Experimental study on injection of ferrous sulphate for remediation of a clayey soil contaminated with hexavalent chromium

In-situ remediation of the Cr(VI) contaminated clayey soil remains challenging due to low hydraulic conductivity and high ion adsorption capacity clays. In this study, injection tests ferrous sulphate (FeSO4) for a with hexavalent chromium (Cr(VI)) were performed explore feasibility FeSO4 solution under different pressures. The results show that pressure 30 kPa, 70 100 kPa caused conductivities specimens decrease by 36.5%, 38.7% 32.2%, respectively. This phenomenon could be attributed formation mixed iron(III)/chromium(III) hydroxide, process which scanning electron microscopy energy-dispersive X-ray microanalysis provided direct evidence. Moreover, mobility Fe(II) was stronger pressures (70 kPa) as indicated Fe profiles in after range iron increment at 3.2–11.9 g/kg. However, maximum only 5 g/kg migration limited, less than 2.5 cm. addition, most efficient experimental condition present work, efficiency 87.43–95.12%. As increased, leaching increased. Therefore, these can used reference in-situ injection.