改良回流模式的UCT工艺处理高氮屠宰废水的工程案例

采用改良回流模式的UCT工艺处理高氮屠宰废水，该系统处理能力为200 m³·d⁻¹。连续130 d的调试运行结果表明，在进水水质较稳定的情况下，该工艺对COD、氨氮、总氮和总磷的去除率分别达到97%、98%、94%和92%，出水水质达到《屠宰与肉类加工工业水污染物排放标准 (征求意见稿) 》的间接排放标准。该工艺调试运行初期，通过投加碳源以及微量元素，有效避免污泥老化问题；在稳定运行过程中，调整硝化混合液回流比、缺氧混合液回流比以及污泥回流比分别至267%、82%和70%，使得工艺处于最佳条件下运行；结合各工艺段荧光图谱分析结果显示，改良回流模式的UCT工艺有效降解色氨酸类物质及可溶性微生物副产物，具有较好的脱氮效果；工程改造成本中涉及设备和调试费用不高，且与传统屠宰废水处理流程比，吨水处理费下降了约30%。该工程案例的改造、调试及运行经验可为同类高氮废水处理工程提供参考。

Engineering case of UCT process with improved reflux mode for treating high-nitrogen slaughtering wastewater

The UCT process with a modified reflux mode was used to treat high-nitrogen slaughter wastewater with a treatment capacity of 200 m3·d-1. Under the condition of relatively stable quality of the inlet water, the results of 130 consecutive days of the commissioning and operation showed that the removal rate of COD, ammonia nitrogen, total nitrogen and total phosphorus could reach 97%, 98%, 94% and 92% respectively, and the effluent water quality reached the indirect discharge standard of the"Discharge Standard of Water Pollutants for Slaughtering and Meat Processing Industry (Draft for Comments)". In the early stage of commissioning and operation of the process, the problem of sludge aging was effectively avoided by adding carbon sources and trace elements. In the process of stable operation, the reflux ratio of nitrifying mixture, the reflux ratio of anoxic mixture and the sludge reflux ratio were adjusted to 267%, 82% and 70%, respectively,to make the process run under the best conditions. Combined with the fluorescence spectrum analysis results of each process section, it was shown that the modified reflux mode UCT process had a good nitrogen removal effect and the tryptophan substances and soluble microbial by-products were effectively degraded during the process. The equipment and commissioning costs involved in the engineering renovation were not high, the cost of treating tons of water was about 30% lower than the traditional slaughter wasterwater treatment process. The debugging and operation experience could provide reference for the commissioning and operation of similar wastewater treatment projects.