自热式高温好氧消化污泥稳定化系统

Autothermal Thermophilic Aerobic Digestion System for Sludge Stabilization

设计了一套自热式高温好氧消化(ATAD)中试系统用于城市污水污泥的稳定化处理。通过批式运行,考察了进泥含固率、消化时间、曝气量及循环污泥流量等因素对反应温度及挥发性悬浮固体(VSS)去除率的影响以及pH值的变化、脱氢酶活性及病原菌的灭活情况。结果表明,适宜的进泥含固率为5%～8%(VSS浓度为26～48g/L);消化时间为10～11d;最佳曝气量为0.8～0.9m3/(m3·h);最佳循环回流量为12～14m3/h;运行期间pH值呈上升趋势,出泥pH值为7.5～8.0。在上述工艺条件下,ATAD系统反应器内温度可达到54℃,对VSS的去除率为48.7%,病原菌的灭活率可达到100%,出泥可达到美国A级污泥标准。

A pilot scale facility of autothermal thermophilic aerobic digestion (ATAD) was designed for stabilization of urban sewage sludge. The influence of incoming sludge total solid content, digestion time, aeration rate, and circulating flow rate on the reaction temperature and removal rate of volatile suspended solid (VSS) was investigated by way of batch operation, and the variation of pH value, dehydrogenase activity and pathogen inactivation were also examined. The results show that the optimal value of incoming sludge solid content, VSS, digestion time, the optimal aeration rate, and the optimal circulating flow rate are 5%-8%, 26-48 g/L, 10-11 d, 0.8-0.9 m3/(m3·h), and 12-14 m3/h respectively. The pH value is on the rise with 7.5-8.0 in outlet sludge. Under the above optimum conditions, the reaction temperature of ATAD system can come up to 54 ℃, and the rate of VSS removal and pathogen inactivation is 48.7% and 100% respectively. It means that ATAD system can produce A-class sludge according to the American standard.