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.

由于缺乏基本的城市污水处理设施，发展中国家大部分城市地区面临水环境严重恶化的问题。由于财力有限，污水处理系统确实需要一种经济有效的合适技术。在这种实际限制下，厌氧工艺对于污水处理来说可能是最有吸引力的，因为它比传统的好氧工艺具有优势，例如不需要曝气并且可以通过沼气生产回收能量。然而，厌氧过程也有一些弱点。厌氧工艺的出水水质往往无法与活性污泥工艺相比。这就是为什么厌氧工艺有时需要进行后处理，以去除残留的有机物和营养物。一种新颖的工艺，由 UASB 预处理装置和随后的 DHS（下流式悬挂海绵幕）反应器组成，用于净化 UASB 废水，无需本研究提出了外部通气输入。我们提出的系统安装在城市污水处理厂现场，并通过以实际污水作为进水进行长期实验来评估其可行性。经验证，所提出的整个系统不仅具有出色的有机物去除能力，而且在 8 小时的总 HRT 下也具有出色的硝化作用。微生物分析和DO微电极表明，DHS反应器具有保留高密度生物质的功能和良好的大气吸氧能力。在整个两年的实验期间，我们的系统没有进行污泥排出。一个简单的模型说明了新系统中没有产生多余的污泥。