乙酸钠和无机盐对部分亚硝化反应器运行性能的影响

通过间歇试验和连续流反应器的运行试验,探索了实现部分亚硝化反应的控制条件,考察了乙酸钠和无机盐对部分亚硝化工艺效能的影响.结果表明,通过控制进水碱度、溶解氧和水力停留时间,可在气升式反应器中实现稳定的部分亚硝化,反应器出水适宜后续厌氧氨氧化反应器处理.乙酸钠对部分亚硝化反应器的运行性能有重大影响.添加乙酸钠后,反应器出水氨氮浓度不变,亚硝氮、硝氮和总氮浓度减小,且变化程度与所添加的有机物浓度呈正相关,乙酸钠引发反硝化是造成影响的主要原因.短期批次试验表明,在摩尔浓度相同的条件下,NaCl、KCl和Na2SO4对氨氧化活性的影响程度接近,盐浓度为150mmol·L-1时,氨氧化活性为未添加盐时的60%.连续流试验证明,通过逐渐提高盐浓度,部分亚硝化反应器能适应25g·L-1盐度的水质.当盐度大于27g·L-1时,出水水质不合要求.亚硝酸细菌对高盐度胁迫比硝酸细菌敏感.

Effect of acetate and inorganic salts on the performance of a partial nitritation reactor

The process conditions for partial nitritation and the feasibility of a partial nitritation reactor for treatment of effluents containing residual carbonaceous compounds and in some cases high salt concentrations were evaluated with batch tests and a continuous-flow experiment. The results showed that stable partial nitritation could be achieved by control of influent basicity, dissolved oxygen and hydraulic retention time. When acetate was used, concentrations up to 800 mg·L-1 did not exert significant effect on the ammonia oxidation to nitrite. But values higher than 500 mg·L-1 resulted in a high denitrification rate, with a detrimental effect on the quality of the effluent from the partial nitritation reactor that should be further treated in an anammox process. When NaCl, KCl and Na2SO4 were tested in batch experiments, similar inhibitory effects were encountered. Molar concentrations of 150 mmol·L-1 caused 40% inhibition of the maximum specific ammonia oxidizing activity. The effect of NaCl on the operation of the partial nitritation reactor was tested at concentrations between 0 and 30 g·L-1. The ammonia oxidation activity remained stable in the presence of 25 g·L-1, while higher salt concentrations up to 27 g·L-1 provoked a great decrease in the activity. Nitrite oxidizers were less affected by salt stress as compared to ammonia oxidizers.