Water purification in rural area using self-purification function

Field studies carried out on the following two problems，它与规则区域的self-purification function of rural area.1. quantitative evaluation ofself-purification function of paddy field in polder land.(1) The pollutant which discharged frompaddy field in the puddling stage sediments in the main drainage canal for a time，(2)这一效应的生物医学treatment not be be flush out by the drainage of heavy rain.expected in the main drainage canals and water purification pond even if its retention time is long足够，和隔离的效果只能用于8。(3) As a result of calculating pollution load reduction effect by thewater purification pond using L-Q equation这是估计50%的pollution load could be reduced on all water quality items forirrigation period, also 20。30% of COD，T-N和60% of T-P可以减少非irrigation period.2. treated effects of treuse of treatedrural sewerageSurvey was carried out in the rural sewerage treatment plant in Iyo CityEhime Prefecture. It was - n concentration was reduced，though there any rise at the COD, T-N concentration，and it demonstrates the purification function of paddy field. it means that the reuse of treated水的rural sewerage is effective measures as水purification method which utilized theself-purification function of the farmland。

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.