1, 4-Dioxane removal in nitrifying sand filters treating domestic wastewater: Influence of water matrix and microbial inhibitors. (May 2023)

• Record Type: Journal Article
• Authors: Lee, Cheng-Shiuan; Wang, Mian; Clyde, Patricia M.; Mao, Xinwei; Brownawell, Bruce J.; Venkatesan, Arjun K.
• Is Part Of: Chemosphere. Volume 324(2023)
• Publication Date: 2023-05
• Subjects: 1, 4-Dioxane -- Biodegradation -- Onsite wastewater system -- Sand filter -- Nitrogen removing biofilter; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2023.138304
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: 1, 4-Dioxane is a recalcitrant pollutant in water and is ineffectively removed during conventional water and wastewater treatment processes. In this study, we demonstrate the application of nitrifying sand filters to remove 1, 4-dioxane from domestic wastewater without the need for bioaugmentation or biostimulation. The sand columns were able to remove 61 ± 10% of 1, 4-dioxane on average (initial concentration: 50 μg/L) from wastewater, outperforming conventional wastewater treatment approaches. Microbial analysis revealed the presence of 1, 4-dioxane degrading functional genes ( dxmB, phe, mmox, and prmA ) to support biodegradation being the dominant degradation pathway. Adding antibiotics (sulfamethoxazole and ciprofloxacin), that temporarily inhibited the nitrification process during the dosing period, showed a minor effect in 1, 4-dioxane removal (6–8% decline, p < 0.05), suggesting solid resilience of the 1, 4-dioxane-degrading microbial community in the columns. Columns amended with sodium azide significantly ( p < 0.05) depressed 1, 4-dioxane removal in the early stage of dosing but followed by a gradual increase of the removal over time to >80%, presumably due to a shift in the microbial community toward azide-resistant 1, 4-dioxane degrading microbes (e.g., fungi). This study demonstrated for the first time the resilience of the 1, 4-dioxane-degrading microorganisms during antibiotic shocks, and the selective enrichment of efficient 1, 4-dioxane-degrading microbes after azide poisoning. Our observation could provide insights into designing better 1, 4-dioxane remediation strategies in the future. Graphical abstract: Image 1 Highlights: Sand filters acclimated with wastewater efficiently degrade 1, 4-dioxane. 1, 4-Dioxane degraders were enriched in sand columns under nitrifying conditions. 1, 4-Dioxane degrading microbes show solid resilience to antibiotic shocks. Azide poisoning selectively enriches efficient 1, 4-dioxane-degraders in columns.