Comparing biochar- and bentonite-supported Fe-based catalysts for selective degradation of antibiotics: Mechanisms and pathway

Zhe Li; Yuqing Sun; Yang Yang; Yitong Han; Tongshuai Wang; Jiawei Chen; Daniel C W Tsang

doi:10.1016/j.envres.2020.109156

Comparing biochar- and bentonite-supported Fe-based catalysts for selective degradation of antibiotics: Mechanisms and pathway

Environ Res. 2020 Apr:183:109156. doi: 10.1016/j.envres.2020.109156. Epub 2020 Jan 22.

Authors

Zhe Li¹, Yuqing Sun², Yang Yang³, Yitong Han³, Tongshuai Wang³, Jiawei Chen⁴, Daniel C W Tsang⁵

Affiliations

¹ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom Kowloon, Hong Kong, China.
² Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom Kowloon, Hong Kong, China.
³ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
⁴ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China. Electronic address: chenjiawei@cugb.edu.cn.
⁵ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom Kowloon, Hong Kong, China. Electronic address: dan.tsang@polyu.edu.hk.

PMID: 32000003
DOI: 10.1016/j.envres.2020.109156

Abstract

The selective degradation of recalcitrant antibiotics into byproducts with low toxicity and high biodegradability has been increasingly popular using peroxymonosulfate (PMS) based advanced oxidation processes (AOPs). In this paper, two Fe-based heterogeneous catalysts, bentonite supported Fe-Ni composite (BNF) and biochar-supported Fe composite (Fe/C), were tailored and comprehensively characterized for distinctive physicochemical properties, crystalline structures, and interfacial behaviors. Two widely used antibiotics, sulfapyridine (SPY) and oxytetracycline (OTCs) at their common concentrations in pharmaceutical wastewaters (250 and 10 mg L^-1) were tested for degradation in three PMS-based oxidation processes, i.e., PMS, PMS-BNF, and PMS-Fe/C, respectively. Results demonstrated that a large amount of PMS (10 and 1 mM) could effectively remove SPY (0.385 min^-1, 100% removal) and OTC (2.737 min^-1, 100% removal) via¹O₂ derived from PMS self-decomposition and non-radical pathway, respectively. Additional Fe-based catalysts (0.5 g L^-1 Fe/C and BNF) significantly reduced the PMS consumption (1 and 0.25 mM) and accelerated the reaction rate (1.08 and 5.05 min^-1) of SPY and OTC removal. Moreover, the supplementary catalysts shifted the degradation route. The biochar matrix in Fe/C composite contributed to predominant interaction with PMS forming ¹O₂, which preferably attacked SPY via hydroxylation. In contrast, the redox-active Fe-Ni pairs induced SO₄^- formation, which could selectively degrade OTC through decarboxylation. Thus, these results are conducive to tailoring advanced yet low-cost heterogeneous catalysts for eco-friendly treatment of antibiotics-rich industrial wastewaters.

Keywords: Antibiotics degradation; Clay mineral; Engineered biochar; Fe-carbon composites; Peroxymonosulfate oxidation; Sustainable wastewater treatment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents*
Bentonite*
Charcoal*
Wastewater
Water Purification

Substances

Anti-Bacterial Agents
Waste Water
biochar
Bentonite
Charcoal