Remediation of contaminated soil and groundwater using chemical reduction and solidification/stabilization method: a case study

• Published in: Environmental science and pollution research international 2021-03, Vol.28 (10), p.12766-12779
• Main Authors: Lu, Shi-Feng, Wu, Yu-Lin, Chen, Zhan, Li, Tao, Shen, Chao, Xuan, Lin-Kang, Xu, Ling
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Arsenic; Atmospheric Protection/Air Quality Control/Air Pollution; Calcium chloride; Chemical reduction; China; Chromium; Contaminants; Dosage; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Restoration and Remediation; Environmental science; Ferrous sulfate; Field tests; Groundwater; Heavy metals; Hexavalent chromium; Iron sulfates; Onsite; Organic contaminants; Organic soils; pH effects; Pollutant removal; Remediation; Research Article; Sodium; Sodium dithionite; Sodium metabisulfite; Soil; Soil chemistry; Soil contamination; Soil lime; Soil Pollutants - analysis; Soil pollution; Soil remediation; Soil stabilization; Soils; Solidification; Stabilization; Waste Water Technology; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-11337-3

This study presents a systematic on-site remediation case involving both heavy metal and organic contaminants in soil and groundwater in a historically industrial-used site in Shanghai, China. Lab-scale experiments and field tests were conducted to determine the optimum parameters for the removal of contaminants in soil and groundwater. It has been found that the remediation goal of hexavalent chromium in soil could be achieved with the mass content of added sodium hydrosulfite and ferrous sulfate reaching 3% + 6%. The total chromium in the groundwater was effectively removed, when the mass ratio of sodium metabisulfite was not less than 3 g/L, and the added quick lime made pH value not less than 9. The concentrations of arsenic and 1,2-dichloropropane in the groundwater decreased evidently after extraction and mixing of groundwater. The pH and calcium chloride dosage added should be larger than 9.5 and 5 g/L, respectively, to remove phosphate in groundwater. The removal efficiency of those contaminants was examined and evaluated after the on-site remediation. The results demonstrated that it was feasible to use the chemical reduction and solidification/stabilization methods for the on-site ex situ remediation of this site, which could be referenced for the realistic remediation of similar sites.