Development of creation technology of tidal flat blotope for reduction of nitrogen and phosphorus loads and efficient use of treated sewage

为开发减少氮磷负荷、高效利用处理污水的滩涂生物栖息地创造技术，对滩涂的自净功能进行了研究，包括芦苇湿地对营养物质的吸收、滩涂营养物质的循环与反硝化作用、海藻床对营养物质的吸收等。根际微生物的硝化和反硝化作用对脱氮起重要作用，在适宜的孔隙度和水面负荷条件下，硝化和反硝化同时发生。除磷主要是通过吸附在载体上进行的。因此，低孔隙率的载体具有较高的去除效率。2)潮汐平板对附着动物Li…的净化作用对东京内湾的护岸工程进行了评估。在192公里的护岸距离下，附着动物对有机物的净化能力为19t-COD/d，相当于东京COD的23%。在降雨期间，底栖动物受到了破坏。这是由于河水的流入和滞留。当降雨增加河水时，喀塞人工滩涂水质因结构问题变为低盐度，部分双壳类死亡。3)海藻床马尾藻养分吸收速率在5~6月份达到最高，生长速率也最高。以松岛湾为研究对象，研究了赤潮鱼吸收营养物质对其营养物质循环的影响。5月份的霍尔纳河床吸收了大约70%的营养盐流入负荷，它对改善水质做出了巨大贡献。较少

In order to develop a creation technology of tidal flat biotope for reduction of nitrogen and phosphorus loads and efficient use of treated sewage, we studied on the self-purification function of tidal flats, such as nutrients uptake by reed wetland, nutrients cycle and denitrification in tidal flat and nutrients uptake by seaweed bed.The results of this study are summarized as follows.1) Reed wetlandThe effect of porosity of the filling carrier on removal capability of nutrients from treated sewage was analyzed. Nitrification and denitrification by the rhizosphere microorganism were important for the nitrogen removal, and the simultaneous reaction of nitrification and denitrification occurred under appropriate conditions of porosity and water surface loading. The removal of phosphorus was mainly carried out by the adsorption to the carrier. Therefore, high removal efficiency was obtained by the carrier with low porosity.2) Tidal flatThe purification function of attached animal that li … More ved for the revetment of the Tokyo inner bay was evaluated. The attached animal purified organic matter of 19t-COD/day at revetment distance of 192km, and this value corresponded to 23% of COD that flows from Tokyo.The environment factors concerning fluctuations of biomass and species of macrobenthos inhabiting in the Kasai artificial beach were analyzed. The benthos was damaged in the rainfall time. It was due to the inflow and retention of river water. When the river water had been increased by rainfall, the water quality in Kasai artificial beach became a low salinity by the structural problem, and some kinds of bivalve died.3) Seaweed bedThe nutrient uptake rate of Sargassum horneri became the highest from May to June in which the growth rate was also the highest We could make the equation of the nutrient uptake rate which was the function of growth stage, nutrient concentration, illumination intensity and temperature. The effect of nutrients uptake by S. horneri on the nutrients cycle of Matsushima Bay was evaluated. The S. horneri bed in May absorbed about 70% of the nutrients inflow load, and it greatly contributes to improving water quality. Less