Development of novel low-cost sewage treatment system applicable to developing countries

开发适用于发展中国家的新型低成本污水处理系统

基本信息

批准号：
10555192
负责人：
OHASHI Akiyoshi
金额：
$ 7.04万
依托单位：
Nagaoka University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10555192/
关键词：
developing countries wastewater treatment low-cost microelectrode FISH UASB DHS nitrification-denitrefication 硝化

项目摘要

Most of urban areas of developing countries are facing severe deterioration of aquatic environment due to shortage of facilities for basic municipal sewage treatment. Because of the limited financial resources, there is a definite need of a cost-effective appropriate technology for sewage treatment system. Under this practical constraint, anaerobic process could be the most attractive for sewage treatment, since it has advantages over conventional aerobic processes, in such points as no need of aeration and energy recovery benefit through bio-gas production. However, anaerobic processes possess some weak points. Effluent quality of anaerobic process is often not comparable with that from activated sludge process. That is why anaerobic process sometimes requires post-treatment for removal of residual organics and nutrients.A novel process, which consists of a UASB pre-treatment unit and the following DHS(Downflow Hanging Sponge-curtains)reactor for polishing up the UASB effluent without external aeration input, was proposed in this study. Our proposed system was installed at a municipal sewage treatment plant site, and its feasibility was evaluated by conducting a long-term experiment with actual sewage as a feed. The proposed whole system verified to perform not only superior organic removal but also excellent nitrification at an overall HRT of 8hrs. Microbial analysis and DO microelectrode showed that the DHS reactor had a function of retaining highly density biomass and excellent oxygen-uptake from atmosphere. Over the whole experimental duration of two years no sludge withdrawal was made in our system. A simple model accounted for no excess sludge production in the new system.

由于缺乏基本市政污水处理的设施，发展中国家的大多数城市地区都面临着水生环境的严重恶化。由于财务资源有限，因此对于污水处理系统来说，确定需要采用具有成本效益的技术。在这种实际限制下，厌氧过程可能是污水处理的最吸引人，因为它比常规有氧过程具有优势，而在不需要通过生物加速器生产的情况下进行充气和能量回收率。但是，厌氧过程具有一些弱点。厌氧过程的废水质量通常与激活的污泥工艺相比。这就是为什么厌氧过程有时需要进行后处理以去除残留有机物和营养。一个新过程由UASB预处理单元和以下DHS（下流悬挂的海绵箱）反应堆（用于抛光UASB液化的外部充气输入），在本研究中提出，在本研究中提出了抛光UASB污水的反应器。我们提出的系统安装在市政污水处理厂的现场，并通过对实际污水作为饲料进行长期实验来评估其可行性。提出的整个系统已验证，不仅可以在8小时的总体HRT下执行优质的有机卸载，还可以执行出色的硝化。微生物分析和DO微电极表明，DHS反应器具有保留高度密度生物量和出色的氧气摄取的功能。在两年的整个实验持续时间内，我们的系统中没有提取污泥。一个简单的模型在新系统中没有过多的污泥产生。