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

Bioresour Technol. 2016 Jun:210:35-42. doi: 10.1016/j.biortech.2016.01.109. Epub 2016 Feb 3.

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.

Keywords: Greenhouse gas; Hydraulic loading; Leachate; Membrane bioreactor; Microbial diversity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Anaerobiosis
  • Bacteria / metabolism*
  • Biodegradation, Environmental
  • Bioreactors / microbiology*
  • Denaturing Gradient Gel Electrophoresis
  • Gases / analysis*
  • Greenhouse Effect*
  • Methane / analysis
  • Nitrogen
  • Nitrous Oxide / analysis
  • Sewage / microbiology*
  • Solid Waste
  • Time Factors
  • Water Pollutants, Chemical / isolation & purification*
  • Water Purification / instrumentation
  • Water Purification / methods*

Substances

  • Gases
  • Sewage
  • Solid Waste
  • Water Pollutants, Chemical
  • Nitrous Oxide
  • Nitrogen
  • Methane