ANNOUNCEMENTS
“Safe drinking water and adequate sanitation are crucial for poverty reduction, crucial for sustainable development, and crucial for achieving any and every one of the Millennium Development Goals” – UN Secretary-General, Ban Ki-moon.
The present research investigates the application of solar energy for water purification and wastewater treatment, especially for arsenic-affected rural areas. The study deals with harnessing solar energy for arsenic free potable water supply and use of phytoremediation, to address the issue of meeting disposal standard to make water treatment unit’s environment safe and risk free and also aid in reducing the arsenicosis rate in arsenic affected locations.
The work essentially explores the performance of solar stills for the production of safe drinking water with variable input water quality and co-treatment of arsenic-enriched brine and sewage using phytoremediation method. The work involves laboratory experiments to evaluate the efficiency and efficacy of identified methods and its replication in-field conditions (Kaudikasa in Rajnandgaon district, Chhattisgarh, India) for the validation of the results. The research is also able to identify the aquatic species Cladophora sp. suitable for removal of arsenic from water environment and establishment of performance of solar stills, especially in the context of microbial contamination and heavy metal removal. The field performance of the method is found to be consistent with negligible maintenance throughout the trials. The research, therefore, brings out a novel concept for water supply and sanitation which is sustainable and low cost. It is especially useful in rural areas which do not have access to grid electricity.
The arsenic biosorption studies were also carried on this algal species. The wastewater stabilization pond enriched with Cladophora sp. algae was able to meet water quality standards for irrigation for arsenic levels (CPCB standard for arsenic is 0.2 mg/L). The Cladophora sp. has high sorption capacity and can uptake arsenic in inorganic (as As III and As V); organic (DMA and MMA) as well as arsenosugars. Arsenic speciation revealed that arsenite, arsenate, arsenosugar are dominating while dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and arsenosugar are in minor concentration.
The co-benefits of the studied system are: health improvement of the community with expected reduction in arsenicosis rate, hygiene and public welfare and a complete removal of Arsenic from water eco-system. The design estimate for arsenic affected Kaudikasa village of Chhattisgarh district India shows that the total cost of the system implementation is about INR 2, 75,18,000 which on per family basis i.e. INR 68,795 can be easily afforded.
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