2001 Fiscal Year Final Research Report Summary
Development of creation technology of tidal flat blotope for reduction of nitrogen and phosphorus loads and efficient use of treated sewage
Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants |
Civil and environmental engineering
|Research Institution||Tohoku University |
NISHIMURA Osamu Tohoku Univ., Graduate School of Eng., Professor, 大学院・工学研究科, 教授 (80208214)
MIZUOCHI Motoyuki National Institute for Environmental Studies, Research Center for Material Cycles and Waste Management, Senior Researcher, 循環型社会形成推進, 廃棄物研究センター・主任研究員 (50260188)
INAMORI Yuhei National Institute for Environmental Studies, Research Center for Material Cycles and Waste Management, Leader, 循環型社会形成推進, 廃棄物研究センター・室長 (10142093)
YAMADA Kazuhiro Tohoku Univ., Graduate School of Eng., Lecturer, 大学院・工学研究科, 講師 (30250723)
SAKAMAKI Takashi Japan Society for the Promotion of Science, Research Fellow, 特別研究員
XU Kaiqin National Institute for Environmental Studies, Watershed Environments and Management Research Project, Senior Researcher, 東アジア流域圏環境管理プロジェクトグループ, 主任研究員 (20250722)
|Project Period (FY)
1998 – 2001
|Keywords||tidal flat / wetland / nitrogen / phosphorus / treated sewage / benthos / reed / seaweed bed|
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 wetland
The 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 flat
The purification function of attached animal that li
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 bed
The 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
Research Products (14 results)