多级A/O工艺强化处理城市污水的效果研究

以宜兴市某城市污水厂多级A/O工艺的运行监测数据为依据,分析了该工艺对宜兴城市污水中主要污染物和遗传毒性的去除效果.结果表明,多级A/O单元对COD、NH_4~+-N、TN、TP的平均去除率分别为:(67.3±7.0)%、(93.7±1.5)%、(65.3±7.9)%、(60.0±18.7)%,在整个工艺流程中对各常规污染物指标的去除起到了绝对主导作用;对污水中的烷烃、卤代烃、醇类去除效果较好,对污水中主要含有的荧光物质(芳香族蛋白质类似物)去除效果不理想;对污水中SOS/umu遗传毒性的去除率为82.8%.多级A/O工艺处理宜兴城市污水的主要问题是有机负荷低、单点进水和碳源单点投加效果不理想,以致后段A/O并没有充分发挥其强化去除优势,建议改为多点进水,调整碳源投加点.研究结果可为同类污水厂运行效果评价提供依据,也为提高该污水厂的运行效率提供技术支持.

Enhanced Pollutants Removal in a Municipal Wastewater Treatment Plant with Multistage A/O Process

Removal of conventional pollutants as well as genotoxicity was studied along a multistage A/O process, which was based on the monitoring data in a Municipal Wastewater Treatment Plant (MWWTP) of Yixing City. The results showed that the multistage A/O process removed (67.3±7.0)% of COD, (93.7±1.5)% of NH₄⁺-N, (65.3±7.9)% of TN and (60.0±18.7)% of TP, respectively, which played a dominant role in the removal performance of the whole wastewater treatment process. The multistage A/O process showed significant ability to reduce alkanes, halogenated hydrocarbons and alcohols in the municipal wastewater, while it failed to remove the aromatic proteins which were the main fluorescent substances of this wastewater. Furthermore, the process removed 82.8% genotoxicity from its influent. Low organic load, single-phase influent and undesirable carbon source feeding pattern, which caused the downstream A/O stages being not fully utilized, were considered as the predominant reasons for the relatively low performance of the multistage A/O process. Multi-phase feeding and adjusting carbon source feeding pattern were thereby proposed. The results were considered to be helpful for improving the operational performance of the MWWTP and useful for performance evaluation of MWWTPs with similar process.