西安第五污水处理厂污泥消化及沼气利用效果分析

Analysis of Sludge Anaerobic Digestion and Biogas Utilization in Xi'an No.5 WWTP

通过对西安市第五污水处理厂污泥厌氧消化系统实际运行参数的测试与分析,探讨了该厂污泥消化池实际运行中影响产气效果的主要因素和沼气实际利用情况。该厂3号消化池由于搅拌设备故障导致碱度和VFA含量有增大趋势;实测产气率为8.5 m^3/m^3泥,产气量为1.186L/g VS,污泥的产气能力较好;沼气锅炉、沼气拖动鼓风机和废气燃烧塔消耗沼气量分别占总产气量的41%、33%和26%,沼气利用率较低。因此,建议在运行中强化沼气拖动鼓风机设备的维护,提高产气量和沼气利用率,以降低污水处理厂运行电耗。

On the basis of the actual operation parameters of the sludge anaerobic digestion system in Xi＇ an No. 5 WWTP, the major influence factors to biogas production in actual operation of sludge digestion tank and actual utilization of methane were investigated. The results showed that alkalinity and VFA concentration in No. 3 digestion tank trended to increase due to failure of mixing equipment. The biogas production rate of digestion tank was 8.5 m3/m3 sludge and biogas production of decomposing unit VS was 1. 186 L/g, which was showing a satisfactory biogas production capacity of sewage sludge. The biogas consumption of biogas boiler, methane air blower and biogas buring tower accounted for 41%, 33% and 26% of the total production respectively, which was showing a low biogas utilization ratio. Thus, it is recommended to intensify maintenance of methane air blower and improve gas production rate and utilization ratio of biogas to reduce energy consumption of wastewater treatment plant in operation.