultural chemicals such as insecticides and herbicides which are discussed as followings: a) Water Pollution by Fertilizer Fertilizer given to crops is not always fully consumed. Parts of these remain in the soil being absorbed by soil colloid and influence the quality of surface water and ground water. b) Water Pollution by Agricultural Chemicals Agricultural chemicals such as insecticides, sterilizers and weed killers have played important roles in the operation of modern agriculture, but they have also caused serious environmental pollution. c) Water Pollution by Storm Water The most significant non-point source of water pollution in most places is storm water, the runoff from rainfall and melting snow. It impairs transportation, farming, and other land-use activities. Storm water is drained from the land as quickly as possible via ditches and pipes.

As a result, all sorts of debris are flushed into streams, lakes, and oceans. In urban areas, the loading of Storm water with pollutions increases with land-use density. Land use density is measured by the percentage of land covered by impervious materials (mainly asphalt, concrete, and roofs), and it reflects the level of pollution, production activities such as automobile traffic, spills, leakage, atmospheric fallout, and garbage production per area or hectre(Marsh & Gross, 2001).

4.5 Constituents of Natural water The common minerals encountered in natural waters are listed in table 4.2. In addition to these minerals, silica and metals such as iron, manganese are also present. Small amounts of phosphates also occur in all waters. Practically aall waters contain gases absorbed from the air. A little organic matter is also usually present.

4.6 Causes of Pollution Many causes of pollution including sewage and fertilizers contain nutrients such as nitrates and phosphates (Table 4.3). In excess levels, the nutrients over stimulate the growth of aquatic plants and algae. Excessive growth of these types of organisms consequently clogs our water ways, use up dissolved oxygen as they decompose, and block light to deeper waters. This, in turn proves very harmful to aquatic organisms as it affects the respiration ability or fish and other invertebrates that reside in water. Pollution is also caused when silt and other suspended solids, such as soil, wash off plowed fields, construction and logging sites, urban areas, and eroded riverbanks when it rains. Under natural conditions, lake, rivers, and other water bodies undergo eutrophication, an aging process that slowly fills in the water body with sediment and organic matter. When these sediments enter various bodies of water, fish respiration becomes impaired, plant productivity and water depth become reduced, and aquatic organisms and their environment become suffocated. Pollution in the form of organic materials enters. Waterways in many different forms as sewage, as leaves and grass clippings, or as run off from livestock feedlots and pastures. When natural bacteria and protozoa in the water break down this organic material, they begin to use up the oxygen dissolved in the water.

Table 4.2: Principle Minerals present in Natural Waters.

Alkaline causing saline Sodium and Carbonate Non-carbonate Potassium Hardness Hardness Alkalinity Potassium Calcium Calcium bicarbonate bicarbonate [Ca sulphate (KMC03) (HCo3)2] (Caso4)

Potassium carbonate (K2C03) Sodium bicarbonate (Soda) (Na HCo3) Sodium carbonate (Na2 Co3 -

Calcium Carbonate (CaCo3) Magnassium bicarbonate (Mg (HCO3)2]

Calcium Chloride (CaCl2) -

Magnassium Magnessium Carbonate (Mg Chloride Co3) (Mgcl2) -

Salinity only Acid Potassium Mineral acids Sulphate (K2 and acid salts So4) are restricted to acid mine wastes and rare mineral waters.

Potassium Chloride (KCI) Sodium sulphate (Naso4) Sodium Cloride (Nacl2)

-

-

Sodium nitrate (NaN03)

Source: Manivasakam, 1998 Many types of fish and bottom-dwelling animals can not survive where levels of dissolved oxygen drop below two to five parts per million. When this occurs it kills aquatic organisms in large numbers which leads to disruptions in the food chain (Krantz & kifferstein, 2005).

Table 4.3: Major causes and sources of water pollution.

Cause Source (industries x others) BOD Content Food processing industry (canned goods, dairy product (organic matter processing, marine product processing, starch processing), brawery, sugarmaking, wool processing (wool washing), pulp and paper industry, leather industry municipal sewenagel nigh soil treatment plant.

Suspended Solids Food processing, paper and leather industries, coal washing, (SS) municipal sewerage, ceramic industry, gravel yard, mining industry.

Oils and fats (oils, Food processing, petrochemical, iron, steel making, metal fats, minerals) finishing, wool processing industries.

Acid or Alkalis Mining, paper making, pulp, electroplating, chemical, textile and leather industries.

Ammonia Gas and Coke plants Phenols Gas and coke plants, synthetic resin and other organic chemical industries.

Sulphides Pulp and gas industries, sewage treatment plants, dyeing and leather industries.

Colour Dyestleff manufacturing, dyeing, paint, manufacturing, leather, chemical industries, night soil treatment plants.

Odor Chemical, pulp, marine product processing, meat processing, sugar making, leather industries, sewage and night soil treatment plants.

Detergent (Surface Municipal sewerage, textile industry, laundry active agent) High-temperature Steam and nuclear power plants. water Source: Trived and Raj, 1997.

4.7 Characteristics of Waste Water of Major Industries It is rather difficult to enumerate the characteristics of waste water of each industry; general characteristics of waste water according to the type of manufacturing industry are as follows: 4.7.1 Food Processing Industry A common characteristic of waste water from all types of food processing industries is the high concentration of organic content. Another common characteristic is the high concentration of solid semi-solid and suspended solid contents in waste water discharged from raw materials treatment process. The quality and quantity vary depending largely on the

season mainly due to the variation of raw materials to process. Materials contained in waste water can be divided roughly into carbohydrates, protein, fat and a mixture of them. In many instances, waste water contains oil, nitrogen and phosphorus. In the case of starch producing, sugar refining and brewing industries the BOD level of waste water is especially high.

4.7.2 Textile Industry There is much difference in the content of waste water between natural and chemical textile industries. Waste water from the wool industry contains high concentrations of BOD, fat and alkali. Waste water from dyeing discharges various pollutants such as dyes; auxiliary additives and other chemicals.

3.7.3 Paper and Pulp Making Industry These are typical water consuming industries and the levels of cod and suspended solids in waste water are extr4emely high. Especially, waste water from the digesting process contains all components of wood except cellulose and has high cod and dense color. A large quantity of waste paper fiber is also discharged as suspended solids together with the waste water.

4.7.4 Petroleum Refining Industry The main component of pollutants is spilled oil; but waste water also contains hydrogen sulfide, other sulfides, ammonia and phenols, etc.

4.7.5 Petro Chemical Industry The waste wale contains hydrocarbons, various organic compounds and catalyst. Its content varies largely depending on the type of product.

4.7.6 Iron and Steel Making Industry This industry is also a water-consuming industry. Waste water bron the cooling and cleaning process for coke furnace gas contains ammonia, cyanide, phenols, etc. Besides, there is wastewater from the dust collecting process of each burn ace, which contains suspended solids (Coke dust and core), and that from the picking process, which contains and iron and oil.

4.7.7 Electroplating Industry Many kinds of raw materials and chemicals are used in this industry, which contains toxic substances. The wastewater also contains various heavy metals (cadmium, fine, copper etc), cyanide, acids and alkalis, etc.

4.7.8 Leather Industry The levels of BOD are high in waste water which comes from tanning used for tanning and raw skins. It also contains chromium used for tanning and lime for pretreatment, suspended solids and dyes.

4.8 Chemical and Physical Aspects of Water Pollution

To analyze the water quality, it is needed to investigate the properties of water. There is a brief discussion on the properties of waters and its characteristics as following: 4.8.1 Dissolved Oxygen (D.O) Oxygen is a clear, colorless, odorless, tasteless gas that dissolves to a limited extent in water.

Aquatic organisms both plant and animal, depend on dissolved oxygen for survival. So the determination of the dissolved oxygen content is probably the most significant test which can perform the quality of the water in a stream, pond, or lake. In general, an acceptable environment for aquatic life must contain no less than 5 ppm of oxygen (5 mg of oxygen per litre of water). Variations from this figure are wide, of cource, and depend on the nature of the organisms its degree of activity, the pollutants present, sms, its degree of activity the water temperature, and other factors (Andrews, 1972).

4.8.2 Carbon Dioxide The dissolved oxygen concentration in a body of water is, in many ways; depend upon the concentration of carbon dioxide in the water. Therefore it is important to consider in some detail the factors that affect the concentration of carbon dioxide in water.

4.8.3 pH The pH of an aqueous solution represents the concentration of hydrogen ions in the solution.

It is a scale that runs from 0 to 14. On this scale, 7 are neutral, below 7 is acidic and above 7 is basic. In other words, the acidity of a solution decrease and its basicity increases as the pH goes from 0 to 14. Recent studies have shown that water having a pH range from 6.7 to 8.6 will generally support a good fish population. So, the pH value within this range is supportive for life. In fact most fish species can tolerate pH values beyond this range. Only a few species, however, can tolerate pH values lower than 5 or greater than 9 (Andrews, 1972).

4.8.4 Alkalinity The alkalinity of a water sample refers to its capacity to neutralize acid. It is caused by bases (alkalis) and basic salts in the water. The most common bases are the hydroxides of sodium, calcium, magnesium and other metals. A solution can have a high alkalinity without necessarily being highly alkaline, that is, without having a high pH. An alkalinity value below 50 ppm is considered low; a value of 200 ppm is becoming quite high.

4.8.5 Acidity Acidity is defined as the ability to neutralize based. If a solution contains weak acids, it may have a high acidity because of its potential to create hydrogen irons. Acidity is commonly classified as free acidity and total acidity. The free acidity is caused by strong acids like hydrochloric acid and sulfuric acid.

4.8.6 Hardness Hardness is water is caused mainly by calcium and magnesium ions. These ions are generally present in water as sulfates, chlorides, and bicarbonates. In most natural waters the hardness is almost entirely due to bicarbonates, mainly calcium bicarbonate and, to a lesser degree,

magnesium bicarbonate. Total Hardness values below 250 ppm are considered acceptable in drinking water with a T.H. value above 500 ppm is considered hazardous to human health.

4.8.7 Nitogen These elements are involved in both photosynthesis and respiration. One of the most important of the nutrients is nitrogen. It is present in all proteins. Proteins, in turn, are a major component of the plank tonic organisms that form the base of all aquatic food web. Studies have shown that plankton averages about 50% protein; it has a nitrogen content ranging from 7-10%.

The water is in contact with atmosphere and consequently, is normally saturated with nitrogen gas. The organic component is extremely difficult to estimate since one has to measure the nitrogen present in the protein of livings and non-living organisms and in the products of their metabolism. This leaves only the inorganic forms (nitrates, nitrites, and ammonia) as convenient indicators of nitrogen pollution. There is a brief discussion about these forms as following: 4.8.7.1 Ammonia Ammonia is a byproduct of the decay of plant and animal proteins and of fecal matter. It is also formed when the area and uric acid in urine decompose. Thus the presence of ammonia can be an indication that sewage is entering the water. Since many fertilizers contain ammonia and ammonium compounds, runoff farms can also contribute to the concentration of ammonia in water (Andrew, 1972).

4.8.7.2. Nitrites Nitrites are formed in natural waters when ammonia is converted to nitrates by bacteria.

Some nitrites are also formed as nitrates are changed into nitrogen by bacteria. Large nitrite concentrations tend to indicate industrial pollution.

4.8.7.3 Nitrates Nitrates are formed chiefly by electrical storms, nitrogen-fixing organisms, and the action of bacteria on ammonia. It is very difficult to settle the acceptable levels of nitrates. Overall most authorities consider that 45 ppm of nitrate in drinking water render the water hazardous to humans and in deed, to most animals. Many deaths occur every year as the result of nitrate poisoning, usually from nitrates in farm well water (Moore, 1972).

4.8.8 Phosphorus Phosphorus, like nitrogen, is an element of major water from many of the same sources as nitrogen. Sewage, industrial effluents, animal wastes etc. It is very difficult to set the acceptable level of phosphorus. One researcher has pointed out that a â&#x20AC;&#x153;well-behavedâ&#x20AC;? lake should not have an inorganic phosphorus content that exceeds 0.0015 ppm at the time of spring overturn. Another source says that the annual average concentration should not exceed 0.015 ppm (Andrews, 1972).

4.8.9 Total Suspended Solids

The solids suspended in water consist chiefly of living and dead phytoplankton and 300 plankton, silt, human sewage, animal excrement, portions of decaying plants and animals and a vast range of industrial wastes. Scientists often measures turbidity to estimate the total suspended solids in a water sample. Since T.S.S determinations include a variety of solids ranging from clay to living plankton, it is difficult to set â&#x20AC;&#x153;acceptableâ&#x20AC;? standards for T.S.S. A sudden increase in T.S.S. could mean erosion of soil as a result of a heavy rain; it could also mean that the municipal sewage treatment plant was taxed beyond its capacity during a heavy rain.

4.8.10 Total Suspended Solids Total dissolved solids (T.D.S.) give the total concentration of dissolved solids in a water sample. Among these dissolved solids could be phosphates, nitrates, alkalis, some acids, sulphates, iron, magnesium etc. A T.D.S gives a quick assessment of general water quality.

T.D.S can be obtained by measuring the conductivity of the water. The degree of conductivity is proportional to the T.D.S. in the water. When the T.D.S. value is below 100 ppm, the body of water is considered oligotrophic. Values above 100 ppm are generally considered to entropic conditions.

4.8.11 Transparency and Color Both suspended and dissolved solids affect the transparency and the color of water.

Transparency, inturn is related to the productivity. A law transparency generally signifies a high productivity. Light can not penetrate very fair into the water because of the high concentration of suspended matter. Color in water indicates a water quality too low to permit its use for most industrial and domestic purposes (Andrews, 1972).

4.8.12 Temperature Temperature is an important element of water quality. The abrupt change of temperature may affect phytoplankton and 300 planktons. Some aquatic organisms can tolerate some deviation from the optimum temperature and in many cases can permanently adapt or acclimate to a temperature significantly different from the optimum temperature. However, if the temperature shifts too for from the optimum, the organism either dies or migrates to a new location. With, most species of fish, an increase of 5°c in the water temperature can completely disrupt life.

4.8.13 Biochemical Oxygen Demand (B.O.D) Biochemical oxygen demand (B.O.D) attempts to replicate the oxidation conditions found in the environment (Reeve, 2002). There is an equation of B.O.D in below: B.O.D= (initial oxygen concentration-final oxygen concentration) mg-1 It is one of the most commonly performed tests of water quality at sewage treatment plants. It is very difficult to determine the level of B.O.D is acceptable. Basically, it depends on many factors, including the velocity of the receiving stream, the volume per unit time of effluent that is dumped and the volume of the receiving body of water.

4.8.14 Chemical Oxygen Demand (C.O.D)

The term chemical oxygen Demand (COD) relates to a family of techniques which involves reacting the sample with oxidizing agent. American Society for Testing and Materials (ASTM) defines chemical oxygen Demand as the amount of oxygen, expressed in mg/1 consumed under specified conditions in the oxidation of organic and oxidizable inorganic matter, corrected for the influence of chlorides (Manivasakam, 1995).

4.9 Water Quality Standard for Bangladesh The drinking water parameters are total hardness, pH, sulphates and organic matter. On the other hand dissolved oxygen, pH and temperature are fishing water parameter (Hussain & Powell, 1974). There are maximum/minimum limit the values of fish population above or below which is consist unsuitable for drinking or detrimental to fish population. Limit (i.e. the standard) varies from one country to the other depending on the local condition and the given water chemistry of surface and sub-surface water (Erikson, 1977). However, there is an international standard propose by the World Health Organization (WHO). There is also a Bangladesh standard adopted water pollution control Board (Karim, 1976) which is a modified from of WHO standard.

In the year 1976, the environmental control pollution board set up preliminary and national committee for formulating water standard in Bangladesh with view to the conservation and enhancement of the overall environment. The committee had rendered concerned effort towards framing the national water quality standard. These standards have been set keeping in view of the specific physical, chemical, and bacteriological characteristic of water for each separate type of uses. In addition to this, the figures for the maximum allowable concentration of toxic substances have been provided. The adopted standards are as follows 4.9.1 Standard for Drinking Water The standard for drinking water has been adopted with cares in keeping with the goal of achieving a healthy. Well nourished community that is capable of enjoying a rich and meaningful life. Logically, therefore, drinking water standard should not possess any undesirable characteristics such as unpleasant taste or pungent odor. Microorganisms that are likely to expert harmful repercussions on the general health of consumers should not be present. The standards (maximum allowable limits) have been suggested as below (Table 4.4).

Physical characteristic

Table 4.4: Standard for drinking water.

(A) Parameter Appearance Turbidity Threshold odor Color Taste EC Total suspended solids (TSS) Total dissolved solid (TDS) Chloride

Bangladesh standard Free form any insoluble matter 25 units Un objectionable Colorless 4 Ă&#x2014; 10-8 mho/cm at 180C 1500 ppm 600 ppm

Chemical characteristics Radio activity

Iron Magnesium Zinc Copper Calcium pH Manganese

1.0 ppm 0.5 ppm

Sulfate Total hardness as CaCO3 Fluoride Nitrate Phenolic stbstaces (as phenol) Hardness Dissolve oxygen (DO)

400 ppm 150-250 ppm 1.0 ppm 45-50 ppm 0.002 ppm

Biological oxygen demand (BOD) Chemical oxygen demand (COD) Mineral oil Gross Alpha activity Gross Beta activity

Nil Nil Nil 3 pcu (pico curie unit) 30 pcu (pico curie unit)

75-200 ppm 6.5-9.2 0.1 ppm

4-8 mg/L

Toxic substances

(B) Parameter Polynuclear hydrocarbon Arsenic Lead Cadmium Ag Selenium Chromium (vi) cyanide

Bangladesh standard aeromatic 0.2 mg/L 0.05 ppm 0.05 ppm 0.01 ppm 0.001 ppm 0.01 ppm 0.05 ppm 0.2 ppm Source: Department of

Environment, 2005.

(C) In 90% of the sample examined through any year, coli form bacteria shall not be detected or the MPN index of coli form microorganisms shall be zero. When the micro-filter technique is used the arithmetic mean number of the coli form group organisms shall be less than 1 per 100 ml in tow consecutive samples or in more than 100 percent of the samples examined.

4.9.2 Standard for Fishing The standard values of fishing water are given (Table 4.5) as follows: Table 4.5: Standard for fishing water.

Parameter Dissolved oxygen pH value Temperature Electrical conductivity Ammonia and its compounds Carbon dioxide

Bangladeshi standard A minimum concentration of 4 ppm required by fish Above 8.5 and below 6.5 may be directly lethal in their effects Values ranges between 20-320C through the year At 250C culture for inland surface water 800 Ă&#x2014; 10-6 micro-mho/cm Maximum concentration to be allowed in 3.0 ppm Maximum concentration to be allowed in 2.0 ppm Source: Department of

Environment, 2005.

4.9.3 Standard Recreational Purpose Water used for recreational purpose is for bathing and swimming pools and in rivers, lacks, beaches standards are recommended (Table 4.6) as follows: Table 4.6: Standard for recreational water.

A) Parameter pH Total residual chloride

Bangladeshi standards 7-10 0.3 ppm Source: Department of

Environment, 2005.

Pool water should be highly transparent. Clearness is adequate only when a black and white des 6 inch in deepest pointing clearly visible form the sidewalk of the pool up to distance of 30ft, measured horizontally.

B) Bacteriological Not more than 15% of the samples covering only considerable period of time shall record. (1) Plate counts of more than 200 colonies per 100 ml or (2) Positive results for coli form bacteria in any of the 10 ml portion of the samples (D.P.E.).

4.9.4 Standard for Irrigation Water The standard values of water are shown in table 4.7. There are other standard values of water are shown (Table 4.8) (Table 4.9) as follows: Table 4.7: Standard values for irrigation water in Bangladesh.

Parameter Units Proposed FAO standards Bangladesh standards Boron mg/L 2 not less than 1 < 0.7 Cadmium mg/L 0.01 Arsenic mg/L 1.0 Chloride mg/L 600 142 Coliforms (faecal) N /100ml 10 Coliforms (total) N /100ml 1000 EC mhos/cm 750 Ph 6.5-8.5 6.5-8.5 SAR 8-16 TDS mg/L 2000 < 450 Source: Department of Environment, 2005.

Table 4.8: Chemical composition of standard water quality (general).

Component Standard Value Dissolved Oxygen

0.4 – 0.5 mg/l

Copper

< 1 mg/l

Iron

01. – 0.2 mg/l

Nitrate

< 10 mg/l

pH

6.5 – 8.5 in pH Scale

Chlorides

< 250 mg/l

Zinc

< 0.106 mg/l

Dissolved Solids

< 500 mg/l

Source: KYWater Watch, 2004.

Table 4.9: Toxic metal composition for standard water quality.

Component General Standard Value Standard Value in Bangladesh Arsenic 0.01 mg/l 0.05 mg/l Barium 0.7 mg/l Boron < 0.5 mg/l < 0.9 mg/l Lead 0.03 – 0.05 mg/l 0.04 – 0.07 mg/l Mercury < 0.002 mg/l < 0.005 mg/l Chromium 0.05 mg/l Fluoride 1.5 mg/l Manganese 0.4 mg/l 0.9 mg/l Molybdenum 0.07 mg/l 0.1 mg/l Selenium 0.01 mg/l Uranium 0.015 mg/l Source: WHO (2006), EPA (2006) and SDNP Bangladesh (2004).

5.1 Introduction The River Buriganga running by the side of the Dhaka City is one of the most polluted rivers in Bangladesh. The Greater Dhaka City is also one of the most densely populated cities in the world, and approximately eleven million people are living here of which less than 25% are served by sewage treatment facility. Many industries have set up in and around the City during the last decade, and the number of new industries are continually increasing. As a direct consequence, the amount of untreated wastewater being discharged into the Buriganga has risen steadily. That is why; in the lean flow period of dry season (six months), quality of water within the 17 kilometres reach of the river is much lower than required for the sustainability of aquatic life, posing a severe threat to dwellers of Dhaka city.

5.2 Causes of Pollution The Buriganga is being polluted through various ways. Thousand tones of untreated and highly toxic liquid and solid wastes are contemning its water everyday. Now the river Buriganga has turned into a stagnant sewage. It can be identified some causes of water pollution of the Buriganga river as follows:

5.2.1 Industries There are a lot of Industries on the bank of the Buriganga River which are polluting the water mostly. The largest concentrations of industries within Dhaka City (DCC area) at present are the export oriented garment industries, numbering nearly 500. There are also several hundred other industries of different sizes and categories of industries, including nearly 300 tanneries.

Every day thousand tones of industrial effluent are falling into the water and polluting the river. At present, colors of water of the river and around the capital has become almost black with bad smells making it impossible for fish to survive as the organic wastes have been absorbing the dissolved oxygen from water The garment factory wastes are generally cloth pieces, and are recyclable, but the factories with dying functions cause liquid chemical waste of hazardous nature. The tanneries produce liquid wastes and seriously pollute the adjoining rivers. These also have solid waste which is partly recycled.

5.2.1.1 Sources of Industrial Pollution Local Government Engineering Department (LGED) and Director of Industry (DI) conducted a survey an sources of industrial pollution and identified 451 polluters industries in Dhaka city from these industries, a lot of polluted waste are coming and most of these are falling into the Buriganga River. Main sources of industrial pollution are Hazaribag tannery industrial area and Tejgaon industrial area. At Hazaribag tannery area there are about 300 leather processing industries and at Tejgaon industrial area there are about 168 various industries which are shown in figure 5.1 and in Table 5.1.

Table 5.1: Distributions of Industries.

Types of Hazaribag Tejgaon Motijheel Old Mirpu Khilgaon Jatrabari Industry Area Area Area Dhaka r Area Area Area Tannery 300 Textile Pharmaceutical Industry -

110

15

31

-

8

04

60

14

20

18

5

6

Chemical 03 Industry Rabar & Plastic Iron & Ispat Pesticides Total 303 Grand Total

08

-

04

5

-

-

7

-

20

04

-

-

12 03 212

10 01 40

09 84

01 28

13 691

01 11 Source: BBS,

2005.

5.2.2 Solid Waste of Dhaka City

Like any other city, Dhaka produces the usual waste, solid, semi-solid and liquid. Solid waste, as is known, are all sorts of solid refuses from households, offices, factories, markets, public institutions, construction debris and rubbish, street sweeping and garden trimmings.

The increasing volume of solid waste and the complex variety in these, including hazardous waste from hospitals and other sources, have become issues of concern to both urban authorities and the citizens because these wastes are polluting water of the Buriganga River.

0 0

200

400

800

1000

1200

SOURCES OF INDUSTRIAL POLLUTION OF BURIGANGA RIVER T

G ON

Road City Boundary

UTTARA

SAVAR

0

LEGEND

I KHA

L

-200

-400

600

River Number of Industry

#

-200

-400

N -600

B

-600

A

CANTONMENT

0 GULSHAN

MIRPUR

-800

L U R I V

33

-800

E R

170

-1000

-1000

TEJGAON

180

B

-1200

SABUZBAG

43

U

R

I G A

-1400

15

LALBAG

20

105

N G A R I V

-1200

DAMRA -1400

SUTRAPUR E R

-1600

-1600

0.1

0

0.1

0.2 Kilometers

-1800

-1800 0

200

400

Figure 5.1: Location of Industries.

600

800

1000

1200

Source:After Nahar, 2000.

5.2.2.1 Waste Generation The estimates for solid waste production for Dhaka has varied from 3500 metric tons to 4500 tons per day on very rough per capita basis, which has been taken to be between 0.45 and

0.50 kg. Taking the mid-figure of 4000 tons per day at present, and with a 5 percent growth rate of population, the city is apprehended to have a proportionate increase in solid waste generation. By 2015 more than 6000 tons of Solid Waste will be generated in DCC area.

Various studies and survey reports have concluded that the formal waste management system of DCC cannot collect and dispose of more than half of the waste produced, the other half remain either uncollected or partly picked up by informal sector people, or gathered in drains.

The magnitude of the problem has alarmed the people concerned.

5.2.2.2 Types of Solid Waste Solid wastes are basically of two types (a) soft wastes or organic wastes, which include vegetables, fruits, leftover food staff from households, hotels and restaurants, and (b) hard wastes, such as pieces of wood, metals, glass, plastics and polythene materials, paper, rubber, cloths and textile factory waste and construction materials.

As is evident from Table 5.2 food and vegetable wastes comprise 60 percent of all wastes in Dhaka city, while about 18 percent comprise of plastic, rubber, wood and leathers, 11 percent is paper products, about 9 percent is garden wastes, while rocks, dirt, debris etc. make 2.3% and metals constitute only 0.15.

Table 5.2: Composition of Municipal Solid Waste (MSW) in Dhaka City Components Food and Vegetables Plastic, rubber, wood and lather Paper products Garden wastes & etc.

Rock, dirt, debris & Misc Metals Total

Percent 59.91 17.67 11.21 8.76 2.3 0.15 100.00 Source: Huda, 2002

5.2.2.3 Source of Solid Waste In terms of sources of solid waste, households account for nearly half of the wastes generated in the city while markets or commercial centers contribute one-fifth, industrial waste account for about 24 percent and hospitals and clinic contribute about 7 percent (Table 5.3).

Table 5.3: Total solid waste generation per day (DCC, 2002).

Types Residential Commercial Industrial Hospital and Clinical Total

Amount (tons) 1718 722 835 255 3500

Percentage 49.08 20.86 23.86 7.29 100.00 Source:

Bhuiyan, et. al. 2002.

5.2.3 Population Growth and Unplanned Development Dhaka City, being the administrative, commercial and cultural capital of Bangladesh has now turned into 26th Mega City and 10th most populous city of the world. It is the nerve center of the country. The population of Dhaka has grown from only 0.1 million in 1906 to 3,36,000 in 1951 and 10.71 million in 2001 (Census 2001). It is growing at an alarming rate (5.6% during 1991-2001 inter-casual periods) (Table 5.4). As per future prediction, this population will further grow to about 20 million by the year 2020 and to 25 million by 2025 (DMDP, 1997) (Table 5.5). Dhaka city is projected to be one of the four largest mega cities in the world by next 10 years. A principal reason of such a rapid growth is over concentration of maximum activities and development works in the city and little improvements in other cities, towns and villages in terms of infrastructures development and economic activities. Improved road communication in the country further made it easy to converge on the capital of searching employment and better quality of life. High-density population as well as shortage of land causes intense densification in the existing built up areas.

5.2.4 Slums of Dhaka City There are many slums and squatters settlement in Dhaka City (Fig. 5.2). The wastes are being produced by the slum dwellers and falling into nearby canals, lakes etc which may also be liable for water pollution.

Table 5.4: Population Growth of Dhaka City.

Year

1991 1995 2000 2005 2010 2015

Dhaka City Corporation Population Growth (000) (% per year) 6100 -6900 3.0 8000 3.0 9000 2.5 9900 1.5 10200 1.0

DMDP Area (RAJUK Area) Pop. Density Population Growth Pop. Density (Person/ha) (000) (% per (Person/ha) year) 169 7300 -48 192 9100 4.2 59 222 10900 3.6 71 251 12600 3.0 83 169 14200 2.4 93 283 15700 1.9 103 Source: Dhaka Metropolitan Development Plan

(DMDP), 1997.

Table 5.5: Growth of Dhaka City Corporation (DCC) Area.

Year 1906 1951 1961 1974 1981 1991 1997

Area (sq. km.)

6.1 15.5 40.1 -131.6 153.8 360.0

Population -276,o33 368,575 1,403,259 2,475,710 3,612,850 6,000,000 Sourc

e: BBS, 1997.

Figure 5.2: Slums and Squatters of Dhaka City.

2001.

Source: Center for Urban Study,

5.3 Discharge Route of Pollutions Industrial waste and household waste of Dhaka City are falling into the Buriganga River through four different routes (Fig. 5.3)these are as follows: Dholai Khal Segunbagicha Khal Girani Khal

Begunbari Khal Japan International Co-operation agency (JICA) identified ten discharge areas and discharge route of Dhaka city through which various kinds of pollutants are falling into the river (Table 5.6) Table 5.6: Discharge area and discharge route.

Serial Discharge Area Discharge Route Area (sq.km) Number 1 Buriganga River Char Kamrangi/Buriganga River 7.25 Area 2 3.

4 5 6 7 8 9 10

Dholi Khal Area Segunbagicha

Dholi Khal/Buriganga River Segunbagicha Khal/Dholi Khal/Buriganga Basabo Area Begunbari Khal/Norai Khal/Balu River Begunbari Khal Paribag Khal + Begunbari Area Khal/Balu River Gulsan-Banani Gulsan + Mohakhali/Begunbari Area Khal/Balu River Kallyanpur Area Kallyanpur Khal/Buriganga River Uttara Area Ibrahimpur Khal/Turag River/Buriganga River Bank Area of Turag Turag River/Buriganga River North-East Area North-East Flood plain/Balu River

7.24 10.92 7.46 13.70 17.64 17.60 31.42 7.69 Source: After

Nahar, 2000.

5.4 Characteristics of Industrial Effluents Pollution characteristic varies from industry to industry. There are shown pollution characteristics of various industries in Table-5.4. In textile industry there is high alkalinity, high BOD, high amount of floating material, in Tannery Industry there is high salinity, high BOD, high dissolved solid materials, presence of sulphide, chromium etc., in Pharmaceutical Industry there is high COD, high BOD, high alkalinity and in rubber and plastic Industry there is, medium salinity, Medium BOD, Phenol etc.

Figure 5.3: Disposal Route of Pollutants.

2000.

Source: After Nahar,

Table 5.7: Characteristics of Pollution.

Types of industry Textile Industry Tannery Industry Pharmaceutical Industry Rubber and Plastic Industry

Characteristics High Alkalinity, High BOD, High amount of floating material High Salinity, High BOD, High Dissolved Solid materials, presence of sulphide, chromium etc.

High COD, High BOD, Alkalinity Aciditic, Salinity, Medium BOD, Phenol

Source: Nahar, 2000.

According to Department of Environment about 15800 m 3 wastes are falling into the Buriganga River from Hazaribag Tannery area, about 3500 m3 wastes from Tejgaon industrial area and 2700 m3 wastes from others area are falling into the Burgganga River and these are increasing gradually (NEMAP, 1995). According to the estimation of 2003 about 30 thousand kg pollutants from Hazaribag tanner area and about 10 thousand kg pollutant from Tejgaon industrial are falling into the Buriganga River daily. There is shown amount of pollutants from various industrial area in Table 5.8.

Table 5.8: Amount of Pollutants.

Industrial Area Hazaribag Tannery Area Tejgaon Industrial Area Dhaka-Narayangonj Area

Number of Industry

Flow of Polluted BOD load water (m3/day) (kg/day)

151 61

13,000 3,000

19,000 4,500

53

3,500

5,000 Source:

Nahar, 2000.

6.1 Introduction Water is a very good solvent, which is not found naturally in a completely pure state (Stoker & Seager, 1976). Water pollution means that state of water where a number of substances are present in sufficient quantity to prevent the water from normal use. Normal areas of use include recreation and aesthetics, public water supply, fish or other aquatic life, agriculture and industry. There are some obvious signs of water pollution, such as a test drinking water.

Growth of aquatic weeds in the water bodies, lakes emitting bad odors, decrease in number of fish etc. To determine the suitability of water for consumption certain experiments are necessary to ascertain the quality of water, such quality is identified in three different ways.

They are physical examinations of water, chemical characterization of water and biological investigation of water.

6.2 Sampling Area To perform a successfully analysis, four sampling area are selected on the basis of most pollution area by various activities. These are as follows: 6.2.1 Hazaribag Tannery Area Hazaribag tannery area is affecting water quality of the Buriganga River mostly. For these reason it is an important station. All kinds of wastes coming from Hazaribag tannery area and falling into Buriganga River through Hazaribag sluice gate. It is know to all that many kinds of tannery industries are located here and polluting the water of the Buriganga River through many ways. Thatâ&#x20AC;&#x2122;s why, the sample has been collected from this point-and examined by the laboratory test.

6.2.2 Chadni Ghat Intake Area Dhaka WASA collected water from this place and after water treatment it supplies to the Dhaka City. For this reason, it has been an important station. There are also many outlays by which various types of water such as household waste, small industries wastes are falling into the Buriganga River. Sample has been collected from here and examined by laboratory test.

6.2.3 Dholai Khal Confluence Urban waste flow and Industries waste flow are falling into the river through Dholai khal.

Sample, also has been collected from here and examined by the laboratory test.

6.2.4 Pagla Discharge Point Sewage treatment plant is located at Pagla. After treatment it was supposed to deliver into the river but they are not maintaining the rules. For these reason the water of Buriganga River is being polluted heavily. To extract the state of water sample has been collected from this point.

6.3 Physical Examination of Water To determine the water quality of the Buriganga river physical characteristics of water has been considered. In physical examination color, conductivity, temperature and odor have been measured.

6.3.1 Temperature

30.4 30.

1

December

October

September

August

July

May

April

March

23.6 23.7 29.3

June

Hazaribag

February

January

Table 6.1: Spatial & monthly temperature data of the Buriganga River, 2007.

(Unit ยบC and Standard 20ยบ-32ยบc) Mont h Location

November

Temperature is one of the most important parameter for aquatic environment because of all physical, chemical, biological activity is governed by temperature. The life cycle and natural process of aquatic organisms are closely related to water temperatures. Sudden increase in water temperature may result in the decrease of dissolved oxygen and increase in chemical reaction in water (Stoker, 1976). Normal life patterns of aquatic organisms may be completely disrupted by artificial changes in water temperature. The standard temperature in the river varies between 20ยบ-30.2ยบ Celsius.

Temperature data of 2007 of various months and average yearly temperature data from 1980 to 2007 are collected from Department of Environment (DoE) are representing in table 6.1 and table 6.2. The temperature data of different months are plotted in graph 6.1 and temperature of yearly data are plotted in graph 6.2 shown the variation of the temperature.

The temperature data are collected by field survey (Table 6.3) is presented in graph 6.3.

-

29.0 29.4 29.0 27.8 25.0 21.

5

Chadni Ghat Dholikhal

23.6 23.7 29.2

Pagla

23.6 23.7 29.2

23.6 23.7 29.2

30.3 30.

0 30.3 30.

0 30.2 30.

0

-

29.0 29.4 29.0 27.8 25.0 21.

5 29.0 29.4 29.0 27.8 25.0 21.

5 29.0 29.4 29.0 27.8 25.0 21.

5 Source: Department of

-

Environment, 2007.

Monthly Temperature Variation of 2007 35 Tem perat ure

30 25

Hazaribag

20

Chadni Ghat

15

Dholikhal

10

Pagla

5 0 January

March

May

July

September

November

Month

Graph 6.1: The variation of monthly temperature.

Table 6.2: Average yearly temperature data of the Buriganga River, 1980-2008.

(Unit ยบC and Standard 20ยบ-32ยบc) Year 1980 1985 1990 2001 2007 Location Hazaribagh 27.2 28.9 29.8 27.2 27.2 Chadni 27.1 29.1 28.6 27.2 27.1 Ghat Dholi Khal 27.1 27.1 Pagla 29.1 27.2 27.1 Source: Department of Environment, Dhaka, 2007.

Yearly Temperature Variation From 19802007 3 5 3 0 2 5 2 0 1 5 1 05 0

Tem perat ure

Hazaribag h hadni C Ghat Dholi Khal Pagl a 198 0

198 5

199 0Yea r

200 1

200 7

Graph 6.2: The variation of yearly temperature, 1980-2007.

Table 6.3: Temperature Data of the Buriganga River, 2008.

(Unit 째C and Standard 20째-32째C) Location

Temperature

Hazaribag

30.2

Chadni Ghat Dholikhal Pagla

30.1 30.1 30.2 Source: Field

Survey, 2008.

Temperature Variation of Different Location

Temperature

30.22 30.2 30.18 30.16 30.14 30.12 30.1 30.08 30.06 30.04 Hazaribag

Chadni Ghat

Dholikhal

Different Locations

Graph 6.3: The variation of temperature, 2008.

Pagla

From the tables we can see in 2007 the highest temperature was 30.4ºC and the lowest temperature was 21.5ºC. From this data it can be said, the water of the Buriganga River is suited for recreation and fish cultivation. In April and May the temperature is normally high because of low discharge and industrial waste. From the tables 6.1 it can be seen the variation of temperature is not much high. Overall the temperature of the Buriganga River is tolerable and effective for fish cultivate, recreation and also for agriculture.

6.3.2 Color Color of the water depends on the humus content of the decaying vegetative matter and industrial waste. Colleted water samples from the lakes had different shades of green color, ranging from light green to dark green (Table 6.7).

6.3.3 Electrial Conductivity It is the measurement of concentration of mineral constituents present in water. In any water body higher electrical conductivity means higher pollution. According to BBS (1998) the proposed standard of fishing water has an electrical conductivity in the range of mg/l in the rivers.

Electrical conductance or conductivity is the ability of a substance to conduct an electric current. Specific electrical .conductance (SEC) is the conductance of a body of unit length and unit cross section at a specified temperature of 25˚ C. This term is synonymous with volume conductivity and is reciprocal of volume receptivity. The presence of charged ionic species in solution makes the solution conductive. The conductance measurement provides an indication of ion concentration. Pure water has a very low electrical conductance, less than tenth of a micro siemens at 25˚C. The EC and TDS are interlinked. The relation can be expressed as follows (Hem, 1989): TDS = KeEC Where, EC = Electrical conductance Ke = Correlation factor

September

572 470 -

500 400

428 380

190 205 189 198 182 180 152 190

650

600

505

500 -

400

328

190 181 192 190

December

August

680 490

November

July

700 490

October

May

762 650

June

April

Hazaribag 850 Chadni 625 Ghat Dholaikha 790

March

th Location

January

Mon

February

Electrical conductivity is measured for understanding the salinity of water. If it in high concentration it means the presence of salinity. Electrical conductivity data are showed in the table and which are collected from Department of Environment and plotted in graph and graph. The data which are collected by field survey is shown in table and plotted in graph.

From these table and figure it is easy to realize the intensity of salinity is much high which is may not be favorable for fish cultivation,recreation and also for agriculture.

Table 6.4: Electrical conductivity of the Buriganga River, 2007.

(Unit µs /Cm and Standard 500/µs/Cm-700 µs/Cm)

l Pagla

650

590

470

480

450 -

418 400 200 185 155 195 Source: Department of Environment,

Dhaka, 2007.

Variation of Electrical Conductivity of 2007

Electrical Conductivity

600 500 400 300 200 100 0 July

August

September

October

November

December

Month

Graph 6.4: Variation of electrical conductivity in 2007.

Table 6.5: Electrical Conductivity of the Buriganga River from 1980-2007.

(Unit Âľs/cm) Year Location Hazaribag Chadni Ghat Dholi Khal Pagla

1980 900.3 301.1 -

1985 1630.83 236.0 -

Department of Environment, 2007.

1990 1391.11 263.3 261.52

2001 380.18 334.45 261.52 334.64

2007 479 417.18 411.45 381 Source:

Electrical Conductivity

Electrical Conductivity from 1980-2007.

2000 1500

Hazaribag Chadni Ghat Dholi Khal Pagla

1000 500 0 1980

1985

1990

2001

2007

Year

Graph 6.5: Variation of yearly electrical conductivity from 1980-2007 Table 6.6: Electrical Conductivity of the Buriganga River, 2008.

(Unit µs/cm and Standard 500 µs/cm-700 µs/cm) Year Location

2008

Hazaribag

851

Chadni Ghat

738

Dholi Khal

755

Pagla

650

Source: Field Survey, 2008.

Electrical Conductivity

Electrical Conductivity of the Buriganga River of 2008 1000 800 600 400 200 0 Hazaribag

Chadni Ghat

Dholi Khal

Different Locations

Pagla

Graph 6.6: Variation of electrical conductivity in 2008.

6.3.4 Odour The volatile compounds produce odor (Khopkar, 1995). The odor can be relatively described as medicinal (phenolic), fishy (due to algae), earthy (decaying matter) or chemical (Chlorine).

The odor of the river water (table 6.7) is very unpleasant due to excessive pollution.

Table 6.7: The Result of Visual Survey of the Buriganga River.

River Name

Color of the Water Clarity Algae Odor

Buriganga river

Blackish

Unclear Lot

Unpleasant

Source: Field observation, 2008 6.3.5. Turbidity The turbidity of water is caused by insoluble and colloidal compounds of inorganic origin (clay minerals, silicic oxide, hydrated oxide of iron and magnesium, etc.), or of organic origin (organic colloids, bacteria, plankton etc.). In the groundwater turbidity is caused mainly by the presence of inorganic substances. Turbidity causes an undesirable appearance of drinking and surface water. The turbidity of the Buriganga River is very high which is also may not be suitable for various activities.

6.3.6 Clarity In general the clarity of water in the Buriganga River is not good. It ranges from quite clear to very unclear. Usually polluted water bodies have unclear water. Table 6.7 shows unclear water Indicating pollution of the water.

6.4: Chemical Characterization of Water Chemical characterization is very important in assessing the quality of water (hopker, 1995); the total solid and the pH value have been calculated from the collected water sample of Buriganga River.

6.4.1 Hydrogen Ion Concentration (pH) pH indicates alkalinity or acidity in the water. A pH scale indicates the strength of acids and alkalis. It runs from 1-14. All acids have a pH less than 7. Lower pH in water is harmful for the aquatic life. A clam cannot survive if the pH of the water decreases below 6 but a wood frog can survive in water with a pH as low as 4. pH is a master variable controlling chemical system. It defined as the negative logarithm of the hydrogen ion activity and describes whether a solution is acidic (pH, l-7), neutral (PH-7), or basic (PH-7-15), pH may be raised by adding a base or by removing CO2 from a solution, e.g., by photosynthetic assimilation. There are three main sources of hydrogen ions in natural waters as follows: i) Hydrolysis H2O = H+ +OH; in pure water107 ii) Dissociation

H2CO3 = H + HCO iii)Oxidation 2FeS2 + 7.5 O2 + 7H2O = 2Fe (OH)3 + 8H+ + 4SO4 Other sources of hydrogen ions include humic and fulvic acids, volcanic gases and acid rain.

Normal range of pH for groundwater is 6 to 8. Water with pH less than 7 are acidic and with pH more than 7 are alkaline. Neutral water has a pH of 7. The pH of groundwater in the upper part of the aquifer varied from 6.5 to 7.3 and in the lower part of the aquifer varied from 6.3 to 8.1. A decrease in pH could lead to the dissolution of carbonates and hydroxides as well as decrease adsorption because composition with the more strongly absorbed hydrogen ion. pH data (Monthly) of the Buriganga River are shown by the table 6.8 and the yearly data from 1980-2007 are shown by the table 6.9, here monthly data has been plotted in graph 6.8 and yearly data has been plotted in graph in figure in 6.9. The pH data collected by field observation is shown in table 6.10 and it is plotted in graph 6.10.

June

July

August

September

7.2 7.1 7.2 7.2

7.3 7.1 7.3 7.2

6.9 7.2 7.0 7.2

-

7.2 7.1 7.3 7.1

7.3 7.0 7.3 7.1

7.4 7.2 7.2 7.2

December

May

7.5 7.4 7.4 7.4

November

April

7.5 7.3 7.3 7.2

October

March

Hazaribag Chadni Ghat Dholikhal Pagla

February

Month Location

January

Table 6.8: pH data along Buriganga River (Monthly), 2007 (Standard 6.5-9.2)

7.1 7.1 7.4 7.2 7.2 7.2 7.4 7.4 7.3 7.4 7.2 7.3 Source: Department of

Environment, 2007

pH Values

Variation of pH values in 2007 8 7 6 5 4 3 2 1 0

Hazaribag Chadni Ghat Dholikhal Pagla

January

April

July

October

Month

Graph 6.8: Monthly variation of hydrogen ion (pH) in 2007 Table 6.9: pH data along the Buriganga River (Yearly) from 1980-2007.

(Standard 6.5-9.2)

Year Location Hazaribag Chadni Ghat Dholi Khal Pagla

1980

1985

1990

2001

7.2 7.3 -

7.1 6.7 -

7.5 7.3 7.4

7.9 7.1 7.3 7.2

2007 7.3 7.2 7.2 7.1 Source: Department

of Environment, 2007 Variations of pH values from 1980-2007

pH Values

10 8

Hazaribag Chadni Ghat Dholi Khal Pagla

6 4 2 0 1980

1985

1990

2001

2007

Year Graph 6.9: Yearly variation of hydrogen ion (pH) from 1980-2007.

Table 6.10: pH data long the Buriganga River, 2008.

(Standard 6.5-9.2) Year Location 2008 Hazaribag 7.5 Chadni Ghat

7.3

Dholi Khal

7.2

Pagla

7.3 Source: Field Survey, 2008.

pH Values of 2008 7.6

pH Values

7.5 7.4 7.3 7.2 7.1 7 Hazaribag

Chadni Ghat

Dholi Khal

Pagla

Different Locations

Graph 6.10: Variation of hydrogen ion (pH) in 2008.

6.4.2 Dissolved Oxygen The data of dissolved oxygen are shown by table 6.10 and 6.11. Like terrestrial animals, fish and other aquatic organisms need oxygen to live. As water moves gills (or other breathing apparatus), microscopic bubbles of oxygen gas in water, called dissolved oxygen (DO) are transferred from the water to their blood. The presence of oxygen in water is a positive sign of a healthy body of water but the absence of oxygen is a signal of severe pollution. The equilibrium concentration of dissolved oxygen in water in contact with air is function of temperature and pressure and to a lesser degree of the concentration of other solutes. Oxygen is supplied to groundwater through recharge and by movement of air through unsaturated material by processes that consume dissolved, suspended or precipitated organic matter. The principal reacting species of dissolved oxygen are organic materials and reduced inorganic minerals such as pyrite and siderite.

The surface water receives oxygen (O2) mainly by absorption from the atmosphere at the surface of the lake and by photosynthesis of the chlorophyll bearing organisms inhabiting the pond. Moreover, the volume of O2 dissolved in water is dependent upon its temperature, the partial pressure of O2 in the air in contact with the water at the surface, and the concentration of dissolved salts. Under the given set of conditions there is a nonlinear inverse relation between water temperature and dissolved oxygen. The solubility of oxygen in water rises above 40% as freshwater cools from 25Ë&#x161;C to freezing point. Monthly and yearly dissolved oxygen data are collected from the Department of Environment are shown in table 6.11 and 6.12. These data are plotted in graph 6.11 and in 6.12. The data which are collected by field survey is shown in table 6.13 and plotted in graph 6.13.

The value of DO ranges from 1.5-7.0 in surface water samples whereas the standard DO ranges from 4.5 to 8 mg/L. Table 6.11: The data of dissolved oxygen (monthly) 2007. (unit mg/L and lowest approval limit 4mg/L)

January

February

March

April

May

June

July

August

September

October

November

December

Month Location

Hazaribag

3.5

1.5

2.8

2.3

2.8

0

6.2

6.7

6.7

6.6

6.0

4.8

Chadni Ghat

4.1

2.0

6.0

5.0

6.0

0

6.8

7.0

6.9

6.0

6.4

5.8

Dholikhal

4.0

1.5

3.2

2.8

3.3

0

6.2

6.1

6.5

5.6

5.5

4.2

Pagla

4.2

4.5

5.0

5.9

5.8

0

6.2

6.1

5.6

4.5

5.8

5.1

Source: Department of Environment, Dhaka, 2007.

Value of Dissolved Oxygen

Variations of Dissloved Oxygen in 2007.

8 Hazaribag Chadni Ghat Dholikhal Pagla

6 4 2 0 January

April

July

October

Month

Graph 6.11: The variation of dissolved oxygen in 2007.

Table 6.12: Dissolved oxygen Density along the Buriganga River 1980-2007 (unit mg/L and Lowest approval limit 4mg/L) Year Location Hazaribag Chadnighat Dholikhal Pagla Dhaka, 2007

1980

1985

1990

5.0 4.6 -

4.5 4.5 -

4.7 6.0 6.0

2001

2007

4.6 4.5 5.7 5.2 4.5 4.4 5.6 5.3 Source: Department of Environment,

Value of Dissolved Oxygen

Variations of Dissolved Oxygen from 1980-2007 7 6 5 4 3 2 1 0

Hazaribag Chadnighat Dholikhal Pagla

1980

1985

1990

2001

2007

Year

Graph 6.12: The variation of dissolved oxygen from 1980-2007.

Table 6.13: Dissolved oxygen Density along the Buriganga River, 2008.

(Unit mg/L and lowest approval limit 4 mg/L) Location

Year

Hazaribag

2008 2.7

Chadni Ghat

5.5

Dholi Khal

3.2

Pagla

5.4 Source: Field observation, 2008.

Value of Dissolved Oxygen

Variation of Dissolved Oxygen at Different Locatins in 2008 6 5 4 3 2 1 0 Hazaribag

Chadni Ghat

Dholi Khal

Pagla

Different Locations

Graph 6.13: The variation of dissolved oxygen in 2008.

6.4.3 Biochemical Oxygen Demand The waste from various sources falling into the river has biochemical oxygen Demand, which also decreases the dissolved oxygen. The incensement of biochemical oxygen demand decreases the dissolved oxygen. Biochemical oxygen demand of Buriganga River is shown by the table 6.14 and table 6.15 which are collected from Department of environment and these are plotted in graph 6.14 and in graph 6.15. The biological oxygen demand data are collected by field survey is shown in table 6.16 it is also presented in graph 6.16.

Biochemical Oxygen Demand or BOD is a measure of the quantity of oxygen consumed by microorganisms during the decomposition of organic matter. BOD 5 is the most commonly used parameter for determining the oxygen demand on the receiving water of any water sources for assessing the productivity. The average BOD of the Buriganga River is 5.25mg/L which indicates the poor condition of the water.

May

June

July

August

September

18 4.5 10 8.4

12 3.8 18 4.2

18 5.0 11 4.2

2.5

3.8 4.0 4.0 -

4.1 4.5 3.7 4.5

3.7 4.1 4.0 4.0

Environment, Dhaka, 2007

December

April

26 13 20 10.5

November

March

10.5 2.1 6.5 3.5

October

February

Hazaribag Chadni Ghat Dholikhal Pagla

January

Table: 6.14: Biochemical Oxygen Demands of the Buriganga River (monthly), 2007.

Month Location

2.8 6.0 2.9 3.5 2.0 3.5 3.2 2.8 2.5 3.5 1.4 3.5 Source: Department of

Biological Oxygen Demand in 2007

Value of B.O.D

30 25 20

Hazaribag Chadni Ghat Dholikhal Pagla

15 10 5 0 January

April

July

October

Month Graph 6.14: Monthly variation of Biological Oxygen Demand in 2007 Table 6.15: Biochemical Oxygen Demand of the Buriganga River (Yearly) 1980-2007 Year 1980 1985 1990 2001 2007 Location Hazaribagh 27.2 28.9 29.8 27.2 9.53 Chandnighat 27.1 29.2 28.6 27.2 4.54 Dholikhal 27.2 7.79 Pagla 29.1 27.2 4.53 Source: Department of Environment, Dhaka, 2007

Values of B.O.D

Variation ofBiological Oxygen Demand from 1980 2007 35 30 25 20 15 10 5 0

Hazaribagh Chandnighat Dholikhal Pagla

1980

1985

1990

2001

2007

Year Graph 6.15: Yearly variation of biological oxygen demand from 1980-2007.

Table: 6.16: Biochemical Oxygen Demand 2008

Location

Year 2008 17 15 15 14

Hazaribagh Chandnighat Dholikhal Pagla

Source: Field observation, 2008.

Biological Oxygen Demand in 2008

Values of B.O.D

20 15 10 5 0 Hazaribagh

Chandnighat

Dholikhal

Pagla

Different Locations

Graph 6.16: Variation of biological oxygen demand in 2008 6.4.4 Alkalinity The natural buffering capacity of water bodies may mask the presence of acidic or basic pollutants. Therefore simply measuring pH may not be sufficient. For a more complete assessment of water quality, most scientists also measure alkalinity. Alkalinity is measured to determine the ability of a stream to resist changes in pH. That is to say alkalinity allows scientists to determine buffering capacity. Industrial waste may contribute high alkalinity.

Alkalinity values of 20-200 ppm are common in freshwater ecosystems. Alkalinity levels below 10 ppm indicate poorly buffered water bodies. These water bodies are the least capable of resisting changes in pH; therefore they are most susceptible to problems, which occur as a result of acidic pollutants. Monthly alkalinity data of 2007 and average annual alkalinity data from 1980-2007 are shown in table 6.17 and in table 6.18 which shown in graph 6.17 and in graph 6.18. The alkalinity data of 2008 are collected by field survey are shown in table 6.19 and represented in graph 6.19. The values are shown in tables are not satisfactory for natural ecosystem.

February

March

April

May

June

July

Location

January

August

September

October

November

December

Table: 6.17: Alkalinity data of the Buriganga River, 2007.

(Unit mg/L and approval limit 250-450 mg/L) Month

Hazaribag Chadni Ghat

230 150

170 120

80 75

78 80

75 72

-

80 80

50 45

60 52

65 54

25 26

38 32

Dholikhal Pagla

180 140

150 110

92 80

78 78

70 80

-

90 78

50 46

62 58

65 24 33 60 32 32 Source: Department of

Environment, 2007

Values of Alkalinity

Variation of the alkalinity in 2007 250 200

Hazaribag Chadni Ghat Dholikhal Pagla

150 100 50 0 January

April

July

October

Month Graph 6.17: Variation of alkalinity in 2007 Table: 6.18: Alkalinity data of the Buriganga River (Yearly), 2007.

(Unit mg/L and approval limit 250-450 mg/L) Year 1980 1985 1990 2001 2007 Location Hazaribag 129.7 277.4 213.2 82.50 86.45 Chadni Ghat 115.8 138.4 125.5 69.64 71.45 Dholikhal 81.55 81.27 Pagla 109.5 70.00 72.18 Source: Department of Environment, 2007

Value of Alkalinity

Variation of the Alkalinity from 1980-2007 300 250 200

Hazaribag Chadni Ghat Dholikhal Pagla

150 100 50 0 1980

1985

1990 Year

2001

2007

Graph 6.18: Variation of alkalinity from 1980-2007.

Table: 6.19: Alkalinity data of the Buriganga River, 2008 (Unit mg/L and approval limit 250-450 mg/L) Year

Location Hazaribagh

2008 81

Chandnighat

78

Dholikhal

78

Pagla

78 Source: Field observation, 2008

Value of Alkalinity

Alkalinity in 2008 82 81 80 79 78 77 76 Hazaribagh

Chandnighat

Dholikhal

Pagla

Different Location

Graph 6.19: Variation of alkalinity in 2008.

6.4.5 Chloride (as Chlorine) Monthly chloride density of the Buriganga River of 2007 and annual average chloride density of the Buriganga River from 1980-2007 are shown in table 6.20 and in table 6.21. These data are plotted in the graph 6.20 and in the graph 6.21 are representing the changing scenario of chloride density. However the data of chloride density of the Buriganga River are collected by field survey are shown in table 6.22 and plotted in graph 6.22 are showing the present state of the alkalinity of the river.

Table 6.20: Chloride Density of the Buriganga River (Monthly), 2007 (Unit mg/L and standard 150-250 mg/L)

May

June

July

August

September

20 20 16 20

16 14 18 12

18 15 16 15

-

12 10 15 10.5

10 5.5 10 8

30 18 18 12

December

April

30 20 20 25

November

March

70 30 58 40

October

February

Hazaribag Chadni Ghat Dholikhal Pagla

January

Month Location

35 08 10 18 06 6.5 18 7.8 9.5 50 06 8.5 Source: Department of

Environment, 2007

Value of Chloride Density

Variation of the Chloride Density in2007 80 60

Hazaribag Chadni Ghat Dholikhal Pagla

40 20 0 January

April

July

October

Month Graph 6.20: Variation of chlorine density in 2007 Table 6.21: Chlorine Density of the Buriganga River, (Yearly) 2007 (Unit mg/L and approval limit 150-250 mg/L) Year Location 1980 1985 1990 2001 2007 Hazaribag 455.98 711.83 161.98 20.18 23.54 Chadni 17.3 23.4 34.5 11.13 14.81 Ghat Dholikhal 17.0 18.75 Pagla 37.92 21.82 19.09 Source: Department of Environment, 2007.

Variation of the Chlorine Density from 1980-2007

Chlorine Denity

800 600

Hazaribag Chadni Ghat Dholikhal Pagla

400 200 0 1980

1985

1990

2001

2007

Year Graph.21: Yearly average chlorine density from 1980-2007.

Table: 6.22: Chlorine Density of the Buriganga River, 2008.

(Unit mg/L and approval limit 150-250 mg/L) Year

Location

2008 Hazaribag 30 Chadni Ghat 16.13 Dholikhal 16.5 Pagla 17.4 Source: Field observation, 2008

Value of Chlorine Density

Chlorine Density in2008 35 30 25 20 15 10 5 0 Hazaribag

Chadni Ghat

Dholikhal

Different Locations Graph 6.22: Variation of chlorine density of different places of 2008

Pagla

6.4.6 Total Dissolved Solid The total dissolved solid (TDS) denote mainly the various kinds of minerals present in water.

TDS do not contain any gas and colloids. Total dissolved solids in surface water samples ranges from 224-554 ppm. Total dissolved solids are collected from various locations of the Buriganga River by field survey are shown in table 6.23 are represented in the graph 6.23.

The highest value is nearest at Hazaribag which is 350 ppm and the lowest value is 150 at Chadni Ghat. At Hazaribag the value is out of the approval limit that means there are a lot of minerals in the water.

Table 6.23: Total dissolved solid of various locations, 2008.

Location

TDs (ppm)

Hazaribag

350

Chadni Ghat

170

Dholikhal

150

Pagla

280 Source: Field Survey, 2008.

Value of Total Dissolved Solids

Variation of Total Dissolved Solids 400 300 200 100 0 Hazaribag

Chadni Ghat

Dholikhal

Pagla

Different locations Graph 6.23: Diagram of dissolved solids of various locations, 2008 .

6.4.7 Comparison of Parameters There is shown average (table 6.22) BOD 5.25 mg/L whereas standard BOD are for drinking 50 mg/L, for fishing 250 mg/L, for irrigation 500 mg/L. The average dissolved oxygen is 4.2 which is lower limit of standard value according to Department of Environment. So all the values represented in the table 6.24 are not satisfactory for various purposes.

Table6.24: Pollution level of surface water in comparison to DoE standard DoE Standard of Chemical Parameters Average Sample Reading Drinking Fishing Irrigation

BOD Chloride (c1) D.O pH

5.25 20 4.2 7.32

50 600 4.5-8 6-9

250 500 600 600 4.5-8 4.5-8 6-9 6-9 Source: Department of

Environment, 2007 7.1 Introduction A reconnaissance survey was conducted in Hazarbag, Chadni Ghat, Dholai Khal in order to get preliminary knowledge about the physical environment and to observe people’s socioeconomic condition. The aim was to get an idea about the study area to plan for the questionnaire survey. Then one set of questionnaire is prepared to conduct a detailed perception study of the people of surroundings area of the Buriganage River. The three locations of the river such as Hazaribag, Chadni Ghat, and Dholai Khal have been selected for questionnaire survey. There were 200 questionnaires prepared and among them 100 questionnaires for Hazaribag area, 50 questionnaires for Chadni Ghat, 50 questionnaires for Dholai Khal. All the questionnaires were conducted randomly. The gathered information’s were analyzed which are discussed as follows.

7.2 At Hazaribag Area The questionnaire survey was conducted among residents of surroundings area especially to the workers. The information’s were collected by questionnaire survey are analyzed which are described as follows: 7.2.1 Age Group of the Respondents The questionnaires were conducted among different ages of people which are shown in table 7.1. It reveals that the age limit of highest respondent is between 30-40 years which indicates 40% of the population which are also shown in graph 7.1.

Table 7.1: Age limits of the respondent populations.

Age Limit Number Percentages 10-30 10 10 30-40 40 40 40-50 34 34 50-60 16 16 Total 100 100 Source: Field survey, 2008.

Age limits of the populations

10%

16%

>30 30-40 40-50 40%

34%

50-60

Graph 7.1: Age limits of the population.

7.2.2 Sources of the Pollutions In table 7.2, shows the probable sources of the water pollution of the Buriganga River. Most of the respondents about 90% think industry and Dhaka City waste are the major causes of the pollution which are shown in table 7.2 and graph 7.2.

Table 7.2: Sources of Pollutions.

Sources of pollution Industry + Dhaka city waste Household waste Other Total

Number 90 6 4 100

Percentage 90 6 4 100 Source: Field

Survey, 2008.

Sources of pollution

6%

4%

Industry + Dhaka city waste Household waste Other 90%

Graph 7.2: Sources of Pollutions.

7.2.3 Uses of the Buriganga River Water In table 7.3 it reveals the number of users of the Buriganga River water. Here, most of the people do not use the water at all and that is the highest number. Few peoples are using this water in agricultural sector, household sector, for bath and for recreational purpose. The number of the users also is shown in the graph 7.3.

Table 7.3: Users of the water Types of uses Number Percentage (%) Agriculture 15 15 Household activities 5 5 For Bath 12 12 For Recreational Purpose 8 8 Not used 60 60 Total 100 100 Source: Field Survey, 2008.

Users of the water

15% 5%

60%

12% 8%

Agriculture Household activities For Bath For Recreational Purpose Not used

Graph 7.3: User numbers of the water.

7.2.4 Impact on Human Health Health status (Table 7.4) of the people living in this area is not satisfactory. They used to suffer from different types of diseases almost round the year. Most of the people are suffering from skin disease and respiratory disease and it is about 36% and 32% of total population (Table 7.5) which is shown in graph 7.4.

Table 7.4: Disease Pattern of the local populations.

Age Limit Disease Type (Year) Diarrhoe Skin Heart Respirato Asthma Number a disease Disease r Disease 1-10 6 11 1 5 2 25 11-20 2 5 4 1 12

Percentag e 25 12

21-30 31-40 41-50 51-60 Total

2 10

8 6 4 2 36

4 1 3 9

15 3 3 2 32

5 2 2 1 13

30 15 10 8 100

30 15 10 8 100 Source: Field

Survey, 2008 Table 7.5: Various diseases and percentage of sufferers.

Disease Types Diarrhoea Skin disease Heart Disease Respirator Disease Asthma

Number 10 36 9 32 13

Percentage 10 36 9 32 13

Various Diseases and Number of sufferers

10%

13%

Diarrhoea Skin disease Heart Disease 36%

32% 9%

Respirator Disease Asthma

Graph 7.4: Various diseases and number of sufferers.

7.3 At Chadni Ghat There are also conducted some questionnaire among the people of various professionals especially to the workers. The collected informationâ&#x20AC;&#x2122;s are analyzed which are described as follows: 7.3.1 Age Group of the Respondents The questionnaires were conducted among different ages of the people which are shown in Table 7.6. The age of the most respondents is between 30-40 years which indicates 40% of the population.

Table 7.6: The age limits of the Respondent.

Age Limit Number

Percentage

15-30 30-40 40-50 50-60 Total

8 20 12 10 50

16 40 24 20 100 Source: Field

Survey, 2008.

7.3.2 Sources of the Population Most of the respondents think the major sources of water pollution of the Buriganga River are Industry and Dhaka City waste that indicates 90% (Table 7.7). These percentages are shown in the graph 7.5.

Table 7.7: Sources of Pollution.

Sources of Pollution Numbers Industry + Dhaka City 45 waste Household waste 3 Other 2 Total 50

Percentages 90 6 4 50

Source: Field Survey, 2008.

Major Sources of Pollution

6%

4%

Industry + Dhaka City waste Household waste Other 90%

Graph 7.5: Major sources of pollution.

7.3.3 Uses of the Buriganga River In Table7.8, this exhibits the number of users of the Buriganga River water. Here most of the people (36%) do not use the water of the river. About 16% people take their bath, 14%

people use the water for their land, and 12% people use the water for their household activates (Table7.8). These percentages are shown in the graph 7.6.

Table 7.8: Users of Water Types of uses Agriculture Household For Bath For Recreational Functions Not used Total

Number 7 6 8 11 18 50

Percentage 14 12 16 22 36 100

Source: Field Survey, 2008.

Uses of the water

14% 36%

Agriculture Household For Bath

12%

For Recreational Functions Not used

16% 22%

Graph 7.6: Uses of the water.

7.3.4 Impact on Human Health Table 7.9 shows the disease pattern of survey area. Most of people (36%) are affected by various diseases whose age limit 21-30 years, of them 36% are suffering form skin disease, 12% (Table 7.10) people are suffering from respiratory problem which are also shown in graph 7.7.

Table 7.9: Disease pattern of the local people.

Age Types of Diseases limit Diarrhoea Skin Heart Respiratory Asthma Number Percentag Disease Disease Disease e 1-10

2

4

-

3

1

10

20

11-20

2

3

-

1

1

7

14

21-30

1

8

1

5

3

18

36

31-40

1

3

3

2

1

10

20

41-50

-

1

1

-

-

2

4

51-60

-

1

1

1

-

3

6

Total

6

18

6

12

6

50

100

Source: Field Survey, 2008.

Table 7.10: Number of people is suffering from diseases.

Diseases Diarrhoea Skin Disease Heart Disease Respiratory Disease Asthma Total

Number 6 18 6 12 6 50

Percentage(%) 12 36 12 24 12 100 Source: Field Survey, 2008.

Number of people are suffering from diseases

13%

13% Diarrhoea Skin Disease Heart Disease

24%

Respiratory Disease 37%

Asthma

13%

Graph 7.7: Number of people is suffering from diseases.

7.4 At Dhulai Khal There were conducted 50 questionnaires among the people of that area and most of them were workers. The gathered informationâ&#x20AC;&#x2122;s are analyzed as follows: 7.4.1 Age Limit of the Respondent

Table 7.11 showing the age limit of the respondent where most of the respondentâ&#x20AC;&#x2122;s age limits is between 40-50 years which also are shown in graph 7.8.

Table 7.11: Age limit of the Respondents at Dhulai Khal.

Age limit 15-30 30-40 40-50 50-60 Total

Numbers 16 12 18 4 50

Percentage 32 24 36 8 50 Source: Field

Survey, 2008.

Age limit of the people

15-30 8% 32%

30-40 40-50

36%

50-60

24%

Graph 7.8: Age limits of the population.

7.4.2 Sources of the Pollution Table 7.12 is representing major sources of water pollution where Industries and Dhaka City are the most polluters according to the respondent; it is also shown in graph 7.9.

Table 7.12: Sources of Pollution.

Sources of Pollution Number Industry + Dhaka City 47 Household waste 3 Others Total 50 Source: Field Survey, 2008.

Percentage (%) 94 6 50

Sources of pollution

6%

0%

Industry + Dhaka City Household waste Others 94%

Graph 7.9: Sources of Pollutions.

7.4.3 Users of the Buriganga River Table 7.13 shows the number of users of the Buriganga River water. People are using water in various ways. About 22% people are using the water for recreational purpose and 16% people are using the water for bath which is also shown in the graph 7.10.

Table 7.13: Users of water at Dhulai Khal.

Types of uses

Number

Percentage

Agriculture

6

12

Household

8

16

For Bath

9

18

For Functions Not used Total

Recreational 12

24

15

30

50

100 Source: Field

Survey, 2008.

Users of the water

12%

30%

Agriculture

16%

Household For Bath For Recreational Functions Not used

18%

24%

Graph 7.10: Users of the water at Dhulai Khal.

7.4.4 Impact on Human Health Table 7.14 exhibits the disease pattern of the people living in this area. Here 36% people are suffering from respiratory diseases, 26% percent people are suffering from skin disease (Table 7.15) which are also shown in graph 7.11.

Table 7.14: Disease Patterns of the local people at Dhulai Khal.

Age Types of Diseases limit Diarrhoea Skin Heart Respiratory Asthma Number Percentage Disease Disease Disease 1-10

3

3

-

4

2

11

22

11-20

1

2

-

3

2

8

16

21-30

3

5

-

6

1

15

30

31-40

2

3

1

2

3

9

18

41-50

-

1

-

1

-

2

4

51-60

-

1

1

2

-

3

6

Total

9

13

2

18

8

50

100

Source: Field Survey, 2008.

Table 7.15: Number of people is suffering from diseases.

Diseases

Number

Percentage (%)

Diarrhoea

9

18

Skin Disease

13

26

Heart Disease

2

4

Respiratory Disease

18

36

Asthma

8

16

Total

50

100 Source: Field Survey, 2008.

Number of peoples are suffering from diseases

16%

18%

26%

36% 4%

Diarrhoea Skin Disease Heart Disease Respiratory Disease Asthma

Graph 7.11: Number of peoples is suffering from diseases.

8.1 Discussions World environment is under threat now and only human being is liable for this situation.

People are trying to safe and to comfortable their life, for these purposes they are busy with various developing activities such as they are constructing industries, roads etc which have a great impact on our environment. People are cutting trees for their transitory interest which have a great impact on our environment. For these reasons environmental pollution created by industries and technologies are most discussable matter over the world. Many countries already have taken steps to prevent environmental pollution. The conception of environmental pollution and its prevention in Bangladesh are comparatively a new theme.

Since Bangladesh is not industry based country, it may raise in our mind that there is no existence of pollution. But at present the environmental pollution is a great problem for us and it is spreading for lack of proper management, low quality full technology, lack of infrastructural development. The intensity of environmental pollution is much high in Dhaka and its surroundings area. Industrial untreated effluents and other wastes are falling into some

rivers especially Buriganga, Balu Sitalakya and the waters of these river has been toxic (Habib, 1998).

River pollution is being considered as a world problem. This problem is being more critical for developing countries because of their intention to develop industry. As a result a massive amount of industrial effluents mixes with household waste and fall into near water bodies and pollutes it.

In Dhaka city rapid urbanization and industrialization are increasing the wastes day by day (Rahman and Rana, 1995). Most of the rivers in our country are being polluted by industrial waste. Various kinds of germs coming from urine, household waste, hospital waste and is polluting surface water. As a result water is considered as a media of some diseases such as typhoid, para-typhoid, Dysentry, cholera, infections hepatitis etc (Nahar, 2000).

Buriganga River is passing through western and southern part of Dhaka city. The Buriganga River originated from the Dhaleshwari River. This river is only 27 km long and the Turag has met with the Buriganga at Kamrangirchar of Dhaka City. However, the main flow of the Buriganga River comes from the Turag and it meets with the Dhaleshwari River at Munsiganj. The Buriganga River has a great economic importance but this river is being polluted at alarming rate. By observation and measurement, it has been found that the river is going to be highly polluted.

In 1992 Department of Environment has emphasized on three determinators (Dissolved oxygen, solid waste, Bio chemical oxygen Demand) to measure the water quality of the Buriganga River for 1984 to 1992 on accumulated collected data. Though, the deterioration of the water quality was less because of its high dissolving power. However by analysis it is found that the density of solid waste is increasing both rain and dry season. The density of solid waste was 225 to 275 mg/L, in both rainy and dry season, BoD was 3 mg/L. In another hand Dissolved oxygen was deteriorating gradually. In day season it was 5 mg/L which is much less than approval limit. Even in 1991-1992 in rainy season, Do was only 6 mg/L. For such a situation from that time fishes in the river was decreasing with mention ably rate (Naher, 2000).

In 1991-1992, Browderâ&#x20AC;&#x2122;s seasional based analysis reveals water quality deteriorates in dry season mostly. In May there is lowest dissolved oxygen in the water and in July it is highest.

In dry season dissolved oxygen exists (4mg/L) less than approval limit from Hazaribag to Pagla. Furthermore there is very little coli form at Chadni Ghat, Dholi Khal and Pagla Station. Where in 1991, Department of Environment set the standard limit of colliform for fishing which was, 5,000 coliform/100 ml but in dry season there is found 12,000, 95,000 and 66,000 coliforms/mL. As a result it can be said easily, in dry season the River Buriganga is not suited for fish and other aquatic animals (Rahman and Rana, 1995).

In 2001 Nahar reveals, the quality of the water of Buriganga River is deteriorating day by day. On study it exhibits Chloride, Temperature, pH, etc are going down from standard value.

In another hand the density of dissolved oxygen and Bio-Chemical oxygen already has exceeded the approval limit. In dry season at Hazaribag, the density of dissolved oxygen was 1.5 mg/L which indicates fish can not live in such water. The present study also reveals the deterioration of the water quality of the river.

With over 5,000 tones of untreated and highly toxic liquid and solid wastes contemning its water every day, the river Buriganga has turned into a stagnant sewerage. The repeated toxic onslaught on the life line of Dhaka has contaminated the ground water and the agricultural land around it. Due to lack of flow in the water during the lean period the wastes are accumulating at an alarming rate. The water is tick and resembles discarded engine oil, emitting an unbearable stench. During eight months of the Buriganga is out off from its sources, the Jamuna River in the upstream near Manikganj (The Daily Star, March 4, 2007).

8.2 Findings of the Study Unprecedented pollution in the river surrounding the capital is not only causing untold suffering to millions living on the banks but also threatening the existence of the river.

Experts said that the rivers Bansi, Turag, Balu and Buriganga remain stagnant for nearly eight months of the year, when millions of gallons of toxic liquid and solid wastes from various industries and homes keep accumulating in the waters everyday. There is virtually no movement in the river waters during these eight months. The only movement that occurs in these rivers during the period is caused by the high tide and low tide, which pushes the polluted water further upstream during high tide and downstream during low tide. The present study is conducted according to selected objectives and tried to extract the expected results which are shown as follows: Water parameters are changing mention ably over the time and are going to out of the standard limit.

Industrial effluents are the major sources of the water pollution however; there are other sources which are also accused of the pollution such as household waste, oils from steamer and launches etc.

Sewage and waste water are coming out from Dhaka metropolitan area which are falling into the river and making the river polluted.

There are standard values of water for drinking, for fishing, for irrigation by which it can be learned……

The effect of water pollution was studied carefully and found a lot of people are suffering from various diseases; most of them are suffering from skin disease, respiratory disease.

8.3 Recommendations To prevent the water pollution of the Buriganga River various attempts can be taken which are as follows: • • • • • • • • • • • •

After proper treatment of industrial effluents it may release to the river.

Illegal residence and buildings have to remove from the bank of the river.

To continue its flow, dredging is needed.

Remove hanging toilet and have to make scientific public toilets.

Remove slums from the dam area.

Industries, which have built up on the bank of the river illegally, have to stop them.

Hazaribag Tannery area is the most polluted area and a lot of untreated effluents are falling into the river daily without treatment which is polluting the water massively.

To refrain from this pollution proper attempt should be taken.

Through Dholi Khal, a lot of untreated industrial effluents household waste are falling into the river which also polluting the water. To the river from these pollution proper treatment should be taken by the authority so that it doesn’t pollute the river.

Pagla sewerage treatment plant should be more effective.

Pollution free technology should be used to all industries.

People should not throw their waste indiscriminately.

To avoid any kinds of pollution, consciousness is the best policy, so people should be aware to their work.

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