title: Treatment of real coal gasification wastewater using a novel integrated system of anoxic hybrid two stage aerobic processes: performance and the role of pure oxygen microbubble.
abstract: A novel integrated system of anoxic-pure oxygen microbubble-activated sludge reactor-moving bed biofilm reactor was employed in treatment of real coal gasification wastewater. The results showed the integrated system had efficient performance of pollutants removal in short hydraulic retention time. While pure oxygen microbubble with the flow rate of 1.5 L/h and NaHCO3 dosage ratio of 2:1 (amount NaHCO3 to NH4 (+)-N ratio, mol: mol) were used, the removal efficiencies of COD, total phenols (TPh) and NH4 (+)-N reached 90, 95, and 95 %, respectively, with the influent loading rates of 3.4 kg COD/(m(3) d), 0.81 kg TPh/(m(3) d), and 0.28 kg NH4 (+)-N/(m(3) d). With the recycle ratio of 300 %, the concentrations of NO2 (-)-N and NO3 (-)-N in effluent decreased to 12 and 59 mg/L, respectively. Meanwhile, pure oxygen microbubble significantly improved the enzymatic activities and affected the effluent organic compositions and reduced the foam expansion. Thus, the novel integrated system with efficient, stable, and economical advantages was suitable for engineering application.
authors.affiliation: School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, 310023, China. zhuanggao1984@163.com.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Han
authors.affiliation: School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, 310023, China.
authors.forename: Shengdao
authors.initials: S
authors.lastname: Shan
mesh_terms: D000693:Anaerobiosis; D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002244:Carbon; D003031:Coal; D004798:Enzymes / Q000032:analysis; D045423:Microbubbles; D009584:Nitrogen; D010100:Oxygen; D010636:Phenols / Q000302:isolation & purification*; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D002244:Carbon; D003031:Coal; D004798:Enzymes; D009584:Nitrogen; D010100:Oxygen; D010636:Phenols; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Coal gasification wastewater; Enzyme activities; Foam; Inorganic carbon; Pure oxygen microbubble