Li Yuyou
Dept. of Civil and Environmental Engineering,
Graduate School of Engineering, Tohoku University
This presentation focuses on the bioenergy production from organic waste and wastewater by anaerobic biotechnology, and the content includes four parts. The first part introduces the fundamental and importance of methane fermentation. The second part summarizes the applications of biogas technology in Japan, including industrial wastewater treatment, anaerobic digestion of sewage sludge and methane fermentation of food/agricultural wastes. Anaerobic treatment of industrial wastewater in Japan was started in the 1960s, and has become increasingly popular recently. Over 300 UASB and EGSB full-scale plants are now in operation treating beer, soft drink, food and chemical wastewaters. Anaerobic sludge digestion began in 1932, and is now used in over 300 sewage treatment plants with a total digester volume of 2.1x106 m3, producing methane to heat the digester or to generate bio-fuel for electricity. Anaerobic digestion was also the main technology to treat night soil during 1953-75; each m3 of night soil produced 8-9 m3 biogas containing 60% methane. the estimated potential of methane recovery from the livestock waste (1.6x109 m3/y) is only slight behind those from the municipal solid wastes (MSW) (1.7x109 m3/y) in Japan. Since 2006, over 70 methane fermentation plants have been operated to livestock waste, and another 80 methane fermentation plants to treat food waste and the organic fraction of MSW.
In the third parts, some new studies for treating food waste and producing biogas will be introduced, including a waterless methane fermentation process, a two-stage process for producing hythane (H2+CH4) and anaerobic membrane bioreactor. A case study was conducted to investigate the effects of sulfate and OLR on VFAs degradation and organic removal of thermophilic anaerobic co-digestion of coffee grounds, milk waste and dewatered waste activated sludge in AnMBR reactor.
The last part is an experimental study on wastewater treatment using AnMBR. A continuous experiment was conducted in order to evaluate the possibility of using AnMBR to obtain the second treatment performance.
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