Performance and kinetic evaluation of anaerobic moving bed biofilm reactor for treating milk permeate from dairy industry

High strength milk permeate derived from ultra-filtration based cheese making process was treated in an anaerobic moving bed biofilm reactor (AMBBR) under mesophilic (35 °C) condition. Total chemical oxygen demand (TCOD) removal efficiencies of 86.3–73.2% were achieved at organic loading rates (OLR) of 2.0–20.0 g TCOD L−1 d−1. A mass balance model gave values of methane yield coefficient (YG/S) and cell maintenance coefficient (km) of 0.341 L CH4 g−1 TCODremoved and 0.1808 g TCODremoved g−1 VSS d−1, respectively. The maximum substrate utilization rate Umax was determined as 89.3 g TCOD L−1 d−1 by a modified Stover–Kincannon model. Volumetric methane production rates (VMPR) were shown to correlate with the biodegradable TCOD concentration through a Michaelis–Menten type equation. Moreover, based on VMPR and OLR removed from the reactor, the sludge production yield was determined as 0.0794 g VSS g−1 TCODremoved.