In recent years, environmental pollution caused by synthetic chemicals has become of serious issue. The prediction of environmental fate of chemicals which have relatively short life is important for the evaluation of their environmental safety in a specific area. In this paper, a concrete procedure for prediction and a method for determination of the volume of environmental compartment were proposed. As for the determination method of compartment volume, the hight of air compartment for the specific area which range from 102 to 104 km2 was proposed to be 1000 m or less. Furthermore, a modified kinetic model taking into account the non-diffusive transfer processes from soil to water and from air to soil and/or water was proposed. Using the proposed procedure and the model, the concentrations of the organochlorine solvents such as trichloroethylene and tetrachloroethylene in the air which was the main compartment for those solvents were predicted in an urban area. Since the predicted values agreed with the measured data, it was proved that the proposed method was appropriate for the prediction of fate of the chemicals in a specific area.

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The behavior of monochloramine, dichloramine and free chlorine in a water treatment plant was examined during three year with the continuous flow method of simultaneous determination. At the point just after prechlorination, the predominant species were dichloramine (from November to March) and free chlorine (from May to September). The concentration of dichloramine decreased to 1/3 with increase in pH from 6.4 to 6.9. The decomposition rate of dichloramine in daytime showed an increase of 10% over that in night. Dichloramine converted to free chlorine at the rate of 18%.

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In taking measures against water pollution caused by domestic wastewater, it is necessary to consider both the financing of measures by local government, which bears the main responsibility for dealing with this probrem, and environmental conservation. In this paper, as an example of cost-effectiveness analysis of wastewater treatment alternatives (sewer and wastwater treatment, septic tank for both brown water and kitchen/bath wastewater, septic tank for brown water only) for the local government, the total cost allocation and pollution generation trends are calculated for each treatment alternative, and analyzed for sensitivity to changes in various parameters for a population of ten thousand people. As performance indicators of each treatment alternative, we chose total pollution loads generated in a planning period, time trends of cost allocated to national government, local government, and citizens.Under the current subsidy scheme used in Japan, there are various factors to be considered, policy of local government (amount of subsidy, sewer rates, combinations of alternative treatment methods), the behavior of people in area not served by sewers, and an estimate of population growth. This paper clarifies the effects of these factors on financing and the degree of reduction of pollution loads in regard to treatment alternatives.

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A dynamic water quality model of a oxidation pond is proposed . The model attemps to simulate the seasonal variation of water quality in a oxidation pond in response to temperature and light intensity . The model consisting of two horizontal layers can explain the seasonal variation of dissolved oxygen, suspended solids, total dissolved phosphorus and dissolved organic carbon concentrations consistently . The water load per unit area mainly determines dissolved phosphorus concentra tion in treatment water. The water load per unit area under 0.1 [m/d] seems to be effective for the elimination of nutrients from the treatment water .

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An on-site assessment using respondents was tried on the measurement of the tastes of the environment at the natural landscape area of Kamikoti in the Chubusangaku National Park. And some physical quantities of the environment were simultaneously measured at the sites. Results were analyzed by the method of CATDAP (Category Data Analysis Program) and the method of regression equation analysis using PSS (Prediction Sum of Square). Useful results were obtained for the measurements of the tastes of the environment. The feeling of the congestion was significantly correlated to the number of people observed at the site. More than a half of respondents felt congestion of site in the case when more than 30 persons had been observed at the site . More than a half of respondents felt congestion on the trail in the case when the respondents had met more than 50 persons on the trail. More than a half of respondents felt pleasant at the site in the case when the wind speed was observed more than 0.5 m/s. More than a half of respondents felt bright at the site in the case when the level of brightness more than 80, 000 lux.

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