The age of a sediment core in Toyano lagoon was measured using radioisotope technique, and dioxins (TCDDs/Fs and co-PCB) amounts were measured. TEQs increased with time, reached its maximum in 1968 and decreased after that. The TEQs of layers from 1960 to 1975 exceeded the Japan environmental criteria for sediments, 150pgTEQ/g. Principal component analysis showed that dioxins from PCP, CNP and PCB products were the principal components. TCDDs/Fs from PCP and CNP accounted for almost all TEQ, and most of co-PCB came from PCB products used past. The results tell us that today's dioxins' pollution comes from the chemicals used not now but past.

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The results of this study are summarized as follows: (1) Differences in electric magnetic reflectivity patterns of soil formed by various kinds of vegetation were explained by root distribution condition and the water content condition of the formed soil. (2) It was verified from the vertical distributions of softness of forest soil and luminance values obtained from the electric magnetic reflectivity profile, that the depth at which the luminance value decreases in shallow subsurface can interpreted as the lower limit of depth of the effective soil layer. (3) A satisfactory negative correlation was found between the water content by volume and the luminance value, which is an electric magnetic reflectivity.

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New fuzzy control system for contaminated ground water was developed with numerical analysis method and its efficiency was examined. The presented model can calculate the optimum pumping rate with considering remediation efficiency and environmental impact based on knowledge of engineer's skill. In a series of the numerical simulations, the virtual conditions were set by using the actual remediation site data. In calculation, the effect of proposed algorism was investigated in detail. In this paper, outline of numerical method is explained and the numerical simulation results are shown. Proposed algorithm would be reduce pumping rate than actual data.

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The distribution of hazardous compounds between particulate phase and dissolved phase in a suspension of a deconstruction effluent was investigated to apply membrane separation technology to the treatment of the suspension. The association of PAHs and dioxins to particulate matters was a function of LogKow. The effect of suspended solid concentration and dissolved organic concentration on the distribution was modeled and experimentally examined. A membrane separation system was designed and applied to the treatment of deconstruction effluent. The system showed an enough performance to keep the environmental standard of 1pg TEQ/l.

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In order to clarify the transportation of floating sand in a sea sand mining area of the Seto Inland Sea, the sectional measurements of current and suspended sediment (SS) were conducted with an Acoustic Doppler Current Profiler (ADCP) in the Mihara Seto Strait. The relationship between the backscatter strength (Sv) of ADCP and the concentration of SS had a high correlation. Then, Sv could be converted into the concentration of SS, and the flux of the SS was estimated. In each section, the total flux of the SS was calculated assuming that the tidal current was sinusoidal wave. As a result, the net of the flux of the SS showed the inflow in the Mihara Seto Strait.

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We calculated the amount of carbon dioxide emission and cost each case of different recover rate of PET bottle material recycling, reuse and not recycling. From a questionnaire, it was made clear citizens' acceptance intention degrees toward recycle and reuse PET bottle in order to evaluate citizens' intention about recycling PET. And, we carried out integrated evaluation of each PET bottle by the amount of carbon dioxide emission, cost and citizens' intention. As a result, material recycling is the best evaluation when recover rate is over 60%. If citizens' acceptance for reuse PET bottle becomes 90%, reuse is the best evaluation over the 50% recover rate.

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A phosphate rock is one of the natural resources of which exhaustion have been recognized in the world. Incinerator ash of sewage sludge is a hopeful substitute resource of phosphate rock. In this study, the increase in phosphorus recovery efficiency in the alkaline elution of incinerator ash of sewage sludge was investigated by adding coagulants to the sludge transported with pressure. PAC, sodium aluminate and poly-iron sulfate were used as coagulants. As a result, coagulant restrained phosphorus discharged from sludge by pH adjustment and decreased phosphorus in supernatant. PAC has wide range of use optimum pH and phosphorus recovery efficiency by alkali solution increased from 49% to 84% at pH4.

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Recently, the projects to protect natural environment and/or to create a better environment have increased with related various projects. Flexible operation of water discharge of dam is one of these projects. Discharge water from dam could improve the downstream river environments. However, it was difficult to measure its effect quantitatively.
In this paper, the method to grasp the effect of environmental improvement by discharge water from dam was examined. As the result, it is shown that the change of chlorophyll a of periphyton quantitatively is estimated by utilizing the near-infrared color image taken with the very low altitude remote sensing.

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Contamination of soil and groundwater by pollutants buried without proper treatment has become a social problem around the world. The objective of this project was to develop a Smart Subsurface Barrier System (SSB) that has functions of enclosing pollutants and remediating contaminated soils. This report describes a method for evaluating the hydraulic conductivity of the SSB using a seepage test, and an assumption method for joint defects using a radioisotope method (RI method). Both methods have been put to practical use. A thorough study has shown that the hydraulic conductivity of SSB is less than k=1.0×10^-7cm/sec, which is one of the strictest criteria of the EPA standard, so it is confirmed that the SSB is effective.

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Triethylamine in air was removed by using the silicagel made from the water glass. Triethylamine react with the silanol groups which exits on the surface of silicagel, and is fixed on silicagel.
In the heat analysis and IR analysis, the amount of the silanol groups changes by heat-treating and condensation reaction of silanol groups started at 200°C and ended at 600°C. The mount of the removal of the triethylamine has decreased along with this when the condensation reaction.
Triethylamine fixed on silicagel was easily excluded by the acid processing, and became former silicagel. There was no change in the removeal performance of the triethylamine though this processing was repeated 20 times.
The highest removal rate was 0.36g of trietylamine/1.0g of silicagel.

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pH, O₂, ammonia and nitrate concentration profiles contained in the attached biofilm on river rocks were measured with microelectrodes. The photosynthesis under the bright lux condition (8000lux) promoted the rapid O₂ concentration increase on the surface of the biofilm. Ammonia consumption activity under the bright lux condition was about twice as much active as under the dark lux condition. As for the attached biofilm on the riverbed rocks obtained from 5 spots in Shimanto river basin, ammonia consumption activity of the rock collected from the upstream was 0.06-0.13μmol/cm²⋅h, which showed more active value than that of the downstream.

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