短程反硝化的启动及多参数优化下NO2--N积累特性

采用本实验室长期培养的厌氧（S-A）、好氧（S-O）和交替厌氧/好氧（S-A/O）活性污泥为种泥，分别启动短程反硝化SBR反应器R1、R2和R3，控制进水C/N比为3，缺氧搅拌时间为1h时，在第15d、7d和4d亚硝酸盐积累率（NAR）分别达到75.34%、84.51%和86.23%.选取C/N比、初始pH值、缺氧搅拌时间和初始NO₃^--N浓度对NAR进行四因素三水平响应面实验，方差分析结果表明，以上因素对NAR均有显著影响（P<0.05），模型R²为0.983.通过模型预测得最佳运行条件：C/N比为3.16，初始pH值为8.51，缺氧搅拌时间为1.27h，初始NO₃^--N浓度为60mg/L的条件下，NAR高达91.32%.

Start-up of partial denitrification and characteristics of nitrite accumulation by multiple factors

Partial denitrification SBR reactors of R1, R2 and R3 were used to inoculate with anaerobic (S-A), aerobic (S-O) and alternate anaerobic/aerobic (S-A/O) activated sludge as seed sludge respectively which cultivated in our laboratory for a long time. When the influent C/N ratio was 3 and the anoxic stirring time was 1h, the nitrite accumulation rate (NAR) of the R1, R2, and R3 reactors reached 75.34%, 84.51% and 86.23% on the 15th, 7th and 4th day, respectively. Four factors and three levels response surface method experiments were conducted on NAR with C/N ratios, initial pH, anoxic stirring time and initial NO₃^--N concentration. The results of variance analysis showed that the above factors had significant effects on NAR (P<0.05), and R² of model was 0.983. The optimal operating conditions were predicted by the model as follows:C/N ratio was 3, initial pH was 8.51, anoxic stirring time was 1.25h, and initial NO₃^--N concentration was 60mg/L, NAR was as high as 91.3%.