Isao Fukunaga*, Osamu Yamamoto** and Zensuke Inoue***

*Osaka City Institute of Public Health and Environmental Sciences
**Global Environment Center (Osaka City)
***Formerly Osaka City Institute of Public Health and Environmental Sciences

+ Correspondence should be addressed to Isao Fukunaga:
Osaka City Institute of Public Health and Environmental Sciences
(8-34, Tohjo-cho, Tennoji-ku, Osaka 543, Japan)

Abstract

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.

Key words: sea-based solid waste disposal, preceding disposal, solid waste disposal site, leaching, lagoon, self-purification