Energy efficiency of food production wastewater anaerobic-aerobic treatment

Abstract

The advanced energyand resource saving technologies of food production wastewater treatment include anaerobic and aerobic steps. At present, various methods of intensification and optimization are used to increase the efficiency of anaerobic processes of wastewater treatment, including selection of active microbial communities, providing the optimum temperature regime, immobilizing biomass by granulation or biofilm formation, reducing various inhibitory effects, phase separation or pre-acidification, chemical or biological pretreatment of wastewater. The aim of this investigation was researching the effect of hydraulic and organic load rates on the energy efficiency of the wastewater treatment process and evaluating the energy efficiency depending on process conditions. Experimental laboratory installation included subsequently connected bioreactors, one from which acted as first stage and other bioreactors as the second stages of anaerobic process. It was shown that the biogas formation at the first and second stages differs significantly. A small volume of released biogas on the first stage allows us to ignore it, but characteristics of biogas formation at the second stage bioreactors are close and are described by general functional dependence. The specific yield of biogas from the organic matter consumed Ybg is independent of the specific organic load rate L, but is dependent on the specific flow rate of the treated water D.