摘要

In this study, biochar (BC) was prepared from bagasse and then successfully loaded with nanoscale zerovalent iron (nZVI) to produce BC-supported nZVI, termed nZVI@BC. Satisfactory results were obtained using a nZVI@BC-activated persulfate (PS), termed nZVI@BC/PS, to remediate total petroleum hydrocarbons (TPH)-contaminated water. The effects of three influencing factors-the dosage of nZVI@BC, D-nZVI@BC, the concentration of PS, C-PS, and the initial pH, pH(i)-on TPH removal were examined through single-factor and batch tests. The results show the following. Each factor considerably influenced the performance of the prepared nZVI@BC/PS reaction system in removing TPH. The TPH degradation process conformed to a first-order kinetic model. The response surface method (RSM) was used in tandem with a Box-Behnken design to optimise the variables involved in TPH degradation. The three influencing variables (i.e., D-nZVI@BC, C-PS, and pH(i)) were set in the range of 0.4-1.0 g/L, 20-160 g/L, and 2.21-9.42, respectively, during the experiment. An optimised quadratic model used to fit the experimental data displayed a high level of significance (p < 0.0001) with a very high regression value (R-2 = 0.9906; adjusted R-2 = 0.9786). Analyses of regression and variance revealed that the quadratic model sufficiently explains the TPH degradation rate. An electron paramagnetic resonance (EPR) spectroscopic analysis of the nZVI@BC/PS system revealed that SO4-center dot, center dot OH, O-2(-)center dot, and O-1(2) participated in the activation and degradation processes. The results of this study show that nZVI@BC-activated PS systems possess great potential for applications in TPH-contaminated wastewater treatment and environmentally sustainable development.

  • 单位
    桂林理工大学