title: The key role of biogenic manganese oxides in enhanced removal of highly recalcitrant 1,2,4-triazole from bio-treated chemical industrial wastewater.
abstract: The secondary effluent from biological treatment process in chemical industrial plant often contains refractory organic matter, which deserves to be further treated in order to meet the increasingly stringent environmental regulations. In this study, the key role of biogenic manganese oxides (BioMnOx) in enhanced removal of highly recalcitrant 1,2,4-triazole from bio-treated chemical industrial wastewater was investigated. BioMnOx production by acclimated manganese-oxidizing bacterium (MOB) consortium was confirmed through scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. Pseudomonas and Bacillus were found to be the most predominant species in acclimated MOB consortium. Mn2+could be oxidized optimally at neutral pH and initial Mn2+concentration below 33 mg L-1. However, 1,2,4-triazole removal by BioMnOx produced occurred optimally at slightly acidic pH. High dosage of both Mn2+and 1,2,4-triazole resulted in decreased 1,2,4-triazole removal. In a biological aerated filter (BAF) coupled with manganese oxidation, 1,2,4-triazole and total organic carbon removal could be significantly enhanced compared to the control system without the participation of manganese oxidation, confirming the key role of BioMnOx in the removal of highly recalcitrant 1,2,4-triazole. This study demonstrated that the biosystem coupled with manganese oxidation had a potential for the removal of various recalcitrant contaminants from bio-treated chemical industrial wastewater.
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Ruiqin
authors.initials: R
authors.lastname: Wu
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Haobo
authors.initials: H
authors.lastname: Wu
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Xinbai
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China. shenjinyou@mail.njust.edu.cn.
authors.forename: Jinyou
authors.initials: J
authors.lastname: Shen
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Faheem
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Sun
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Weiqing
authors.initials: W
authors.lastname: Han
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China.
authors.forename: Lianjun
authors.initials: L
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu Province, 210094, China. liuxd@mail.njust.edu.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liu
mesh_terms: D008345:Manganese / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D014230:Triazoles / Q000737:chemistry*; D062065:Wastewater
chemical_list: D008345:Manganese; D017895:Manganese Compounds; D010087:Oxides; D014230:Triazoles; D062065:Wastewater; C045575:1,2,4-triazole; C027424:manganese oxide
keywords: 1,2,4-Triazole; Biodegradation; Biogenic manganese oxide; Biological aerated filter; Manganese-oxidizing bacterium; Secondary effluent