| 摘要 |
<p>PURPOSE:To prevent the deterioration of activated sludge, keep the activated sludge highly active and stabilize treatment by using a reaction sludge formed from excess sludge as a microorganism adsorbent. CONSTITUTION:The contaminant in raw water is treated with activated sludge as follows. Namely, 100 parts of raw water and 1-30 parts, preferably 3-15 parts, of return sludge are mixed and agitated, the reaction sludge is floated, concentrated and separated, and a sludge contg. >=0.5%, preferably >=2%, solid and treated water are obtained. The treated water and return sludge are aerated in an activated-sludge aeration tank, solid is separated from liq., and a final effluent and return sludge are obtained. The return sludge is anaerobically and aerobically digested in a concd. sludge digestion tank to biologically decompose the contaminant adsorbed by the reaction sludge, and a digested sludge is obtained. The digested sludge is drawn off as the excess sludge.</p> |
