title: Enhanced azo dye removal in a continuously operated up-flow anaerobic filter packed with henna plant biomass.
abstract: Effects of henna plant biomass (stem) packed in an up-flow anaerobic bio-filter (UAF) on an azo dye (AO7) removal were investigated. AO7 removal, sulfanilic acid (SA) formation, and pseudo first-order kinetic constants for these reactions (kAO7 and kSA) were higher in the henna-added UAF (R2) than in the control UAF without henna (R1). The maximum kAO7 in R1 and R2 were 0.0345 and 0.2024 cm(-1), respectively, on day 18; the corresponding molar ratios of SA formation to AO7 removal were 0.582 and 0.990. Adsorption and endogenous bio-reduction were the main AO7 removal pathways in R1, while in R2 bio-reduction was the dominant. Organics in henna could be released and fermented to volatile fatty acids, acting as effective electron donors for AO7 reduction, which was accelerated by soluble and/or fixed lawsone. Afterwards, the removal process weakened over time, indicating the demand of electron donation and lawsone-releasing during the long-term operation of UAF.
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China. Electronic address: hjg@hdu.edu.cn.
authors.forename: Jingang
authors.initials: J
authors.lastname: Huang
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China.
authors.forename: Mengke
authors.initials: M
authors.lastname: Wu
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China.
authors.forename: Xiuyan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China.
authors.forename: Junhong
authors.initials: J
authors.lastname: Tang
authors.affiliation: Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, PR China.
authors.forename: Zhengmiao
authors.initials: Z
authors.lastname: Xie
mesh_terms: D000693:Anaerobiosis; D001391:Azo Compounds / Q000302:isolation & purification*; D018533:Biomass; D004396:Coloring Agents / Q000302:isolation & purification*; D005374:Filtration / Q000295:instrumentation*; D031564:Lawsonia Plant / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents
keywords: Electron donor; Henna plant biomass; Lawsone; Redox mediator; Up-flow anaerobic bio-filter (UAF)