Water Journal March 1975 by australianwater

j 1ssN 0310 - 035 7 1

Official Journal of the

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Vol. 2 No. 1 - March 1975 - Price $l

An A.P.M . Mill Pond.

Water is life Water is as necessary for papermaking as are forests. And, like a forest, water is a renewable resource provided man works with nature to conserve it. Water conservation has always been a feature of A.P.M.'s activities in the company's mills as well as in the forests, especially in recent years. Fairfield Mill, near Melbourne, for example, has managed by intensive recycling to reduce the amount of water

it uses to make each tonne of product to about one third of what it needed ten years ago. This is the result of research, constant care, and the installation of advanced filtration and reclamation plant. And the improvement is continuing. At A.P.M.'s mills elsewhere the story is similar maximum possible recycling of water within the plant and purification of the used water before it is released . At Petrie,

Broadford and Maryvale mills the company has built large aeration ponds to help nature's sunlight, wave action arid oxygen recondition the used water. Nature has responded with an increase in waterfowl and fish life in these areas. We make paper to do things better.

Australian Paper Manufacturers Limited. 466

EDITORIAL COMMITTEE Chairman: C.D. Parker Committee: G. R. Goffin M. Dureau F. R. Bishop L. C. Smith Joan Powling R. L. Clisby A. G. Longstaff B. S. Sanders W. Burnett W. Nicholson A. Macoun A. F. Herath Hon. Editor: A. H. Truman

Publisher: John G. Craig

IISSN0310 - 0367J

• alellSTEWATER

Official Journal of the

··~

!AUSTRALIAN WATER..ANQJ ASSOCIATION ]

Vol. 2 No. 1

Mar. 1975

CONTENTS

BRANCH CORRESPONDENTS CANBERRA, A.C .T.: A. Macoun, P.O . Box 306, Woden, 2606

NEW SOUTH WALES: M. Dureau, Envirotech Australia Pty.Ltd., 1 Frederick Street, Artarmon. VICTORIA : A. G. Longstaff, Gutteridge Haskins & Davey, 380 Lonsdale Street, Melbourne, 3000. QUEENSLAND: L. C. Smith, 24 Byambee Street, Kenmore, 4069. SOUTH AUSTRALIA: R. L. Clisby, c /- E. & W. S. G.P.O. Box 1751 , Adelaide, 5001. WESTERN AUSTRALIA: B. S. Sanders, 39 Kalinda Drive, City Beach, 6015.

Editorial- Clean Air ......................................................................................................

Association News ..............................................................................................................

The Mutual Destruction of polluting Factors in Waste Liquors-W.M. Drew & W.R.B. Martin ...................... ..

Heat Treatment of Sewage Sludges - R.B. Brooks .....

Desiderata: Desired Engineering Excellence Dr. Clair Sawyer .................................................................................................................... ..

Valley Design in Urban Growth CentresAlan S. Bonham .......................................................................................................................

Report on AWWA Summer School.. ........................................................ ..

New Products & Projects ..........................................................................'. ............ ..

Conference Calendar .................................................................................................... .

TASMANIA: W. Nicholson, 7 Swansea Court, Lindisfarne, 7015. NORTHERN TERRITORY: A. F. Herath, 59 Allwright St., Casuarlna, 5792. Editorial Correspondence: Hon. Editor, A. H. Truman, c/ - Davy-Ashmore Pty. Ltd., P.O. Box 4709, Melbourne, 3001. Or to State Correspondents.

Advertising Enquiries: John Craig, 'Water' P.O. Box 100, Caulfield East , 3145 Phone : 211 7978 - 874 2133

COVER STORY 2500mm diameter Rocla reinforced concrete pipes being laid for the South-Eastern Outfal l, Melbourne . The 33 km pipeline is Australia 's largest precast concrete pipeline and will convey purified effluent from the Board of Works' treatment plant at Carrum to Bass Strait. The pipes were made in mainly 5m lengths at a special manufacturing complex in Melbourn.e where special machines and handling gear were installed to handle the pipes weighing up to 14.5 tonnes each. Pipes were made by the Rocla roller suspension process and design inc luded the innovative use of shear reinforcement .

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How ENVIROTECH Physical Chemical Treatment gives waste water the old one, two, three Ochemica1 coagulation , @f1occuation, 81iquid-so1ids separation . The Envirotech treatment system ensures that all three are completed efficiently. Remova l of suspended so lids and phosphorus to low residuals from waste water is normall y achieved by some form of chem ica l treatment. Alum, ferric sa lts or li me are common ly used to prec ipitate phosphorus and cause coagu lation of suspended matter. The Reactor-Clarifier Solids Contact Unit ensures efficient ch emic al usage and produces a high quality effluent.

ENVIROTECH

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For more information on Envirotech advanced waste water treatment tec hnology and equipment for industrial and municipal waste water,

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EA5

Predict effluent quality and obtain valuable process design data with this ...

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The BIO-OXIDATION SYSTEM creates a physical / chemica l environment comparable to pilot-plant or full-scale operation by maximum, independent control of process variables : amount of air; liquid residence time; culture volume; and rise velocity in the clarifying tube. Liquid flow, air supply, and sol ids removal are simply controlled with the turn of a switch -a ll of this from a single cabinet. For treatment of dairy, meat processing, petrochemical and municipal wastes-this BIO-OXIDATION SYSTEM is the perfect

unit for determining what strain of organism for 'seeding' treatment tanks and other experiments in biological oxidation.

Australian Agents:

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Telex: 24741

Telephone: (02) 604 1411 Queensland Quantum Scientific (072) 36 2544

South Australia Laboratory Supply Pty. Ltd. (08) 43 6610

Western Australia Westral Scientific (092) 61 7099 3

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Utilizing the proven sonar-in-air principle , the UFM-200 ultrasonically measures water flow to precisely meet your pollution and water code recording requirements . Accuracy is 1% at ANY point of the scale, a vast improvement over flow monitors claiming 1% of full scale . The UFM-200 sonar sensor is mounted over the flume and the ultrasonic signal is converted electronically to volume as gallons per minute (GPM). Meters, recorders.. counters, volume totalizer and electronics are all conveniently contained in one enc losure. The sensor, which is Explosion Proof as rated by Factory Mutual Research, is connected with coaxial cable to the enclosure .

UFM· 200

The UFM -200 is maintenance-free due to no moving parts or mechanical linkages and its unique non-contact measurement. The unit is factory ca librated for the size of flume or weir to be used . Its circuitry has the capabi lity to accept and power a water sampler and the samp le rate counter is adjustable for taking samples after a predetermined volume has passed. Circuitry also includes portable capability so addition of a battery is possible for convenient remote operation . Contact us today for comp lete information on the Ultrasonic Flow Monitor JFM -200.

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CHEMICAL ANALYSIS BY COLOUR ·c oMPARISON Chemical analys is can be comp li cated. Comparing colours is simp le and quick - a task that even an un skilled operator can perfori,, . Tintometer have taken more th an 300 analytical tests and produced complete and simplified procedures and instructions for carrying them out by visual, colorimetric methods.

The instrument used is the Lovibond 1000 Cominexpensive and robust with interchangeab le discs carrying permanent gl ass colou r filters. parator -

For each test a solution is produced from the samp le, if the samp le is not already in liqu id fo rm. A reagent is used to produce co lour in the solution. -Then the co lour is compared and matched against the filters on the disc, and the quantitative answer read di rect.

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Rocla awarded its 20th prestressed concrete pressure pipeline in Australia Since 1952 over 2000 km of Rocla prestressed concrete pressure pipes have been used in important projects throughout Australia and 15 other countries. Now Townsville City Council has chosen Rocla for the Ross River Dam Water Supply Pipeline. Talk to Rocla's major contracts people about the ever in creasing advantages of Rocla prestressed concrete pressure pipes.

Rocla Industries Limited - Major Contracts Division Branches in all States 6

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FEDERAL SECRETARY: R. F. Goldfinch, P.O. Box 359, Canberra, 2601 BRANCH SECRETARIES: Canberra, A.C.T.: D. M. Philp, cl- Dept. of Housing & Construction Phillip, A.C.T., 2606 New South Wales: Dr. D. T. Lacey, 16 Fairy Dell Close, Westleigh, 2120. Victoria: R. Povey, cl-S. R. & W. S. Commission, 590 Orrong Rd., Armadale, 3143. Queensland: A. Pettigrew, P.O. Box 129, Brisbane Markets, 4106. South Australia: M. C. Sanders, cl- Engineering & Water Supply Dept. Victoria Square, Adelaide, 5000. Western Australia: B. S. Sanders, P.O. Box 356, West Perth, 6005. Tasmania: P.E. Spratt, C/- Fowler, England & Newton, 132 Davey St., Hobart, 7000. Northern Territory: N. R. Allen, 634 Johns Place, Nightcliff, Darwin, 5792.

Two A.W.W.A. Tours for 1975 A.W.W .A. " World Tour" -

October, 1975.

A.W.W .A. " lndo-Au strali an Wo rks ho p." (See Assoc iation News for further det ails .)

EDITORIAL Clean Air I have spent the past week at the ' Clean Air Conference ' held by the Clean Air Society of Australia and New Zealand , at Rotorua, a marvellous spot for holding any conference but perhaps incongruous for this one. Rotorua could be described as heaven with connotations of hell. With a volcano in violent eruption on ly eighty miles away and positive local signs of its 'fall-out '; with sulphuretted steam gushing and hissing its way into my hot mineral bath and spluttering and explod in g from mud puddles and geysers ; with Maoris singing their love songs and shouting their war chants ; with warm sultry days and fi erce stormy nights ; with tales of clean emissions and morbid prophecies of choking cities , the whole effect was one of precarious balance . The conference started with an invitation from the Mayor to clean up his city 's natural odour problem , and finished with a commendation from the N.Z. Minister for Health , Mr . McGuigan , on the Society 's binational character (A & NZ) and the international representation at the Conference which was indeed a major strength. The international speakers came from the U.K. , U.S.A., Canada, France , Sweden , Tahiti and Japan , and although most countries have made considerable progress in maintaining or improving their amb ient conditions , it was apparent that there was no c lear way ahead, because there is insufficient understanding of the medical , physical and social effects of air pollution . During the conference , one thing became apparent - that most engineers and chemists and planners and economists the world over are not aware of the effects of their actions and there is no-one else prepared to put a value to the social benefits and losses with which we are all gamb lin g . But with all the social awareness in the world' and the selfinterest of vocal individuals and groups , would technicians alone be able to pass down acceptable judgments? Who is prepared to say what the environment can stand , what man and his co-existers need , what industry and the community can or should afford? We trust doctors with the lives of individuals and panels of doctors with the health of communities and nations ; we trust lawyers to determine the future of an individual and the courts to deal with the wealth and welfare of groups such as unions and industries . Is it too much to ask that we entrust the protection of our environment to a properly constituted , well advised , professional body or bodies? I suppose it is too much to ask at this stage - who trusted doctors in the days when they were trained only as barbers , who trusted lawyers before they had developed a code and tradition , or even , who trusted the police when they were employed by the potentate? We have some way to go before we can say we have a tried and proven trustworthy structure for dealing with our environment. In the meantime , we must continue to make our educated guesses and resist the pressures of the extremist bloodletters so that we don 't kill too many people by asphyxiation or starvation , or destroy too much natural beauty or too many of the aspirations of industrious man. A.H. Truman Editor 7

VICTORIA

A . Strom K. Chiller

ASSOCIATION NEWS TASMANIA OFFICE BEARERS 1974/75

Presid ent V. President

Dr . D. Weiss

Past Pre siden t

R. Povey

Secretary

K. Wood

Treasurer

F. R. Bishop

I. Lowther

A. G. Longst aff

W. Du ller

Mi ss J. Pow ling

C. D. Parker

E. P. Sorenson

G. R. Gollin

E. R. SwintoÂˇn

J. D. Lang

R. B. Turn er

J. S. Rogerson

0. R. Walters

President Immediate Past President

H.H. McFie

Secretary

P.E. Spratt

Treasurer

W. Nicholson

P.G. Craw ford E.R. England G.E. Lister M. H.R . Shipp J.F. Pot tinger J.R. Stephens

Committee:

Th e Branch 's final meeting for 1974 was a visit to the Glenorc hy City Council on Wed nesday 26th Nove mber. Members we re guests of the Mayor and Council lo rs for re freshment and buffet tea before proceedi ng on an in spection of wastewater treatment fac ili ties. Glenorc hy City Cou nc il is the Branch 's first sustaining member and the reception g iven members by the Cou nci l was noteworthy for this reason alone. Members we re co nducted over th e Berrieda le Wastewater Treatment Plant by Eng in ee rs of Scott & Furph y, designers , and the Co un ci l 's Cle rk of Works. PROGRAMME FOR 1975 1. March 19th

NEW COMMITTEE:-

Genera l Meeting

2. Mid-May Symposium

Paper yet to be decided.

RECENT ACTIVITIES:-

Operator Tra ini ng Course for Water Tre atment Pl ant Operators held at the Natural Resources Conservation League , Sprin gvale South from 7th - 11th October, 1974. 25 operators attended , 20 on a " live- in" basis. Cou rse run by R. Povey wit h notes and lectures given by leading engineers , c hem ists and bio logists . Addresses J.D. Lang , Chie f Engineer, Town Water Supplies , S.R. & W.S.C. 'Reuse of Wastewater '. Il lustrated add ress out lin ing some of the international t rends towards wastewate r reuse whi ch were exam in ed by Mr. Lang during his recent ove rseas mission on behalf of th e Victo ri an Government . T. Staz iak - Special meet in g to enable Mr. T . Staziak , Process Applications Engi nee r wit h the U.S. firm Orion, to address members on th e top ic 'Th e Continuous Monitoring of Ions in Po llution Process Contro l '.

14th - 16th M arc h - Reg ion al Con ference was held at the Canobolas Hote l, Orang e , with th e t itle "Decentrali sati o n and Water". Th e co nference was ope ned by the Mayor of Orang e, Alderman R.O. Thomas and the dinner speaker was the Hon . Sir John Fu ller, MLC, Minister fo r Plann ing and Environment. Whi le the ladies were enjoying a pleasant day away from th e po lluted Sydney air and tripping aro und to orchards and park s, the members were deep ly in volved w ith the fo llowing te chnic al program:-

" Treatment and Disposal of Waterborne Wastes Associated with Dece ntralised Industries " by Dr . D. T . Lacey , Assistant Principa l, Water Pol lution and Con trol En ginee r, State Pollu tion Control Com mi ssion.

Paper yet to be decided . In spect ion visit to Glen il a Chi cke n Abattoir , So rell. Wastewater disposal an d re cyc lin g.

Add ress Mr. R.W.G. Evans, Se nior Exec uti ve Engineer, Local Author ities Di vision, S.R. & W.S.C., to address members in March on the subject - ' International Review of Wastewater Treat men t ' - illu st rated.

Full detai ls of meetings wi ll be advise d to Branch members when avail able. Th e committee is planning to have the M ay Symposi um repeated in the north of the State for the benefit of members and othe rs in that area.

Th e waste treatment gaunt let has been taken up by another educati onal body which is organis ing two intens ive schoo ls on the sub ject. It was thousiht th at th ese

On th e 19th February, Mr. Tim Swain of Joh n Taylor & Associates - London , addressed a Genera l Meeting of the AWWA and discussed the new Blackbirds Activated Sludg e Treatment Pl ant at West Hertfordshire.

A most enjoyable social night was held for members and th eir wives at th e City and Overs eas Club in the form of a din ner dance. The annual fun ct ion was attended by 78 persons and was vo ted as a success by all who atte nded .

lnspect ion John Lysag ht Pty. Ltd. 's sheet m anu fac turing and wastewate r treatment fac il it ies at the Hastings factory to be in spec ted in February by 70 members .

4. October

The second confe rence is tentative at this stage but is proposed for 5th - 9th May and w ill be ent itled " Waste Control in the Food Industry". It is planned that the AWWA NSW Branc h wil l be one of the sponsors and will provide % large number of the speakers.

Ladies Night -

Annual General Meeting

Between 9t h - 14th February , a summer school was held on th e pub lic health aspect of " Food and Water Sciences " and 25 papers were g iven by 19 authors many of whom we re AWWA members. Th e conference was spec if ica ll y designed for health surveyo rs , was fu lly subscribed and was jointly sponso red by three organisations , " Th e Australian Institut ion of Health Surveyors ", " Th e Div ision of Ana lyt ica l Laboratories , Health Commission o f NSW ", and the " Sc hool of Food Sciences , Hawkesbury Ag ricu ltural Co llege " .

" Trends in Urban and Regional Pl anning and its Conc;ern for Water Resou rces in N .S.W. " by Mr. G. Andrews , Assistant C hi ef Pl an ner , N .S.W. Pl ann ing and Environment Commission.

Recyc lin g of Water in Ind ustry. Repco backed by Consultants.

3. MidAugust

sc hool s might be of interest to members in other states.

FUTURE ACTIVITIES:-

NEW SOUTH WALES

" Deve l o pm e nt of a Sewerage St rategy for an Expanding Commun ity " by Mr J. Kn ight , Director, Sinc lair Knight and Partners. " Wool Processing i n a Decent r a li sed Environment f or Decent rali sed Industries " by the Hon. R.B. Roland-Smith , MLC , Dire c tor , Canobolas Woo l Topmaki ng Pty . Ltd. " Email a Decentra li sed In dust ry" by Mr. K. Tucker, Producti on Man age r, Em ail. " Decentralisation and Open Forum.

Water " -

Turn to page 25

The Mutual Destruction of Polluting Factors In Waste Liquors by *w.M. Drew and W.R.B . Martin SUMMARY Treatment of waste liquors has in the last years presented industry with an urgent challenge. The need to comply with newly created water quality cirteria and to come into line with environmental policies supported by heavy fines now faces all industries in the State of Victoria, and in other states where environment protection laws have been passed. Existing treatment processes if installed and operated correctly can produce acceptable effluents from concentrated waste liquors fmm many industries. Biological treatment processes are in certa in insta nces, part icul arly at hi gh diluti o ns, economic altern ati ves to conventional method s; often surp ri si ngl y, treating waste li quo rs in w hi c h it might be assume d, th at microorganisms cou ld not survive . As an exampl e this paper reports a rece nt investigation w herein a liquid wastes disposal problem in the Latrobe Va lley area of Victoria was studied. INTRODU CTION

Th e Latrobe River drainage basin (Fig. co mmonly known as " the Latrobe Valley" in th e Gippsland reg ion of south easte rn Victo ria is a rich part of th e flats of Vi ctori a. Within it under thin cover occur vast deposits of brown coa l of whi ch 80,000 million tonnes have been " proved " 1) -

ftc.. /.

to date . These togeth er with availability of sufficient water in the catchment basins is th e basis on which steam turbine generation of four fifths of Victoria 's elect ricity has been developed . The energ y c risi s will certainly accelerate development of these resources. Also c limate , topography an d soil fertilit y have resulted in one third of Victoria 's dairy indu stry being developed in th e region . Furth ermore , power, wate r, coa l and ind ige nous forests and land su itable for planted forests but not for dairying has attracted a larg e paper pulp mill co mple x to the area. Eac h of th ese three industries i.e. power generation , pulp , and dairy , pro duce large quantities of liqu id wastes, 4.54, 22.73 and 0.45 Ml /day respectively .

Locollfy mop Showing outfall pipeline ond channel plus power station and

paper mill.

These wastes enter th e sewe rag e system trave rsing th e lo wer and populated part of the valley as ope n and c losed co nduits to a treat ment farm at Dutson Downs. The effluent receives treatment by way of pond ing (removal of suspended so lid s and B.O .D.) and irrigation on pasture land s. Howeve r, it is quite ev iden t from obse rvat ion that an efflu ent ofÂˇsign ificant co lour st ill manag es to find its way in to nearby Lake Co leman . In add ition to the degradation of the lake , the fact that the efflu ents of high odour flow for a distance of some twe nty miles throug h open chann el ad jace nt to farming co mmunities also provides a stimulus to devise suitable means of the treatment of these wastes. Moreover the recently promulgated (March 1973) Environment Protection Act of 1970,' w ill cause th e industries co nce rn ed to seek meth ods of reducing the pi:>llution load of their efflu ents. Those ind ust ri es discharg ing to sewers will be indirect ly co ntrolled by the fact that th e disc harge from the sewage plants are to be li censed by the Environment Protection Authority. Th e waste li quo rs in question in dividually are in fact, to some extent , already treated . The precipitator ash slui cin g liquor from Hazelwood powe r stat ion is directed fi rst to settling ponds where most of the suspended so lids are remove d. Th e remai nin g supernatant liquor co ntaining so lubilised ash (the ash is approximate ly 40 to 50 percent so luble) is discharged to the sewer. Black liqu o r conta ining ce llulose fibre from the pulp mill operat io n s is directed thr ough oxidat io n lagoo ns before ente rin g the Latrobe River. Untreated liquor goes to the sewerage system. Milk wastes are disposed of in a number of ways including pig food , fert ili zer, dumped on land , dumped in lakes and streams, and into town sewerage. The sp lit up for this latter case is given in the following table (table 1.1). From this table it w ill be 'ev ident that in Gippsland whilst some 45.842 Megalitres (10.084 million ga llon s) per year of whey (mainly case in whey) enters th e town sewerage system there is a significa nt amount , 21.944 Megalitres (4.827 million gallons) , dumped on land or in water bodi es. It will also be noted that a larg e volume of whey 79.40 Megalitres (17.477 million gallons) is used as fertilizer. However, th e disposa l of waste whey as fertilizer on land is a questionable prac ti ce 1n that the land is often ad jacent to water courses, grass sco rching occurs, stag nate pools putrify and the "fe rtilized " land requ ired ca reful management and frequent neutralization with lime' .

S.E.C.

power stot iOl'I

SALINE WATER ... ,..,_

PIPELINE

Taking into accou nt th e limited success of th e exist ing methods of treat in g these liquors and th e relative unacceptab ility of their co mbin ed residuals in open chann el and lakes, a proposal for mutu all y reducing part if not all of the unacceptab le c haracter ist ics appeared to merit in vestigation . Appreciation of the above in formation led to an investigation being un dertake n by the principal author, in fulfill ment of requirements for a high er degreeâ&#x20AC;˘, to determine th e possibility of treating the

"'! 1____ _

*W.M.

Drew , State Rivers & Water Supply Com mi ssion of Victoia.

W.R .B. Martin , University of Melbourne , Chemical Enginee rin g.

Continued ovarleaf 9

End Usage of Whey (Megalitres for year 1969(703) Table 1.1 End -Use

Western Di strict

N.E . Di st ri ct

0.455 15.256 9.028 39.5 14

159.651 30.358 49.188

Uti lization Pi gs Fertil ize r Dump ed on land Dumped in lakes and streams Town sewerage

Gippsland

96.303

TOTAL S

160.556

239.206

Pulp Mi ll Liquor Analyses -

Total

96.671 79.450 4.792

0.455 27.578 118.837 93.502

O.Q7 42.19 18.45 14.53

113.455 45.842

11 3.455 45.842

17.63 7.12

243.907

643.668

100

Table 2.1

Samp les Used in Experiments Determination

Samp le No . and Date

1 1.9.72 7.0 3450 2930 1000 93 73 3.6 3.1

pH Co ndu cti vityµ. Siemen /cm Suspended Sol id s mg /I Sodium as Na mg /I Potassium as K mg /I Ca lcium as Ca mg /I mg/I Mag nesium as Mg · Iron as Fe mg /I Ch lo rid es as Cl mg /I Sulfate as SO 4 mg /I Organic matter ext racted from mg /I ac id ified efflu ent Co lour Pt-Co units

Casein Whey Ana lys is SAMPLE USED

DETERMINATION

Ash Sluici ng Liquor Analys is -

20 3. 0 5 2.0 151

363

1290 10,000

2104 10,000

Table 2.2

ACCEPTED AV. ANA LYS IS FOR GIPPSLAND 4.2 0.1 1.0 5.0 0.45 36,000

Hazlewood Power Plant -

Table 2.3

Sample taken 19.5.72

Determ in at ion

12.5 18200

7 mg /I mg /I mg /I mg /I mg /I mg /I mg /I mg /I mg /I mg /I mg /I

three liquors in a cent ral plant co njointly by culture ot micro-o rganisms. The invest igation did not necessari ly have to be undertaken with the view to ju stifyin g th e process on econonic grounds , because having regard tor the licence co ndit ions that can be imposed by the Environment Protection Authority , any reasonab le pro cess mig ht be acceptable when the alter-

7.4 2380 2104

4.3 0.75 1.22 6.46 4.5 0.6 0.5 1 120 27 ,000 (· 2.7 % )

pH Fat % Prote in % Total solids % Lactose % Ash Content % Titrable Acidity % Su lphate as SO 4 mg/I BOD 5 mg /I

pH Conductivity µ. Siemen /cm Turbidity Alkalinity Total as Ca Co 3 Sodi um as Potassium as K Silica as SiO 2 Ph osphate as PO 4 Iron as Fe Calcium as Ca Magnesium as Mg Chloride as C l Sulph ate as SO Nitrate Nit rogen as N

7.9 2070

860 730

3 26.10.72

2 20.4 .72

2400 2800 103 N.D . N.D. N.D. 880 49 1100 3540 3.9

native to no treatment is considered. (i.e. c lose down). To full y investigate all the alternat ives of treating the efflu ents in question wou ld take some considerab le effort and time. However, it was suspected that the objectionable odours arise principa ll y from the bio logical redu ction of inorgani c su lphat e

to hydrogen sulphide in the deoxygenated lagoons , thus it was decided to attempt to grow a mixed bacterial cu lture co ntaining microorganisms of the gen us Desu/fovibrio desu/furicans, in representative mi xtu res of the three principal effluents . 0. desulfuricans is a well understood (6, 7, 8) ob li gate anaerobic bacterium which ob_ta ins th e oxygen requ ired for growth and viabi li ty f rom . oxygenated ino rga nic sulphur molecules such as su lphate which is abundant in the power station ash sluicing liquors . The expe ctat ion is that if properly managed cu ltures can be made to effect prior removal of sulphur preferably in some economically recoverable form , su lphate reducing organism s in the efflu ent stream in open flow or in residu e ponds wi ll not proliferate and produce h ydrogen su lphide . The following sections give the details and t he results of the inve stigatio n designed to determine the feasibilit y of such a process 5 the aspects, the comparison of eftluents, materials balance, selection of microorganisms , results of experimental work and recommendations for furth er wo rk . 2. COMPOS ITION OF WASTES AND MATERIALS BALANCE 2.1 Composition The follo w ing tab les (tab les 2. 1, 2.2, 2.3) give typical analyses tor the three effluents as sampled and used in the investigat ion .

From the above analyses it will be noted that the pulp mill liquor vari es in composition over quite a wide range and in tact the expe riments were conducted using samp les hav ing all three of the above composit ions . The reason tor not using a samp le of one compos ition was because of the need to use much more of this particular effl uent in , compar ison to the other two. As a general co mment it can be said that pulp mill li quor samples used in the experiments fell within the range expected . Th e composit ion of the ash pond efflu ent as per tab le 2.3 ca n be taken as being reasonab ly representative of the liquor discharged from the pond over a five month period s. The casein whey sample can also be regarded as being fairly representative of the whey being d ischarged as waste in the district. 2.2 Materials Balance In comput ing the materials balance two co nstitu en ts required tor th e cu lture of th e proposed organism were considered. (1) Total availab le lactic acid. (2) Tota l avail able su lphate ion . 2.2 (a) Total available lactic acid on a daily basis. It is evident from the analyses (see tables 2.1 , 2.2 , 2.3) that th e major source of lactic acid is casein whey , however, it is possible that some lactic acid could be form ed from cellu lose fibres in the pu lp Continued overleaf

i I

mili waste accord in g to the simplified equat ion. (C 6H 10O 5)n + n H 2O - 2n(C 3H 6O 3) Ce ll ulose Lact ic Ac id -(2!) Further it was estim atedS that the average amount o f fi ltrab le mater i a l avail ab le in the efflu ent was 0.3 percent. Ass umin g th at on ly 20% of the tot al amount of this material is conve rtibl e io lactic ac id then th e ava il able lactic ac id is 0.2

0.3

;~g

C12H22O11 + H 2O- 4 C H3 .C HOH.CO 2H Lactose Lacti c ac id MW = 342 MW = 360 -(2.2) Taking the ave rage lactose fig ure at 5.0 percent the available lact ic acid is:-

~~g

= 5.3% Lactic ac id .

Tota l Lacti c ac id = 5.3

0.5 1 = 5.8 1%

Th e tota l avail ab le lac tic ac id in all wastes (assu mi ng th at the Haze lwood Power Stat io n ef fl ue nt co nt ai n s zero orga ni c materia l) is comp uted as fo llows:150~ X 0.455 = 4.0

106

+ ~ X 22.730 X 106

104 kg /day

2.2 (b) Tota l ava il ab le sulph ate on a daily basis Ave rage co ncent rat io n data fo r th e three liquors 5 puts the co nce ntration of su lphate io n at 2500 mg /I, 500 mg /I ana 120 mg/I for ash sluicing li quor , pulp liquo r and whey respect ive ly. Th e tota l avail able sulphate was co mputed as fo llows:1~ X 0.455

Case in Whey

°°

28 X 4.546 106 As h liquor

Observat ion of the rate of product io n of sulfide during iso lat ion and cu ltu re phases was a g uide to the growth and viabili ty of the mi croorgani sms.

Lactic Ac id 4.08 x 104 Sulfate ion = 2.27 x 1O~ = 1 -8

Gas flushing to remove th e H 2S produced , used high purity nitroge n .

This figure indi cates that there is potentially ju st abo ut the right amount of lact ic ac id avail able as a subst rate for the red uct ion of su lfate by su lfate reducing organi sms.

= 0.06 %

To find th e tota l lac ti c acid in th e case in whey , the tit rab \e ac idity (0.5 1% for sample used) plu s the hyd ro lysab \e lac to se mu st be added toget her. Hydrolysis of lactose takes place accord ing to the fo ll owin g eq uat ion:-

5. x

2.4 Actua l amou nt of substrate ava ilabl e for su lfate The actual ratio of lact ic acid to su lfate ion was found to be

106

+ ~ X 22.73 X 106 + Pu lp milk liquor

1Q6 = 2.27

10 4 kg /day

Total

2.3 Th eoret ical requi reme nt o f substrate fo r reduct ion of su lph ate The chemica l equ at io n for reduct io n of sulph ate w ith lactate as substrate is as fol lows:2C H,C HOH CO2H + SO 4 Lact ic Acid Su lph ate 1 mo le 2 mo le 2CH 3OOOH + 2CO 2 Acetic Acid Carbo n dioxide 2 mole 2 mo le 2H 2 O + s + Su lfide Water 2mo le 1 mole -(2.2) Thus th e th eoreti ca l (or sto ic hiometri c) lact ic ac id requirement for th e reduc tion of su lfate is 2 mo le: 1 mo le whic h, on a weight basis , g ives th e following ratio:Lact ic Acid = 180 = 1 84 Sul fate 10n 96 ·

3. DETERMINATION OF EXPERIMENTAL CO NDITIONS AND SU ITABLE MI C ROOR GA NI SMS FROM THEOR ETICA L CONSID ERATION S D. desulfuricans can be desc ribed as mesophilic (i.e. preferred temperat ure for growt h 15 to 45°C) , heterotropic (i.e. energy derived from organi c com po unds) , an obligate anaerobe , (cannot to lerate an oxyge nated env iro nm ent) of a di ssimil atory natu re ( in that they reduce mo re su lfate than th ey requ ire n ut rit io n all y), non sporul ati ng and be long in g to the genus Desu/fovibrio. In addit ion th e abi lit y of th e o rgani sms to g row in sali ne or mari ne en v ironmen ts was a dec id ing po in t when the hig h sali nity of the wastes is co nsidered. Inf o rm at i o n gained from the li terature s.10, such as th e inhibitory nature of th e end product , H 2S, on the organi sm and th e need to establi sh th e optimum ope ratin g temperature for the particu lar strai n in the· proposed substrate liquor d ictated th at initially the se lected organi sm sho uld be cu ltured in a c losed vesse l with facilities for inert gas flu shing plus temperature var iat ion. An extensive review of literatures also ind icated that very little work had been undertaken in th e area of co ntact anae rob i c waste treatmen t espec iall y usi ng c ultu res conta inin g predominantly su lfate reduce rs. Th erefore it was see n to be appropri ate to set up bench sca le equ ip m en t t o test th e feasabi lity of a cont inu ous co ntact process. 4.

EXPER IMENTAL

4.1 Iso lat io n of mi c roorgani sms I n orde r to i so l a t e a strai n o f microorganisms suited to su lfate red uction in a sali ne environ ment a samp le of mud and water was taken from an esturin e sou rce where there was ev idence of sul fide production . An analys is of th e water revea led th at the conce ntrat ion of Tota l Di sso lved Sa lts (approx. 24 ,000 mg /I) was c lose to th at of th e ash slui c ing li quor (approx. 18,000 mg /I). It was therefore reasoned th at the esturi ne li quor with added nutrients as spec ifi ed by Postgat e6 wo uld serve as an isolation medium and a medium for subseque nt inoculations for the test cu ltu res. 4.2 (a) Appa ratu s fo r iso lation and batc h fermentations The apparat us used co nsisted of a sta inl ess stee l temperature co ntro ll ed water bath plus a se ries of Drec hse l bottles fitted wit h porosity No. 1 frits fo r th e reac ti on vesse l and lin ked to simil ar flasks w ith str aight tubes fo r su lfide absorption.

4.2 (b) Apparatus tions

Continuo us fermenta-

A diagram of th e apparatus use d is shown 1n figure 2, i.e. a co mmerc ially avai l ab l e " Mini - fer m e nt e r " by New Brunswick . Other key features being a peristaltic pump and a syph o n overfl ow. Su lfide production was again measured by absorpt ion of th e flu shed hydrogen su lfide in a Drec hse \ bottle. Th e apparatus was sealed and operated anaero bi ca lly. 4.3 Sulphide est im at ion

...

Th e procedure laid down in " Th e Standard Methods of Water and Wastewater Examination" 13th Edition, were used for esti m atio n purp oses fo r su lf id e. T he met hod briefly in vo lves th e absorpt ion of hydrogen su lfide produced in a so lution of zi nc acetate fo llowed by a back titrat ion of unreacted adde d iod in e so luti o n wit h .025N thiosu lfate. 4.4 Expe rim ental determi nati o ns Th e batch apparatus described under 4.2 (a) above was used to determine the opti mum gas flushing rate and opt imum ope ratin g temperat ure. Both variables were determin ed by measuring the tota l sulphid e produ ced ove r seven days and plotting this va lue aga in st t he flu shing rate or te mperature. Using the batch apparatus an o rd er of mag n itude est im ate of the spec ifi c growth rate µ, , and th e doubling t ime , l ct, were determined by g ravi metri ca \l y measuring (by ce nt rifuging and drying a sam pl e at 105°C) the amo unt by weig ht of ce ll s present per unit vo lume at a g ive'r1 t ime during th e incubation and then co mputing the increase in th e dry we ight of ce ll s. A furth er expe rim ent was conducted to test th e effec t of va ryi ng the rati o of casei n whey and time of add ition in co mpari son to the oth er liquors . Operating te mperature and gas flu shin g rate were as determined in th e preceding experimen ts . As a fin al phase of experi ments the "M ini-ferm enter" was set up to run co ntinu o usly wit h a feed soluti on co ntainin g pulpmill , ash sluicing and case in whey li quors in th e rat io of 500 :100:10 (thi s rati o was use d in all th e abovementi oned experiments unless oth erwise state d). Th e fermen ter was initi all y c harg ed with 680ml of waste mi xt ure fo ll owed by 20ml of stock cu lture inoc ul ant and th en all owe d to run fo r a period of two weeks at seven different fee d rates ranging from 675ml per day to 5400ml per day (i.e. a dilution rate ,.!.. f v, 0 0.93 day- 1 to 7.73 day-1). Th e temperature was set at 40°C and th e gas rate at 30 I per day. Thi s gas flow rate was c hosen to taKe acco unt of th e larger reacto r vo lume as co mpared to the batc h experim ent in w hich a flow rate of 25 I per day was found to be requi red. Continued overleaf 11

Thu s equat io n 5.6 becomes ,

-(5.8)

whic h redu ces to , µ. = D at steady state

-(5.9)

µ.x - XO

NI TlfO@EN G AS IN

Using eq uat ion , 5.3 the Monad equati o n and 5.9 the fo llowing equation can be written : D -- /J.maxK

rVe / ~ TO tJt,«.KSV/"Pl.7 ~

,,,-,rrb

s+ S

-(5.1 0)

10,1. (.JT ~dN

Equation 5. 10 -can now be rearranged to g ive

S (µ.ma x - D)

- (5.11)

/,,E~N~-N T,.Tt dtV V#SS6J.

( IL)

Now since Kx is defined as a co nstant whi ch is so over a w ide range of dilution and substrate conce nt rations equation 5.1 1 can be used to derive the fol low ing equation

,.11_y11.1,."/ 7,mr.q

ML(/- eEAMENTFA

~ - ~ ~ ,m

- (5 .12) F/G.2. .

.5.

TREATMENT OF RESULTS

For the batch experiments the specific growth rate , µ. , was found using the follow ing equat io n . dx dt = µ.X

-(5. 1) whereµ. = spec ifi c growth rat e, day- 1 x = conce ntration of mi croo rganism expressed as dry weight , mg /I t = time , day. Equation 5.1 can be rearrang ed to give:-

= : ~;

-(5.2) Thus from a plot of ce ll dry weight versus time µ. ca n be ca lc ulated by dividing th e slope at any g ive n point on the curve by th e we ight of ce lls. µ.

In o rder that th e gro wt h kinetic s might be mo re precisely desc ribed th e co nstant values in the Monad equ ati on 13 be low , we re determined.

µ.

= /J.maxKs + S

whereµ. /J.max

-(5.3)

= specific growth rate , day- 1

ma x imum specific growth rat e ,day-1 = substrate co nce ntrat ion , mg /I · sat u ra ti on cons t a nt , num eri ca ll y eq ua l to the limiting nutrient co nce ntration at one-half the maximum growth rate , mg /I.

Also the do ubling tim e for t he mi c roo rg anisms was ca lc ulated using th e fo ll ow in g eq uat ion . ln 2 -(5.4) µ. = td where td = doubling tim e, day . A table of resu Its (Table 5.1 (a) ) at the e·nd of this section shows the values obtained and co mpares th e result s t o li terature va lues. In th e case of the co ntinuous ferme nt at ion ex perim ents th e same parameters as col114'.l uted for th e batc h experim ents were found i.e. K 5 , /J.max • td. Th e proce dure used was based on the fo ll owi ng reason ing : -

for a singl e stage stirred reactor, operated

co ntinuou sly the fo llowin g expression ca n be written:Rate of in c rease in ce ll co nce ntrati on Rate of growth - Rate of outfl ow

- (5.5)

Th e above can be writt en mathematicall y as dx -(5 .6) dt = µ.X - xD where

D= dilut io n rate , day·1iD = 0!,

where f V

= flow

rate , 1/day

= reactor va lu es , 1

At steady state co ndit ions dx di = o,

- (5.7)

Usi ng eq uat ion 5. 12 it is possible to find th e va lue ofµ. ax by si mp ly operating the fermentation two d ilutio n rates and by measuring the substrate co nce nt rati ons in th e media after the fermentation has gain ed equi libri um . However in app lying 5. 12 it must be remembered that it only appl ies for D val ues greater than the va lue req uired for maximum product output , for lower D va lues th e substrate conce ntration , S, is at a minim um and does not c hange over quite a w ide range of D. Also a crit ica l va lue of D, sho uld not be exceeded as " was ho ut " will occ ur. Washout can be defined as that cond ition in a cont inuo us process where the d ilu tio n rate exceeds the specific g rowt h rate .

Th e doub ling tim e, t d, at the max imum spec ific growth rate , µ.m , was c'alc ul ated using equat ion 5.4 . Tab les of results co mparing the va lues o bta ined wi th others in th e literatu re given be low (Tab les 5.1 (a) and (b) ). Compari so n of expe rim ent all y determined val ues for K 5 , td, and /J. max with li terature va lu es. Co ntinuo us Cultures - Table 5.1 (a) So urce of data

Param eter

0.53 2.0 8.26

K 5 (g/1) /J.max (day -1 ) t d (hr) at /J.m ax

Expe rim enta l 2

0.65 2.2 7.5

0.4 1.75 9.5

Hall berg

0.08 208 (8.65 days)

Compari son of experim ent all y determined va lu es for K 5 , td , and /J.m ax w ith li terature va lues . Con tinu ous Cu ltures - Table 5.1 (b) Parameter

So urce of data

K 5 (mg /I) /J. max (day - 1) td (hr) at /J.max

Experim enta l 1 2 25 .75 0.14 118

22 .5 0.23 72

Laseter (10) 1 (a) 2 (b} 2 (a) 2 (b) Complex media Simple media 3.27 5.1

1.157 14.4

1.136 14 .65

0.144 115 (4 .8 days)

Continued overleaf

RESULTS AND DI SC USS ION S

Fro m figure 3 below it is ev ident that the opt imum tempe rature for the growth of the strai n of microorganisms iso lated in the waste mi xture was fo und to be near 40°C this val ue is seen to com p are favourably with that obta in ed by Truper 12 whose resu lts are plotted on the same graph. The resu lt is also of the same order as obtained by a range of other workers s .

~1 i

W ith respect to t he expe rim e nt s designed to determine the various kinetic constants (i.e. µm ,Ks,t d) it w ill be noted from tab le 5. 1 (a) and (b) that the res ults at least bear a resemblance to those of other workers. A lth ough it appears that the batch results compare better to the cont inu ous cu ltures of other worke rs9,15 and vice-versa for the co ntinuous cu ltures. Differences in the media used and the viab ility of the strain s of microorganisms iso lated are thought to be reasons for the differences. A subjective , yet im portant result of the con tinu ous fermentations was the effectiveness of the process for odour reduc tion. Sig nificant ly, uncovered samples of th e mixed effl uents we re decidedly obnoxious prior to treatme nt , however, after passage through the " Mini-fermenter " the odour was suffi cie ntly reduced suc h th at the rece ivi ng vesse l (a 1 li tre beaker) required no cove ring at all and no comp laints from other laboratory personnel were recorded . 7. CONC LU SION S AND RECOMMENDATIONS It may be conc luded that from the in vestigation undertaken that three differin g waste li qu ors can be t reated in a specif ica lly des igned treatment p lant with the benefits of suc h treatment being the reduction of odour and su lfate co ncentration. Reduced leve ls wou ld serve to reduce co rrosion in concrete pipe sections of the sewerage system , plu s the recovered elementa l su lfu r wou ld be saleable (est imated 5000 tonnes at between $20 and $40 per ton ne) thus contribut in g to the ope rat ing cost of th e plant.

SLU..E/12.E

'PAOOt.JC fi'()N c oMP/9,tt#Z>

VE"".AS'VS

""""

TEMPE~fl/ V R.S

OF F.ER.MENT~Tl "N

1?r.su1..T"S FA"n r..-e- ,,ll'T£~N T ()</E

r-._

,rl''i,iAltrLr"'L

( 12) 300

~E,f/NIN/Jfi.

The flushin g rate for nitrogen to promote maximum sulfide production was found to be of the order of 25 1 per day for the reaction vessel , distributor frit and subst rate mi xt ure used figure 4. Th e va lue was found to be approx im ately twice that observed by Bullin et a114 for experiments performed o n su lfate enr ic hed sewage sludge. The difference in the resu lts is not thought to be sign ificant when the variat ion in substrates and ap paratus are considered. Figures 5 and 6 ind icate that the Oest tim e for the addit ion of whey to batch fermentations is some period after the co mm encement of the in cubat ion. The precise time is hard to judge , however, it wou ld seem to be somewhere between the second and fourt h day. Approximately one quarter of the casein whey norm all y avail ab le shou ld be mixed w ith the othe r wastes for the init ial charge to the fermenter. These results also show that .33 mg of sulfide is recoverab le from an ava ilab le source of 35 mg of sulfi de (117 mg su lfate) whi ch is an effic iency of conversion of approximate ly 95 % .

FIG. 3 .

~ f'.:

I•

l>O

/4-

2#0

~ ii: ::l

!50~

~1-.:

~ '" ~

<::,

~ V)

"' I

'" 30

:J.C

~ £ RRTVRE

4<)

F£RMENT,i?T101'{,

·c

FIG. 4. -roT /1,!..

z. .O,Q z::_ GAS

2.G

SUL ? rfr.PE PRQDVCTION "gRSUS F£.(,IS/,'! NG R/lTE '9T A O "C

~ 0-' ~

"'~

0 (!)

:,.o

0 0

<:> ~

::,

~ ~

• 0

,½ c;~s

.to

Ft (JS/ONG

Conside ration of the type of plant required to treat the wastes on a large sca le leads one to propose a system uti lizin g an anae rob ic co ntact stabi li zatio n unit possibly based on a design put forwa rd by Gates et al 16 and in tegrated w ith an act ivated sludge unit. Th e type of plant required to recover hydrogen sulfide from the fl ushi ng gas, in th e form of su lfur, has not been indicate but it cou ld be any one of a number of diffe rent processes. Total treatment of th e wastes to no rmal leve ls of acceptabi li ty fo r disc harge into rece ivin g wate rs wou ld require an in tegrated system (i.e . anaerob ic co nt ac t

R;>r;;;

.2,$"

~"'".Y

stabi lizati o n plus activated sludge) as the anaerobic process has litt le or no effect on co lour. Woodard et a11e c laims that in excess of 90 percent redu ction in lignin co ncentrat ion using an act ivated sludge deve loped from a spec iall y se lec ted cu lture of microorgani sms . As an overa ll co mment it can be stated that the experiments we re purely ex ploratory and by no means ex haustive. However, th ey d id se rve to show that dissimilar wastes shou ld not be seen to be mu t uall y exc lu sive rather they should be invest ig ated to test their co mp ata bility . The pos Continued overleaf

FIG, crr&CT

o, .'lb/J/NG

9VRN/IT/£S 2'l/Al,1(6, CQ<UlSF {lf _,:-£~MGl'+IT/IT/O/I,/ P,tOC.£.E.t>ING WITH "9"(R W(Tt(OVT

C,,9$FhV

WK.Ry IN .,?/ U:l6 E

C"1SEltv

WHq

O IVG IN/AL

FL.ASK N#

w-':,-\ @•® \

5 ·0" / cul~u~

c.,.;. fl,uAs

I,;

RA r10

5. Drew , W.M. " An investigation into the mutual treatment of pulp mill black li quor, ash sluici ng liquor and casein whey using su lfate reducing bacteria", Master of Engineering Science Thesis, University of Melbourne , February 1973.

O"'" Eh,.~ vrwr.J

C ASL,..., l,(,W)'

A . P.f"1.

S -E - C .

soo

/00

s oo

100

500

/00

,4.

soo

/00

6. Postgate , J.R., and Campbe ll, LL , " Classification of Desulfovibrio species , the non-sporulating sulfate reducing bacteria ", Bacteriological Reviews , Vol. 30 , 1966, PP732-

7. Peck , H.D ., Jr. , " Enzymatic basis for assimilatory and d issimi latory sulfate reduction ", Journal of Bacteriology , Vol. 82, 1961 , PP933-93~ .

T/ME:

.S&/,t.Plftl>E

F IG. G.

8. Campbel l, LL , and Postgate , J.R. , " C lassificat ion of the spore -forming sulfate reducing bacteria " , Bac teriological Reviews , Vol. 29, 1965, PP359-362 .

//VC ',!;!3/ITIC)N

PAOO//CTION

T. .l)/1.?c_S '

WITH /)/F'Ff'P.IN6

CASEINWh'll F0LL0WfP 4Y F//ATNE,'\

//11/TI/U,

9. Knight , J.C , and Cove lli , P. , " Prelim in ary report on the feasibi lit y of microbiological production of sulfur from gypsum " , Report prepared for Davey Ashmore , by the Department of Microbiology , University of Me lbourne , Parkvi ll e, Vic ., Aust.

CONC£NTffl!TIONS

19/Jl)/T/Ol'(S

Wl(EY

_______________ ____________ ,,,,

10. Laseter, J.L . and Associates , "A feasibility study using microbiological methods to recover elemental su lfur from gypsum" , Report prepared for Davey-Ashmore Pty . Ltd ., Melbourne , Australia , 1969.

'------------:~-----" 1 ' ~:;;1 t:·:;i:.';J.. V0/v,.,.c • f f!.. 1/rs ,c £,-o- 1. r.1.,,,,.e •I,,-,,,,·_-,~ ;1.. ,1r - ,2,,,.,1.

11 . Standard Methods of Water and Wastewater Examination , A.P.H.A. , A .WW .A. , W .P.C.F., 13th Edition , 1971. 12. Truper, H.G. , " Hot brines - recent heavy metal deposits ir\ the Red Sea" , Ed. by E.J. Degens , Springer-Ve rl ag, New York , 1969, PP263-271.

0 ,-1,.9,;,,,af l?o:'t/0 "/ E{'f'fve1trs

/'las/< N' /1.P.M

S . E.C.

C/ISGtiVr/K,Q'

500

JOO

2·5

500

100

500

100

7·5

500

100

13. Monad , J. , " The growth of bacterial cu ltur es ", Annual Review of Microbiology , Vol. 3, 1949, PP371 -394 .

3 TIME

lNCt.J/3//TloN, T,

sibil it ies of producing saleable by-products are seen to be a bonus . In fact the thesis is put forward th at indu stry should be located in industrial areas such that their effluents might be directed through short pipe run s to ce ntral treatment works tor treatment with other se lec ted effluents so as to gain the maximum effic ienc ies of treatment. Finally, it is envisaged that in the future treatment works wi ll be so establi shed as to afford, at any time , the se lection of individual waste or waste mixtures for treatment in the most suitable combination of a number of available unit processes. 5'orage facilities for incoming effluents should be provided so that optimum ratios might be maintained. Planned gro uping of

4. Oborn , J. , " A review of methods available tor whey utilization in Austra li a", Australian Journal of Dairy Technolqgy, Vol. 23 , No . 3, 1968 PP131 -136.

6 D.4;,'S

industry and thorough knowledge of their efflu ents would go a long way to ensuring the success of such an operation.

REFERENCES

14 . Butlin , K .R. , Selwyn , S.C and Walkerley, D.S ., " Microbial su lfide production from sulfate enriched sewage sludge ", Journal Applied Bacteriology , Vol. 23, 1960, PP158-1. 15. Hallberg , R.O., "An apparatus for the continuous cu ltivation of sulfatereducing bacteria and its application to geomicrobiological purposes ", Antonie van Leuwenhock 36 , 1970 , PP241-254.

1. Anonymous , " Hazelwood Power Station", Published by the State Elec tri c it y Commission of Victoria , July 1967 .

16. Gates , W.E. , Smith , J.H. , Shun-Dar Lin and Ris, C.H. , " A rational model for the anaerob ic contact process " , Journal Water Pollution Contro l Federation·, December 1967, PP1951 -1970.

2. Anonymous , The Environment Protec tion Act , 1970, No. 8056, Government Printer, Melbourne, Victoria, 1972.

17. Davis , J .C , " Add-on processes stem H.2S ", Chemical Engineering , May 15, 1972, PP66-68.

3. Siemon, J.R. and Sitnai, 0. , " Whey disposal - Survey of member factories of the Victorian Whey Utilization Assoc iation ", C S. I.R .O. Division of Chemica l Engineering , Memorandum No. CE/M-28, Jan . 1971.

18. Woodard, F.E. , Sproul , O.J. , and Atkins , P.F. , " The biological degradation of liquid from pulp mill black liquor", Journal Water Pollution Control Federation , Vol. 36, No. 11 , Nov. 1964, PP1401-1410.

Heat Treatment of Sewage Sludges by R. B. Brooks, B.Sc., M.Sc., Ph.D. Microbiological Engineer Millaquin Sugar Mill, Queensland.

seeds and th ere is no increase in the we ight of so li ds to be disposed of. Th e process may also be made se lf-susta in ing by using the pressed sludge as fu el. The ca lo rifi c va lue of heat treated dry sludge is 13,000 BTU 's/lb (ash free). However , for any process to be adopted by the sewage industry 1t must be shown to be relia. ble , pred ictab le and understandable. A researc h team was formed with th e object of produ ci ng data whic h cou ld be used to pred ict both the degree of sludge cond itioning and the type of liquor formed from a variety of sewage sludges and to exp lain why heat co nditi oning produced suc h changes .

RESULTS Laboratory Reactor

SUMMARY In 1966, a survey of the sewage industry revealed the need for a thorough investigation into the heat conditioning of sewage sludges. A research project was therefore begun at the University College, Cardiff in 1967. In 1970 the results were presented in a Ph.D. thesis titled "Heat Treatment of Sewage Sludges". This paper gathers together the most pertinent facts of that thesis, showing that heat conditioning of sewage sludges is predictable, reliable and understandable. It will alter a biological sludge so that it can be dewatered by filter or centrifuge to a much higher sludge solids content than any other chemical or physical means. Introduction In 1966, a survey was conducted in England to find a field of research usefu l to the sewage industry. All the sewage works managers consu lted expressed a need for researc h into the treatment and d isposal of sewage sludges. In particular , to invest igate the heat conditioning of sewage sl udges and put the process on a scie ntif ic basis . Th e purpose of heat condit ion ing a sludge is to chang e its physical c haracter so th at it wi ll give up its water more readily. Both the sett leabil ity and filterabi lity of a sludge is improved and it wil l also be steri lised. Although fu ll scale heat treatment plants were in operation in 1967 , litt le contro ll ed experiment al work had been ca rri ed out to asce rt ain the phys ica l and associated chem ica l changes that took place. The heat treatment process fo r alter ing the st ructure of sewage sludges was first used by Ni ls Testrup in 1911 , being an adaptat ion of a system for dewatering peat. Interest was rev ived in 1934 by W. K. Porteous at Wand ie Va lley and a few smal l batch plants were bui lt. Of these , only the unit at Hal ifax , treat ing a mi xed activated/humus sludge has co nti nued to the present day. Many of the early plants had troub les and the Porteo us process fe ll into disrepute . The two main reasons were :(a) the process was not understood and th ere fo re could not always be guaranteed to work, and (b) an unknown part of the BOD, load normal ly removed fro m the plant as sludge so lids , was returned to the plant as heat treatment liquor. (It is shown that an extra 5-10% BOD, load is put on the plant and an increase of perhaps 15 mg / 1 NH ,-N is expected in the effl uent from suc h a liq uor .) In 1964 , the fi rst of a new breed of cont inuous plants was built at Morley. They gave 90% heat recovery co mpared to the 80 % achieved w ith earlier batch plants. Lewin ' drew attention to the renewed interest in heat treatment and to the need for fu ndamental data on both the physical changes that took place in the sludge and on the liquor so produced. Potentiall y, heat condition ing , to enable a sludge to be dewatered more eas ily, has many advantages over chemica l cond ition ing. A sterile product is formed , free of pathogens and weed

A three litre labo ratory batch reacto r was made from a so lid stain less stee l bar. It was both e lectri ca ll y heated and water coo led , exte rn ally. Internal temperature profiles showed ' that eve n . when heat ing a very ge lat inous 4% act ivated sludge , no locali se d hot spots occ urred , so no ag itati on was installed . Expe rim en ts showed ' th at the sho rtes.t heat ing and coo ling tim es for a one litre cha rg e we re less than any fu ll scale plant in ope rati on . The refore , th e labo ratory heat treatment system was co nsidered adequate to simulate th e therm al cyc le of fu ll sca le operations.

Physical Changes in Sewage Sludges Whe n disposing of any slud ge on land it is ne cessa ry to reduce the bu lk as much as possible to make th e best poss ible use of the land avail able. A liquid , organic sludg e wi ll de-compose producing sme ll s an d possib ly ca use a health hazard. Sewage sl udges must therefore be dewatered to the point where they wil l not reabso rb moisture and become a ge latinous mass again . Th e two basic prope rti es whi ch need to be improved , therefo re, are sett leability and filte-rabi lit y. More than one hundred sewage sludges we re heat co ndi tioned and their settlin g rates and sludge vo lum e indices measured. Th ese resu lt s have been publi shed'. Typica l 1 hr. S.V .l. 's are shown in Tab le 1. SLUDG E

% Sol id in Settled Sludge

Activated Humus Digested Primary/Act ivated

7.0 7.2 5.4 5.0

% Vo lume of Settl ed Slu dge

1 hr . S.V.I.

18 20 30 33

2.6 2.8 5.6 6.6

Table 1. Settleab ilit y of 3% solid sludges heat co nd iti oned at 190Â°C for 30 mins. . Specific resistance , whi c h is an inde x of fi lterabi li ty, was the primary cr iterion c hosen to in d icate the degree of sludge cond itio ni ng by heat. Th e co nce pt of spec ifi c resistance to fi ltration is wel l documented , hav in g been used in the sewage industry for twenty yea rs, sin ce Coakley appl ied Carm en's th eory of fi ltration. Swanw ick an d Davidson ' we re respon sib le for producing the method of measuring spec ific resistance on a routine basis acc urate ly. In sim p lified form , the rate of filtrat io n is given by:-

whe re

dt dV dV

nrc V + a 2PA' rate of fi ltrat ion

V n

filtrate vo lume filtr ate viscos ity spec ific re sistance so lids fi ltered /unit vo lum e of fi ltrate pressu re drop ac ross fi lter bed (500 g/c m' stand ard) area of fi lter consta nt (filter suppo rt res istan ce measure)

a:r r C

p A

Th e spec ific resistance may vary from 5 x 10" m/kg for an activated sludge , through 5 x 10" m/kg for a we ll digested sludg e to 2 x 10 11 m/kg for a heat cond iti oned slud ge.

Continued overleaf

Ov er a two year period , sludges from Abergavenny (activated and primary /activated), Wenv oe (humus) and Swindon (digested) were heat cond itioned under a wide variety of co nditions . Th e specific resistan ces measured are presented in Figs. 1-4. From the earliest tim es up to the present day, thirty minutes was conREACTION CONDITIONS , SYMBOL TEMP.

sidered the shortest react ion time which cou ld safely be used to co nd ition sludges , yet it is c learly shown that this is a time /te mperature phenomena and proc ess time sho uld be dec ided o n economic grounds . If the process is designed as thermal ly se lf-supporting by burning pressed sludge, or there is a

INITI AL CONDI TIONS SOLIDS ASH SPECIFIC RESISTANCE

180

2 . 90 2.82 2 . 92 2.80 2.89

14. 3 20.l 21.9 19.l 16.8

REACTIOO CONDITIONS SYMBOL TEMP .

44,000 39 , 000 37 ,500 34,500 20 500

10 , 000 'v

Ill

s:'_

1 60 1 70 1 80 190 200

°''

rl rl

(x 10

(/)

r-"'

IN I TIAL CONDITIONS SOLIDS ASH SPECIF IC RESIS TANCE % %

X 0

1 , 000

2 . 94 2.88 2.9 1 2.92 3.00 3.00 3.00

t, §

44.4 34.1 36.0 36.8 43.8 47 .9 48. 5

11 m

1, 050 4,550 4,9 00 3 , 400 1,4 70 1 , 230 2 ,300

°'

~ ........0 ....

"" ~ "' u

, H

;Ij

(/)

H (/)

"'u "'" "'

u H

~ u

"'"'

(/)

REACTION TIME (Minutes )

Fig. 1. Conditioning of activated sludge by heat. REACTION CONDITI ONS SYMBOL TEMP . 0

(x 10

10,000180 190 200

2.56 2. 79 2.83 2.88 3.00

25. l 27 .9 28. 2 28 .6 14 .3

REACTION TIME (Minutes )

INITIAL COND ITIONS SOLIDS ASH SPECIF I C \ % RESISTAN CE

Fig. 3. Conditioning of humus sludge by heat.

REACTION CONDITIONS SYMBOL TEMP.

3,200 3 , 250 3,1 50 2, 450 6 , 900

1 , 000 N

""'

+ 6

<fl

.... 2:

~ ........0

IN:j:TIAL CONDITIONS SOLIDS ASH SPECIFIC RESISTANCE

150 160 170 180 190

3.00 3.00 3.00 3.00 3 . 00

( x 10

29 . 5 29 . 5 31. 2 31. 2 31. 2

2,280 2 ,280 2 , 920 2 , 920 2 , 920

100 40 ·

....

! <fl

~ u H

f'.I

0. <fl

REACTION TIME

(Minutes)

Fig. 2. Conditioning of primary/ activated sludge by heat. 16

~ 15

REACTION TIME

m/kq;

(Minutes)

Fig. 4. Conditioning of cold-digested sludge by heat.

source ot c heap 220°C steam , then a time much shorter than 30 min utes shou ld be used , thus altering the reactor from a large holdin g vessel to a short heat exc h ang er.

As sludge solids dissolved , the COD of the heat treatment liquor increased , Fig . 5, in the proportion COD

Comparison Between Laboratory and Full Scale Conditioning

+ 2,000 mg /1

1.23 D.S.

The Kje ld ahl nitrogen also increased as more sludge went into It was im portant to establish whether results of small scale ex- · solution , Fig . 6, overleaf . periments in the laboratory batch pressure vesse ls could be Org. N = 0.11 D.S . - 30 mg /1 (activated) satisfactorily scaled up. Heat treated and untreated sludges were co ll ected from Farnboroug h, Wokingham and Swi ndon . The untreated sludges were then cond itioned in the laboratory under norma l fu ll scale conditions. Specific resistance measurements were made and the liquors were analysed. The laboratory scale resul ts were simil ar in all respects to those of fu ll scale operation , Tabl e 2. (a) and (b). Tre nds fro"1 laborato ry expe rim ents cou ld co nfi dentl y be used to predict full sca le operat ion , therefore . Laboratory

Woki ngham Farnborough Swindon

Full Scale

Feed So lids

Spec ific Resistance (x 10" m /kg)

Feed Solids

Specific Resistance (x 10" m/kg)

3.56 5.03 2.30

3.0 2.4 2.2

2.64 3.82 2.30

8.0 5.6 2.4

Org . N.

,ooo

20,000 Concentration (mg /1) Suspended So lids Di sso lve d So lids C.0 .D. Organic N. Amm . N . pH

Wokingham

= 0.07

D.S.

49 mg /1 (pr im ary /hu mu s/ ac tivated)

It was shown ' that with activated sludge , the solubi lis ation of organic nitrogen reached a maximum and from then on , any further increase in reaction temperature or holding time caused a conve rsion of Kjeldah l nitrogen to am monia .

Activated Primary + Humus 'I' Digested 00 X Primary/Secondary oD F Farnborough 0 / w Wokingham 0 M Manchester Fx o/ 0 Oxford OTHERS - Abergavenny /0 0 o Wx 0 I',_

Farnborough

Laboratory Ful l Scale Laboratory Fu ll Scale 6650 2320 3690 148 75 5.15

6150 2835 4460 187 88 5.10

5780 1690 2580 113 39 5.05

5670 1780 2560 114 32 5.10

/ ~ M

10,000

Tab le 2. Comparison between sl ud ges condit ioned in th e laboratory and on full sca le at t he same process conditions . Initi al spec ific resistance of sludges approximate ly 4000 X 10"m/kg. A. (upper) So li d parameters. B. (lower) Liquor parameters (per 1% feed solids) .

- . -- . _

100% protein

/ 0 .___ _ _...___ _ _..___ _ _.,___ _ _...J.__ __ _ _ J

Th e heat co nditi onin g process is know n to produce an odourous, dark brown , po llut ing liquor. The process at Luton was closed down because of the extra load this liquor put on the biologica l t reatment plant when the liquor was recyc led . An estimate o f th is poten ti al pol lution h azard , wh ic h is shown in Table 3 for act ivated sludge , was essenti al. Th e amo unt o f t he var ious s ludges th at dissolved during co nditioni ng has been pub li shed in detail ' . It in c reased with temperature to a small extent , but under typical p lant operating ;;onditions was approximately 55% for acti vated, 35% for primary/activated , 40% for humus and 30 % for d igested sludge o n an ash free basis.

Suspended So lids Dissolved So lids Volatile Acids C.O.D . 3-min . PV 4-h . PV Organic N. Amm .N. Pho sphate (as P) Ash in Feed Sludg e (per ce nt) N . in Fe ed Sludge (per cent)

Oxford

DISSOLVED SOLIDS (mg/1)

The 3 minute and 4 hour P.V . and BOD , of heat treatment liquors can be estimated from the COD for activated and primary/activated slu dges and probab ly for h umus and digested slu dges , Table 4.

Abergavenny Manchester

4970 4080 256 5700 310 950 430 132 20

4400 4400 370 5960 420 930 461 155 38

7.2

8.0

5700 3960 5500 760 399 107 13 27 5.9

Tabl e 3. Activ ated sludge heat treatment liquor (per 1% feed so li ds) Prepared at 190°C for one hou r.

,ooo

Fig. 5. Relationship between COD and dissolved solids in heat treatment liquor.

SLUDGE Concentration (mg /1)

' 20

10,000

PROCESS CONDITIONS °C (h)

3-mi n . PV 4-h. PV

BOD

COD

Act ivated 100( ½) Act ivated 130( ½) Activated 163 (½) Activated 192( ½) Primary/Activated·192 (½) Act ivated 197 (½) Activated 230(½)

2.16 2.43 2.34 3.14 2.64 2.22 2.60

Oxford (Tab le 3) Abergavenny (Table 3)

190 (1)

3.06

18.4

190 (1)

2.20

14.2

9.85 9.55 8.77 4.30 4.84 4.91

17.8 16.9 12.8

• Average of four tests Table 4. Oxygen demands of various heat treatment liquors .

Continued overleaf

3 ,000 ~ - - - - - - - - - - - - ;,--- - - ,

o 6.

~ 2,000

Activated Primary + Humus 'I' Digested x Primary/Secondary F Farnborough W Wokingham M Manchester Oxford / OTHERS - Abergavenny '

I 0

I I

The liqui d prod uced during this heating pro cess does not remain in the orig inal che m ica l state . The re are four main types of compou nds in biological co mpounds ; protein , ca rbo -hyd rate . lipid and nu c leic acid .

Proteins can be hydro lysed and degraded into many compounds from po lypept ides to am ino ac ids , and then in to a nu m ber of lowe r aliphatic ac ids and ammonia. Egg albumen coagu lated into a w hite so lid at 100°C , but pressure cooking above 150°C produced a ligh t brown solution w ith some organ ic nitrogen be ing conve rt ed to ammonia.

iE @

It is known that ce ll wa lls are ruptured by heat , as in steri li sa tion , and that co llo idal gels ca n be broken down by heat . As heat is app li ed to sewage sludges the ce ll wa ll s rupture and both the ext ra and intracellular ge ls release water , leaving main ly solid ce ll wa l l materia l undissolved.

Industria ll y, carbohydrates are hydrolysed at 160°C to lower mo lec ul ar weig hts an d this results in a corresponding reduction in viscos ity , suc h as in the production of dextran , a blood plasma substitute.

E-< H

z ~

~ 1,000

Lipids, the oi ls, fats and waxes , are esters w hi c:'h on hydro lysis produce an alcohol and an acid. The acids are mainly pa lmitic , stearic and o l eic , though some con tain nitrogen an d phosphorous . Certain ly, a lipid layer se parated out of the surface and wal ls of the reacto r each ti me it was used. It was found to be main ly palmitic acid.

Nucleic acids can degrade re leasing pentose , nitrogen an d phosphorous into so lution. The COD : P rat io of li quo rs was approximately 300: 1.

0"--------'----....L----~---~---~ 10,000 20 ,000 DISSOLVED SOLIDS (mg/1) Fig , 6, Relationship between organic nitrogen and dissolved solids in heat treatment liquor,

Treatability A laboratory fill and draw unit was o perated for two years at a variety of conditions, mainly to produce BOD seed . However, it did show. Table 5, that at a loading of 71 lbs BOD/ 1000 ft'/day . a BOD of 12 mg / 1 cou ld be produced . Historicall y, heat treatment liquors have been co nsidered intractab le, but this was not the case. Conce ntration in p.p.m.

Influ ent

Effluent

Mixed Liqu or S.S. Disso lved Solids C .O. D. B.O .D. 4-h PV Organ ic N . Amm . N . Nitrate/Nitrite N . Tota l Ph osphate Suspended So lids

1020 1260 460 180 90 37.2 06 5.3

488 282 12.1 72 20.7 71.2 06 2.0

6.8

7.8

Retention Time Feed Rate Temperature

3400

9.6 hours 1.25 li tres/6 hours 22°c

Table 5. Operat ion of fi ll and draw p lant. DISCUSSION In sewage sludge. there is an extrace llular co lloida l ge l containing protein and carbo hyd rate. Th ere is also an intrace ll ular col loida l material , more proteinaceous in cha racter , the protop lasm of the bacterial and vegetabl e ce ll s. Th ese ge ls are viscous and difficult to filter. Even if the ext race ll ular ge l cou ld be removed , the sludg e wou ld st ill have a high moisture content after centr ifugat ion or fi ltration because of th e water held inside the ce lls. 18

In suc h a mi xed system. a large number of interactions w il l occ ur . Th e Mai ll ard (Browning) type of rea ct ion prod uces brown co loured com pounds from amino ac ids and redu c in g sugars. When steri lising ferm entation med ia the ca rbo hydrate and nitrogen con taining so lutions are often sterilised separately to avo id th is happening. The fact that heat treatment liquor was brown and the colour increased in intensity with in c rease in re actio n conditions was there fore expected.

CONCLUSIONS The condition ing of sewage sludges by heat is predi ctab le. re li ab le and understandable.

Predictab le because the deg ree of sludge con dit ioni ng in terms of both specific res istan ce of th e sludge and' strength of the liq uor produced by the labo ratory unit described , was simi lar to full scale operations. Reliab le because all the primary. activated , humus and digested sludges from all the sewage wo rks tested c ou ld be co ndit ioned to a speci fi c resistance low enough to be dewatered easil y by mechanical means. Understandab le because all of the physical and c hemi ca l c h anges which took place cou ld be related to the c hemical and physical make up of the sludge . REFERENCES 1. Lewin, V. H., El -Sharkey, M. H. "Sewage Sludge Dewatering" . Wat. & Waste Treat (5) , 1966, 19. 2. Brooks R. B. "Heat Treatment of Se wage Sludges" Wat. Pollut. Control, 69 (2 ), 1970, 221. 3. Brooks , R. B. Ph.D . Thesis. University Co llege of South Wales and Monmouth, 1969,bep 4. Brooks, R. B. ,·, Heat Treatment of Se wage Pollut. Control, 69 (1 ), 1970, 92.

Sludge"

Wa t.

5. Swanwick, J. D., Davidson, M. F. "Determination of Spec ific Resistance to Filtration" Wat. and Waste Treat. J. 8, 1961, 386.

DESIDERATA Desired Engineering Excellence The following article contains extracts from a paper to a U.S. audience by Dr. Clair Sawyer, Consultant, Sun City, Arizona. It is not the policy of 'Water' to reprint articles published elsewhere but an exception is believed justified in this instance to permit.all members to share the basic wastewater purification philosophy of one of the senior members of the profession. In any situation , the operator is the victim of des ign limitations , inadequate eq uipmen t, or personal fo lly . There is no escape hatc h except correction of the deficiencies. Because everyone is desiro us of having treatment plants that are eas ily ope rated and serve their intended purpose , present and future , this paper wi ll address itse lf to how these ends . ca n be met more fu lly in the future. All wastewater treatment systems worthy of the name are the result of carefu l plan ni ng. In this country most of this planni ng has been comp leted and large capital investments in sewerage , pumping stations, and treatment plants have already been made. The majority of new works relate to expans ion, substitution, or addition of new fac ili ties for secondary or advanced waste treatme nt . In all of this work a pre liminary report is a necessity. This should inc lude a sound assessment of flows andÂˇ wastewater characterist ics for a design period of from 15 to 30 years. In addit io n , the report should include a d iscussion of possible methods of treatment , costs (capital, operat ing and annual} , and the recommended method. Fundamenta lly , the pre lim inary report should lead to the se lection of the ideal so lutio n to the problem. This is not always the case and there are several factors that may significant ly influence the final selection . They are time , economics , politics , and judgement. TIME. Too often the eng ineer is forced to pre pare a report in a lim ited time . This requi res short-term studies that can lead t o f a u lty co n c l usions. Assessing wastewate r flows is one of the areas in which poo r evaluat ions are commonplace . Many treatment plants have excellent reco rd in g dev ices for flows that reac h the plant but no information on the sewer system where overflows occur. Providing fac ili ties for measuring overflows from the sewe r system can be expensive , and the tim e req ui red is co nsiderab le. One method th at e li mi nates the need for an expensive gaug in g program involves a carefu l sam p l ing and analytica l program , which shou ld be conducted anyway, and applicat ion of the laws of di lution to estimate wastewater flows. In one instance , where plans were being made to bui ld a plant to hand le peak flows of 6 US.mgd (22,710 cu m/day), a rev iew of the analytical data indicated peak flows of 10 US.mgd (37 ,850 cu m/day). This knowledge led to a sewer sea li ng program to correct a serious infil tration prob lem .

Short-term samp ling programs can also lead to serious errors , particularly on combined sewer systems or in locations where industries are present with seasonal or " campaign " operations . Time limitations may force a sampling program to be conducted when the seasonal or intermittent industry is "down " . If so , great pains shou ld be taken to gain information about the industrial operation to determine whether it is typical of the industry, and records of water consumption and production shou ld be reviewed. The time element often eliminates the possibi lity of conducting outdoor pilot plant studies , which are needed in many situations . In the translation to a laboratory study, certain sacrifices are common ly made . One difference is to substitute grab or compos ited samp les for the feed stock , rather than continuous suction from the flowing wastewaters . A second difference, one sometimes missed in the outdoor pilot investigat ions , it to fa il to mim ic the flow pattern env isioned for the prototype. This is especial ly important in any system of treatment using short-term contact periods. ECONOMICS . The numbers fol lowing the dol lar sign usually determine the amount of time and work an engineer can put into the prelim inary report. This is more true today in the U.S. than it was in the past , when it was understood that a municipality engaged engineers for the whole job - pre liminary report, design and supervision of construction. As a result , eng ineers were more inclined to spend extra funds for deve lopment of a good preliminary report .

JUDGEMENT. Because engineering in the realm of wastewater treatment is not an exact science , good judgement is probab ly one of the greatest attributes of suc c essful sanitary engineers . Nowhere is this more important than in the prognostication of wastewater flows . This invo lves population growth , including annexations, and industrial expansion. The latter has been a vexing problem in many southeastern states , where industry often has been we lc omed with open arms and not many questions asked . The prelim inary report normal ly recommends a preferred method of treatment based upon a number of criteria and cost comparisons, invo lving capita l and annual expenditures for amortization , operat ion , and maintenance . The se lection of a process can be fraught with considerable

hazard where industrial wastes or mixtures with domestic wastes are present , un less the engineer has had wise experience or has piloted the process. Even when pilot studies are conducted , the results can be mis leading because of factors that are overlooked . A few illustrations seem justified . Samples of a texti le waste were ship ped to a laboratory for bench-scale treatment studies. A trickling filter installat ion was recommended . The prototype was a complete failure because the high temperature of the wastes had been ignored. The filters fluctuated between thermophilic conditions during the working week and mesophi lic cond itions over the weekend and ho liday shutdowns in the hot summer months. A satisfactory growth never did develop on the filter. An activated sludge pitot plant using a 2,000-gal (7 .57-cu m) aerat ion tank served by a final clarifier and continuous return sludge facilities was operated for an entire year to obtain des ign criter ia on a wastewater with a hig h solub le biochemic al oxygen demand (BOD) content . The prototype failed to yie ld resu lts close to those obtained in the pilot plant . The pi lot plant had been operated as a comp lete ly mi xed system with unlimited air supply . The prototype was designed to operate as a stepped aeration system , with air supp ly based on average loadings . No attention had been paid to oxygen uptake rates or the alpha and beta va l ues of the wastewater, in spite of its high percentage of industrial wastes. Some years ago the author was engaged to investigate a " rising sludge " pro blem in an activated sludge plant in a midwestern city . A major factor was found t o b.e the inabi lity of the final clarifier mechanisms to move sludge rapid ly enough to the central draw-off wel l. The mechan ism had been accepted as an alternate because of bett~r delivery rate and had been approved as " equal " by a well known consultant . The fau lty mechanisms were eventuall y replaced by those of the type orig ina ll y specified.

REUSE OF WASTEWATER Idea lly , the population should be uniform ly distributed over the arable land area. Under suc h circumstances each person would have in excess of 1 acre (0.4 ha) of land for disposal of wastes or about 5 acres (2 .0 ha) per fami ly, and it would be uneconomical to practise anything but land disposal. For the 75 percent of the population living in cities or urban areas comprised of 2,500 or more persons , reuse of wastewaters in agricu ltura l pursuits is essential ly impossible except in areas where land or forests are av ailable for groundwater recharge during the non growing season .

RECHARGE The use of treatment plant effluents for direc t recharge of groundwaters is being questioned because of increased nitrates and total dissolved so lids that resu lts. The on ly feasible means of reducing the nitrates is to either operate treatment plants to minimize the amount of aitrogenous matter remaining in the effluent or to li mit the

Continued overleaf

protein intake of the people served. The total dissolved solids can be reduced in two ways: by restricting the salt content (bui lde rs) in synthetic detergents or by making sure that nitrogenous residues in effluents are well nitrified before application to the land . Âˇ

WATER SUPPLY Although a great deal of wastewater is reused for public supply , this occurs o nly after di lution in rivers or groundwaters and after a sig nifica nt time lapse occ urs. In spite of the fact that this situ ation is we ll recognised no city in this country with a surface supply , except Chanute , Kansas , has purposely recyc led treatment plant effl uent back to its source of water supp ly. Even wi th the te chno logy avai lable today, little consideration is being given to direct recycle . It is quite like ly that this situation will not c hange unti l such time as the cost of water comes to just ify a hi gh degree of renovation , nitrogen and total dissolved solids contro l being the more expensive aspects.

EUTROPHICATION Although a great deal has been said and written about the damaging effects of wastewater discharge nutrients on surface wate rs, mu ch misunderstanding st ill exists . At present the fo llow in g conc lusions seem to be we ll establi shed. - Carbon dioxide, per se , does not promote eutroph icat ion and does not serve to limit it except in ac id or very low alkali ne waters . - Both nitrogen and phosphorus can pro mote eutrophicat ion by supporting growth o f both green and blue -gree n (nonnitrogen-fixing) algae. Phosphorus alone can support the growth of nitrogen-fixing blue-green algae. A large part of the nitroge n and phosphorus appl ied as fertilizers to farm lands is exported to urban areas in the food supply for the inhabitants . A major part of t he ni trogen and phosphorus contai ned in the food ingested by man during a lifeti me is excreted and carried in wastewaters. - Convent iona l treatme nt systems normall y retain onl y a small fract ion of the nitrogen and phosphorus, particularly where anaerobic sludge digestion is practised . - Domest ic wastewaters are excessively rich in phosphorus. Under normal cond itions in surface waters , nitrogen will be co nsumed leaving excess phosphorus. Th e majority of the nitrogen and phosphorus contained in treatment plant effluents is discharged to rivers, lakes or impoundments , estuaries , or oceans, at po int sources that number only a few thousand. - Enrichment of marine waters is normall y of little conce rn except in bays , where adequate d il ut ion does not occur and g rowths of "sea lettuce " deve lop.

- In rivers or other swiftly moving waters , nitrogen is normally the limiting e lement and excess phosphorus is of no particu lar signif icance, beca use nitrogen-fixing blue-green algae do not flourish under such circumstances. - In lakes , impoundments , and the freshwater sections of estuaries both nit rogen and phosphorus are of great co ncern: nitrogen because it normall y limits the growth of the green and blue-green (nonnitrogen-fixing) algae, and phosphorus because it is always in excess in domestic wastewaters and is capab le of supporting extensive blooms of nitrogen -fix ing bluegreen algae after available sources of nitrogen have become depleted. Althoug h the co nc lusion expressed above should be understood by al l, the facts dictate that attention should be focused on two situations.

There seem to be two trends that wiH affect the welfare of mankind in the future unless cor rective measures are taken . These are a dec lining enrolme nt in eng ineering co ll eges and a threatened decrease in federal financia l support of programs. The latter is particularly serious as it co mes at a time when increased perso nne l are needed to accompli sh the goals for improving the environment. The fa ll acy in the scheme 1s obvious when one considers the great amount of funds being advanced for plan ning and co nstruction and at the same tim e the rest ri ct io n of funds for trai nin g people to help wit h the job . The idea that personnel shortages can be covered by displaced engineers and scientists fro m the other industries by waving an educationa l wa nd seems to be in adequate.

OPERATION When disc harge is to rivers that do not flow into lakes or impoundments with long detention t imes , nitrogen control shou ld be the only concern. This usually means oxidat ion of ammonia to nitrates to reduce nitrogenous oxygen de m and o n the receiving stream and avo id ammon ia toxicity. Some consideration should be given to nitrate leve ls in the receiving stream if it is used as a public water supp ly. However, th ere is a growing awareness that the nitrate problem, in terms of methemoglobinemia in infants , can be solved more economically in other ways than through expensive nitrogen remov al processes.

Th e tra inin g of personnel at the operationa l level has been one of the most difficult problems . In the past it was alleviated to some extent by short schoo ls that key peop le attended. With the advent of m andatory operator certi ficati on programs and the inclusion of tertiary or advanced waste treatment methods , the need for ope rator training has increased great ly.

The discharge of effluents into lakes, reservoirs , or the freshwater sections of estuaries with many weeks detention is quite another matter . The cont ributions of phosphorus have usuall y been singled out , in part because of the role synthetic detergents have played in increasing the level of this nutrient in domestic and certain industrial wastes. However, there has been a tendency to overlook the ro le of nitrogen . This condition must be corrected in many situations if good contro l of eutrophication is to be expected. The on ly exceptions wi ll be where th e phosphorus budget ca n be con tro lled to suc h an extent that growth of green and non-nitrogen-fixing blue-green algae can be stunted by a phosphorus deficiency.

There seems to be no sing le so lution to the di lemma of operator education . At least two approaches seem necessary . One feas ible sc he m e is to deve lop wastewate r p rograms t h roughout the country at technical schoo ls or co mm unity col leges. This would help those wis hing to enter the field of operations. For practicing operato rs it seems necessary to take the schoo lroom to places near their homes or places of emp loyment and offer late afternoon and evening classes.

EDUCATION

The Ed itor wishes to state that this story failed to make clear that the units of the waste water plant shown were part of an overall augmentat ion of water s upply and sewerage faci li ties for the Canungra Jungle Training Centre.

Education is the foundation of al l understanding , and it shou ld be of co ncern in the planning , desig n and operating stages .

PLANNING AND DESIGN Planners and designers have been pre dom in antly trained in civi l eng in eerin g conce pts with support from other engineers and scientists . Those engineers specializing in water supplies and wastewater treatment have referred to themse lves as sanitary or environmental engineers. Because of the speciali zed nature of the work done by sanitary and environmental engineers , much of the training has been unobtain ab le except at the graduate level .

Correspondence systems su ffer from a lack of personal con tact and teaching by demonstration , whi le practice schools require that a person be away from his or her job for an extended period of time , often at considerab le fina nc ial sacrifice.

DECEMBER COVER STORY CORRECTION.

Th e Consu ltin g Engin ee rs for the design for the overall proj ect were John Wil son & Partners , Brisbane and the supervision of the Works were by Com monwealth Department of Work s and the co ntractors were Messrs. J. & A. Engwirda Pty. Ltd. , of the Gold Coast.

ED ITOR .

of supercritical c hann els 1s m at local pond in g and storage of water is often el imin ated in floodways and on the o ld flood plain , and the time of f low is mu ch reduced ofte n resu lt ing in a flood with a much higher peak . The use of long lengths of large storm-water pipes may have similar effects. The system wi ll also respond to much shorter rai nfal l events wit h consequent ly more severe combinat ions of intensity and frequency .

VALLEY DESIGN IN URBAN GROWTH CENTRES by Alan J. Bonham A.K.C., B.Sc. {Eng.), M. Eng. Sc., M.I.C.E., M.I.W.E., M.I.E. Aust. Summary: A critical study of the design of major storm drainage systems has been made with special reference to the new urban growth centres and with Canberra as a model. The study reveals that public open spaces may be located on designed flood plains thus preserving the environmental quality of the valley, reducing the storm peak discharges downstream and at the same time substantially reducing the overall cost of storm drainage works.

ticu lar rainfa ll o n that particular day and the effect of the drainage works provided on the way the flood waters arrive at a parti c ular locat ion . Disc harges in urb an storm drains are generally more sens itive to small in fluen c es than natural streams , and the po ssib le range of peak discharges in resp onse to a storm event wil l be much wider fo r an urban storm drain age system. The mature natural st ream has evo lved a re gime capab le of withstanding the erosive influences of a hi storic al sequence of floods and adequate stabi li ty against major floods is provided by the flood plain and c hannel morphology. One prob lem w ith the use of a system

These effec ts combi ned w ith reduced infiltration after urbanisation result in Canberra in a twenty fold increase in instantaneous peak storm water d isc harge after urbanisat ion (ref. 2). Anot her problem is that as the storm bu il ds up , the water fl ows deeper and fas ter in the smooth c hann el w ith the possibility of a flood -wave or bore effec t as deep fast fl ow ing water overtakes the shal low slower f low . A cons iderable floodwave may arrive wit h very little warn in g , and one suc h flood was reported in detail in the accou nts of the Woden Va ll ey fl oods of 1971 (re f . 3). Chil dren may we ll be crossing or playing in the chan nel when the f lood wave arrives.

ALTERNATIVE DESIGN PHILO SOPH IES There is so me co nt rove rsy amongst eng in eers and plann ers as to how flood plains shou ld be developed and how urban drainage systems should be established in the new urban growt h centres . Where a sing le autho rity provides the full range of urban developmental works suc h as housing , roads , water , schoo ls, serviced land , sewe rage and d rain age , then considerab le scope may exist for obtain in g bette r so lutions to plann ing and eng ineering prob lems than in the o lder cities. For instance , in the new towns of Can berra the hill tops and ri dges are preserved in their natural state and the suburbs are gene rall y located on hill side slopes. The question then arises as to the way in wh ich the va ll ey floor should be developed and the means of prov iding storm drainage and flood protection . The conven ti onal wisdom is to prov ide high ve loc ity concrete 01 masonry lined c hannels and a typical system may be seen close to comp letion in the Woden Valle y in Canberra . The lined c hanne l is usual ly designed to conta in perhaps the five year peak discharge and when flowing bank fu ll the supercritica l ve loc ity may be 7.5 to 9.0 metres per second. Design prov ision is also made fo r the 100 year flood by allowing the grass verges to flood. Simi lar stee p va ll eys may be found at oth er g rowt h centres such as Orange-Bat hurst , Coifs Harbour , and also at Campbel ltown and various ot her system cities near existing capita ls. Th e recogn ised methods of computing the magn itudes of floods of various return periods are being revised by the In stitut ion of Eng in eers of Australia and are not very controve rsial (ref. 1 ). However, the method of com puting the one year or the 100 year desig n flood says very li tt le about the respo nse of the urb an catchment to a par-

ORIGINAL

SHEEP

3..

HIGH

ROUGH

VALLEY

FLOOD

BEFORE

PLAIN ZONE

GRAZED

INITIALLY - ~S_IG_N_A~ TE ~D _ _

VALLEY

CHANNEL

FLAT

VEE

SETTLEMENT

BEFORE

DESIGN

CHANNEL

WITH

URBAN

__,"'

DEVELOPMENT

WODEN

DESIGNED

VALLEY

FLOOD

PLAJN

Alan J. Bonham is a lecturer in Civil Engineering at the University of New South Wales in Canberra.

Yet another problem exists when the flow is steady because the supercritical flow may appear smooth and stable and yet may have the speed and weight of a freight train. Members of the public and particularly children have a quite inadequate concept of the fatal power of swiftly flowing water in a smooth channel. Many young people have lost their lives after entering such channels. In older cities where the flood plains have long since been built over and the use of supercritical channels cannot be avoided , then continuous security fencing is usually provided . Yet another problem is that the weepho les and granu lar filters backing the channel lining may eventually block up and unless the channel is heavy and weighted down it may self destruct by floatation after the rapid drawdown of water levels . Masonry walls may collapse as happened in various locations in the Woden Valley in 1971 (ref. 4) . A better design philosophy for dealing with flood waters in growth centres must be devised. In order to understand the problem and obtain a solution it must be remembered that water draining away from the va lley was the principle agent for the erosion which formed the natural environment , at least in the mature valley with stream in valley tract . Although some sediment movement will be taking place , the shape of the valley floor and the natural creek bed represents a natural long term dynamic stability . In systems concepts , this is the natural system in equilibrium which if minimally disturbed will require minimal correction to restore equi li brium (ref. 5) . The building of a c ity brings c hanges affecting this stability , so that some stabi li sing works wi ll be required. A major change such as the deliberate elimin at ion of the flood plain calls for expensive engineering works and the natural environment will respond with a chain Âˇ reac tion of events some of which may have expensive and unfortunate consequences , espe c ially when the stream is steep. The huge drainage works required may be extravagent in cost , dangerous in operation, may even be self destructive and are generally out of step with attempts to design a sensitive built environment . Public open spaces will be required for various purposes and some of these spaces can be well accommodated on flood plains designed to give a high degree of flood protection to the adjacent built up urban areas whilst at the same time preserving the quality of the va ll ey . Zones which before urbanisation were liable to regular and extreme flooding should be identified and designated as such at the very first stage of planning (ref. 6 and 7) . Open catch drains designed to protect a bui lt neighbourhood from upstream flooding must always connect with an open floodway route to the flood plain. The stormwater pipe subsystem in a suburb shou ld be modest and inexpensive. Excess discharges shou ld be conveyed along open floodway routes . The pro-

posals made by the Commission for a new development at Hall seem to be excellent in th is respect. Open spaces for sports ovals, less intensive outdoor recreational activities and landscaped tree planting should be located as a first choice on the designed flood plains and open floodwavs. The major drainage channels should be on ly just big enough to prevent the grassy flood plai.ns from getting soggy too frequent ly (ref. 8) . Roughly pitched rocks and shrubs shou ld be used on the gradual ly sloping channe l sides to slow the flow of water. The flood plain w ill have to be shaped to some extent to accommodate inevitable increases in stormwater runoff brought about by urbanisation. This will enable any desired standard of flood protection to be given to adjacent built urban areas. At the same time flood storage will be provided to mitigate floods of extreme magnitudes . Brief details of how to achieve an optimum design is given using a typical cross sect ion of the Woden Valley as a model. THE WODEN VALLEY AS MODEL Four models are presented showing the original valley before settlement , the sheep grazed val ley before urban development , the supercritical channe l design as constructed , and the alternative design philosophy which may be described as a rough flat vee subcritical channel with designed flood plains. The four cross sections are shown , figures 1, 2, 3 and 4. Extreme and 100 year flood levels shown as double and single chain lines respectively. The diagrams are not to scale. 1. ORIGINAL VALLEY BEFORE SETTLEMENT The Canberra area was grassland wit h spear and kangaroo grasses or woodland with eucalypts and wallaby grass . Beneath the trees an understorey including wattles and tea trees. In the stream banks were river oaks and occasional tree ferns . Often the stream wou ld be choked with timber. The flood plain was we ll defined . 2. SHEEP GRAZED VALLEY BEFORE URBAN DEVELOPMENT Exot ic grasses were introduced , trees ring barked , vestigal bushes sheep nibbled. Occasional ri ll and sheet erosion occurred after overgrazing . Unimpeded flood waters often gashed out deep gulley erosion , but not where wi llows were used. High sediment movement in the creek in hibited weed stabilisation. Valley flooding was reduced . 3. HIGH VELOCITY CHANNEL DESIGN AS IN WODEN VALLEY The smooth lined high ve loc ity channe l contains the five year flood and grass verges co ntain the 100 year flood. Corners of low lying suburbs are effected by extreme floods. The flood plain is ill defined and may even be land filled away from the channel.

4. ROUGH FLAT VEE CHANNEL WITH DESIGNED FLOOD PLAIN A shallow channe l is proposed with a smooth concrete invert and rough ly placed rock side slopes. Large quantities of suitable stone exists in the Canberra area as quarry waste. The rock will be keyed in place using pumped concrete. The flood plain will be graded f lat and used for recreation . The original native trees and bushes will be reintroduced to c hann el sides and to se lected areas of the flood plain. Th e flood plain and channel as designed wi ll resemb le the original va lley in most important respects except the erosion will be fina lly stabi li sed. Comp lete flood protection wi ll be given to bui lt urban areas. The flood plain is designed to obtain the maximum flood protection from the minimum width of flood J?lain . This is achieved by grading the flood plain substantially 'flat' and level in cross section so that the maximum safe velocity of flow and hence the maximum discharge pe r foot width flows even ly across all of the g rass. The flood plain will then make the most of the ability of the grass to wit hstand inun dation and the flow of wate r. Experiments indi cate that grass turf wi ll w ith stand occasional inundation and can withstand ve locities of at least 2.5 to 3 metres per second , for two or three hours. It is considered that these velocities are conservative and are suitable for design purposes (refs. 9 and 10). Care in the establishment of the grass is important and subsequent maintenance such as resodding of scour holes left after a flood is also important as bare soi l ca n be eroded by velocities as low as 0.5 metres per second. It is important to maintain a hea lthy turf by regu lar mowing and watering , by provis ion of adequate subsoil drainage to prevent waterlogging of the roots ca used by a too frequently hi gh water table and by provi sion of a sufficiently large lined c hanne l to prevent too frequent inundation by flood waters. However, the occasional immersion and consequent deposition of some suspended sediment load material will not be detrimental to the grass. The rough f lat vee channe l wit h designed flood plain alternative wil l contain the maximum probable flood (and in deed in the unlikely event of a 100% runoff from the catchment the maximum poss ible flood) and in this examp le comp lete flood protection wi ll be given to adjacen t bui lt up areas; whereas with the co nventio nal high velocity supe rcritica l flow design , low level flooding of adjacent suburbs wil l probably occur when the 10 or 20 year flood is exceeded. This is the first of several advantages of the flat vee channe l and designed flood plain alternative. The rough flat vee channel with designed flood p lain alternative has a second advantage relating to pub lic safety. Water veloc ities c lose to the brink shou ld not exceed 1.0 metres per second where the channel sides are steep , except where a continuous hand railing is provided . Members of the pub lic and particu larly chi ldren have an inadequate co nce pt of the power of swift ly flowing water in a smooth flume. Many fatalities have occurContinued overleaf

red when ch il dren ha_ve entered bank-ful l cha nne ls. Ho weve r a wide flat vee c h anne l with rough and gradua l side slopes w ill h ave an impressively turbu l ent appearance w hen in flood. If the c hanne l ve loci ty does not exceed 1.0 metres per seco nd in app roximate ly 0.2 metres of water depth near to the brink then the hazard is ev ident and the cha nn e l wi ll be reasonably safe even if higher ve locities ex ist in mid-channel. The thi rd advantage of the flood pl ain desig n is that the prese rv at ion of the essent ial shape of the va lley minimises earth moving costs. The modest rough lined c h anne l for sub-critical ve l ocities minimises c hannel lining cost s. The co mpact location of publi c open spaces on the good soi l of the flood pl ain minimises th e main tenance costs of these faci lities . The fourth advantage of the rough fla t vee c hann el and designed floo d plain is that flow retardance due to rough c han nels an d storage of water on the flood plain w ill tend to attenuate flo ods of any magni tude and te nd to reduce downst ream peak disc harges. For this reason any existing low lying areas shou ld not be . land filled above the level of the flood plai n and shou ld be w idened and extended w here at all poss ible . The fifth advantage is that it may no longer be neces sary to make a gross and arbitrary decision as to the design recurren ce interval to be ad opted for the design of a major c han ne l when space is made avai lab le to give almost com plete flood protection. The sixth advan tage of the fl ood plain design is that recreation al oppo rtu nities w ill be created c lose to residential areas and the n atu ral stream and open va lle y envi ronment will be preserved.

We have a situtation perhaps unique in the annals of environmental conservation in whic h public safety and major env ironmental improvements can be ac hi eved by a course of action w hi c h wi ll also result in substantial cost econom ies. In short , a ph ilosophy of designing stormwater sewers w hi ch may be appropriate to o lder cities must be rep laced by a philosophy of ri ver design and management app ropriate to urban national parks. REFERENCES 1. Institution of Engineers , Australia ' Australian Rainfall and Runoff'. Sydney, 1958. (Under revision.) 2. Fitzgerald, B., I. E. Aust . Hydrology Symposium, 1975. 3. Canberra Times, 23rd February , 1971 . 4 . Department of the Interior and the Na-

tional Capital Development Commission, 'Woden Valley, Canberra , Flood of 26th January, 1971 ' Australian Government Publishing Service, Canberra , 1971 .

5. Brochie, J. F., 'Some Systems for Urban Planning ' R.A.P .I. Journal , Vol. 12, No . 2, April 1973. 6. Bonham, A. J., ' Storm Drainage System Design and New City Planning ' . Civ . Engg. Trans. I. E. Aust., Vol. C. E. 16, No. 1, June 1974. 7. Bonham, A. J., ' Urban Stormwater Drainage Planning and Environmental Design'. R.A.P.I. Journal Vol. 12, No. 3, July 1974. 8. Bonham , A. J., ' Flash Flood Control with Designed Flood Plains' , Public Works, July 1974.

COMMENT

No more add itional space is required for des ign ed flood plains than wi ll be required in any new c it y_for the major sports ovals. less intensive outdoor recreational activities and landscaped tree planting areas. Land use of fl ood plains for flood plains is highl y appropri ate. and is in complet e accord wit h minimal disturbance con cepts. Major cross ings of the flood plain by maj o r transportati on routes w ill require ex tra bridge spans to c ross over the flood plains , but this additional expenditure wi ll be mo re th an off set by the greatl y reduced cost of the proposed suburban pipe network storm drainage systems and the inexpens ive roug h channe ls designed for su bc riti ca l ve loc ities whic h are used in co njun ction wit h the designed fl ood plains. In the Woden Val ley the hilltop and ridge environment has been very success ful ly preserved , but the stream and valley env ironm ent has been redu ced to a supercritical c hannel as desc ribed herein . Yet it would seem that the aest hetic pleasu re to be derived from a sensitive development of the valley floor wou ld rival the pleasure to be derived from the hilltops if on ly bec ause the valley receives more usage.

9. Young, K. C. , and Stone, D. M., 'Resistance of Low Cost Surfaces for Farm Dam Spillways'. U.N.S.W. W.R.L. Report No. 95, April 1967. 10. Young, K. C., ' Scour Resistance of Farm Dam Spillways with Grass Dormant'. U.N.S.W. W.R.L. Report No. 104, April 1968.

Manufacturers are invited to send news of any new products, pro jects or services for inclusion in the New Products & Projects section of this Journal. Editorial should be around the 250 to 350 words, photographs of the products would be welcome. Articles will be published in the earliest possible edition, subject to approval by the editorial committee. Post to John Craig, P.O. Box 100 Caulfield East, 3145

LOWER YARRA VALLEY SCHEME APPROVED The first stage of the Lower Yarra Water Supply Development approved in principle by the Board early this month, will cost an estimated $73.7 million, and comprises a weir and pumping station on the Yarra River at Yering Gorge; Sugarloaf Reservoir and ancillary works; a water treatment plant; and pipelines to convey treated water into the distribution system. The scheme adopted is one of a number of alternatives considered by the Board following an exhaustive environmental study into the implications of the proposals. .a. Detailed site investigation and preliminary design work for the project is under way. The Board has recommended to the Government that: * Towns in the

Yarra catchment upstream of Yarra Brae be sewered as a matter of highest priority and before the commissioning of the first stage;

* The

Environment Protection Authority develop, implement and enforce standards, regulations and conditions of licence and all other protective measures necessary to ensure that the Yarra and its tributaries will be properly protected as a source of drinking water; and

* The portion of the Yarra Brae catch-

ment which is not at present controlled by the Board be proclaimed as a water supply catchment and subsequent land use cteterminations made under the provisions of the Soil Conservation Utilisation Act. The second stage of the Lower Yarra Development, including the proposed Watsons Creek Reservoir, will, on present population trends, not be required before 1992/93, assuming the proposed Thomson Dam near Erica is built, and may not be required until even later if population growth downturn in the metropolitan area is further confirmed. The existing Town Planning Zoning of the Watsons Creek area for water supply will remain, but compulsory acquisition of properties in the area is not expected to be required before 1985, and possibly later. Although the Board will n~t be acquiring properties, it will continue to negotiate with property owners who wish to dispose of their properties. Approximately 530 properties are involved in the area, comprising some 4,964 hectares (12,410 acres). Of these, 180 properties covering approximately 1,880 hectares (4,700 acres) have been purchased. 23

ment Comm ission , program managers for the Summer Schoo l, served as guides on the two buses. Geoff Henkel also of the Commission and a participant at th e Sum mer Sc hoo l assisted durin g th e to ur. The tour, wh ile general in nature, in c luded several items of engi neeri ng interest:

REPORT ON A.W.W.A. SUMMER SCHOOL The Canberra Branch of the Australian Water & Wastewater Association recently conducted the second Summer Schoe>I on behalf of the Federal Council. The Summer School, which was held at the Australian National University from the 3-7 February 1975, focused on the theme "Water in the Urban Environment". The first Summer School also was held in Canberra, two years previously. Registration for the Summer School totalled 124, including 18 lecturers. There were people in attendance from the United Kingdom, U.S.A., Papua New Guinea, several Asian countries, and all parts of Australia. All lectures were held in the H.C. Coombs Lecture Theatre at the Australian National University. Most of the participants resided during the Sc hoo l at Burgmann Co llege. The Common Room in the Co llege was a popular meeting place in the evenings for informal discussion and test ing of hydrauli cs principles. Attendance of the Asian cont in gent at the Summer Schoo l was sponsored by the Australian Development Assistance Agency as part of the In ternat ional Public Health Eng ineerin g co urse which the agency co nd ucts at intervals of about 2 years for engineers from Colombo Plan co untr ies . The Summer Sc hoo l Committee also org anised on behalf of ADAA a two day Ground water Sem in ar on 10 and 11 February for the Co lombo Plan fe llows .

LECTURERS Dr. A. L. Down ing , former Director of the Water Pollution Research Laboratory, Stevenage U.K. was the principal lecturer at the Summer Sc hool. He presented a tota l of 5 lectures including the Pub li c Lecture at the Acade my of Sc ience on the evenin g of 3 February. The 18 lecturers at the Schoo l are respected resea rc hers, teachers and prac tition ers in the water and wastewater field who were drawn from a variety of State and Austra li an Govern ment departments and agenc ies, consu lting firms, un ive rsiti es and commercia l organisations. Much of the credit for the success of . the Summer Sc hoo l goes to the lecturers for their able presentations and contr ibutions to the various discussions. Dr . Downing deserves spec ial ment ion for his competent performance of a heavy lecturing com mitment and for his leadersh ip at the School generally.

PROGRAM The Summ er Schoo l program , which is li sted be low, co mprised 20 lectures, a Public Lectu re, three Workshops, a Sightsee in g Tour and a Forum.

LECTURE NOTES Cop ies of the lecture notes were prepr'inted and mailed to participants abo ut a mon th and a half in advance of t he Schoo l. Extra sets of lecture notes were pro duced for sale after the Sc hoo l and a num ber of these are availab le for purc hase . The notes are bound in two loose-leaf vin yl covers and are sold on ly in comp lete sets . The price is $20.00 per set whic h inc ludes packaging and postage withi n Austra li a.

• a visit to the o ld Kambah homestead, wh ich is be in g prese rved as a com munity faci lity . There Mr. Bob Bosler, Planner w ith th e Nationa l Capita l Deve lopment Commi ssion, gave a brief talk on the plannin g of Canberra and its ne w c ity of Tuggeranong. • a visit to the Tuggeranong Temporary Sewage Treatment Plant . This is a Pasveer Ditch type of plant w ith secondary sed imentation hav in g a popu lat ion capac ity of 7,500 and is suitab le for expansion to 15,000 . Wayne Harri s, an engineer w ith the pepartment of Housing and Construction described the operat ion of the plant to the visitors.

Detai ls for ordering copies of the lect ure notes are elsewhere on thi s page. All participants at the Su mm er School and purc hasers of the lecture notes will rece ive a copy of the transcript of the pro ceed in gs of the Forum.

FINANCES The fee for the Summer Schoo l was $200 .00 per st ude nt, wh ic h inc lu ded reg istration, a set of lecture notes, and room and board for t he week. At the t ime of writin g all bill s are not in ; however it ap pears that the Summer School w ill net a modest profit.

BRIEF DESCRIPTION OF WEEK'S EVENTS Official Opening Mr. Peter Manger , President of th e Can berra Branch , introd uced Dr. T. L. Judell, Federal President , who offic ially opened the Su mm er Schoo l. Dr. Jud ell then in troduced Dr. A. L. Downin g, who gave the first lectu re of the Sc hoo l. Public Lecture A Public Lecture was held in co nju nction with the Sum mer Sc hoo l to give people who were unab le to attend the Schoo l and members of th e general public the opportun ity to hear Dr. Downing . Following a brief introd uct ion by Dr. T. L. Jud ell , Dr. Downing spoke on "New Trends in the Deve lopment and Exp loitation of Water Reso urces " and il lu strated his lecture with co loured slides. Mr. E. G . Warrell, Chairman of Cities Com mi ssion, thanked Dr. Downing for his lecture on behalf of t hose in attend ance. A supper was provided at the conc lusion of the even in g. Atte nd ance at t he Public Lecture was about 160.

WorkshopsIn a departure fro m the program for the first Summer Sc hoo l, three works hop sessions were held in which part ic ipants were divided into three rotating groups of about 40 each . The purpose of the works hops was to expose participants to design problems in three speciali sed subjec ts, allowin g them to work in small er gro ups to faci litate disc ussion with the Workshop leader. Sight-seeing Tour In another departure from the program for the first Summer Sc hool, one aftern oo n was left free of lectures. A sight-seeing tour of Canberra was conducted for the benefit of approximate ly 50 peop le who indicated an interest. John Mi lls and Ian Lawrence of the Nat ional Capital Deve lop-

• a drive through various parts of Tuggeranong to enab le visitors to view a new urban deve lopment at all stag es in th e land servicing process.

ForumA Forum was held on Thursday evening under the capab le Chairmanship of Mr. D. A. Stockd ill , Assistant Director of th e Department of Housing and Construction, Canberra. The purpose of th e Forum was to give part icipants the opportu nity to explore in greater detail issues ra ised durin g the preceding fou r days of lec tures . All avai lable lect urers sat on th e panel and responded to quest ions fro m the stud ent aud ience. Prior to the Forum the lec turers were w in ed and dined before being fed to th e lions. Discussion at th e Forum was lively. The proceed in gs of the Forum we re recorded by two Court Reporters for in c lusion in the lecture notes.

OFFICIAL CLOSE Fo llowing the last lecture on Frid ay afternoon Mr. R. F. Goldfinch , Federal Secretary of the Association, briefly sum med up the week 's events to offic ially c lose th e 1975 Su mmer Sc hool.

FUTURE SUMMER SCHOOLS It has been dec ided by Federal Counci l that the next AWWA Su mm er School will be held in 1977. The Sc hool wi ll be held in Hobart and will be organ ised by the Tasman ian Branch of the Association.

1975 A.W.W.A. SUMMER SCHOOL PROGRAM TITLE SESS ION LECTUR ER NO. Monday 3 Feb . OFFICIAL OPENING 1 Basi n Management- A Progress Report 2 Mathemat ical Mode llin g - An Introd uct ion 3 Basin Stud ies in Austra li a 4

Env iron mental Impact Stud ies

Dr . A. L. Downing Dr. R. Melchers Mr. D. A. Reinsch Mr. R. G. Calvert

Continued overleaf

5- (Eveni ng) PUBLIC LECTURE New Trends in the Development and Exp loitation of Water Resou rces

-(Evening) WORKSHOPSDr. A. L. Downing

Tu esday 4 Feb. 6 Urban Stormwater Quality Dr. B. T. Hart 7 Improvement of Quality of Dr. G.R. Stormwater Discharges to Grantham Rivers and Lakes Mr. I. C. 8 Nutrient Effects of Stormwater Discharges to Smalls Rivers and Lakes Mr. N. A. 9 Ocean Outfall Systems Brodie WORKSHOPS 10 Design of Water Dr. G. R. Treatment Plants Grantham 11 Design of Sewage Mr. R. C. Aberley Treat ment Plants 12 Design of Ocean Outfall Mr. N. A. Systems Brodie & R. S. Stokes -(Evening) WORKSHOPS - Groups Rotate Wed nesday 5 Feb. 1.3 Australian Sewerage Mr. R. L. Co llection Systems: Duance State-of-the-Art 14 Sewerage Odour Control Mr.CD. Systems Parker Mr. R. J. 15 Design of Sewers for Prevention of Odours McGrath - (Afte rn oon)- Sightseeing Tour

Thursday 6 Feb. 16 Upgrading Existing Wastewater Treatment Plants 17 Packaged Wastewater Treatment Plants 26 Effluent Re-use for Agricultural Purposes 18 New Developments in Water Supply Treatment Plant Design 19 New Development in Sewage Treatment Plant Design 20 Reclamation of Chemicals in Water & Wastewater Treatment 21 (Evening) FORUM

Groups Rotate Mr. J. J. Ryan Mr. R. J. McGrath Mr. R. Wetselaar Dr. A. L. Downing Dr. A. L. Downing Mr. M. B. Dureau

Friday 7 Feb. 22 Municipal Versus Onsite Mr. C. D. Treatment for Industrial Parker rx Wastes 23 New Developments in the Dr. A . L. Treatment and Disposal ofDowning Industrial Wastewaters 24 Effluent Recycling in Mr. M. B. Industry Dureau 25 Virus Removal Processes Mr. B. G. Stone CLOSE

PLEASE SUBMIT CHEQUE FOR $20.00 PAYABLE TO AWWA SUMMER SCHOOL AND MAIL TO HON . SECRETARY AWWA SUMMER SCHOOL P 0 . BOX 359 CANBERRA CITY. A.C.T. 2601. PAYMENT INCLUDES PACKING AND POSTAGE WITHIN AUSTRALIA. LECTURE NOTES ARE SOLD ONLY IN COMPLETE SETS .

QUEENSLAND Local Branch activities for the year commenced on February 19. Guest Speaker was Geoff Cossins with a talk on " New Flood Control System for Brisbane " .

Symposium '75 This will be the main branch activity for the year. The theme will be:"Wastewater. What To Do With It ." Date: 17th April , 1975. Venue: Morris Hall , Church of England Grammar School, East Brisbane . Speakers will include representatives of the Water Quality Council and Brisbane City Counci l and in addition there will be six short papers on case studies. Emphasis will be placed on giving maximum time for discussion . Members will receive notices and registration forms in due course .

The statement " the necessary flow capacity of the pipe line does not have to be as great as the peak demand flow " should be qualified in the light of policy considerations. Norma l practice design flow rate criteria based on estimated future demands during a period from 10 to 25 years ahead , depending on economic considerations , are :Major Storage

Chairman: Mr. D. A. Stockdill

TO PURCHASE A COPY OF THE LECTURE NOTES FOR THE AWWA SUMMER SCHOOL, CANBERRA 1975:

Association News continued from page 8.

(d) Increase in per capita comsumption , living standard , living pattern and density of residential development or zonings . (e) Conjunctive use of water from different sources of supp ly and provision for pumping during periods of peak demand .

LETTER TO THE EDITOR Dear Sir , I have read with interest Professor Gould 's synopsis on "Persistence of High Daily Demands in Australian Water Supply Systems" in the September '74 issue of 'Water' the A.W.W.A . - Journal and would like to make the following comments to various assertions in ti;e article . Whilst it is agreed that a water supply system should be designed such that " unwarranted extravagance of design and overdesign " be avoided , there are matters of policy to be taken into account before a decision as to the criteria of design for watermains is adopted. (a) Restrictions and /or limitations to use , types of land development and allowab le depletions of storage reservoirs . (b) Degree (maximum or not) of fire protection required. (c) Requirements for continuity of supply during main breaks or other emergencies .

- Average Day requirement Trunk Mains - Maximum Day requirement Local Storage -One day maximum day requirement for surface reservoirs , smal ler capacities for elevated reservoirs . - Maximum hour, Distribution & Reticulation Mains day requirement or fire fighting requirement wh ichever is the larger. Regarding figures 1, 2 & 3 Graphs of peak T-day flow ratios as functions of time , rainfall & persistence index an analysis has been made comparing localities of vastly different characteristics . Unless flow ratios are compiled and compared on an equal basis of deve lopment no realistic com parison for planning purposes is possible . As a mater of interest it might be noted that some high-class medium density residential areas â&#x20AC;˘ in Sydney have recorded maximum day to average day flow ratios of consumption of up to 3.8 . A great deal of investigat ion is sti ll required into pattern of water usages in high rise residential and commercial development and any research could also include a survey as to water consumptions of industrial enterprises , similar to the one undertaken by the U.S. Bureau of Census 1964. F. Pojer M.I.E. (Aust .) Member, N.S. W. Branch.

Personnel Appointments Mr. K. O. Trevarton, formerly of Braemar Engineering, has been named Managing Director of a new Company, Abtech Environmental Services Pty. Ltd., which will specialize In water treatment and Ion exchange applications. Mr. B. W. Browning has been appointed Technical Director. Additional services to manufacturers Include design and development of new products, product improvement and design evaluation.

THE MOLONGLO VALLEY INTERCEPTOR SEWER

NEW PRODUCTS AND PROJECTS

Further to this project which featured in the December issue of Water, Humes Limited manufacturer of the large diameter pipes involved , has announced comp letion of the contract for pipe manufacture.

ADELAIDE'S SEWERAGE SCHEME GETS IMPETUS

McKEE-PEDERSEN MP-1502A ELECTROANALYZER

With $A15 million al located this finan c ial year and between $50 and $60 mi lli on spent on sewerage in the last 5 years , Ade laide, cap ital city of South Australia, has over 90% of its homes and industrial sites served by sewerage.

The MP-1502A is a new instrument for anodic stripp ing analys is, d.c. polarography , cyclic vo ltammetry , and contro lled potential coulometry .

Adelaide thus beats other Australian capitals for sewerage coverage at a time when pollution and the environment are big issues. Typical of major current const ruction being undertaken by the Engineering and Water Supply Department is the North-East Trunk Sewer, a re lief sewer servin.g the newly developed eastern suburbs where much open land , some used for market gardens , has been .built on in recent years. Origina ll y estimated to cost $A3 mi llion, the concrete pipe sewer will pass through and serve such well known suburbs as Hackney, St Peters and Marden. The pipe protection method specified to combat the corrosive environment was a one-inch minimum thickness sacrificial layer of concrete made with calcareous aggregate. The pipes , as supplied by Rocla Concrete Pipes Limited , are made comp lete ly with calcareous aggregate and conform in every way to the E& WS Department 's stri ct and rig id specification . Roc la has just co mpleted the manufac ture and de livery of some 1660 metres of 1350mm diameter pipes with rubber ring joints in Australian Standard load c lasses of Y and Z for the second stage of the North-East Trunk Sewer. The company was recently awarded the contract for pipe supply and delivery for stage 3 of the sewer. This involves 3100 metres of 1050mm diameter pipes made with calcareous aggregates. Manufacture of the ca lcareous aggregate pipes is ideall y su ited to the Rocla ro ller suspen sion process where the relatively dry co ncrete mix is compacted main ly by ro lling compression. There is no segregation of concrete materials and the aggregate is evenly distributed in the pipe wall. In the project just completed , Rocla were required to separately test one in 20 pipes for load test and hydrostatic test. A joint test of two pipes in every 50 was also specified.

Manufacturers are invited to send news of any new products, projects or services for inclusion in this section. Editorial should be around the 250 to 350 words, photographs of the products would be welcome. Post to John Craig, P.O. Box 100, Caulfield East, Vic., 3145.

The whole project required production of some 3880 pipes of 2550mm diameter and a further 380 by 1950mm and to meet requirements for thi s $1 ,966,000 co ntrac t , the Company in stalled a specia l pl ant at its Queanbeyan factory. Full production began in June 1973 and the work has been completed on schedu le. The alignment of th is sewer line involved curvatures unusual in a li ne of this diameter and some forty percent of the pipes were produced with the splayed joint illustrated in the previo1Js article and developed by Humes Limited for this purpose. Orientation and handling of unusual pipes of this nature introduces spec ial problems and these were met by the use of special equipment deve loped by the deliv ery contracto r, A. Pittman Ply . Ltd .

It features a three electrode potentiostat and a unique voltammetry con troller . The controller allows the generation of voltage ramps between fixed potentials and of triangular waves . With an extra reference voltage , saw-tooth waves c an also be generated . The instrument is available in table -top and rack mounting versions. Applications of the MP-1502A include general electroanalytica l work, trace metals analysis, and studies of electrode reactions and their kinetics. The versatility of the instrument makes it ideal for analytical methods deve lopement.

BIOLOGICAL COMPLEX PELLETS A locally developed biological co mplex in stabilised pellet form is now avail ab le from Southern Cross Laboratories Pty. Ltd. This complex named ACTIZYME is being successfully uti li sed throughout Australia as an aid in the effective treatment of many types of organic wastes e.g. household and industria l septic systems and greasetraps, effluent from abattoirs, poultry and food processors, council waste eff luents etc. ENQU IRI ES: Southern Cross Laboratori es Pty. Ltd . P.O. Box 2, Round Corner, Dural. N.S.W. 2154. Te lephone: 65 1 1536.

Specifications for the MP-1502A are c urrent range 10-9 to 10-2A, full scale; scan rates adjustable from O to 4000mV /min (plug-in resistor changes for rates up to 60kV /min} ; initial potential adjustable from 0 to ± 4V , directly settable in millivolts; compliance voltage ± 18V; input impedance 1013 ohms. Size is 16½" wide by 5¼" high by 8½" deep. Weight is 16 lbs. For further information , please contact:John Morris Ply. Limited , P.O . Box 80, CHATSWOOD , NSW 2067. Telephone: 407 0206.

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McKee-Pedersen Electroanalyzer

'RISING PRICES' Owing to the rising cost of postage we are seeking to obtain a postal concession. To do so we must conform to certain requirements - we must have a 60% subscription (paid) circulation. Would those who have previously received this journal without charge

(Municipal Engineers and some Government Departments) please be so kind as to subscribe so that we shall be able to continue to supply the journal to you and not have to reduce our circulation to meet the demands of bureaucracy.

NEW CARBON ANALYSER R. & D. INSTRUM ENTS PTY. LTD. have announced details of a new process control organic carbon analyser. This is expected to be released in Australia in th e early part of next year. Literature is avai lab le from the suppliers. This new in strument, the D.C.60 has been developed by the Dohrmann Division of Envirotech to cate r for an on stream · analysis req uirement. Beca use of in creased concern w ith eco logy, interest in the fast and accurate measu re ment of organic load ing in water is high . Historically, this water quality parameter has been evalu ated by determining the 5-day biochemical oxygen demand (BOD5). Researchers have demon strated , however, that determining the total organic carbo n (TOC) co ntent of water is also an effecti ve method for estimating organic load in g. While there is no rigorous correlation between BOD5 and TOC valu es, these two water qu ality parameters show the same trend . A high TOC value indicates the strong possibility of a high BOD5 valu e. A low TOC value invariably indicates a low BOD5 value . The outstanding feature of the TOC determination is speed . At 5 minutes per determination , it can be used for control purposes. The standard 5-day BOD value has on ly historical signific ance . The DC-60 is designed to provide rugged, reliable , accurate in strumentation to automatically measure either tota l organic carbon (TOC) or total carbon (TC) in water. Featuring high stability and unattended operation, th is monitor provides a perm anent record for reg ulatory purpose s and high level output signals for remote monitoring and contro l. ENQ UIRIES: R. & D. In struments Pty . Ltd ., 2 Corr St., Moorabbi n, 3189.

ADDITIONS TO VALVE RANGE The type DW/H and type H Red Valves complement the range of type A Red Valves whi ch are purely for pn eumatichydraul ic actuation . The type H is for manual co ntrol. The handwh ee l mechanism features two pinch bars which shut off th e elastomer sleeve from opposite directions . This twin-pinch effect places less strain on the elastomer sleeve compared to a single pinch bar and also provides a greater shut-off area to en sure tight closure even with so lid particles in the lin e. The DW/H valve has an additional seal in the v a lve body to a l low pneumatic /h ydrau lic operation and the manual handwheel for emerge ncy air failure operation . All Red Valve models are avai lab le with both full and reduced bores and sizes range up to 36 inches . ENQU IRIES : Automatic Accessories Pty. Ltd ., Sydney, Melbourne.

PODDY ORIFICE FLOW SYSTEMS

si ze and for all li quids and gases for which the meter is suitab le.

Paddy Orifice Flow Systems provide an inexpensive reliable direct indication of li quid and gas f lows ·in pipes ranging from 1;. inch to 8 inch diameter . The systems comprise an orifice plate in a plastic carrier which in sizes 2 inch to 8 inch are suitable for insertion between pipe flanges and in th e smaller sizes are co nta ined in orifice unions which may be screwed , cemented or slipped into the line.

KENT VORTEX METERS wi ll be avail able in th e following sizes:- 2in . (50mm) ; 3in. (75mm) ; 4in . (100mm) ; 6in . (150mm) ; Bin . (200mm) ; 9in . (225mm) and 12in . (300mm ).

Close -coupled or remote mounted is a liquid column flow -gauge measuring the differential pressure and indicating in fl ow units . The desig n of the Paddy Orifice Flow System is based strict ly on British and In te rn ational standards for flow measurement. Since there is no flow through the indicating instrument , it does not suffer from blockage or fouling that may cause reading difficulties and inaccuracy. Paddy Orifice Flow Systems are avail able with 7 inch indicating scale length , pressure rat in gs to 500 p.s .i. and temperature ratings to 350°C. Paddy Flow and Pressure products are avai lable from ACROMET PTY. LTD. , 12 Fury Court , South Clayton , Victoria (P.O. Box 491, Clayton, 3168).

A NEW METHOD OF MEASURING FLOW OF LIQUIDS An entire ly new method for the measurement of the f low of liquids and gases in proc_ess plants, power stations, steel works , 01 1-, gas- and petrochemical p lants , public water supp lies and many other app li cat ions is annou nced by Kent Instruments (Australi a) Pty . Ltd . The new method - whi ch was devel oped by Kent lstruments Ltd ., U.K. ; the main process control subsidiary of the George Kent Group - is based on electrica l measurem·ent of the vortices (eddies) wh ich are caused when a fluid flows past a bluff (unstream li ned) body placed in a pipe . The new flowmeter - known as the KENT VORTEX METER - combines high acc uracy at low cost with inh erent linearity and a very wide turn -down range . As they have no movin g parts , KENT VORTEX METERS shou ld prove to be particularly reliable in operation and to have a long service life . Among the man y advantages KENT VORTEX METERS offer - apart from their low cost - is the fact that they require no separate co nverters or transmitters and provide frequency or analogue output. In add ition they are intrinsically safe and thus can be used in hazardous locations. The KENT VORTEX METER does not require ca librating. Its output is abso lutely dependent on a natural phenomenon whi c h is determined by the dimensions of the meter. A unique feature of the KENT VORT EX METER is that this relationship will be constant for all meters of a given

The parts of KENT VORTEX METER in contact with the metered fluid can be made of carbon st eel, stainless steel or brass and thus they are compatible with virtua lly any industrial liquid or gas . For fu rth er informat ion please contact:Mr. D.J . Ri c kard , Technical/Marketing Manage r, Kent Instruments (Australia) Pty. Ltd ., 70-78 Box Road (P .O. Bo x 333) , CARINGBAH , N.S.W. 2229 Telephon e: (02) 525 2811 Or con tact the Kent office in yo ur state .

LARGE SEWAGE PUMPS FOR N.S.W. PROJECT Four larg e vertical split case sewage pumps designed and manufactured by Ke lly & Lewis Pumps will be installed in the new Captain Cook Drive pumpi ng station at Cronulla , N.S.W. The new pumping station now nearing completion will be one of the biggest in t he Metropolitan Water Sewerage and Drainage Board of New South Wales ' system . It is designed to cater for the large scale ampl ificatio n of the Board ' s sewerage network on the Suthe rl and Shire . This Shire is one of the fastest expanding perimeter areas in Syd ney and th e Board has now expended over $30 million in the last two years whi ch is a record expenditure in one area. Th is new pumping station is a vita l component in the expansion programme of the Board 's facilities and will pump sewage from the new ly reticu lated areas to the Cronu ll a Water Pollution Control Plant which is bei ng greatly expanded to cope with the increased inflow . The new pumping station is a cyli ndrical structure. The internal diameter is 22 metres, and walls are 1.07 metres thick. It wi ll house two large pumps and two sm aller units . The vert ica l centri fu gal pumps have c ast iron split casings and are designed with renewable side plates so that one half can be dismant led and the shaft assembly removed without breaking the joints of the suct ion branch and without mov in g the motor. Ke lly & Lew is also supplied pumps and ancillary equipment for the Cronul la Water Pollution Control Works. For furt her information contact :Kelly & Lewis Pumps, Newcomen Road, SPRINGVALE , Vic. 3171 .

CONFERENCE CALENDAR

The 1975 Chemical Engineering Conference Mildura, AuQust 20-22nd , 1975.

INTERNATIONAL ASSOCIATION FOR WATER POLLUTION RESEARCH 8TH INTERNATIONAL CONFERENCE SYDNEY OCT. 17, 23 - 1976 Official Opening : The Opera House Venue : The Wentworth Hotel CONGRESS SECRETARIAT G.P.O. BOX 2609, SYDNEY, N.S.W., 2001. Teleph one (02) 27 6940 Preliminary Brochures and Details regarding Registration and Submission of Papers are available from the Secretariat and from: Dr. M . Fl ynn , Secretary-Treasurer,1.A.W.P .R. Austra li an Committee I.A .W.P.R. G.P.O. BOX 2609, Sydney . 2001 . All A.W.W .A . State and Federal Secretaries . The A.W.W.A. is a member of the I.A.W.P.R. and recom~ends your support for the 8th International Con ference .

" Treatment , Recycle, Reuse and Disposal of Wastes. " Plenary sessions covering environment study, planning , protect ion and legi slation , and departmental sessions on waste management in the fields of : - Mining and metals Extraction, Forest Pulp and Paper, Manufacturing Industry , Food Processing , Chemical , Petroleum , Agriculture and the Urban System. Further details and instructions for authors of papers for the Conference , available from Dr. D. V. Boger, Dept. of Chemical Engineering , Monash University , Clayton , Victoria 3168. Sponsors- I. Ch.E . in association with LE .Aust., RAC.I. and A.I.M .M.).

I.A.W.P.R. CONFERENCE ON NITROGEN ASA WATER POLLUTANT Technical University of Denmark Copenhagen, 18th - 20th August, 1975

PLEASE NOTE For this issue you may have received a complimentary copy. Should you wish to continue to receive the quarterly issues, you are invited to complete and return form on this page.

SUBSCRIPTIONS AUSTRALIAN WATER & WASTEWATER ASSOCIATION JOURNAL

I enclose herewith the sum of $ ....... (Australian) as prepayment for supply of the following issues of 'WATER ' June o Sept . o Dec. o 197March o Note:AII subscriptions conclude with the December issue, renewals are due by the end of February for a full year's subscript ion . Price , including surface mail to all countries, is $1.00 (Aust.) each issue, made payable to the A.W .W.A. - 'WATER '. Name ..... ..... .......... .... .... ....... ... ... ............ ................. .

Sponsored by The Danish National Committee under IAWPR The International Association of Water Pollution Research (IAWPR)

For information and application forms contact IAWPR National Committee Secretary

A.W.W.A. MEMBERSHIP Request for App/ica tion Form for Membership of the Association To the Hon. Secretary, Australian Water & Wastewater Assoc .. Mr. R. F. Goldfinch , P.O. Box 359, Canberra City, A.C .T., 2601

1, .............. .. ... .. ... .... ..... .................. ... ......... .......... .. .. . (Name)

of, ...... ...... ... ........... .......... ,... ............. ,................... ... (Address} do hereby request an application form for membership in your Association.

Address .. .................. ......... ...... ....... ...... ... ... ........... ..

Mail this form to : John Craig , 'Water ', Box 100, Caulfield East, 3145, Victoria, Australia. 28

Membership is in four categories. 1. Member - qualifications suitable for membership in the In st. of Engineers, or other suitab le professional bod ies . 2. Associate - expe rience in the W.& W.W. Industry , without formal qualifications. 3. Student. 4. Sustaining Member - an organisation involved in the W.& W.W. Industry wishing to sustain the Association . Â·

ACROMET 900 METERING PUMPS

DELTA MODEL 2260 CONTINUOUS BAND

SPECTROPHOTOMETER A revolutionary new spectrometer with unprecedented features for accuracy - speed - convenience.

for accurate metering of water treatment and process additive chemicals.

Low cost rugged construction. In materials of construction to handle all liquids and slurries.

SIMPLEX or DUPLEX DIAPHRAGM CONSTRUCTION * MICRO ADJUSTMENT * SINGLE or DOUBLE VALVING * MANUAL or AUTO CONTROL * PRESSURE RATINGS TO 500 PS I * CAPACITIES TO 200 I.G.P.H. * TOTALLY ENCLOSED NO EXPOSED MOVING PARTS * ADJUST ABLE WHILE RUNN ING OR AT REST

* DOUBLE

,.. ~

240 VOLT AS WELL AS INDEPENDENT OPERATION FOR 14 HOURS BETWEEN CHARGES ULTRA PRECISE ABSORPTION CELLS. Optically polished walls for highest possible measuring accuracy.

EXCLUSIVE "SPECTRO MEMORY" Optional pre -calibrations optional certi fied accurate ca libration charts individually prepared for all co lorimetic tests. The Delta Model 2260 brings you more features than any other Spectrophotometer in its price class - and it has advantages not available in others AT ANY PRICE.

Ideal low cost unit for accurate analysis of water wastes and process fluids. Fast multiple testing of 200 readings per hour. 15 EXCLUSIVE FEATURES ASSURE YOU OF

P.O. Box 491, Clayton, Vic., 3168 PTY. LTD. Phone Melb. 547 3077, Sydney 982 8055 PERTH - HENDERSON INSTRUMENTS PTY. LTD. 81 4477 ADELAIDE - F. R. MAYFIELD PTY. LTD. 87 3161 BRISBANE - QUEENSLAND METERS & CONTROLS PTY. LTD. 58 3533 HOBART - ELECTRICAL & ENGINEERING SUPPLIES PTY. LTD. 72 8833 LAUNCESTON - ELECTRICAL & ENGINEERING SUPPLIES PTY. LTD. 31 6155

HIGHEST ACCURACY, CONVENIENCE AND USEFULNESS.

JOHN MORRIS PTV LTD P.O. Box 80, Chatswood, 2067. Phone: 407 0206. J.M. Scientific Pty. Ltd. lltlbourno: 2 Bea11110nt St., Vermont, Pllono: 173 2711

John Morris Pty. Ltd. Adelaide: 30 Aquamarine Dri,o, Salisbury East, Phone: 251 5966 Quunsland: 50 Can'l)btll Street, Bowen Hills, PIion,: 52 4072

Water. at 24.000 gallons an hour from 600 feet below ground. Mono borehole pumps operate against total heads of 50 to 600 feet in all deep-well and inclined river bank bores. Mono 's se lf-priming abi lity against high suction lifts up to 25 ft. is better than any other positive displacement pump. This is because Mono use their own design of rotor and resi lient stator and this combination can pump almost anything. Like any kind of underground water at 50 to 24,000 gallons an hour for year after year. And Mono 's borehole drive heads handle drives from petro l or d iese l engines, e lectric motors , or tractor PTO shafts . Bore ho le Pu mps, e ng ine dri ve n . Your choice of di esel, petrol , kero or PTO.

' E' type Borehole Pump. Closecoup led. o. 75 hp elec. motor. 4101 ,560 gph ; depths to 150 ft.

Bore hol e P umps. 50-24,000 gph. Allweat her , ca nopy is standa rd w ith electri c drive.

Mono have over a dozen pumps in their borehole range, why not call for details?

[?{1[}~[?@ (AUSTRALIA) PTY. LTD. Head Office and Works : "Mono House", 338-348 Lower Dandenong Rd., Mordialloc, Vic. 3195. Phone : 90 5211. Interstate Offices: NEW SOUTH WALES: Kirrawee, telephone 521-5611 0 QUEENSLAND: Kedron, telephone 59-6466 0 SOUTH AUSTRALIA: Flind ers Park, telephone 43-9754 0 WESTERN AUSTRALIA: Be lmont, telephone 65-5244 0 TASMAN IA : Moonah, telephone 28-0353 0 NORTHERN TERRITORY: Win nel lie, tel epho ne 84-3099. Al ice Springs, telephone 2-2913 D AG ENTS IN : Papua and New Guinea, Indonesia, Fiji, The Phi lippines. 344.P.038W

approved* ---- ---

The DC-50 organic analyzer makes al/of these measurements accurately and rapid ly. Based on p roven , EPA appro ved· meth ods, it avoi ds interferen c es and und esirabl e pyro lysis reactio ns that historically have resu lted i n si gn ifi cant erro rs.

• DI RECT READOUT : Fo ur-d igi t prese ntati on shows carbon content direct ly in mg /lite r or ppm . No recorder needed! e DIRECT MEASUREMENT: A Si ng le sampl e injection gives either Organ ic Carbon or Total Carbon co ntent directly, not by difference. • INDEPENDENT MEASUREMENT : Vo latile Organics are determin ed separate ly from Total Org ani cs to aid in source identi fi catio n . e RELIABLE MEASUREMENTS : Dete rmines important , lightwe ight vo latiles suc h as lo w molec ul ar we ig ht alc o ho ls and ketones , no rm ally lost by acid ificati on and sparging . • FAST : 5 minutes per determi nation . • ACC URATE: Repeatabi lity of ± 1 mg /liter or.,± 2%. • WIDE RANGE : 1 to 2,000 mg /lite r (ppm) wi th ou t dilution . · ENVI RONM ENTAL PROTE CTI ON AGENCY, WATER PROGRAMS, Gui deli nes Establishing Test Proce dures for An al ysis of Po llutants. FEDERAL REG ISTER Vo l. 38. No. 199, Part II , Oc t . 16, 1973.

* New model D.C. 52 now available, offering approximately ten (10) times lower limit of detection.

DOH RMANN DIVISION

ENVIROTECH N .S. W. Enquiries: WA YNE ELECTRONICS PTY LTD 52 Great North Road, FIVE DOCK. N .S. W. 2046

choice! donkin Frontrunners ,n

gas compression and control

Two major Australian public authorities recently chose Bryan Donkin compressors for their new sewage treatment plants. The equipment is being installed at the South Eastern Purification Plant of the M.M .B.W. at Carrum, Victoria and the Lower Molonglo Water Quality Control Centre of the National Capital Development Commission in the A.C.T.

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·liii,_Backed by over a hundred years of manufacturing experience, the Bryan Donkin Company is dedicated to continued development of gas handling technology. For more information, contact the Australian machinery agents Hawker Siddeley Brush Pty. Ltd.

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HAWKER SID D ELE Y BRUSH PTY LTD In co rpo rated in NSW

VIC. 262-284 H e ide lb e rg Road , Fa irf iel d , 3078. Tel. 4892511. N . S. W. 12 Fred e ri c k Street , St . Leon ard s, 2065 . Tel. 43 1502 . QLD. 193 Ma ry Street , Bris ban e . 4000 . Te l. 21 2926 . W.A. 113 Ke w Street , We lshpo o l, 6106. Tel. 61 7944 . H awke r Sidde l ey G roup supplie s mechanical, ele ctrical and aerospa ce equip m ent w ith wo rld-wid e sales and se r vic e.

5760HSBD

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((ID) INDUSTRIAL ENGINEERING LIMITED restore the ENVIRONMENT .. !

CLEAN AND CLEAR WATERWAYS

withfflud Cat UNDERWATER WASTE REMOVER

MUD CAT dredges have been specifically designed for the economical removal of pollutant substances from waste settling ponds, weed-i nfested lakes and streams and for channel clean -out. Their unique features permit the removal of deleterious matter, weeds, si lt, sand, sludge and industrial wastes with the minimum of water turbidity, thus allowing the pond , lake , stream or channel Developed by th e National Car Renta l System Inc., of U.S.A. AUSTRALIA WIDE DISTRIBUTORS:

to operate or flow normally during the clean-up operation . Two machines are available, the MC1 0 which will operate to a depth of 10'6" and the larger MC15 which operates to a depth of 15'0". Both mach ines are propelled in both the forward and reverse directions by winching along a wire rope wh ich is furnished in the form of a harnessing kit.

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INDUSTRIAL ENGINEERING LIMITED \\Ill) :~~~~11:~~i.Tr:oe:; ~~~;;,c~:~exAA 307 56 Sates and Service through the I.E.L.-CONTRACTING PLANT ORGANISATION CONTRACTING PLANT IQLD.I DIV. CONTRACTING PLANT IN .S.W.I DIV. CONTRACTING PLANT (VIC.I DIV. SOUTH AUSTRALIAN DIV. INDU STRIAL AVE NUE WACOL 288 PARRAMATTA RD. AUBU RN (JASMANJAJ 585 GRANO JUNCTION RD . PHONE 72 2122

PHONE 648 0301

cnr. FOOTSC RAY RO. & DUDLEY ST..

WEST AUSTRALIAN DIV.

cnr. RU SSELL & SPARKS RO S. GE PPS CROSS . PHONE 62 66 12 STH.COOGEE. PHONE 90 142

WES T MELBOURN E. PHONE 328 457 1 M C1

If clean water is an essential part of your process plant ... or the economic separatiqn of suspended, entrained or dissolved materials such as chemicals, minerals, oils, spirits, etc .... then you need the specialised skills and equipment available from Permutit. De-ionisers/ Filters Reverse osmosis

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Nobody treats water more cleanly than Permutit!

IPERMUTITI The Permutit Company of Australia Pty. Ltd. A subsidiary of The Permutit Company Ltd. , England. A member of The Portals Group. Cnr. Wattle Road and Short Street, Brookvale , N.S.W. 2100. Telephone : 93-0311. Telex : AA24742. Cables : Thepermulit, Sydney. P.O. Box 117, Brookvale, N.S.W., Australia 2100. 2-6 Hardner Road, Mount Waverley, Victoria 3149. Telephone: 544-2811. Telex: AA31868. P.O. Box 237, Mount Waverley, Victoria, Austra lia 3149.

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pettigrevv . e e e

A COMPLETE SERVICE

INW'aterPOLWTIONCONTROL

SURVEYS AND CONSULTING

e OVER 40 YEARS ' EXPERIENCE AND

PILOT STUDIES Of WASTEWATER

e INSTALLATION, TESTING AND

DESIGN AND MANUFACTURE

e CONTINUOUS AFTER-SALES SERVICE

RELIABILITY COMMISSIONING

B.O.D. REDUCTION by PLASTIC FILTER MEDIA The "Flocor" Tower shown above was designed by Pettigrew Engineering as part of a complete process for an Industrial Wastewater Treatment Plant. This segment of B.O.D. reduction is achieved by the high efficiency of "Flocor" plastic filter media from I.C.I. Australia, assembled for the local Â·site by Pettigrew Engineering.

PETTIGREW ENGINEERING CO PTY LTD 34 REGINALD STREET, ROCKLEA, OLD., 4106, AUSTRALIA TELEPHON E (072) 46 3322 - CABLES "PECOTRADE " Gardner Print, N unawadi ng. 874 2133.