title: Influence of COD/sulfate ratios on the integrated reactor system for simultaneous removal of carbon, sulfur and nitrogen.
abstract: An integrated reactor system was developed for the simultaneous removal of carbon, sulfur and nitrogen from sulfate-laden wastewater and for elemental sulfur (S°) reclamation. The system mainly consisted of an expanded granular sludge bed (EGSB) for sulfate reduction and organic carbon removal (SR-CR), an EGSB for denitrifying sulfide removal (DSR), a biological aerated filter for nitrification and a sedimentation tank for sulfur reclamation. This work investigated the influence of chemical oxygen demand (COD)/sulfate ratios on the performance of the system. Influent sulfate and ammonium were fixed to the level of 600 mg SO(4)(2-) L⁻¹ and 120 mg NH(4)(+) L⁻¹, respectively. Lactate was introduced to generate COD/SO(4)(2-) = 0.5:1, 1:1, 1.5:1, 2:1, 3:1, 3.5:1 and 4:1. The experimental results indicated that sulfate could be efficiently reduced in the SR-CR unit when the COD/SO(4)(2-) ratio was between 1:1 and 3:1, and sulfate reduction was inhibited by the growth of methanogenic bacteria when the COD/SO(4)(2-) ratio was between 3.5:1 and 4:1. Meanwhile, the Org-C/S²⁻/NO(3)(-) ratios affected the S(0) reclamation efficiency in the DSR unit. When the influent COD/SO(4)(2-) ratio was between 1:1 and 3:1, appropriate Org-C/S²⁻/NO(3)(-) ratios could be achieved to obtain a maximum S° recovery in the DSR unit. For the microbial community of the SR-CR unit at different COD/SO(4)(2-) ratios, 16S rRNA gene-based high throughput Illumina MiSeq sequencing was used to analyze the diversity and potential function of the dominant species.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Chuan
authors.initials: C
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Youkang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Aijie
authors.initials: A
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Dezhi
authors.initials: D
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Cong
authors.initials: C
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Xijun
authors.initials: X
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Duu-Jung
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China E-mail: waj0578@hit.edu.cn.
authors.forename: Nanqi
authors.initials: N
authors.lastname: Ren
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000254:growth & development; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000302:isolation & purification; D004867:Equipment Design; D059013:Microbial Consortia / Q000235:genetics; D009584:Nitrogen / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S; D012722:Sewage / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D013455:Sulfur / Q000302:isolation & purification; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000737:chemistry
chemical_list: D002244:Carbon; D009584:Nitrogen; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D013431:Sulfates; D013440:Sulfides; D013455:Sulfur; D062065:Wastewater