Enhanced degradation of trichloroethene by sodium percarbonate activated with Fe(II) in the presence of citric acid

Trichloroethene (TCE) degradation by Fe(II)-activated sodium percarbonate (SPC) in the presence of citric acid (CA) in aqueous solution was investigated. The results indicated that the presence of CA enhanced TCE degradation significantly by promoting HO• generation. The presence of Cl−, HCO3− and the initial solution pH appeared to be not negligible on the effect of TCE oxidation, while humic acid has no influence on TCE degradation. The generation of HO• and O2−• in the SPC/Fe(II)/CA system were confirmed with chemical probes, and the radical scavenging tests showed that TCE degradation was due to the direct oxidation by HO•. Acidic pH condition was favorable for TCE degradation. In summary, this study provided detailed information for the application of CA-enhanced Fe(II)-activated SPC technique for TCE contaminated groundwater remediation.