污水处理厂强化脱氮过程中碳源投加策略研究

Strategies for Dosing Carbon Source for Enhanced Nitrogen Removal in Wastewater Treatment Plant

针对昆明市某污水处理厂A^2/O工艺出水总氮提标改造技术需求,分析比较前置缺氧段投药、后置缺氧段投药和增设后置反硝化滤池投药这3种外碳源(甲醇)投加策略。设定出水总氮浓度分别为10、7、5和3 mg/L四个目标值,对3种碳源投加模式进行了经济评价。在4个目标值条件下,各种碳源投加模式的处理成本均随目标浓度值的降低而升高;药耗成本占强化脱氮处理成本的62%~100%,是主要经济成本贡献者。综合考虑经济成本和改造难易程度,确定控制内回流比为200%、将好氧段末端改造为缺氧段并投加碳源进行强化脱氮是最佳改造策略。

According to the technical A2/O process in Kunming, three strategies zone, post-anoxic zone and post-denitrifying requirements in upgrading a wastewater treatment plant with for adding the carbon source （methanol） into pre-anoxic biofilter were analyzed and compared. The economic assess- ment was carried out for the three strategies with the targeting effluent total nitrogen concentration of 10 mg/L, 7 rag/L, 5 mg/L and 3 mg/L, respectively. Under the four targeting concentrations, the treat- ment costs of the three strategies increased with decreasing the effluent total nitrogen concentration. The cost of chemicals contributed significantly to the total cost, with proportions of 62% to 100%. Integrating the economic cost with the feasibility of construction, using the internal recycling ratio of 200% and con- verting the later section of the aerobic zone to the anoxic zone with addition of the carbon source were the optimal strategy for enhanced nitrogen removal.