This study, which uses examples from inner Osaka Bay, will show the improvements in flow environment promoted by installation of a permeable breakwater. In addition, it demonstrates, improvements in the coastal environment as shown by an index of growth of the biotic community adhering to gentle slope-type seawall, which enable the evaluation of the technology considered in this report. Hydraulic model testing shows that improvements in flow environment can be realized, and laboratory experiments and onsite field research that changes in the flow environment should result in a diversification of the bioecology.

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In this study, applicability of one-dimensional infiltration model for NAPL pure liquid behavior in unsaturated/saturated porous media was investigated. The progressing rate of TCE front in glass beads layers, vertical distribution of TCE and water, and total amount of volatilization of TCE were used as observed values to evaluate the model. The result revealed that it is needed to introduce residual NAPL saturation in unsaturated/saturated zones to the model in order to present the observed data. The residual NAPL saturation tended to increase with water saturation in unsaturated zone. In addition, the model could present the TCE distribution when an injection rate was changed.

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At an extremely small-sized oxidation ditch (OD), intermittent aeration has been required for the nitrogen removal from domestic sewage. This paper examined the effect of high-loading operation on nitrogen removal in the OD process with continuous aeration. High-loading operation made it possible to obtain more than 80% nitrogen removal even under the conditions of the recirculation time less than 10min.. DO recirculation rate (R_DO) was demonstrated theoretically as one of the important operational parameters in the process. The experimental results also showed that the increase of R_DO led to the deterioration of the nitrogen removal. Nitrogen removal in the process was also affected by net C/N ratio for denitrification (η value) which was defined after consideration of DO inflow into the anoxic zone.

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Two SBR reactors were operated with feed of domestic sewage (Run-S) and enriched sewage with particulate organic matters (Run-SP) until stable EBPR process was developed, while the third reactor was fed with acetate (Run-A) for a reference. Microbial community of activated sludges was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. Based on the analysis of DGGE band patterns, three bands were found commonly in all the lanes. Four bands were common between Run-A and Run-SP. There was no remarkable difference in band patterns between Run-A and Run-SP, which indicated that the addition of POM did not affect significantly the microbial community change in the activated sludge. The DNA sequences of the bands C1 and A/SP corresponded to the related sequences of Thiothrix sp. and Rhodocyclus sp., respectively.

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To study transport phenomena of petroleum hydrocarbons in vadose zones, capillary rise experiments using acrylic and glass columns containing Toyoura standard sand for three different hydrocarbons-gasoline, kerosene, and diesel oil-together with water and ethanol were performed in dry and water-wet conditions. The experimental results show that transportability of oils decreases in conditions of residual saturation by water compared with dry conditions, and that gasoline has the highest transportability and diesel fuel the lowest while kerosene intermediate. Analytical solutions to Washburn and Green-Ampt's equations for dynamic capillary rise were derived to show their equality, and these solutions showed excellent agreement with the experimental results. Parameters such as contact angle and equivalent diameter of capillary tubes were estimated using Powell's method with experimental data

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The amount of incinerator ash of sewage sludge produced in wastewater treatment plants in Japan has increased year by year as the percent of sewered population increases. The incinerator ash is considered to be hopeful resource of phosphorus, because phosphate ore has some fear for the exhaustion in the world today. In this study, the influence of temperature on alkaline elution of incinerator ash of sewage sludge was investigated using X ray analysis and elution experiments. Heating alkaline elution of incinerator ash at 40°C eluted phosphorus without the elution of zinc. It was found that the substance eluted from incinerator ash was aluminum phosphate which occupies about 50% of total phosphorus compounds contained in the ash.

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This paper evaluated the effects of the pump-and-treat technique and natural attenuation of trichloroethylene (TCE) at a contaminated site. At this site, the pump-and-treat technique for 14 years succeeded in the decontamination of shallow groundwater. During this time, the restoration rate, which was the rate of the decrease in TCE concentration, was observed to increase with the amount of groundwater extracted while the concentration exceeded the environmental standard, but this relationship ceased when the concentration came within the standard. In the meanwhile, dichloroethylene concentrations were about 64% of the TCE concentrations and natural attenuation shortened the restoration period by 2 years.

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