Leaching of As(III) and As(V) from exhausted calsico--a case study.

Batch leaching experiments were conducted to estimate the leaching of As(III) and As(V) from exhausted CalSiCo. The leaching of As(III) and As(V) was found to be function of time and concentrations of anions such as Cl-, NO3-, SO4(2-) in extraction fluid. Extraction tests were carried out to determine the maximum leachable concentration under the chosen conditions of leaching medium and leaching time. It has been observed that the leaching of As(III) is more than As(v) in all the cases. Leaching of As(III) and As(v) from exhausted CalSiCo is also carried out in rainwater and in tap water. It is observed that leaching of As is more in rainwater than tap water. Further higher leaching is observed in case of fluids containing chloride compared to those containing nitrate and sulphate.