title: Microbial nitrate removal by waste iron shavings from the biological and catalytic ozonation treated dyeing and finishing wastewater.
abstract: The concentration of total nitrogen (TN) (between 40 and 60 mg/L, mainly nitrate) in the biological and catalytic ozonation treated dyeing and finishing wastewater needs to be reduced before discharge. The present study investigated the feasibility of using waste iron shavings as electron donor for nitrogen removal by biological denitrification. Two anoxic sequencing batch reactors (AnSBR) were continuously operated for more than 100 days. The results showed that the TN removal efficiency increased from 12% in the control reactor (AnSBR-C) to 20% in the reactor with waste iron shavings (AnSBR-Fe). The TN removal was mainly achieved by the reduction of nitrate by heterotrophic denitrification and autotrophic denitrification for AnSBR-Fe. The residual COD (38.4 mg/L) in the effluent of AnSBR-Fe was higher than that (22 mg/L) in the effluent of AnSBR-C, which could be due to that the bacteria preferred to use iron instead of the recalcitrant organics that present in the wastewater. Furthermore, 3DEEM, UHPLC-QTOF and GC-MS analysis were used to characterize the organics in the wastewater, and the results showed that the addition of waste iron shavings affected the degradation of organics during the biological denitrification process.
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
authors.forename: Jieting
authors.initials: J
authors.lastname: Ma
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
authors.forename: Yunlu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China. gangl@fudan.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Luo
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Nie
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China. guozgg@fudan.edu.cn.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Luming
authors.initials: L
authors.lastname: Ma
keywords: Biological and catalytic ozonation treated dyeing and finishing wastewater; Effluent organic matter; Nitrate removal; Waste iron shavings