title: Effect of hydraulic retention time and sludge recirculation on greenhouse gas emission and related microbial communities in two-stage membrane bioreactor treating solid waste leachate.
abstract: Methane (CH4) and nitrous oxide (N2O) emissions and responsible microorganisms during the treatment of municipal solid waste leachate in two-stage membrane bioreactor (MBR) was investigated. The MBR system, consisting of anaerobic and aerobic stages, were operated at hydraulic retention time (HRT) of 5 and 2.5days in each reactor under the presence and absence of sludge recirculation. Organic and nitrogen removals were more than 80% under all operating conditions during which CH4 emission were found highest under no sludge recirculation condition at HRT of 5days. An increase in hydraulic loading resulted in a reduction in CH4 emission from anaerobic reactor but an increase from the aerobic reactor. N2O emission rates were found relatively constant from anaerobic and aerobic reactors under different operating conditions. Diversity of CH4 and N2O producing microorganisms were found decreasing when hydraulic loading rate to the reactors was increased.
authors: Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand.
authors: Nararatchporn
authors: N
authors: Nuansawan
authors: Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand.
authors: Jarungwit
authors: J
authors: Boonnorat
authors: Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand.
authors: Wilai
authors: W
authors: Chiemchaisri
authors: Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand. Electronic address: fengccc@ku.ac.th.
authors: Chart
authors: C
authors: Chiemchaisri
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D058645:Denaturing Gradient Gel Electrophoresis; D005740:Gases / Q000032:analysis*; D017752:Greenhouse Effect; D008697:Methane / Q000032:analysis; D009584:Nitrogen; D009609:Nitrous Oxide / Q000032:analysis; D012722:Sewage / Q000382:microbiology*; D062611:Solid Waste; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D005740:Gases; D012722:Sewage; D062611:Solid Waste; D014874:Water Pollutants, Chemical; D009609:Nitrous Oxide; D009584:Nitrogen; D008697:Methane
keywords: Greenhouse gas; Hydraulic loading; Leachate; Membrane bioreactor; Microbial diversity