| 摘要 |
<p>PURPOSE:To reduce the amt. of sludge with an existing digester as such and to obtain an economical sludge digesting system by providing an ultrafilter membrane in the stage for discharging digested sludge to concentrate the digested sludge and specifying the sludge withdrawal amt. per day in accordance with the capacity of a sludge digesting tank. CONSTITUTION:A sludge inlet pipe 4 is provided to a sludge digesting tank 1, the digested sludge is transferred to an ultrafilter membrane 2 by a pump 3, and the digested sludge is filtered therein and separated into the concd. digested sludge and water. The concd. sludge is returned to the tank 1. The sludge is periodically withdrawn by a pump 6 to keep a fixed amt. of sludge in the tank 1. The sludge in the amt. corresponding to 1/100 to 2/100 of the capacity of the tank 1 is withdrawn per day. An agitator is furnished in the tank 1 to uniformize the digested sludge. Since the amt. of sludge to be withdrawn is thus reduced, the sludge digesting bacteria are kept in the tank 1 for a long time.</p> |
