臭氧在中试规模污泥原位减量中的应用

为探究高、低浓度臭氧旁路处理对中试系统出水水质、污泥减量率的影响,采用两组系统(对照组:厌氧/缺氧/好氧(A/A/O),试验组:A/A/O+臭氧旁路处理)在5个工况下运行183d.结果表明,利用剂量为13mg/g MLSS(25mg/g MLVSS)臭氧处理占生物反应池容积20％的回流污泥时,系统运行性能良好;在此操作...

Studies on the application of ozone in the pilot-scale in-situ sludge reduction system

The effects of partial ozonation of returned sludge via high-and low-concentration ozone on effluent quality and sludge reduction rate in a pilot-scale system were explored. The pilot-scale system of anaerobic/anoxic/oxic(A/A/O)+ozonated sludge recycle(OSR) process was operated under 5 conditions for 183 days. This system showed superior operation performance when 20%of the total volume of returned sludge in the A/A/O module was treated by the dosage of 13 mg/g MLSS(25 mg/g MLVSS) per day.Under this condition, the COD, NH₄⁺-N and TN of effluent could reach the first-class B standard of "Discharge standard of pollutants for municipal wastewater treatment plant"(GB18918-2002) with the treatment of both low-and high-concentration ozone(150 mg/L and 380 mg/L, respectively). In addition, compared with the low-concentration ozone treatment, the reduction in nutrients removal rate via high-concentration ozone treatment was lower, indicating the advantage of high-concentration ozone treatment in nutrients removal. The optimal SRT for low-concentration ozone treatment was 25 days, and the reduction rate of organic matters in excess sludge was 14.07%, and of total excess sludge was 8.33%. The optimal SRT for high-concentration ozone treatment was 75 days, and the reduction rates of organic matters and total excess sludge were 41.53% and 25.92%, respectively. At the same ozone dosage, the sludge reduction efficiency after high-concentration ozone treatment was obviously higher than that of low-concentration one. In addition, low temperature had no significant effect on the reduction rate and effluent quality when high-concentration ozone treatment was applied. Thus, the application of the "A/A/O+OSR" system was not significantly affected by temperature. The application of high-concentration ozone in WWTPs in this study provides practical guidance for the improvement of in-situ sludge reduction technology.