基于全流程分析的低碳氮比进水污水处理厂运行调控

为使某污水处理厂出水达标排放，对该厂进行了全流程测试，分析其主要污染物沿工艺流程分布特征以及活性污泥特性，评估工艺运行现状，为该污水处理厂优化调控提供基础数据。研究发现，该厂进水ρ（BOD₅）/ρ（TN）仅为2.45，属于典型的低碳氮比进水。此外，通过活性污泥特性测试发现，反硝化潜力为9.0 mg/（g·h），反硝化菌群相对丰度较高。进水碳源不足及外部碳源投加位点设置不合理是该厂无法实现TN达标排放的主要原因。在采取改变碳源投加位点、减小好氧池末端曝气量、增加碳源投加量等措施后，出水ρ（TN）由32.0 mg/L降至12.7 mg/L，实现了TN的达标排放；此外，厌氧释磷潜力由1.3 mg/（g·h）提升至2.6 mg/（g·h），生物除磷能力也有了较大提升。研究提供了一种解决污水处理厂出水水质超标问题的思路，可为含低碳氮比进水的城镇污水处理厂运行调控及稳定达标提供参考。

OPERATION REGULATION OF WASTEWATER TREATMENT PLANT WITH LOW CARBON-TO-NITROGEN RATIO INFLUENT BASED ON WHOLE PROCESS ANALYSIS METHOD

In order to make the effluent of a wastewater treatment plant(WWTP) reach the emission standard, the whole process test was carried out. After analyzing the changes of pollutants along the process as well as the characteristics of activated sludge and assessing the current status of process operation, basic data for optimal regulation was provided. The study found that the BOD₅ to total nitrogen (TN) ratio of the influent was only 2.45, which belonged to low carbon-to-nitrogen ratio influent. In addition, the activated sludge characteristics test found that the denitrification potential was 9.0 mg/(g·h), and the relative abundance of denitrifying bacteria was high. Therefore, insufficient carbon source in the influent and unreasonable dosing site of external carbon source were the main reasons for the poor nitrogen removal effect of the WWTP. The total nitrogen of the effluent was reduced from 32.0 mg/L to 12.7 mg/L by changing the carbon source dosing site, reducing the aeration volume of the biochemical reaction tank and increasing the amount of carbon source dosing, which realized the standard discharge of total nitrogen. In addition, the anaerobic phosphorus release potential increased from 1.3 mg/(g·h) to 2.6 mg/(g·h), which meant that the biological phosphorus removal capacity had also been greatly improved. This study provided a way to discover and solve problems in WWTPs with effluent exceeding the standard, which provided references for controlling operation and reaching standard for discharge of WWTPs with low carbon-to-nitrogen ratio influent.