Harada H, Dong N T, Matsui S
Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo, Kyoto, 606-8501, Japan.
Water Sci Technol. 2008;58(6):1305-11. doi: 10.2166/wst.2008.715.
Although many cities have planed to develop sewerages in developing countries, sewerage establishment still requires huge investment and engineering efforts. Improvement of existing sanitation facilities may contribute the betterment of urban sanitation before sewerage establishment. The purpose of this study is to propose a measure to improve urban sanitation in areas where a sewerage development plan is proposed but has not been yet established, based on a case study in Hanoi, Vietnam. We found that 90.5% of human excreta flowed into septic tanks. However, 89.6% of septic tanks have never been desludged in the past and their performance was observed to be at a low level. The study also showed that if they introduce regular desludging with a frequency of once a year, they can eliminate 72.8% of COD loads from septic tanks. It was indicated that the performance can be dramatically recovered by regular desludging, which could contribute urban sanitation improvement in Hanoi. In conclusion, the performance recovery of septic tanks by regular desludging was proposed as a provisional-and-urgent measure for urban sanitation improvement, together with the septage treatment in sewage sludge treatment facilities, which should be established earlier than other facilities of sewage treatment systems.
尽管许多发展中国家的城市都已规划建设污水处理系统，但污水处理设施的建设仍需要巨额投资和巨大的工程投入。在污水处理系统建成之前，改善现有的卫生设施可能有助于提升城市卫生水平。本研究的目的是基于越南河内的一个案例研究，提出一项措施，以改善那些已提出污水处理发展规划但尚未建成地区的城市卫生状况。我们发现，90.5%的人类排泄物流入了化粪池。然而，过去89.6%的化粪池从未进行过清淤，且观察到它们的性能处于较低水平。该研究还表明，如果每年定期清淤一次，化粪池中的化学需氧量（COD）负荷可消除72.8%。结果表明，定期清淤可显著恢复化粪池性能，这有助于改善河内的城市卫生状况。总之，建议将定期清淤恢复化粪池性能作为改善城市卫生的一项临时紧急措施，同时还应在污水处理系统的其他设施之前尽早建立污水污泥处理设施中的污泥处理。
