Treatment of Source Separated Greywater Using Microbial Electrolysis Cell and Granular Activated Carbon Biofilter

• Author / Creator

  Dhadwal, Mayank

• Source-diverted greywater contributes to 60-70 % of conventional wastewater in volume and has a low organic matter concentration as compared to conventional wastewater. Greywater constitutes a high concentration of surfactants that are toxic in nature for the microbial community, which poses a major obstacle to treat source-separated greywater biologically. This study focuses on the development of an integrated process of anaerobic Microbial Electrolysis Cell (MEC) followed by a passively aerated biofilter system as a polishing step for treating source-separated greywater.
  A bench-scale dual-chamber MEC reactor was used to treat greywater. The semi-continuous operation was performed at ambient temperatures over different Hydraulic Retention Time (HRT) of 4 days, 3 days, 2 days and 1 day. An average Chemical Oxygen Demand (COD) removal efficiency of 58.4 %, anionic surfactant removal of 59.7 %, and peak volumetric current density of 0.66 A/m3 were achieved at an HRT of 4 days. With an HRT of 1 day, the MEC reactor removed 31.7 % COD and 39.7 % anionic surfactants, with a maximum peak current density of 0.65 A/m3.
  MEC reactor produced comparable current density at HRT 1 day to that of HRT 4 days. Hence, MEC effluent from 1-day HRT was treated in a Granular Activated Carbon (GAC) biofilter as a polishing step. The biofilter was operated at HRTs of 30 minutes and 60 minutes. The integrated process provided 99.3% COD removal, and up to 98.7% surfactants removal. Also, the final effluent had no odour or color. The treatability of raw greywater was also assessed with biofilter and the performance was compared to the integrated MEC-GAC biofilter combined system. During the 120 days reactor operation, no process instability/disturbance was observed, and stable performance was achieved throughout. The results are promising in the direction of developing more sustainable treatment of source-separated greywater.

• Subjects / Keywords

  • Source-separation
  • greywater
  • microbial electrolysis cell
  • bio-filter
  • granular activated carbon

• Graduation date

  Spring 2021

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-mndk-3y93

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.