Rapid Degradation of Nitrochlorobenzene by Activated Persulfate Oxidation With Biochar Supported Nanoscaled Zero Valent Iron

Abstract

Although pesticide intermediates are a kind of typical toxic pollutant in contaminated sites, the remediation of these contaminants in groundwater and soils is of limited concern. In the present study we investigated the performance of a novel heterogeneous oxidation system, biochar supported nanoscaled-zero valent iron (nZVI/BC) activated persulfate (PS), in the oxidative degradation of nitrochlorobenzene (NCB), a typical pesticide intermediate. Peanut shell based nZVI/BC was prepared and used as the PS activator. The degradation kinetics of m-, p-, and o-NCB isomers in the aqueous phase were investigated. The effects of BC/nZVI composition (Fe/BC mass ratio), the amount of BC/nZVI and PS, and initial contaminant concentration on NCB removal were also examined. Results suggest that over 90% removals of three NCB isomers could be obtained by the nZVI/BC activated PS system at initial NCB concentration of 10 mg L−1. The combination of nZVI/BC composite and PS showed superior performance to PS alone. The optimal treatment condition was supposed as the Fe: BC ratio of 1:1, Fe amount of 6 mmol L−1, and the mole ratio of Fe to perfulfate of 1:1.

A review of recent studies on nano zero-valent iron activated persulfate advanced oxidation technology for the degradation of organic pollutants

“…The results demonstrate that when the molar ratio of PS/BC-nZVI is 3 : 1, the pH value is 3, and the reaction temperature is 40 1C, the removal efficiency of BDE209 in the soil using the BC-nZVI activated persulfate (PS) system can reach 82.06%. Xiang Wang et al 47 studied a novel heterogeneous oxidation system, namely, nZVI/BC activated persulfate (PS), for the oxidation and degradation of a typical insecticide intermediate, nitrochlorobenzene (NCB). The results demonstrated that the nZVI/ BC-activated PS system achieved a removal rate of over 90% for all three isomers of NCB when the initial NCB concentration was 10 mg L À1 .…”