Improvement of the anaerobic treatment of potato processing wastewater in a UASB reactor by co-digestion with glycerol

The effect of three different types of glycerol on the performance of up-flow anaerobic sludge blanket (UASB) reactors treating potato processing wastewater was investigated. High COD removal efficiencies were obtained in both control and supplemented UASB reactors (around 85%). By adding 2 ml glycerol product per liter of raw wastewater, the biogas production could be increased by 0.74 l biogas ml−1 glycerol product, which leads to energy values in the range of 810–1270 kWhelectric per m3 product. Moreover, a better in-reactor biomass yield was observed for the supplemented UASB reactor (0.012 g VSS g−1 CODremoved) compared to the UASB control (0.002 g VSS g−1 CODremoved), which suggests a positive effect of glycerol on the sludge blanket growth.