Development of Advanced Treatment Systems of Rural Sewerage by the Combination of Biogeofilter and Biotope Pond

通过对秋田市农村污水深度处理植物的筛选，明确了夏季植物包括饲用水稻、田菁、黑麦草，秋冬植物包括野菜、野菜和野菜具有较强的氮磷吸收能力。并以某农村污水处理厂为研究对象，进行了生物滤池深度处理农村污水的试验。在沸石填充的秸秆还田中，由于沸石吸收了大部分养分，2004年饲用水稻植株的生长状况很差，但到了2005年，其生长和磷的去除速度都得到了改善。在此基础上，提出以平均氨氮浓度33 mg/L的二级处理水为滤池，每隔一天半向滤池投加NH4-N，沸石填充剂可在两年内几乎完全去除NH4-N。我们在这些BGF中种植了花卉、蔬菜和田菁、纸草等资源植物。在生物栖息地池塘里，我们从周围的稻田里带来了剑鱼和泥鳅，并观察了它们的生长。我们观察到，池塘中的生物多样性得到了保持。在种植植物、观察生长和学龄儿童的最终陈述后，明确了儿童的环境意识得到了激发，教师对这次实验给予了很高的评价。这些研究表明，要有效地深度处理农村污水，必须根据滤料和植物的营养吸收能力，构建合适的滤料和植物组合模式，才能达到处理后的水质目标。

As a result of the selection of plants suitable for the advanced treatment of rural sewerage located in Akita City, we clarified that summer plants including forage rice plant, sesbania, Italian rye grass, and fall-winter plants including potherb mustard and nozawana have high nitrogen and phosphorus absorbing ability. And we conducted experiments of advanced treatment of rural sewerage with Biogeofilter (BGF) that was built in a rural sewerage plant. In a BGF filled with zeolite, we demonstrated that in 2004 the growth of forage rice plant was very bad because zeolite absorbed most of nutrition, but that in 2005 its growth and the removal rate of phosphorus were improved. Moreover it was suggested that NH_4-N was almost completely removed by the filled zeolite for two years when the secondary treated water of the average NH_4-N concentration 33mg/L was provided to a BGF at the time interval of one day and a half.We also constructed three series of BGF for the environmental education for elementary school children. We planted flowers, vegetables and resource plants such as sesbania and papyrus in these BGF. In biotope ponds we brought killifish and loaches from the surrounding paddy fields, and observed their growth. We observed that the bio-diversity in the ponds was maintained. After the plantation of plants, the observation of the growth and the final presentation by school children, we clarified that the environmental consciousness of the children was stimulated and that teachers gave a high evaluation to this experiment. These researches suggest that it is important, for effective advanced treatment of rural sewerage, to make up appropriate combination models of filter materials and plants considering their nutrition absorbing abilities so that we could reach the target of treated water quality.