Enhancing inhibition of disinfection byproducts formation and opportunistic pathogens growth during drinking water distribution by Fe2O3/Coconut shell activated carbon. (1st January 2021)

• Record Type: Journal Article
• Authors: Xing, Xueci; Li, Tong; Bi, Zhihao; Qi, Peng; Li, Zesong; Wang, Haibo; Lyu, Lai; Gao, Yaowen; Hu, Chun
• Is Part Of: Environmental pollution. Volume 268(2021)Part B
• Publication Date: 2021-01-01
• Subjects: Biological activated carbon -- Interface modification -- Water quality stability -- Biofilms -- Shaping microbial community -- Drinking water distribution systems; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115838
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The effects of biological activated carbon treatment using Fe2 O3 modified coconut shell-based activated carbon (Fe/CAC) were investigated on the occurrence of opportunistic pathogens (OPs) and formation of disinfection by-products (DBPs) in simulated drinking water distribution systems (DWDSs) with unmodified CAC as a reference. In the effluent of annular reactor (AR) with Fe/CAC, the OPs growth and DBPs formation were inhibited greatly. Based on the differential pulse voltammetry and dehydrogenase activity tests, it was verified that extracellular electron transfer was enhanced in the attached biofilms of Fe/CAC, hence improving the microbial metabolic activity and biological removal of organic matter especially DBPs precursors. Meanwhile, the extracellular polymeric substances (EPS) on the surface of Fe/CAC exhibited stronger viscosity, higher flocculating efficiency and better mechanical stability, avoiding bacteria or small-scale biofilms falling off into the water. Consequently, the microbial biomass and EPS substances amount decreased markedly in the effluent of Fe/CAC filter. More importantly, Fe/CAC did significantly enhance the shaping role on microbial community of downstream DWDSs, continuously excluding OPs advantage and inhibiting EPS production. The weakening of EPS in DWDSs resulted in decrease of microbial chlorine-resistance ability and EPS-derived DBPs precursors supply. Therefore, the deterioration of water quality in DWDSs was inhibited greatly, sustainably maintaining the safety of tap water. Our findings indicated that optimizing biological activated carbon treatment by interface modification is a promising method for improving water quality in DWDSs. Graphical abstract: Image 1 Highlights: The performance of Fe2 O3 /coconut-shell activated carbon (Fe/CAC) was studied. Fe/CAC enhanced extracellular electron transfer and biodegradation effect. Less microbes and smaller microbial clusters occurred in the effluent of Fe/CAC. Fe/CAC enhanced the shaping role on the microbial community of DWDSs. Fe/CAC further enhanced the water quality in drinking water distribution systems. Abstract : Fe/CAC did control the microbial biomass, EPS characteristics and microbial community in the water simultaneously, maintaining the safety of tap water.