Technical analysis of designs of biogas digesters for treating domestic sewage from rural areas

Through investigation in Sichuan, Zhejiang and Jiangsu Provinces, some designs of the biogas digesters for treating sewage from rural areas were collected. Among these digesters, the technical characteristics of five representative types were analyzed, in order to advance the technology. There were some common characteristics in the designs of the biogas plants; those were the processes of two stage anaerobic digestion plus multi-filters under alternative oxidation. But some differences in the designs of treatment units were also presented. As compared with early designs, new designs of the digesters took with favor on simplifying the unit installed. Some problems, caused by random selection of design parameters and rough utilization of packing material affected the final results of treating sewage.