Stable long-term methanogenic treatment of pre-acidified dairy effluent at high organic loading rates in upflow reactor with anaerobic magnetite-embedded granular sludge

The present study employed magnetite-embedded granules in UASB reactor combined with a pre-acidification process to mitigate the adverse effect of carbohydrate-rich substrate, related to the excessive production of extracellular polymeric substances, especially at high OLRs. In addition, the effect of external voltage application (0.6V between the anode and cathode in the sludge bed) was evaluated to explore the possibility of further stimulating DIET to improve the process stability and resilience under overloading conditions.