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 center dot 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 had no influence on TCE degradation. The generation of HO center dot and O-2(-)center dot in the SPC/Fe(II)/CA system was confirmed with chemical probes, and the radical scavenging tests showed that TCE degradation was due to direct oxidation by HO center dot. Acidic pH condition was favorable for TCE degradation. In summary, this study provided detailed information for the application of the CA-enhanced Fe(II)-activated SPC technique for TCE-contaminated groundwater remediation.