Simultaneous remediation of arsenic and organic chemicals contaminated soil and groundwater using chemical oxidation and precipitation/stabilization: a case study.

ABSTRACT

After the departure of industrial facilities, reuse of the land in developed cities in China is problematic, due to the land contamination issues. The rapid remediation of sites with complex contamination is crucial and urgently needed. Herein, the case of on-site remediation of arsenic (As) in soil, as well as benzo(a)pyrene, total petroleum hydrocarbons, and As in groundwater was reported. For contaminated soil, the oxidant and deactivator (consisting of 20% sodium persulfate, 40% ferrous sulfate (FeSO4), and 40% portland cement) were applied to oxidize and immobilize As. As a result, the total amount and lixivium concentration of As were constrained under 20 mg/kg and 0.01 mg/L, respectively. Meanwhile, for contaminated groundwater, As and organic contaminants were treated by FeSO4/ozone and FeSO4/hydrogen peroxide with mass ratios of 15 and 18, respectively. The continuous monitoring of contaminants in 22 monitoring wells shown that all contaminants in groundwater were treated to meet the standards. In addition, the risk of secondary pollution and operation cost was effectively reduced by proper disposal and resourceful utilization. The findings indicated that the method of oxidation and precipitation/stabilization is technically, environmentally, and economically feasible for the remediation of contaminated sites with similar complex pollutants.