Isao Fukunaka*, Zensuke Inoue*, Kazuhiro Takamizawa**, Toshihiko Hasebe***, Miyoji Konae***, Kiyoshi Hatano***, Takao Takemika****, Hiroshi Iida**** and Syoichi Mori*****,

*Osaka City Institute of Public Health and Environmal Sciences,
**Agricultural Faculty of Gifu University,
***Osaka City Port and Harbor Bureau,
****Environmal Protection Research Center
*****Mori Institute of Ecology, Ltd.

+ Correspondence should be addressed to Isao Fukunaga:
Osaka City Institute Publ. Health Environm. Sci.
(8-34, Tohjo-cho, Tennoji-ku, Osaka 543, Japan)

Abstract

The North Section of the Osaka North Port Solid Waste Disposal Site was used from 1973 to 1986, and after that landfilling work was switched over to the South Section. The water quality of the site caused no problem in the early phase of landfilling; however, following the progress of landfilling, increases of COD and SS were brought about in the stabilization pond through logarithmic growth of phytoplankton, and it was found necessary to treat wastewater, removing suspended solids mainly composed of phytoplankton. It was found that sand filtration is effective for water pollution control from the Site. The problems are filtration blockade and a low filtration rate, that is 6.3m3/m2/day, with a head loss of 1m. Treatment by higher organisms was found to apply, depending upon the conditions of the Site.

Key words: Osaka North Port Sea-Based Solid Waste Disposal Site, Stabilization pond, phytoplankton, sand filtration, higher organisms