C/N值对短时曝气SBR高标准脱氮除磷效能的影响

Effect of C/N Ratio on High-standard Nitrogen and Phosphorus Removal Efficiency of SBR with Short-time Aeration

针对现有城镇污水脱氮除磷效率低、碳源对深度脱氮除磷制约等突出问题,提出了基于短时曝气SBR的城镇污水高标准脱氮除磷技术,考察了进水C/N值对短时曝气SBR脱氮除磷效能的影响。结果表明,进水C/N值对短时曝气SBR的脱氮除磷效能影响显著。当温度为25℃,SRT为40 d,进水C/N值分别为4、5、6、7时,系统对NH4+-N的平均去除率分别为83.3%、99.3%、99.4%、99.5%,对TN的平均去除率分别为58.8%、82.6%、88.1%、93.8%,对TP的平均去除率分别为14.6%、54.5%、76.6%、97.5%。当进水C/N值为7时,系统出水COD、NH4+-N、TN、TP平均浓度分别为18、0.20、2.46、0.13 mg/L,COD、NH4+-N与TP指标满足地表水Ⅳ类水质标准,TN指标接近地表水Ⅴ类水质标准。

A series of problems existed in sewage treatment such as low nitrogen and phosphorus removal efficiency and shortness of carbon source.A high-standard nitrogen and phosphorus removal technology based on SBR with short-time aeration was proposed for sewage treatment,and the effect of influent C/N ratio on nitrogen and phosphorus removal efficiency of the SBR system was investigated.Results showed that C/N ratio had a significant effect on the nitrogen and phosphorus removal efficiency of the SBR with short-time aeration.When the temperature was 25℃,the SRT was 40 days and the influent C/N ratios were 4,5,6 and 7,the removal rates of NH4+-N were 83.3%,99.3%,99.4%and 99.5%,respectively,the removal rates of TN were 58.8%,82.6%,88.1%and 93.8%,respectively,and the removal rates of TP were 14.6%,54.5%,76.6%and 97.5%,respectively.When the influent C/N ratio was 7,the average concentrations of COD,NH4+-N,TN and TP in the effluent were 18 mg/L,0.20 mg/L,2.46 mg/L and 0.13 mg/L,respectively.The concentrations of COD,NH4+-N and TP in the effluent could meet the levelⅣstandard of surface water,and the TN concentration in the effluent was close to the levelⅤstandard of surface water.