Technical Session S9 : DOMESTIC WATER QUALITY – ISSUES AND MITIGATION
DECENTRALIZED HOUSEHOLD DRINKING WATER TREATMENT SYSTEM TO TREAT MUNICIPAL SUPPLY WATER April 9, 2013
Debashree Dutta Brijesh Nair
Pranav Nagarnaik Pawan Labhasetwar
India Water Week ‘13
Introduction • • • •
Lack of safe drinking water Quality insufficiently monitored Lack of residual chlorine Cross contamination – Microbial – Heavy Metals • Disinfection byproducts
Municipal Water Distribution Network
Source: http://www.campbellriver.ca/CityHall/Departments/Utilities/Water/Pages/Distribution.aspx
Survey and Sampling
• 87% low income and 50% household had microbial contamination in their drinking water. • 83% in middle income and 100% in low income had residual chlorine below 0.1 mg/L. • 78% samples without residual chlorine had microbial contamination.
Basic Water Quality Household Treatment • Using Natural Products – Rice Husk Ash
SEM micrograph of RHA (4000x. mag.)
• Removal – Turbidity – Heavy Metals • BET Surface Area 231.92 (± 0.51) m2/g FTIR spectra of RHA, RH, As-RHA and Cr-RHA samples
Experimentation Water + bacterial culture + copper
Saline solution + bacterial culture + copper strip
ICP-OES ICP-OES
EMB agar for E.coli (Green metallic sheen colonies)
Membrane Membrane Filtration Filtration
Control
BS agar for Salmonella (Black colonies)
Disinfection Outcomes • 99.99% of all cells damaged between 60 mins to 75 mins.
• Reduction was faster in copper vessel as compared to copper strips. • Salmonella in copper vessel showed slower destruction rate compared to E. coli
Antibacterial activity of copper strip and copper vessel
Disinfection Outcomes
Negative Control
Surface released copper ions from copper strips and copper vessel
Design Consideration
Conclusion Disinfection with Copper - Point of use solution for microbial purification. - Effective touch surface - Low cost, low tech, easy maintenance, no chemical addition and environmentally compatible technology. - Potential application in decreasing the bacterial load in household drinking water purification system.
Household System
Safe
Acknowledgement CSIR-NEERI, Nagpur Dr. S. R. Wate , Director Viji John JNRDC, Nagpur SMBS, VIT University , Vellore Dr. Shanti, Director
Thank You “Unfortunately not all of us live close to a mountain stream where we can fill up our water bottles and drink some of the best water on the planet for free – the way nature designed it”