Rural methods to mitigate arsenic contaminated water

Consumption of arsenic contaminated water is one of the burning issues in the rural world. Poor public awareness program about health effects of drinking arsenic contaminated water and the rural methods to mitigate this problem poses a great threat of arsenic poisoning many people of the rural world. In this thesis, arsenic removal efficiency and the working mechanism of four rural and economical arsenic mitigation technologies i.e. solar oxidation and reduction of arsenic (SORAS), Bucket treatment unit (BTU), Sono filter and Arsenic bio sand filter (ABF) are described by studying the articles of several researchers. All of these technologies are based on the principal of adsorption, ion exchange, oxidation, co-precipitation and coagulation methods. In SORAS technology, transparent PET bottle containing arsenic contaminated water and natural acids like lemon juice is exposed to the sunlight. Sunlight causes a photochemical oxidation of arsenic, which lowers down the arsenic level of contaminated water by over 80 %. In BTU technology, arsenic was filtered using two buckets. Alum and potassium permanganate were used to enhance the reaction. This technology removed the arsenic contaminated by 90 % of 34 tube wells selected for experiment in 55 days of installation. After 55 days this system required cleaning for efficient removal of arsenic. Similarly, the sono filter removed the arsenic by 90-95 % at the flow rate of 20-30 L/h. Arsenic biosand filter which proved to be the best among all above technologies removed 95-97 % of arsenic concentration from contaminated water and filtered at a rate of 40 L/day. In short, all above mentioned technologies were capable of reducing the arsenic level of contaminated water to WHO permissible limit. In addition, these technologies also removed other contaminants such as bacteria, viruses, turbidity, pathogens. Cleaning the filter in regular interval of time lengthen the life of these filters