Arsenic Removal from Ground Water by Coagulation Process

Abstract

Arsenic Removal From Ground Water By Coagulation Proces is well recognised as an element of public health concern. Various technologies have been reported for removal of arsenic from drinking water. These include conventional coagulation-flocculation, lime softening, ion exchange, adsorption on activated alumina/activated carbon, etc. Conventional coagulation process has been found to be the most effective treatment for removal of arsenic from ground water to meet the WHO guideline value of 10 μg/L.

In a laboratory study, alum and poly aluminium chloride (Vikram Powder PAC AC/190) have been studied as coagulants in the removal of arsenic from ground water. In order to simulate arsenic concentration levels found in ground waters of West Bengal, well water collected from the NEERI premises at Nagpur was spiked with stock arsenic solution in three concentration ranges viz. 100, 500 and 1000 μg/L and coagulation-flocculation studies were conducted for its removal. The findings of the studies have shown that, the dose of poly aluminium chloride (PAC) is almost half that of alum for obtaining the same level of arsenic removal.

Conclusion

We systematically investigated arsenic removal from Bajío groundwater by EC using aluminum as a sacrificial anode in a FM01-LC reactor. The influence of current density and mean linear flow rate was analyzed. Arsenic removal was performed after arsenite was oxidized to arsenate by addition of hypochlorite at a concentration typically used for disinfection. Arsenate removal by EC might involve adsorption on aluminum hydroxides generated in the process. The resulting sample meets the Mexican arsenic standard of  25 g L–1
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