Greenhouse gas emissions from membrane bioreactors: analysis of a two-year survey on different MBR configurations

Giorgio Mannina, Kartik Chandran, Marco Capodici, Alida Cosenza, Daniele Di Trapani, Mark C. M. van Loosdrecht

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)
15 Downloads (Pure)

Abstract

This study aimed at evaluating the nitrous oxide (N2O) emissions from membrane bioreactors (MBRs) for wastewater treatment. The study investigated the N2O emissions considering multiple influential factors over a two-year period: (i) different MBR based process configurations; (ii) wastewater composition (municipal or industrial); (iii) operational conditions (i.e. sludge retention time, carbon-to-nitrogen ratio, C/N, hydraulic retention time); (iv) membrane modules. Among the overall analysed configurations, the highest N2O emission occurred from the aerated reactors. The treatment of industrial wastewater, contaminated with salt and hydrocarbons, provided the highest N2O emission factor (EF): 16% of the influent nitrogen for the denitrification/nitrification-MBR plant. The lowest N2O emission (EF = 0.5% of the influent nitrogen) was obtained in the biological phosphorus removal-moving bed-MBR plant likely due to an improvement in biological performances exerted by the co-presence of both suspended and attached biomass. The influent C/N ratio has been identified as a key factor affecting the N2O production. Indeed, a decrease of the C/N ratio (from 10 to 2) promoted the increase of N2O emissions in both gaseous and dissolved phases, mainly related to a decreased efficiency of the denitrification processes.
Original languageEnglish
Pages (from-to)896-903
JournalWater Science and Technology
Volume78
Issue number4
DOIs
Publication statusPublished - 2018

Keywords

  • global warming
  • MBR
  • nitrous oxide emission
  • wastewater treatment

Cite this