A^2O工艺污水处理厂优化脱氮及节能效果分析

Analysis of Nitrogen Removal Improvement and Energy Saving Effect of A^2O Process in WWTP

为了提升昆明市某污水处理厂A2O工艺的脱氮效果和节能潜力,利用该污水厂A^2O生化池(处理规模为5×104m^3/d)进行生产性调试。通过调节生化池好氧区的曝气量等措施,分别将好氧区前端(1#和2#廊道)、中端(3#廊道)、后端(4#和5#廊道)的DO浓度维持在(0.1~0.3)、(0.5~1.0)、(2.0~4.0)mg/L,在不同工况条件下,通过长达200 d的试验考察A2O工艺的优化脱氮效果及降低供氧能耗的可行性。结果表明:与现行工况相比,降低1#廊道的曝气量和同时降低1#、2#廊道的曝气量,脱氮效果可分别提高9.8%和18.5%,实际供气量分别节省32.1%和34.1%,年运行成本分别节省48.0和51.6万元。

In order to improve the nitrogen removal efficiency and energy saving potential of the anaerobic/anoxic/aerobic （A^2O） process in a wastewater treatment plant （WWTP） in Kunming City, a full-scale experiment was performed in an A=O tank with the treatment capacity of 50 000 m^3/d in the WWTP. The dissolved oxygen （DO） concentrations in the front （1^# and 2^# corridors）, middle （3^# corridor） and terminal （4^# and 5^# corridors） of aerobic zone were maintained at 0.1 to 0.3 mg/L, 0.5 to 1.0 mg/L and 2.0 to 4.0 mg/L respectively by regulating the aeration rate. Under three different operation conditions, the feasibility of improving nitrogen removal efficiency and reducing aeration cost of the A^2O process was investigated through a 200-day test. Compared with the original operation condition, the nitrogen removal efficiencies under two conditions of reducing aeration rate of 1^# corridor and reducing aeration rate of 1^# and 2^# corridor were improved by 9.8% and 18.5% respectively, the actual air supply quantities were reduced by 32.1% and 34.1% respectively, and the annual operation costs were saved by 480 000 Yuan and 516 000 Yuan respectively.