| 摘要 |
<p>PURPOSE: To nitrate the sewage at a high rate by forming a packed bed with a specified packing with nitrating bacteria immobilized on its surface and passing a liq. mixture of activated sludge and sewage through the packed bed under aerobic conditions. CONSTITUTION: A bed C packed with a packing with nitrating bacteria immobilized on its surface, having <=0.1 sp.gr. and which is not deformed by pressure and having the water passage void not hindering the passage of activated sludge is formed in a nitration part. A denitrifying soln. is supplied upward from a diffuser pipe 3, air is supplied by an air-lift effect, and a liq. mixture 12 of activated sludge and sewage is passed through the packed bed C under aerobic conditions. In this case, the packing ratio of the packed bed C having the water passage void not hindering the passage of activated sludge is controlled to <=25%. The packing is formed with a small bent bar made of expanded polystyrene, etc. Consequently, nitration is performed at a high rate.</p> |
