Anaerobic biofilm reactors are attractive with their high loading capacities, concentrated biomass, resistance to hydraulic or organic overloads, and no requirement of mechanical mixing [28–43,14,44,45]. Compared to conventional anaerobic treatment systems, biofilm reactors could significantly reduce start-up time and increase organic loading rates up to fivefold [46]. Biofilms are microbial communities attached to support materials and they have ability for effective removal of organics and methane production [47–49]. Various types of biofilm reactors have been successfully applied for the treatment of high-strength effluents from food industry and dairy production [50,51].