盐度和曝气时间对包埋颗粒短程硝化启动的影响及其动力学分析

Effect of salinity and aeration time on the start-up of partial nitrification of immobilized particles and its kinetics analysis

针对短程硝化反应器启动时间长、效果不稳定等问题,使用水性聚氨酯(WPU)制作硝化污泥包埋颗粒,利用SBR设置盐度梯度以及不同曝气时间进行批次实验,启动短程硝化;通过控制最佳反应条件启动UASB短程硝化反应器,同时进行动力学分析。结果表明:在批次实验过程中,随着盐度的增加,氨氮去除率(ηA)及NO2^--N积累率(RNAR)先上升后下降。当NaCl浓度为10 g·L^-1时,短程硝化效果最佳,ηA为55%,RNAR为90%;不同曝气时间对短程硝化的稳定性有较大的影响,曝气时间为8 h时短程硝化效果最稳定,ηA和RNAR分别达到56%和96%。控制NaCl浓度为10 g·L^-1,HRT为8 h,成功实现了UASB短程硝化反应器的启动;包埋颗粒对氨氮的动力学特性符合Haldane基质抑制动力学模型,具有优良的动力学特性。研究可为包埋颗粒与短程硝化工艺的耦合脱氮提供参考,并为含盐废水的处理提供技术支持。

In view of the long start-up time and unstable effect of partial nitrification reactor,waterborne polyurethane(WPU)was used to prepare the immobilized particles of nitrification sludge.The partial nitrification was started up through batch tests in the SBR reactor at different salinity gradients and different aeration times.The UASB partial nitrification reactor was started up by controlling the optimum conditions,and the kinetic analysis was performed simultaneously.The results showed that the ammonia nitrogen removal rate NO2^--N accumulation rate(RNAR)increased firstly and then gradually decreased as the salinity increased in batch tests.The partial nitrification effect reached the best when the NaCl concentration was 10 g·L^-1,and ηA and RNAR were 55% and 90%,respectively.Different aeration time had a great influence on the stability of partial nitrification.The partial nitrification effect was the most stable when the aeration time was 8 h,andηA and RNAR reached 56% and 96%,respectively.The UASB reactor was successfully started up by controlling the NaCl concentration at 10 g·L^-1 and HRT at 8 h.The kinetics of the immobilized granules on ammonia nitrogen was in accordance with the Haldane matrix inhibition kinetics model,which indicated that the immobilized granules had excellent kinetic characteristics.The study can provide a reference for the coupling denitrification of immobilized granules and partial nitrification processes,and provide technical support for saline wastewater treatment.