Anaerobic treatment of low-strength municipal wastewater with electroactive magnetite-embedded granules under mainstream conditions

The study developed conductive magnetite-embedded granules for treating low-strength municipal wastewater in expanded granular sludge bed reactors at 25 degree Celsius. Magnetite improved the granules' settleability, stability, and electron transfer capabilities. MEG-EGSB reactors showed superior performance in organic removal and methane production compared to control reactors, especially under higher loading conditions. They maintained around 90% organic removal at 8 to 12-hour retention times and exhibited potential electro-syntrophic interactions between exoelectrogens and methanogens. These findings suggest the MEG-EGSB process is promising for anaerobic treatment of municipal wastewater.