改良多级A/O对低C/N生活污水强化除磷效果研究

针对传统多级A/O工艺处理低碳氮比生活污水除磷效果差的问题，通过增设前置厌氧段改良多级A/O工艺，重点研究了除磷效果的可行性。结果表明：在温度为17℃±3℃、流量分配比为100%∶0∶0、水力停留时间为10h、污泥回流比为50%、污泥龄为14天的条件下，系统总体除磷效果较好。其中COD、TP平均去除率分别为89.81%、90.35%，出水平均浓度分别为32.65mg/L、0.49mg/L，均优于GB 18918—2002《城镇污水处理厂污染物排放标准》一级A排放标准。由于受到硝化反硝化的综合影响，对污水中含有的氮素去除效果一般，其中NH₃-N、TN去除率均为50%左右，出水平均浓度为30.32mg/L、30.41mg/L，可通过外加碳源的方式增强反硝化能力，进一步提高系统脱氮效果，出水有望达到一级B标准。改良工艺在保证有机物去除效果的基础上基本实现了脱氮除磷，可为实际生活中处理低C/N生活污水提供参考。

Study on enhanced phosphorus removal effect of improved multi-stage A/O on low C/N domestic sewage

The problem is that the traditional multi-stage A/O process is inferior to the phosphorus removal effect of low-carbon nitrogen and domestic sewage, by adding a pre-anaerobic section to improve the multi-stage A/O process, the feasibility of the phosphorus removal effect was mainly studied. The results show that under the conditions of temperature 17℃±3℃, flow distribution ratio of 100%∶0∶0, hydraulic retention time of 10h, sludge return ratio of 50%, and sludge age of 14d, the system of the overall phosphorus removal effect is better. Among them, the average removal rates of COD and TP were 89.81% and 90.35%, and the average effluent concentrations were 32.65mg/L and 0.49mg/L, which were better than Grade A of GB 18918—2002 "Emission Standards for Pollutants of Urban Wastewater Treatment Plants" Emission Standards. Due to the comprehensive influence of nitrification and denitrification, the removal effect of nitrogen in sewage is general. The removal rate of NH₃-N and TN is about 50%, and the average concentration of effluent is 30.32mg/L and 30.41mg/L. By adding a carbon source, the denitrification capacity is enhanced to further improve the denitrification effect of the system, and the effluent is expected to reach Class B standards. The improved process basically realizes the removal of nitrogen and phosphorus on the basis of ensuring the removal effect of organic matter, which can provide a reference for the treatment of low C/N domestic sewage in actual life.