PROBLEM TO BE SOLVED: To provide nutrient solutions for hydroponics of vegetables simply and sustainably, which are obtained by treating sewage consisting of human excrement.SOLUTION: In a toilet circulation treatment system at least having: a first step of nitrifying sewage by contacting an organic matter-decomposing bacteria-carrying porous body under an aerobic atmosphere； a second step of treating with activated sludge； and a third step of denitrifying by contacting the organic matter-decomposing bacteria-carrying porous body under an aerobic atmosphere or an anaerobic atmosphere, when treated water in any one of the first to third step or during the steps has a pH of 6 to 7 and a nitrate nitrogen concentration of 30 to 100 ppm, the treated water is used for hydroponics of vegetables.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2020,JPO&INPIT【課題】人の排泄物からなる汚水を処理して簡易かつ持続的に野菜の水耕栽培用養液として提供すること。【解決手段】少なくとも、好気的雰囲気下で有機物分解菌担持多孔体と接触させて汚水を硝化処理する第１の工程、活性汚泥処理する第２の工程、好気的雰囲気下又は嫌気的雰囲気下で有機物分解菌担持多孔体と接触させて脱窒化処理する第３の工程、を備えるトイレ循環処理系において、前記第１～第３工程のいずかの工程又は工程間の処理水が、ｐＨ６～７、かつ、硝酸態窒素濃度３０～１００ｐｐｍである場合に、当該処理水を野菜の養液栽培用とする。【選択図】図５
