颗粒粒径与数量对硝化与反硝化过程的影响

Effect of Size and Number of Aerobic Granules on Nitrification and Denitrification

以实验为基础,建立了一个基于多底物的多种微生物生长、维持和衰减过程的好氧硝化颗粒SBR反应器一维动力学模型,分析了颗粒粒径及数量对硝化、反硝化等过程的影响.研究发现,在相同生物量条件下,氨氮的消耗随颗粒的数量增加而增加,表明氨氮的消耗主要与NH4+-N和颗粒接触表面有关.同时,系统中所产生的NO2--N及NO3--N与颗粒数量和粒径有密切关系,而在NH4+-N不足时才只与数量有关,表明DO对颗粒的渗透决定NO2--N及NO3--N的产生.就反硝化过程而言,当粒径>1 000μm时反硝化会随粒径的增加而加强,而小于该值时,虽然反硝化也会发生但与颗粒粒径关系不大,表明颗粒粒径>1 000μm时粒径对DO的扩散限制才会明显从而加强反硝化过程.

Based on experimental results,a one dimension dynamic model was developed for describing the growth,maintenance and decay processes of microbes using multi substances,and consequently,the effect of size and number of aerobic granules on nitrification and denitrification were investigated.It was found that the consuming of ammonia nitrogen increased with the larger number of granules given the same biomass amount,indicating that the consumption of ammonia was dependent on the surface area of granules.The resulting amount of NO-2-N and NO-3-N was dependent not only on the amount but also on the diameter of granules,and the effect of the diameter became negligible only when the ammonia concentration was very low,suggesting the penetration depth of oxygen determines the production of NO-2-N and NO-3-N.Regarding on denitrification,for those granules with the diameter more than 1 000 μm,the denitrification increased with the increase of diameter,however,for those ones less than 1 000 μm the effect of diameter became negligible,indicating that the limitation of oxygen diffusion in granules of big granules more than 1 000 μm could help the process of denitrification.