Preparation of Calcium Polysulfide to Remediate Groundwater Contaminated by Hexavalent Chromium

Polysulfide has been verified to exhibit a strong ability in reducing hexavalent chromium (Cr(VI)). This study prepared CPS by using calcium oxide and sulfur powder to investigate the removal efficiency of Cr(VI) by the self-prepared CPS and the effects of pH and dissolved oxygen of groundwater on the reduction of Cr(VI) by CPS. The results show that the CPS produced by mixing calcium oxide, sulfur powder, and distilled water at a ratio of 1:2:10 and heating the mixture for 60 min can effectively reduce the Cr(VI) in groundwater. This method can be provided to produce the agents required for contamination remediation, which can reduce the monetary cost on purchasing the agents and the amount of carbon emission resulting from long-distance transportation, achieving the goal of green remediation. CPS prepared in this study, the removal rate of Cr(VI) can reach more than 90% when application rate was 200 at sample/CPS volume ratio.