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Country/Region： Japan

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Country/Region： Japan

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Committee type：Municipal

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Grant amount：\15730000 （ Direct Cost: \12100000 、 Indirect Cost：\3630000 ）

The purpose of this work was to select water quality indicator organisms for the rivers in Shanxi province, China, and to study their application for environmental education. Overall, 29 such organisms were selected from Japanese biological water quality classes I to IV. Aquatic organisms inhabiting the Sin he River, the Sang gan he River and the Fen he River, the major rivers of Shanxi province, were investigated. Based on the findings, we propose four species in water class I, three in II, four in III, and one in IV that are considered equivalent to the indicator organisms in Japan. Based on the results of these surveys, we developed a Shanxi Provincial Version of a teaching material (card game) which can be used to learn about water quality indicators and causes of river pollution.

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Grant amount：\13200000 （ Direct Cost: \13200000 ）

In this study, bench scale and pilot plant experiment using a swine waste were carried out in order to develop thermophilic oxic fermentation process for high rate degradation of livestock organic waste and recovery of nitrogen and phosphorus resources. The results obtained by this study are summarized as follows.
1) In bench scale experiment, it was possible to remove carbon of about 86% and moisture of 98% under the conditions of BOD loading of 3 kg m^<-3> day^<-1>, air flow of 100 L m^<-3> min^<-1> and adding edible oil of 120 mL.
2) 55% was optimum as average water content, and ATP concentration and thermophile number became highest under this condition.
3) As a result of the long-term operation in bench scale experiment, it was able to treat swine waste efficiently during first 60 days and the treatment efficiency lowered after that. The treatment efficiency was recovered by changing cedar chip of 50% on day 86.
4) In the pilot plant experiment, 64℃ of fermentation temperature and weight loss rate of 91% were achieved. In the water, which accumulated in the cooler, high concentrated T-N was detected, though TOC and T-P were not detected. It was cleared nitrogen was removed as an ammonia gas.
5) By shortening input interval of organic waste from 24 hours to 8 hours, treatment volume increased over the double. It was shown that the optimization of input condition of organic waste enabled the high rate degradation.

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Grant amount：\12200000 （ Direct Cost: \12200000 ）

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 lived 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.

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Grant amount：\1500000 （ Direct Cost: \1500000 ）

The objective of this is study was to investigate the behavior of nitrogenous biological oxygen demand in river ecosystem, to search a method to create an ecological river environment through the biotope method, to clarify the relationship between river structure and the water purification function, and the role of riffles and pools in river water purification systems. The results obtained can be summarized as follows :
1) Nitrogenous biological oxygen demand (N-BOD) was detected in high frequency in rivers if the effluent from the wastewater treatment plant flows into the rivers, especially, when C/N ratio is low, NH4-N concentration and water temperature are high. This result suggested that the flow of the effluent from sewer system might have negative impact on the river ecosystem due to the defect of DO in the river especially in the pools.
2) It was predicted from a simple simulation model based on the laboratory experimental results that the DO concentration in the pools of the river may decrease to 4 mg/l if the nitrogen compound is high. In order to keep the DO concentration more than 7.5mg/l in pools, it is necessary to decrease the NH4-N concentration less than 0.5mg/l.
3) To maintain a sound river ecosystem environment, it is important to use the ecological river improvement and natural diverse river restoration methods such as biotope and ecological engineering. It is effective to create riffles and pools in strait river banks to improve river water purification function. Riffles and pools play an important role in river ecosystem not only for water purification but also for the habitat of microorganisms.
4) It was proved that to use the purification blocks and nets to create riffles and pools in the river channels, effective removals of organic matter and nitrogen can be expected.

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Grant amount：\2200000 （ Direct Cost: \2200000 ）

本研究では,水質汚濁防止のために普及・整備が急がれている小規模合併処理浄化槽についての,その設計・管理に求められる,小規模な生活排水からの各種汚濁負荷量を算出し,さらに排出特性を多変量解析等を用いて明らかにして,それらの排水を処理している合併処理浄化槽の機能評価を行なっている。平成10年度では,主に家族人数4〜6人程度の戸建住宅排水を対象に,各種汚濁負荷量(BOD,窒素,リン,陰イオン界面活性剤など)等を算出し,さらに生活様式を考慮した排出特性をふまえ,合併処理浄化槽の処理機能を評価した。得られた成果をまとめると以下の通りである。
1. 戸建て住宅排水の汚濁負荷量は既往の知見と同程度であり,その負荷特性についても,平日と休日の汚濁負荷量を比べると,休日の方が平日に比べて1.0〜1.4倍高かった。一方,排水の排出特性は個々の生活様式によって異なり,農家よりもサラリーマン家庭,さらに家族人数の少ない家庭ほど短時間に多量の排水が排出された。またBODおよび陰イオン界面活性剤について時間平均負荷量に対する時間最大負荷量の比を求めたところ,両方とも休日よりも平日の比の方が大きかった。
2. 総負荷量に対する3時間最大負荷量の割合および総排水量に対する3時間最大排水量の割合と,処理水中の平均BOD,陰イオン界面活性剤濃度との関係を検討したところ,負荷量については関係がみられなかったが,排水量についてはその割合が大きくなるに従い,処理水中の平均濃度が上昇する傾向がみられ,処理機能に対する流量変動の影響が示唆された。

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神奈川県庁が株式会社エイスリーに業務委託された「水の実験」に関する動画に対して、専門家の立場で監修、および動画内での解説をした。

水環境の調査や保全活動を手掛けるための入門書