| 摘要 |
<p>PROBLEM TO BE SOLVED: To decrease excess sludge, to simplify equipment and to lower cost by treating an org. waste water with an aerobic product, then separating solid from liq., forming and accumulating a low molecular org. acid under feebly aerobic conditions in the stage for solubilizing a part of the obtained sludge at a high temp. and then aerating the water to an aerobic state. SOLUTION: The raw waste water A in a row waste water storage tank 10 is introduced into an aerator 14 through a line 12 and aerobically treated, and then the treated water B is introduced into a settling device 16 to separate solid from liq. A part D of the separated sludge is joined to the line 12 through a reflux line 18 and introduced into the aerator 14, and the remaining sludge E is introduced into a solubilizer 24. The sludge is aerobically solubilized at a high temp. in a feebly aerobic tank 24a under feebly aerobic conditions and then aerobically digested at a high temp. in an aerobic tank 24b, and the solubilized liq. F is joined to the line 12 through a return line 26 and a heat exchanger 28, introduced into the aerator 14 and undergoes aerobically biological treatment.</p> |
