In previous studies (part I) it has been established that methane fermentation of chromium-free tannery wastes results in partly stabilised post-fermentation sludges, rich in nitrogen and phosphorus. This part of the investigations have confirmed that in view of the quality of fertilising material, the composting of post-fermentation sludges is most beneficial; and composting of non-fermented wastes is less beneficial. The sludges from short fermentation (only partly stabilised) and after prolonged fermentation were subjected to composting. The composting of sludges allowed to obtain material, rich in basic fertilising components and organic soil-forming components. The paper shows that it is possible to reduce the arduousness of direct composting (with the omission of fermentation) of chromium-free tannery wastes. The dependence of the quantity of basic fertilising and soil-forming components in the obtained material on the applied processing conditions has been shown.

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