Enhanced transformation and dechlorination of p-chloronitrobenzene in the combined ZVI–anaerobic sludge system

Zhu, Liang; Lin, Haizhuan; Qi, Jiaoqin; Xu, Xiangyang

Enhanced transformation and dechlorination of p-chloronitrobenzene in the combined ZVI–anaerobic sludge system

2013

Zhu, Liang | Lin, Haizhuan | Qi, Jiaoqin | Xu, Xiangyang

The combination of zero-valent iron (ZVI) with anaerobic sludge for enhancing reductive transformation and dechlorination of p-chloronitrobenzene (p-ClNB) was investigated in this study. p-ClNB was quickly reduced into p-chloroaniline (p-ClAn) and subsequently dechlorinated into aniline in the complex system, and the strengthening factor for pseudo-first-order transformation rate constant of p-ClNB (Q, k ZVI ₊ ₛₗᵤdgₑ/(k ₛₗᵤdgₑ + k ZVI)) was above 3. The Q values for the different ZVI types with anaerobic sludge were as following: Reduced ZVI (RZVI) > Industrial ZVI > Nanoscale ZVI (NZVI). Thereinto, the aggregation of NZVI occurred, and its reaction activity declined. Furthermore, the increase of ZVI dosage promoted the p-ClNB transformation, but the p-ClAn dechlorination rate and Q value were not improved. With the anaerobic biomass increasing, the dechlorination rate of p-ClAn was significantly enhanced, and the Q value had positive relation with the mass ratio of anaerobic sludge to RZVI.

Показать больше [+]