| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce generated sludge to zero by taking out a larger quantity of activated sludge than that of sludge increased by the assimilation of BOD in water to be treated from an aerobic treatment line and after solubilizing the activated sludge, introducing again to the aerobic treatment line. SOLUTION: Sewage 1 is treated with the aerobic activated sludge in a biological reaction tank 2 while supplying air 4 from an air diffusing device 3 and solid-liquid separated in a final settler 5. The solid-liquid separated sludge is returned to the biological reaction tank 2 as return sludge 7 by a return sludge pomp 6. The larger quantity of the activated sludge than that of the sludge increased by the assimilation of BOD in the sewage 1 is taken out by a supersonic treatment taking out pump 8 and introduced into a supersonic treatment reaction tank 9 as a part of the return sludge 7 to break the cells of microorganism constituting the sludge by supersonic wave generated by a supersonic generating device 10. The supersonic treated sludge is returned to the biological reaction tank 2 by a supersonic treated sludge return pump 11 to decompose into water, carbon dioxide and the like.</p> |
