Treating starch wastewater reclaim bioenergy by EGSB process and high value use of biogas

The expanded granular sludge bed (EGSB) reactor-anoxic/aerobic (A/O) process has been used for treating highly concentrated starch wastewater, and the biogas produced in EGSB was purified. Under the condition of 35°C, the COD volume load of EGSB reaches up to 20 kg/(m³·d), and the combined process removal rates of COD, BOD₅ and SS were 98.5%, 99.5% and 95%, respectively. After being treated by the combined process, the effluent quality is able to satisfy the demands of discharge. After purification treatment, the methane content of biogas was high than 98%, and the hydrogen sulfide content was below 30 mg/Nm³. The natural gas production was 6000 m³/d, the high value use of biogas was achieved.