Lia Wang,Xu He,Lan Liang,Yanshan Wang,Beibei Yan,Guanyi Chen,Ning Li,Li’an Hou
The conventional Fenton process generates large amounts of Fenton sludge during wastewater treatment. Achieving effective utilization of Fenton sludge and reducing its production remain pivotal challenges. In this study, Fenton sludge biochar catalysts (Cat) were prepared using Fenton sludge via pyrolysis. In addition, chemical oxygen demand (COD) from secondary effluent was removed by Fenton sludge biochar catalysts activated with H2O2/Fe(VI). Specifically, the removal efficiency of COD could reach 46.2% in the Cat−2/H2O2/Fe(VI) system under weakly alkaline conditions. The mechanistic analysis confirmed that high-valent iron,•OH, O2•−, and1O2all participate in the degradation process. Furthermore, a continuous-flow reactor was applied to treat secondary effluent, with COD decreasing from 65 mg/L to 36 mg/L. This study provides new insights into the resource utilization of Fenton sludge and the treatment of complex wastewater.
A novel composite biochar synthesized from Fenton sludge (FS) and sewage sludge (SS) was employed to catalyze persulfate for the removal of 1-H-1,2,4-triazole (TZ). The optimized conditions for the synthesis and operating process were identified through response surface methodology as follow: SS/FS mass ratio = 5:1, catalyst dosage = 0.9 g L −1 and PDS concentration = 0.5 g L −1 . The removal efficiencies of TZ, TOC and organic nitrogen were found to be as high as 97.6%, 80.33% and 100%, respectively, with the addition of Fe 3 O 4 -doped biochar in persulfate catalytic system. Besides, Fe 3 O 4 -doped biochar exhibited superior stability and tolerance to wide range of pH (2–12), temperature (15–45 °C) and co-existing substrate. The reactive oxygen species, which resulted in the catalytic degradation of TZ followed the order of SO 4 ∙− > ∙OH > O 2 ∙− > 1 O 2 , were identified by electron spin resonance and quenching tests. It demonstrated that the radical pathway accomplished with non-radical pathway contributed to the enhanced degradation of TZ, which was further identified by electrochemical experiments. Moreover, the possible degradation pathway of TZ was ascertained and proposed through DFT calculation and LC-MS analysis. These findings illustrated that the novel magnetic biochar would be a promising persulfate catalyst for the treatment of refractory organic matters. In addition, it also provided a new alternative method for the resource utilization of FS and SS.
危险品化学品经营许可证（带存储）