| 摘要 |
<p>PURPOSE:To enhance the efficiency of denitrification and reduce the running cost by fermenting org. sludge with acid producing bacteria at a specified pH or below under anaerobic conditions to form org. acid and utilizing the acid as a carbon source for denitrification with microorganism. CONSTITUTION:Org. sludge is introduced into thickener 4, concd., and introduced into reactor 22. Reactor 22 is heated to about 30-70 deg.C with steam 24 from a steam generator, and after adjusting to <=6.8pH with sulfuric acid or the like 23 the sludge is fermented with acid producing bacteria under anaerobic conditions such as in a hermetically sealed container to form org. acid. The fermentation product is then subjected to solid-liq. separation in thickener 25, the sludge is discharged from the bottom, and org. acid-contg. separated liq. 18 is fed to denitrification reactor 15. In reactor 15 denitrification is carried out with facultative anaerobic bacteria using the org. acid as a carbon source. The denitrified liq. is degassed in degassing tank 16 and subjected to solid-liq. separation in clarifier 18. Separated water 9 is drained, and part of the solid is returned to reactor 15.</p> |
