Degradation of Sulfonamides by UV/Electrochemical Oxidation and the Effects of Treated Effluents on the Bacterial Community in Surface Water

Xinwei Jiang; Julin Yuan; Zhijie Zheng; Yufang Tao; Xiaogang Wu

doi:10.1021/acsomega.3c02637

Degradation of Sulfonamides by UV/Electrochemical Oxidation and the Effects of Treated Effluents on the Bacterial Community in Surface Water

ACS Omega. 2023 Jul 21;8(31):28409-28418. doi: 10.1021/acsomega.3c02637. eCollection 2023 Aug 8.

Authors

Xinwei Jiang¹, Julin Yuan², Zhijie Zheng¹, Yufang Tao³, Xiaogang Wu¹

Affiliations

¹ School of Urban Construction, Yangtze University, Jingzhou 434023, China.
² Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture and Rural Affairs; Key Laboratory of Fish Health and Nutrition of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou 313001, China.
³ College of Chemistry & Environmental Engineering, Yangtze University, Jingzhou 434023, China.

Abstract

This study evaluated the effects of ultraviolet (UV) photolysis combined with electrochemical oxidation on sulfonamides (SAs) as well as its treated effluent on the bacterial community in surface water. In terms of degradation rate, the best anode material for electrochemical oxidation was Ti/RuO₂-IrO₂, which had the highest degradation kinetic constant compared to Ti/Ta₂O₅-IrO₂ and Ti/Pt. Experiments showed the highest degradation rate of SAs at 8.3 pH. Similarly, increasing the current leads to stronger degradation due to the promotion of free chlorine production, and its energy consumption rate decreases slightly from 73 to 67 W h/mmol. Compared with tap water, the kinetic constants decreased by 20-62% for SAs in three different surface water samples, which was related to the decrease in free chlorine. When extending the reaction time to 24 h, the concentrations of chemical oxygen demand and total organic carbon decreased by approximately 30-40%, indicating that the SAs and their products could be mineralized. The diversity analysis showed that the effluents influenced the richness and diversity of the bacterial community, particularly in the 4 h sample. Additionally, there were 86 operational taxonomic units common to all samples, excluding the 4 h sample; significant differences were derived from changes in the Actinobacteriota and Bacteroidota phyla. The toxicity of the products might explain these changes, and these products could be mineralized, as observed in the 24 h sample. Therefore, the extension of treatment time would greatly reduce the ecological harm of treated effluent and ensure that the UV/electrochemical process is a feasible treatment option. Overall, this study provides valuable insight into the optimization and feasibility of UV/electrochemical processes as a sustainable treatment option for sulfonamide-contaminated water sources, emphasizing the importance of considering ecological impacts and the need for extended treatment times that address environmental concerns and ensuring improved water quality.