Embedded side stream sludge reduction wastewater treatment system

An innovation wastewater treatment system, which can reduce sludge production, separate inorganic solids, recover phosphorus, and enhance nutrient removal simultaneously, was developed to decrease the excess sludge yield in activated sludge process and solve the problem of inorganic solids(grit) accumulation in wastewater treatment plant. The capacity of the pilot scale reactor was 10m3/d and it had operated stablely for more than 90days. The effluent concentration of NH4 +-N, TN, TP and COD was(0.5±0.3)mg/L,(8.6±1.6)mg/L,(0.14±0.04)mg/L and(26.8±8.8)mg/L, respectively. The effluent quality met the first class A criteria, and far less than the limit value. During the period of system operating, the ratio of mixed liquor volatile suspended solids(MLVSS) to mixed liquor suspended solids(MLSS) gradually increased from 0.33to 0.52. The results indicated that this process effectively prevented the accumulation of inert or inorganic solids in the activated sludge. Furthermore, the observed sludge yield Yobs of the system was 0.103g VSS/g COD, so the system shows a good performance of sludge reduction.