Keiichi Kawai

Faculty of Agriculture, Gifu University
(1-1 Yanagido, Gifu 501-11 Japan)

Abstract

To elucidate the removal mechanism of leachate's organics from solid waste by microorganisms in an aerated lagoon at a sea-based solid waste disposal site at the North port of Osaka city, we examined the microflora and microbial activities in the aerated lagoon. There were no pathogenic bacteria of the genera Pseudomonas, Salmonella, shigella and Vibrio in the aerated lagoon. Most bacteria living in the aerated lagoon were non-fermentative for glucose and non-decomposable for urea, showing that they utilized low molecular organic acids and inorganic nitrogen. The dominant genera in the aerated lagoon were Alcaligenes, Micrococcus, Moraxella, Aeromonas and Acinetobacter during the lower leachate loading period. During the high loading period, in addition to the above genera, Flavobacterium and Paracoccus were also detected as dominant genera.

Treatment studies of leachate by dominant genera (Micrococcus, Paracoccus, Acinetobacter, Aerococcus and Moraxella) revealed that COD, total nitrogen or NH4-nitrogen was reduced by bacterium isolated from the aerated lagoon.

Key words: microflora, aerated lagoon, leachate, sea-based solid waste disposal, dominant bacterial genera