In this study, we examined three advanced oxidation processes and compared their performances in the treatment of landfill leachate. The ozone/hydrogen peroxide process, the ozone/ultraviolet process, and the hydrogen peroxide/ultraviolet process were examined. The results we found were that the ozone/hydrogen peroxide process and the ozone/ultraviolet process were effective in decreasing the COD, TOC and colour, and also in the degradation of micropollutants. The hydrogen peroxide/ultraviolet process was not effective in the decrease of COD and TOC, but it was effective in the degradation of micropollutants. The ozone/hydrogen peroxide process showed a higher performance in the decomposition of tris (2-chloroethyl) phosphate than the ultraviolet processes.

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Experiments on oxidation in supercritical water were carried out with a batch reactor system in order to treat organic waste with a high water content and low calorific value, such as organic garbage. 22 kinds of vegetables, meats and fishes were chosen. This study focused on understanding the differences or similarities in the oxidation reaction among selected types of garbage and the effect of reaction parameters.
Certain selected vegetables were easily oxidized and no significant difference among them was found, but meats and fishes were more difficult to oxidize than vegetables. Beef suet was found to be the most difficult substance to decompose by supercritical water oxidation. No remarkable difference of kinds of meat and fish on the TOC decomposition was found. The intermediate residual product was acetic acid in all cases.
To obtain a TOC decomposition higher than 99% in a 10 minute reaction, the reaction temperature must be above 400°C in the case of vegetables and 450-C in the case of meat and fish. By supplying excess H₂O₂ and/or increasing the temperature, the TOC decomposition can be accelerated. However, a further increase in the reaction time had little effect on the decomposition of the residual organic substance, that is acetic acid. The variation of water fill rate, that is the reaction pressure or the water density, in the range of 30 to 50% (35 - 58 MPa) appeared to have little effect on the TOC decomposition.

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The life cycle energy consumption (LEC) and CO₂ emission (LCE) of soap made from recycled food-oil waste (FOW) by the S-plant of Kawasaki were compared with those of the following alternative FOW treatments : (A) discharge into the municipal sewage system, (B) disposal as combustible trash after being treated with an oil-solidifying reagent, and (C) disposal as combustible trash after being absorbed in newspaper. An inventory analysis of the production of regular recycled detergent indicated that it is unfavorable with respect to both energy consumption and CO₂ emission compared with detergent made from vegetable oil. On the basis of the official data concerning the municipal sewage and garbage treatments of Kawasaki along with several tacit assumptions, the LEC and the LCE per kg of recycled detergent and those of the equivalent amount of oil waste were calculated as follows : (Treatment/MJ/kg CO₂) : Recycled soap/ 13/ 1.8; A/ 9.8/ 2.3; B/ 0.7/ 2.2; C (0 % newspaper recycling) /- 1.7/ 2.0; C (100% newspaper recycling) / 8.2/ 6.2.

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An availability test, a pH-dependent test and a Japanese leaching test were applied to untreated and phosphate treated fly ash from municipal solid waste melting facilities in order to determine the leaching potential and behavior of metals. The results of the leaching tests show that the treated fly ash had a lower leaching potential and releaserate of metals than untreated fly ash. XRD analysis revealed that chloropyromorphite (Pb₅ (P0₄) ₃Cl) was formed in the treated fly ash.

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As an effective utilization of waste stillage, which will be banned from being dumped into the sea from the year 2001, the authors have been studying and succeeded in making sosei paper by using waste stillage from a sweet potato shochu distillery.
However, sweet potato waste stillage (hereafter, SPWS) which has been used as the material for the making of sosei paper is difficult to supply, because it is produced only from September to December. On the other hand, barely waste stillage (hereafter BWS) is produced constantly through the year, and so it is in large quantity.
This research has tried to make it clear that sosei paper can be produced by using BWS and to compare the physical and mechanical properties of sosei paper produced by using each waste stillage and also to consider the weight and property of waste water on molding samples. The following results were obtained :
1) Barely sosei paper was greater in destiny and less in strength than sweet potato sosei paper. 2) As for the grain size distribution, SPWS consisted of grains of different particle sizes. On the other hand, BWS consisted of grains of equally small sizes. 3) In order not to produce waste water in the process of adding pressure, BWS requires about 1.7 times more old newspaper than SPWS. 4) As for the molding samples, the ratio of old newspaper to waste stillage is 1 % and more than 70% of the COD, TOC, T-N components can be removed from the waste water in the case of SPWS, and more than 45% in the case of BWS.

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Ethanol washing (with distillation as a cleanup process) of benzo (a) pyrene (B (a) P) -contaminated soil was investigated in this study. A multistage-cascade-solvent washing process was applied to three different types of soil, i. e., sandy soil, alluvial soil, and ando soil, with an initial concentration of 10 and 100 mg B (a) P/kg soil. The ethanol used as the washing solvent was re-used after distillation. Satisfactory results (i. e. less than 1 mg B (a) P/kg soil, which is equivalent the Canadian soil standard for residential and park areas) for three types of soil with 10 and 100 mg/kg soil were obtained by washing the soil five-six times at most. It is suggested that the organic content in the soil decreased the efficiency of removal by ethanol washing.

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