氨氮生物硝化分段动力学特性研究

本文利用富集培养的硝化污泥研究了氨氮生物硝化动力学的基本规律.结果表明,氨氮浓度对硝化速率有显著的影响.主体溶液中氨氮质量浓度小于2.3 mg/L时,硝化符合一级反应动力学.随着溶液中氨氮浓度升高,将会出现半级(本文为0.35级)或零级反应动力学,对应的氨氮质量浓度范围分别为2.3～18.2 mg/L和18.2～100 mg/L.各级反应的速率常数分别为0.16 d-1/(mg/L)、0.23 d-1/(mg/L)0.35和0.61d-1.氨氮质量浓度不同,动力学级数不同,硝化速率不同,达到相同的硝化效率反应时间有很大的差别.由于完全混合式反应器的硝化速率主要取决于出水氨氮浓度;因此氨氮出水浓度要求越低,硝化速率越低,反应时间越长,达到较彻底的硝化程度就越困难.

Study on characteristic of subsection kinetics of nitrification

This paper has done a study on the nitrification kinetics by using enriched nitrifying sludge. The results indicate that the concentration of ammonia has a remarkable influence on nitrification rate. When the bulk concentration of ammonia becomes less than 2.3 mg/L, the nitrification follows first kinetic order. As bulk ammonia concentration increases, half-order (0.35 in this paper) or zero-order reactions will occur. The rate constants of the first-order, half-order and zero-order are 0.16 d -1/(mg/L),0.23 d -1/(mg/L) 0.35 and 0.61 d -1 respectively. The time to achieve the same nitrification efficiency is very different for nitrification kinetic and the rate is different. Because the nitrification rate of Completed Mixed-Activated Sludge mainly depends on the effluent ammonia concentration, the lower the ammonia concentration is, the lower the nitrification rate is and the more difficult to reach thorough nitrification.