中文摘要：

就C／N对Carrousel 2000氧化沟同步脱氮除磷的影响进行了研究。结果表明，进水C／N值在5～13之间时，进水C／N不影响氧化沟系统对NH3-N的去除效果。出水NH3-N浓度〈1mg／L，平均去除率达到97．40％。当C／N低于11时，TN、TP的去除率随C／N的升高而快速大幅提高，分别从5时的26．47％和14．99％升至11时的93．48％和97．03％。当C／N〉11时，氧化沟TN去除率达到93．48％，TP去除率接近100％，氧化沟具有了良好的同步脱氮除磷的效果，出水水质满足国家《城镇污水处理厂污染物排放标准》（GB18918．2002一级A标准）要求。TP去除率与TN去除率相关系数R^2=0．985。

英文摘要：

The effect of C/N ratio on simultaneous nitrogen and phosphorus removal in Carrousel 2000 oxidation ditch was studied. The experimental results show that when the influent C/N ratio was between 5 and 13, ammonia nitrogen removal efficiency in oxidation ditch was not affected by influent C/N ratio. The ammonia nitrogen concentration in the effluent was below 1 mg/L,the average removal rate was 97.40%. When influent C/N ratio was lower than 11, TN and TP removal rates increased sharply as C/N ratio increased,from 26.47% and 14.99% of 5 to 93.48% and 97.03% of 11 respectively. When influent C/N ratio was bigger than 11 ,TN removal rate was 93.48% , TP removal rate approached to 100%. Oxidation ditch achieved a good effect of simultaneous nitrogen and phosphorus removal. The characteristics of the effluent satisfied the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants （GB18918-2002 primary standard A）. The removal rate of TP was related to TN,the correlation index R^2 = 0. 9396.