Reactive dechlorination of PCE using zero valent iron plus surfactants

Abstract

Zero valent iron (ZVI) is particularly useful as a reductant of chlorinated hydrocarbons because of its low cost and lack of toxicity. Surfactants also have been used widely for decontamination of subsurface soil and groundwater. The objective of this study is to examine the effect of various surfactants on enhancing the dechlorination of perchloroethene (PCE) by ZVI. Three surfactants-anionic, nonionic, and cationic-were chosen: sodium dodecylbenzene sulfonate (SDDBS), Triton X-100, and cetylpyridinum chloride (CPC). The rate of dechlorination of PCE using ZVI with CPC and Triton X-100 was much higher than withoutout surfactant. The combination of nonionic and cationic surfactants with ZVI increased the degradation of PCE, because PCE that bound with the surfactant in aqueous phase was readily available for dechlorination. Using SDDBS resulted in no observed dechlorination of PCE with ZVI, because no trichloroethene (TCE) was detected. However, PCE was immobilized on the sorbed SDDBS phase.