温度阶段性下降对 A^2／O 污水处理系统效能的影响

我国北方地区污水温度的季节性变化对城镇污水处理工艺的运行效果有很大影响，尤其是冬季低温状态下，严重威胁着系统出水的达标排放．对污水处理系统效能随温度季节性变化规律的了解，将有助于应对措施的制定和实施．以常规厌氧-缺氧-好氧（ A^2/O）生活污水处理工艺的运行为基础，考查了水温从23℃分阶段下降为18、14、11℃时的处理效能．结果表明，在HRT 10 h，进水COD、NH3-N、TN和TP平均值分别在275、46、50和5．3 mg/L时，当温度从23℃下降到11℃，A2/O系统出水COD、TP分别从28、0．2 mg/L升高到40和0．3 mg/L，满足GB18918-2002要求的Ⅰ级A排放标准，但NH3-N和TN残留量高达7．58和16．58 mg/L，不能满足Ⅰ级A的排放标准．因此，在低温条件下对A2/O工艺的管理，重点应放在系统硝化与反硝化功能的强化方面．

Study of influence of temperature decreasing in stages to nutrient removal in A2/O process

The seasonal change of temperature in north China has significant impact on the performance of urban sewage treatment process , especially low temperature in winter make the effluent difficult to meet the Chinese national discharge standards （ GB18918-2002 ） . Thus , it is important to understand the performance of sewage treatment system following sea -sonal temperature variations .Based on the operation of a lab -scale A2/O sewage treatment process , the performance characteristics following the temperature drop from 23℃to 18℃, 14 ℃and 11 ℃, step by step were investigated .The HRT for the A2/O process was 10 h, with an average influent COD , NH3-N, TN and TP of 275, 46, 50 and 5.3 mg/L, respec-tively.The results showed that the average effluent COD and TP could meet the First Grade A of the Chinese national discharge standards （ GB8918-2002 ） , even though their con-centration raised from 28 and 0.2 mg/L to 40 and 0.3 mg/L, respectively, when the tem-perature dropped from 23℃to 11℃.On the contrary , the residual NH 3-N and TN in the effluent was up to 7.58 and 16.58 mg/L at 11℃, respectively, unable to meet the First Grade A.The results suggested that the regulations and control measures to ensure the efflu-ent quality should focus on the enhancement of nitrification and denitrification in the A 2/O process .