Low energy single-staged anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for wastewater treatment

- Ceramic membrane was applied in anaerobic fluidized MBR for low-strength wastewater.
- Membrane net flux of 17 LMH was achieved with only periodic maintenance cleaning.
- No adverse effect of the maintenance cleaning on organic removal was observed.
- Average SCOD in membrane permeate of 23 mg/L was achieved.
- Electrical energy required to operate the AFCMBR was only about 0.038 kWh/m3.

An aluminum dioxide (Al2O3) ceramic membrane was used in a single-stage anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for low-strength wastewater treatment. The AFCMBR was operated continuously for 395 days at 25 °C using a synthetic wastewater having a chemical oxygen demand (COD) averaging 260 mg/L. A membrane net flux as high as 14.5-17 L/m2 h was achieved with only periodic maintenance cleaning, obtained by adding 25 mg/L of sodium hypochlorite solution. No adverse effect of the maintenance cleaning on organic removal was observed. An average SCOD in the membrane permeate of 23 mg/L was achieved with a 1 h hydraulic retention time (HRT). Biosolids production averaged 0.014 ± 0.007 gVSS/gCOD removed. The estimated electrical energy required to operate the AFCMBR system was 0.039 kWh/m3, which is only about 17% of the electrical energy that could be generated with the methane produced.