Biogas production by co-digestion of municipal wastewater and food waste: Performance in semi-continuous and continuous operation

Water Environ Res. 2021 Feb;93(2):306-315. doi: 10.1002/wer.1413. Epub 2020 Aug 17.

Abstract

Municipal wastewater has recently attracted interest in relation to anaerobic wastewater treatments. Biogas production with co-digestion of mixed substrates has been proposed and has many potential benefits for municipal wastewater. The aim of this research was to assess the performance of biogas production during co-digestion of municipal wastewater and food waste under semi-continuous and continuous operation with various hydraulic retention times (HRTs). A laboratory-scale continuous stirred tank reactor (CSTR) at room temperature operation (27-32°C) was employed in this research. The highest methane yields of 167.41 ± 66.52, 194.35 ± 85.44, and 214.81 ± 85.44 ml/g-Vs were found in semi-continuous mode, respectively, at 30, 10, and 10 days of HRTs with a 10:90 ratio of municipal wastewater to food waste (based on TS). Result finding of optimum condition (10 days of HRTs) presented a methane yield of 485.58 ± 82.35 ml/g with continuous operation. Hence, food waste has practical implications for use as a co-substrate with the optimization condition of HRT and operation mode for biogas production from municipal wastewater. PRACTITIONER POINTS: Food waste has good potential for use as a co-substrate for biogas production from municipal wastewater. HRT reduction from 30 to 10 days in semi-continuous, biogas production from municipal wastewater and food waste increased by 59%. Co-digestion of municipal wastewater and food waste with continuous mode and 10 days of HRT was the effective biogas production.

Keywords: biogas production; co-digestion; food waste; municipal wastewater.

MeSH terms

  • Anaerobiosis
  • Biofuels / analysis
  • Bioreactors
  • Digestion
  • Food
  • Methane
  • Refuse Disposal*
  • Sewage
  • Waste Water*

Substances

  • Biofuels
  • Sewage
  • Waste Water
  • Methane