title: Treatment of coal gasification wastewater by a two-continuous UASB system with step-feed for COD and phenols removal.
abstract: A two-continuous mesophilic (37 ± 2°C) UASB system with step-feed was investigated as an attractive optimization strategy for enhancing COD and total phenols removal of the system and improving aerobic biodegradability of real coal gasification wastewater. Through the step-feed period, the maximum removal efficiencies of COD and total phenols reached 55-60% and 58-63% respectively in the system, at an influent flow distribution ratio of 0.2 and influent COD concentration of 2500 mg/L; the corresponding efficiencies were at low levels of 45-50% and 43-50% respectively at total HRT of 48 h during the single-feed period. The maximum specific methanogenic activity and substrate utilization rate were 592 ± 16 mg COD-CH(4)/(g VSS d) and 89 ± 12 mg phenol/(g VSS d) during the step-feed operation. After the anaerobic digestion with step-feed, the aerobic effluent COD concentration decreased from 270 ± 9 to 215 ± 10 mg/L. The results suggested that step-feed enhanced the degradation of refractory organics in the second reactor.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Hongjun
authors.initials: H
authors.lastname: Han
authors.forename: Min
authors.initials: M
authors.lastname: Yuan
authors.forename: Huiqiang
authors.initials: H
authors.lastname: Li
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D003031:Coal / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D005740:Gases / Q000032:analysis; D007220:Industrial Waste / Q000032:analysis; D008697:Methane / Q000032:analysis; D010636:Phenols / Q000302:isolation & purification*; D012212:Rheology; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods*
chemical_list: D003031:Coal; D005740:Gases; D007220:Industrial Waste; D010636:Phenols; D008697:Methane