改进SBR处理垃圾渗滤液深度脱氮的启动与实现

Startup and realization of advanced nitrogen removal of landfill leachate by modified SBR

为了在去除渗滤液中有机物的同时实现深度脱氮,利用SBR法灵活多变的反应过程,采用交替曝气和搅拌至硝化结束,然后在不添加任何外碳源的条件下以充分缺氧搅拌至内源反硝化结束的方式运行SBR系统.系统通过交替硝化反硝化、同步硝化反硝化和内源反硝化的协同作用,可以在不添加任何有机碳源的条件下,使系统出水的总氮含量小于40 mg/L,去除率达到95%以上,达到中国最新颁布的渗滤液总氮的排放标准.同时,由于50%左右的总氮是利用原水碳源在内源反硝化的作用下脱除的,试验期间的污泥浓度在没有排泥的条件下始终稳定在6 g/L左右,污泥产量大幅度减少.不同操作模式下的对比试验表明:污泥中PHA的含量是决定系统脱氮效率的重要因素;硝化前的厌氧搅拌以及短间隔曝气有利于增加污泥的储碳量,提高了系统的脱氮效率;传统的持续曝气后搅拌无法通过内源反硝化实现深度脱氮.

In order to achieve advanced nitrogen removal while removing organics in the landfill leachate,SBR（sequencing batch reactor） was applied with the operation in which the stir and aeration were alternately proceeded until the completion of nitrification and then anoxic stir was well proceeded until the completion of endogenous denitrification without any external carbon source added.Under the synergistic effect of alternate stir and aeration,SND（simultaneous nitrification and denitrification） and endogenous denitrification,the effluent TN（total nitrogen） can be less than 40 mg/L and TN removal reaches over 95% without any external carbon source added,which meets the Chinese latest TN discharge standards of leachate.Meanwhile,since 50% TN is removed through endogenous denitrification,the mixed liquor suspended solids maintains at about 6 g/L and the yield of sludge reduces greatly.The contrast tests under different operation modes indicate that the content of polyhydroxyalkanoates in the activated sludge is the key factor of the nitrogen removal efficiency of the system.The previous anaerobic time before nitrification and the short interval time during the nitrification are good to increase the carbon storage of the sludge and improve the nitrogen removal efficiency.Conventional continuous aeration without stirring can not achieve advanced nitrogen removal via endogenous denitrification.