Food waste leachate treatment using an Upflow Anaerobic Sludge Bed (UASB): Effect of conductive material dosage under low and high organic loads

In this study, the performance of UASB for treating food waste leachate was investigated, with the objective of studying the effect of conducive material on anaerobic digestion (AD) enhancement at two organic loads. Conducive and control materials (i.e. graphite and glass) were first compared for their surface porosity then dosed in UASB for side-by-side comparison of the corresponding AD performance. In the first phase (organic load of 2660 mg-COD/L), compared to glass-added UASB, 29.5% reduction of effluent COD was observed in graphite-added UASB, however, only a little biogas enhancement (2.3%) was achieved. In the second phase (organic load of 4140 mg-COD/L), the results show that it could promote better AD enhancement in graphite-added UASB, where 36% effluent COD and 38% biogas production enhancement were simultaneously observed. The overall results support that utilization of conducive material is a viable approach for enhancing biogas production in UASB, especially for high organic loads.