3种运行模式下CAST工艺脱氮性能

以模拟城市污水为处理对象，采用循环式活性污泥法（CAST）反应器，对3种运行模式（M1：常规模式，M2：缺氧好氧模式、M3：缺氧好氧交替模式）下系统的脱氮性能进行了研究，比较了各模式下CAST反应器的氨氮和总氮的去除效率，并对各模式下典型周期内氮基质浓度变化进行了考察，以确定系统的脱氮模式。结果表明，在氨氮去除不成为限制条件（去除率〉90％）的条件下，3种运行模式下系统总氮的平均去除率分别为67．3％、70．6％和82．4％，以缺氧好氧交替模式下的最高；M1、M2和M3均可实现亚硝酸型硝化，但随着温度的升高，亚硝酸型硝化逐渐消失。静态实验分析表明，3种模式下系统的氨氧化速率大小次序为：vN：M1〉vN：M2〉vN：M3，反硝化速率大小次序为：vDN,M2〉vDN,M3〉vDN,M1。

Nitrogen removal performance of CAST process with three operation modes

Fed with simulated domestic sewage, three reactors were operated under three operational modes （ M1 ： conventional mode, M2 ： anoxic-aerobic mode, M3 ： alternant anoxic-aerobie mode） in order to evaluate the nitrogen removal performance of cyclic activated sludge technology （CAST） system. The removal efficiencies of total nitrogen in three operational modes were analyzed. In addition, in order to investigate the nitrogen removal pathway, nitrogen concentrations of a typical cycle under three operation modes were analyzed. Results showed that when NH4＋ -N removal efficiencies were above 90% , the average removal effieiencies of total nitrogen under three operational modes were 67.3% , 70.6% , 82.4% , respectively. Furthermore, nitrification via nitrite was a- chieved under all operation modes. However, along with the rising of temperature, nitrification via nitrite disap- peared. The static tests demonstrated that the ammonia oxidation rates under three operation modes were ：vN：M1〉vN：M2〉vN：M3 and denitrifieation rates were：vDN,M2〉vDN,M3〉vDN,M1