The quantity and quality changes of the leachate from a bed packed with incinerated ash from municipal solid waste were investigated under real meteorological conditions for one year. A tank model taking into account the actual precipitation and leaching phenomenon in the packed bed, was constructed and used for evaluating the fluctuations of both water quantity and quality. Main conclusions obtained in this investigation were as follows: (1) Neither the monthly mean ratio of leachate quantity to precipitation (=monthly leaching coefficient) nor the monthly mean ratio of evaporation from the packed bed surface to evaporation from water surface (=monthly specific evaporation) were constant during the course of the experiment. These were fluctuated with a change in meteorological conditions. (2) The change of Cl^- concentration in the leachate could be explained by the water quantity tank model and the water quality tank model based on two-step leaching of Cl in the ash. In the two-step water quality tank model, it was assumed that the easily leachable Cl in the ash first leached, and then the non-easily leachable Cl (total Cl content-easily leachable Cl) leached at a slower rate. (3) Under real meteorological conditions, even in a bed packed only with incinerated ash from municipal solid waste, it was likely that the COD and TN contents in the ash were partially biodegraded. The contributions of the biodegradation were small compared to the original total contents, but large compared to the amounts in the leachate.

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At the first site of the Osaka North Port Sea-Based Solid Waste Disposal Site, BOD and COD values of the water of facultative pond had been graduallyincreasing from the beginning of preceding disposal (1985) . When sea-based disposal started in April of 1987, the values had suddenly increased and then BOD values had levelled off while COD values had only a slight increase. But from the beginning of the second layer disposal (on April in 1990) those values had declined until another sea-based disposal started again in January of 1992. After this, the values had increased by September of 1992 when the sea-based disposal stopped and second layer disposal started again. And then those values declined until now, December of 1993.
We consider that the reason for these changes is the differences in sea-based disposal and second layer disposal. By analysing factors of those results one model will be proposed for leaching of organic substance and its disintegration mechanism in the Lagoon. Data used for the model are observed water data, quantity and area of preceding disposal, quantity of disposed solid waste of sea-based disposal, and second layer diposal area of sea-based disposal and area of second and third layer disposal. Next conditions were then supposed. The first is that leaching quantity of organic substance of preceding disposal is proportional to its disposal area and that of sea-based disposal, second layer disposal and the third are proportional to the quantity of disposal. The second is that disintegration coefficients of preceding disposal is different from that of sea-based, second and third layer disposal. Calculated results of the model coincided very well to observed data. As for the disposal procedure, there are two methods. One is total disposing of sea-based disposal before second and third layer disposal and the other is repetion of sea-based disposal and second and third disposal. From these results it should be concluded that the selection of two methods depends on conditions of discharge of effluent and wastewater treatment.

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Proliferated yeasts were recovered from the wastewater treatment process of the food industry and yeast cell contents were extracted with various procedures. Of these extraction methods, autolysis and heat treatment under acid or alkaline condition were evaluated to be rather effective. Alkaline hydrolysis ranging from 100°to 120°C at pH over 12 resulted in more than 80% of the extraction yield. The three yeast extracts prepared were applied to the medium component for microorganism growth and mushroom cultivation. Since they equally supported the growth of lactic acid bacteria which invariably had complex nutritional requirements in comparison to the commercial ones, three yeast extracts were confirmed to stand comparison with them. Furthermore, the promoting effects of the yeasts and the yeast extract through autolysis on mycerial growth and fruiting of mushrooms was also proved.

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Glasses were prepared bymelting the sewage sludge slag, and the relation between the properties and the chemical composition of the glasses, especially, the ratio of Fe²⁺/ (Fe²⁺+Fe³⁺) was analyzed in detail. The glasses were dark brown and not transparent due to high concentration of iron oxide. It was found that the properties of the slag glass were similar to those of aluminosilicate glasses which are available commercially. It was possible to control the ratio of Fe²⁺/ (Fe²⁺+Fe³⁺) in glass by adding graphite powder to the raw materials of glass. It was found that, as the fraction of Fe²⁺ion increases, the thermal expansion coefficient increases, density decreases, glass transition temperature decreases and viscosity also decreases.

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