高氨氮废水半短程硝化控制及曝气经济性运行优化

本研究进水模拟了污泥消化液、晚期垃圾渗滤液等高氨氮低碱度低碳氮比的废水，在碱度缺乏（不足以实现完全短程硝化）条件下获得了稳定的半短程硝化，并通过曝气量和污泥浓度（MLSS）双因素调控，实现了半短程硝化的高效经济运行.研究表明，进水碱度缺乏条件下短程硝化体系出水亚硝氮/氨氮浓度比值y与进水HCO₃^-∶NH₄⁺物质的量的比x之间存在化学计量关系 y=x/（2-x），当进水HCO₃^-∶NH₄⁺物质的量的比为1，即进水碱度/氨氮浓度（mg·L^-1）比值为3.6时可实现半短程硝化，并通过游离氨（FA）和游离亚硝酸（FNA）联合抑制能够实现稳态运行，亚硝酸盐积累率平均可达95%以上.实验探究了MLSS和曝气量对短程硝化反应器曝气经济性和氨氧化率的影响，通过平衡两因素作用，在保证处理效果的同时最大程度提升了反应系统的曝气经济性：当曝气量为36 L·h^-1和MLSS为2243 mg·L^-1时，反应器的曝气经济性较好，可节省约40%曝气量，且能维持较高的容积氨氮负荷（0.93 kg·m^-3·d^-1）.

The control strategy of partial nitrification of ammonia-rich wastewater and the economical optimization of aeration

The optimum control of partial nitrification was studied when treating wastewater characterized by high ammonia nitrogen, low alkalinity and low C/N (e.g., sludge digester liquor and mature landfill leachate). The stable operation of partial nitrification was achieved when lack of alkalinity, and the aeration process was optimized for more efficient and economical by controlling the aeration rate and mixed liquid suspended solids (MLSS). Results showed that there was a stoichiometric relation (y=x/(2-x)) between the ratio of effluent NO₂^--N/NH₄⁺-N (y) and the molar ratio of influent HCO₃^-/NH₄⁺ (x), and the ratio of effluent NO₂^--N/NH₄⁺-N was approximately 1 when the ratio of influent alkalinity/NH₄⁺-N(mg·L^-1) was 3.6. The stable operation of partial nitrification could be achieved through inhibition of NOB by free ammonia and free nitrous acid, with the average nitrite accumulation rate more than 95%. The study also explored the effects of aeration rate and MLSS on partial nitrification system. Through balancing the effects of these two factors, the aeration process of the partial nitrification could save 40% of the aeration under the aeration rate of 36 L·h^-1 and 2243 mg·L^-1. The reactor could maintain a higher ammonia nitrogen volume loading of 0.93 kg·m^-3·d^-1.