In Situ Chemical Stabilization of Arsenic-Contaminated Soils Using Ferrous Sulfate

In this paper, a probe into the stabilization effects of ferrous sulfate (FeSO₄) came from two aspects-stabilization efficiency and leachate content. Fe/As molar ratio, arsenic pollution intensity, soil pH, reacted time interval, competitive ions, such as sulfate(SO₄^2-), phosphate(PO₄^3-) and zinc ion(Zn²⁺), were studied in order to discuss their effects on the stabilization of arsenic. Results show that ,to all different levels of arsenic contaminated soils ,when Fe/As molar ratio reaches 6, arsenic stabilization efficiency exceeds 90%,and arsenic concentration in leachate could also reduce to less than 5 mg/L; in the soil pH range from 8.10 to 8.57,ferrous sulfate has obtained the preferable results, and pH=8.23 is the optimum value; because of existing of competitive actions ,the exogenous adding of SO₄^2-, PO₄^3- and Zn²⁺ could lead to much poorer performance for FeSO₄.