On the basic study of gas flow and mixing in the combustion chamber of an MSW incinerator, the effectiveness of the computational fluid dynamic method were evaluated by comparison with the data of visualization, gas tracer, and reaction experiment.
Correspondence between the experimental value, and calculated one of velocity vectors and tracer distributions were discussed by the error of mean square and plotting. The inlet boundary condition of turbulence kinetic energy (k) and turbulence dissipation rate (ε) were evaluated. Reaction results with NO and O₃were also compared. In addition, turbulence model constants of thek-ε model were discussed regarding fitness.
Calculation conditions of computational simulation method were confirmed through the comparison of detailed experimental data of this study.

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To obtain public acceptance for construction of landfill sites, it is important to consider not only the theoretical presentation of non-hazardousness of landfill sites, but also public confidence and public involvement at any planning stages of the landfill site construction. People living around a proposed landfill site tend to demand a non health-hazardous landfill site, which means improvement of the functions of the landfill site, on a negotiation table. On the other hand, an administration finds difficulty in constructing the improved landfill site because of budgetary restriction on public works. Therefore, those contradictory relations cause many difficulties in the negotiation.
The objective of this paper is firstly to examine the above mentioned contradictory relations between improving functions and construction cost of landfill sites, and secondarily to demonstrate the possibility of improved and less expensive landfill sites. Namely, thirty-two typical existing landfill sites were analyzed with regard to construction cost and functions related with improved landfill sites. Based on this case study, three ideally-improved landfill site models were proposed and their costs were estimated. It is concluded that each of the three models is sufficiently equipped with non health-hazardous functions and that the construction cost is reasonable.

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Sub-critical water hydrolysis of fish meat was studied at 513 K (3.35 MPa), 528 K (4.32 MPa), and 548 K (5.51 MPa) . Reaction conditions significantly affected the total organic carbon (TOC) distribution among aqueous, oil, and solid phases. Inorganic acid (IC) yields were much lower than TOC yields, and carbonic acid was found as the major inorganic carbon. The addition of H₂O₂as an oxidant significantly affected the product composition of the reaction, suggesting that the yield of a specific product could be controlled by the addition of suitable amounts of the oxidants.

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As a method of comprehensively evaluating human activities from the viewpoint of the global environment, LCA has been introduced. However, noting LCCO₂in which CO₂is assessed, we investigated CO₂discharge affecting global warming during the construction and operation of smallscale wastewater treatment plants, as well as changes in CO₂discharge according to the size of the plant in the range of the evaluated scale. The findings are as follows :
(1) The CO₂discharge during construction was the highest in the smallest scale plants that require construction of an inflow pump tank, but decreased as the scale of the plant increased. The maximum CO₂discharge by a johkasou system at a BOD concentration of 20 mg/L of effluent was 30% higher than that by a johkasou system at a BOD concentration of 60 mg/L of effluent.
(2) When advanced treatment was added to the johkasou system at a BOD concentration of 20 mg/L of effluent, the CO₂discharge during construction increased threefold.
(3) In the johkasou system at a BOD concentration of 20 mg/L of effluent, the maximum CO₂ discharge during operation was 26 times that during construction.
(4) In the johkasou system at a BOD concentration of 20 mg/L of effluent with an inflow 65 m³/d, the CO₂discharge by the RC system was 1.6 times that of the FRP system.
(5) The CO₂discharge during operation accounted for 94-97% of all CO₂discharge during both construction and operation.

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PVC powder added CaCO₃or Ca-Fe composite oxide were burnt and the capturing rates of hydrogenchloride by those additives were measured. The capturing rate of hydrogenchloride by CaCO₃increased with the increasing specific surface area, and the dependency of the capturing rate on a specific surface area by Ca-Fe composite oxide was also observed and those capturing rates increased to 1.5 - 2.1 times of the values by CaCO₃. Furthermore, the capturing rate of hydrogenchloride at combustion and the thermal stability of PVC sheets in which each additive was kneaded were measured. As a result, it was confirmed that both performances of the PVC sheet added composites were very superior.

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