PRODUCTION OF DRY SLUDGE FERTILIZER AND DRY SLUDGE FERTILIZER

摘要

PURPOSE:To reduce the production cost by mixing sludge incineration ashes and/or scum incineration ashes into sludge produced in night soil treating facilities and adjusting the N content of the formed dry sludge fertilizer, then drying the fertilizer. CONSTITUTION:The scum 1 is removed from the night soil 1 collected in the night soil treating facilities and is then treated to form the sludge 4 which is subjected to a dehydration treatment to form the dehydrated sludge 5 [80wt.% (hereinafter referred to as %) moisture, 20% solid content and 6.5% of the solid content is an N-component]. The dry sludge 6 (10% moisture, 90% solid content and 6.5% of the solid content is the N-component) is obtd. from the dehydrated sludge 5 at the time of starting and the dry sludge fertilizer 9 (10% moisture, 90% solid content and 5% of the solid content in the N-component) is obtd. from a mixture 8 (75% moisture, 25% solid content contg. ash content, and 5% of the solid content is the N- component) during stationary operation in a next drying stage A. On the other hand, the dry sludge 6 is distributed to proper ratios in a distributing stage B and is sent to an incineration stage C. The dry sludge 6 or the dry sludge fertilizer 9 and the scum 2 are incinerated to form the incineration ashes 10 (sludge incineration ashes 7 and scum incineration ashes 3). These incineration ashes are mixed with the dehydrated sludge 5, by which the mixture 8 is obtd.