The present situation and the future of sludge disposal in Japan is briefly described. Sludge has been re-used as the earth mixed in top soil or in garden soil, some technological resources and some manufactured goods. A table shows these applications. Research into the freezing-thawing method and sand drying bed without relying on any chemical treatments, is carried on. For the future the following guidelines are considered: This requires a decrease of the amount of the coagulant for flocculation, introduction of a direct filtration system, use of a submerged biological filter process.
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