The present invention avoids the direct flow of scruff from the first sediment tank and the second sediment tank to the digestion tank to raise its utilization rate.

• 本发明一沉池和/或二沉池的浮渣输送回曝气沉砂池进行收集，由于曝气沉砂池收集的浮渣含水率比较低，避免了一沉池、二沉池收集的含水率高的浮渣直接流入消化池，提高了消化池的有效利用率。