Injurious trace adsorptive ollutants influences on the health has become a problem, and the discharge criteria has been controlled generally. The influences of several heavy metals and organic chroline compounds are also noted.
The purpose of this study is quantative explanation of transport phenomenon of the discharged dissolved matter that is represented by physical and chemical activities in the river.
And it was made several experiments and analysed theoretically to investigate the characteristics and the mechanism of adsorption and distribution of dissolved matter onto suspended substances and bed sediments.
To examine the adsorptive and distributive characteristics onto suspended solids, the witers took the initial concentration of ions (Pb²⁺, Cr³⁺, Hg²⁺, Cd²⁺, AsO^3-₄ ) as discharged criteria concentration and evaluated the distribution coefficient “Kd” between the solution and several kinds of clay minerals and pond sediments.
The order of “Kd” was mostly Pb²⁺>Cr³⁺>Hg²⁺>Cd²⁺>AsO^3-₄. As to transport of heavy metals from river water to bed sediments was tested with physical transport model.
Adsorption of Hg2+, Cd2+to sand layer and pond sediment was examined. The order of adsorption was pond sediment>Kaolinite>sand in the case of Hg2+with city water.
From these experimental results, as the method to explain the outline of phenomenon, apparent diffusion coefficient “ Da” was defined and analysed theoretically.

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A large volume of agricultural water containing the low level of contaminants was treated with the rotating disc apparatus, and the results showed that NH₃-N and Org-N in the water were effectively vemoved, and the values of COD and DO were greatly improved.

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The behaviors of NH₃ and N₂O in NH₃-O₂-N₂ and NH₃-N₂O-O₂-N₂ mixture were studied under UV irradiation at room temperature. NH₃ in NH₃-O₂-N₂ mixture decomposed to N₂, N₂O and H₂O under a high pressure mercury lamp irradiation. The selectivity of N₂O formation was constant independent of O₂ concentration in the presence of excess O₂ and was approximately 14 % of the amount of NH₃ decomposed. The decomposition rate of NH₃ was independent of O₂ concentration and proportional to the concentration of NH₃. While, under a low pressure mercury lamp irradiation, NH₄NO₃ formed with N₂, N₂O and H₂O. The decomposition rate increased remarkably with increasing the concentration of O₂ and expressed by the following equation
- d (NH₃) /dθ= k [NH₃] + k' [O₂] ^1/2 [θ = W/F (watt⋅min⋅l^-1) ]
The selectivity of N₂O formation increased with increasing the concentration of O₂ and decreased rapidly with further increasing over than 10 %. The results may be caused by the oxidative consumption of the intermediate HNO for N₂O formation to give NH₄NO₃. No effect of N₂O was observed in the decomposition of NH₃ in NH₃-O₂-N₂ mixture under a high and low pressure mercury lamp irradiation. N₂O increased a little by the oxidative decomposition of NH₃ in N₂O-NH₃-O₂-N₂ mixture under a high pressure mercury lamp irradiation and in the early stage under a low pressure mercury lamp irradiation, while decreased in the later stage under a low pressure mercury lamp irradiation. The decomposition rate of N₂O was not affected by the presence of NH₃.

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