| 摘要 |
<p>PURPOSE:To recover P from org. waste water contg. P components in parallel with the purification of the waste water by purifying the waste water through a biological treatment, maintaining the P components incorporated into the sludge in an anaerobic state and releasing the same into a soln. CONSTITUTION:Org. waste water contg. phosphates is subjected to an activated sludge treatment, whereby org. materials are removed therefrom; at the same time, the phosphates contained therein are incorporated into the sludge. This sludge is settled and separated. The supernatant is released to the outside of the system. The sludge is separated to return sludge and excess sludge. Part or the whole of the return sludge is concd. to >=1.5% sludge concn. and is fed into an anaerobic phosphorus releasing tank. In the phosphorus releasing tank, the P in the sludge is released when the sludge is agitated, whereby the supernatant of high P concn. is obtained. The P is recovered by a known method from this supernatant.</p> |
