1. Removal of herbicide atrazine by a novel biochar based iron composite coupling with peroxymonosulfate process from soil: Synergistic effect and mechanism.
- Author
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Diao, Zeng-Hui, Zhang, Wen-Xuan, Liang, Jing-Yi, Huang, Shi-Ting, Dong, Fu-Xin, Yan, Liu, Qian, Wei, and Chu, Wei
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ATRAZINE , *IRON composites , *HERBICIDES , *BIOCHAR , *REACTIVE oxygen species , *SOILS , *IRON alloys - Abstract
• A synergistic effect between BC/PMS and nZVI/PMS processes has been achieved. • ATZ removal of BC-nZVI/PMS was higher than that of BC-nZVI/H 2 O 2 or BC-nZVI/PS. • SO 4 − was the predominant radical species responsible for ATZ degradation. • ATZ was degraded through de-alkylation, dechlorination and hydroxylation processes. • A reaction mechanism of PMS activation by BC-nZVI for ATZ degradation was proposed. Over the past decade, herbicides contaminated soil poses a serious threat to humans and environment. In this study, a novel biochar supported zero valent iron (BC-nZVI) was used as a heterogeneous catalyst activating peroxymonosulfate (PMS) for the removal of herbicide atrazine (ATZ) from soil. The results revealed that the removal of ATZ by BC-nZVI/PMS process was superior to that of BC/PMS or nZVI/PMS process. A synergistic effect between BC/PMS and nZVI/PMS processes has been successfully achieved in BC-nZVI/PMS process, and nearly 96% of ATZ removal was obtained at optimum reaction conditions. BC-nZVI/PMS process exhibited an excellent performace on ATZ removal compared with BC-nZVI/H 2 O 2 or BC-nZVI/persulfate (PS) process. PMS decomposition by BC-nZVI/PMS process was higher than the sum of BC/PMS and nZVI/PMS processes. A low Cu concentration accelerated ATZ removal, and Cu was also effectively immobilized. SO 4 − was the predominant reactive oxygen species responsible for ATZ degradation, and OH and 1O 2 also took part in reaction. Four kinds of ATZ degradation products were identified, and ATZ degradation could be achieved through de-alkylation, dechlorination and hydroxylation processes. A reaction mechanism of PMS activation by BC-nZVI was proposed based on the synergistic effect of BC and nZVI. In addition to ATZ, coexisting pollutants such as 2,4-dichlorophenol (2,4-DCP), Cu and Cd were also simultaneously removed from soil. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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