Leaching of Arsenic from Iron Oxide Impregnated Brick Sands (Shapla Filter Media) Using Common Chemicals and Water

Leaching of Arsenic from high Arsenic loaded iron oxide impregnated brick sands (IOI CBCM) was investigated using common household chemicals like common salt and soda ash, the industrial chemicals caustic soda and the phosphates used as fertilizers such as potassium hydrogen phosphate and TSP. Leaching by ordinary ground water was also investigated on the arsenic saturated iron oxide impregnated brick sands from filters. A 10% caustic soda solution could leach ~95% arsenic, 20% sodium chloride solution could leach ~17.28%, 10% sodium carbonate solution 11.34%, 10% potassium dihydrogen phosphate solution 11.85%, and a 10% TSP solution could leach 34.56% arsenic from high arsenic rich (~1000 ppm As) iron oxide impregnated brick sands. Since ordinary water in the environment rarely contain such high concentration of chemicals, very little dissolution of As from arsenic loaded brick sands is expected. Natural groundwater showed negligible or no leaching from waste arsenic-rich iron oxide impregnated brick sands from filters both in flow and static tests at pH 4 and 7. 182 Fate of Arsenic in the Environment