Water purification in rural area using self-purification function

利用自净功能净化农村水

• 批准号: 09460108
• 负责人: TAKAHASHI Tsuyoshi
• 金额: $ 5.06万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09460108/
• 关键词: pollution load; self-purification function; circulation irrigation; water reuse; sedimentation; rural area; water quality preservation; 水田排水; 循環かんがい; 現地実態調査

Field studies were carried out on the following two problems, which related to the self-purification function of rural area.1. The quantitative evaluation of self-purification function of paddy field in polder land.(1) The pollutant which discharged from paddy field in the puddling stage sediments in the main drainage canal for a time, and then flush out by the drainage of heavy rain.(2) The effect of biological treatment could not be expected in the main drainage canals and water purification pond even if its retention time is long enough, and the effect of sedimentation is obtained only for 8。ォ24 hours of retantion time.(3) As a result of calculating pollution load reduction effect by the water purification pond using L-Q equation, it was estimated that the 50% of pollution load could be reduced on all water quality items for irrigation period, and also 20。ォ30% of COD, T-N and 60% of T-P could be also reduced in non-irrigation period.2. The effects of reuse of treated water of rural sewerageSurvey was carried out in the rural sewerage treatment plant in Iyo City, Ehime Prefecture. It was shown that the NOx-N concentration was reduced, though there were any rise at the COD, T-N concentration, and it demonstrates the purification function of paddy field. It means that the reuse of treated water of rural sewerage is effective measures as water purification method which utilized the self-purification function of the farmland.

对涉及农村自净功能的以下两个问题进行了实地研究。滩地稻田自净功能的定量评价：(1)淤泥阶段稻田排出的污染物在排水干渠中沉积一段时间，再被暴雨的排水冲刷出来。(2)生物处理在干渠和净水塘中的停留时间即使足够长，也不能达到预期的效果，只有8个月才达到沉淀效果。ォ24小时滞留时间。(3)利用L-Q方程计算净水池的减污效果，估算出灌水期内所有水质项目均可减污50%，减污20%。非灌溉条件下，ォ、T-N和T-P的降幅分别为30%和60%。农村污水处理厂回用效果调查对爱美县爱护市农村污水处理厂进行了调查。结果表明，在COD、T-N浓度有所上升的情况下，NOx-N浓度有所下降，体现了稻田的净化作用。说明农村污水处理水回用是一种有效的利用农田自净功能的净水方法。