title: [Feasibility study on coke wastewater treatment using membrane bioreactor (MBR) system with complete sludge retention].
abstract: A laboratory-scale submerged anaerobic-anoxic-oxic membrane bioreactor (A1/A2/O-MBR) system was used to treat real coke wastewater and operated continuously for 160 d with complete sludge retention. Pollutants removal performance of the system was investigated through long-term operation. The characteristics of dissolved organic matters (DOMs) in influent and effluent coke wastewater were analyzed using hydrophilic/hydrophobic fractionation, and further discussed based on fluorescence excitation-emission-matrix (EEM). The results showed that A1/A2/O-MBR system could stably remove 88.0% +/- 1.6% of COD, > 99.9% of volatile phenol, 99.4% +/- 0.2% of turbidity, and 98.3% +/- 1.9% of NH4(+) -N, with individual average effluent concentrations of 249 mg/L +/- 44 mg/L, 0.18 mg/L +/- 0.05 mg/L, 1.0 NTU +/- 0.2 NTU and 4.1 mg/L +/- 4.3 mg/L, respectively; moreover, the maximum TN removal rate also reached 74.9%. During the whole operation period, the MLVSS/MLSS appeared to be constant as 90.2% +/- 1.0% and no inorganic matters accumulation occurred. The observed sludge production (MLVSS/COD) decreased with time and stabilized at 0.035 kg/kg. DOMs in coke wastewater were fractionated as hydrophobic acids (HOA), hydrophobic neutrals (HON), hydrophobic bases (HOB) and hydrophilic substances (HIS); HOA was found to be the most abundant constituent in terms of DOC and color intensity both in influent and effluent, which accounted for 70% and 67% of total DOC, and 75% and 76% of total color intensity, respectively. Humic-like substances were suggested to be the major refractory organic and color-causing compounds coke wastewater effluent according to EEM analysis.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. zwt02@mails.tsinghua.edu.cn
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Zhao
authors.forename: Xia
authors.initials: X
authors.lastname: Huang
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D019149:Bioreactors; D003077:Coke; D005240:Feasibility Studies; D006812:Humic Substances / Q000032:analysis*; D007220:Industrial Waste; D008567:Membranes, Artificial; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D003077:Coke; D006812:Humic Substances; D007220:Industrial Waste; D008567:Membranes, Artificial; D012722:Sewage