Continuous village sewage treatment by vermifiltration and activated sludge process

• Published in: Water science and technology Vol. 60; no. 11; pp. 3001 - 3010
• Main Authors: Li, Yin-Sheng, Xiao, Yi-Qun, Qiu, Jiang-Ping, Dai, Yi-Qi, Robin, Paul
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01.01.2009
• Subjects: Activated sludge; Activated sludge process; Animals; Biodiversity and Ecology; China; Composition; Contaminants; Environmental Sciences; Experimentation; Filtration; Humans; Hydraulic loading; Hydrogen-Ion Concentration; Influents; Inhabitants; Load distribution; Loading rate; Oligochaeta - physiology; Outflow; Oxygen - analysis; Oxygen content; Refuse Disposal - methods; Removal; Rural Population; Seasons; Sewage; Sewage - analysis; Sewage disposal; Sewage treatment; Sludge; Variation; Waste Disposal, Fluid - methods; Waste Management - methods; Wastewater treatment; China; FILTER MATERIAL; RURAL SEWAGE; WASTE-WATER; TOXICITY; VERMIFILTRATION; SLUDGE PROCESS; EISENIA ADREI; VILLAGE SEWAGE
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2009.715

Rural sewage treatment is now paid more and more attention in China. Vermifiltration technology could be one of the practical options under the review of previous studies. It showed good removal rates of contaminants on small to pilot scales for short-term tests. However, the impacts of season, temperature or other unknown factors are usually not taken into account. In this study, a larger vermifilter was designed to treat the sewage on village scale for long-term operation. Filter material composition was optimized by a half year experimentation. The treatment effects of vermifiltration were also compared with traditional activated sludge process for the same influent sewage. The results showed that the designed vermifiltration system could continuously treat the sewage produced by more than 100 inhabitants per day. COD, BOD5 and SS concentration in outflow were rather stable despite the fluctuation of hydraulic loading rate and organic input during one year test. It can also remove N and P to some extent. A suspending design of vermifilter bed cause adequate oxygen content in outflow of vermifilter. The comparative test showed that the treatment efficacy of vermifiltration was similar as activated sludge process. Generally, this vermifiltration system has practical application value for village sewage treatment.