Soluble substances of the Kinokawa-river increased down the stream. Excluding weathering of limestone, soluble substances in the upper stream of the catchment covered with forest were very low and main components were HCO^-₃, SO^2-₄, Na⁺, and Ca²⁺. Soluble substances in the upper stream of the forest catchment with limestone were high and the main components were Ca²⁺ and HCO^-₃ Ca²⁺ and HCO^-₃ concentrations increased from the upper stream to the middle stream with forest, but Na⁺, Cl^- and SO^2-₄ concentrations remained unchanged because of weathering of limestone and feldspar. In the lower stream of the catchment with farm land and housing site, the concentrations of Na⁺, Cl^-, NO^-₃ and SO^2-₄ were very high. It was concluded from the relation between land uses and water qualities that Na⁺ and SO^2-₄ origin were farmland, and Cl^- origin was sewage respectively, and NO^-₃ was derived from both origins. Isotopic study of oxygen and hydrogen indicated that the river water originated from precipitation and isotopic ratios depended on mainly precipitation altitude.

抄録全体を表示

　本研究では、災害時に活用可能かつ移設可能なユニット型下水処理システムの実用化を検討するため、実規模スケールの施設について運搬、設置、立上げ、長期運転、撤去、移送の実証実験を実施した。検討の結果、ユニット型下水処理システムの運搬、設置、装置の立上げを特殊な重機を用いることなく短期間で行うことができることを確認した。また、建設費、維持管理費について算出するとともに、OD法を15年使用する場合とユニット型下水処理システムを比較し、30％程度安価に導入可能であることを示した。加えて、ユニット型下水処理システムから発生するGHGについて試算した結果、従来技術とほぼ同程度であることを確認した。

抄録全体を表示