快速启动短程硝化过程起始pH值对亚硝酸盐积累的影响

为利用实际生活污水快速启动短程硝化,试验采用3个SBR装置在温度为25℃、ρ_DO=2 mg/L、曝气时间分别为T/2、3T/4、7T/8(T为从曝气开始到“氨谷”出现的时间)时考察亚硝酸盐积累的情况.运行12个周期后,3个反应器中的亚硝酸盐积累率分别为5%、2%、5%.反应器混合液初始pH值从小于7.5水平调节到7.7~8.0,稳定运行几个周期后发现,亚硝酸盐积累率分别提高到了50%、47%、70%,曝气时间为7T/8时的反应器中的亚硝酸盐积累率上升速率最快,成功启动短程硝化.结果表明,在适当的曝气时间下,利用反应体系内pH对硝化菌群结构的影响及FA对硝酸菌的抑制作用可以提高亚硝酸盐积累率,快速启动短程硝化.

Effect of Initiative pH Value on Accumulation of Nitrite During the Process of Rapid Start-up of Partial Nitrification

In order to realize rapid start-up of partial nitrification by using real domestic wastewater,the experiment of three same sequencing batch reactors(SBR) and the temperature is 25 ℃,the dissolved oxygen(DO) is 2.0 mg/L,the aerobic time is respectively T/2、3T/4、7T/8(T was the time from the beginning of aerobic to the appearance of the "ammonia valley"),is conducted to investigate nitrite accumulation.The nitrite accumulation ratios(nar) were increased by 50%、47%、70% in the three reactors when the initiative pH value is 7.7-8.0,the nar increases fastest in which the aerobic time is 7/8T,the partial nitrification is achieved.The nar can be increased by appropriate aerobic time,by the effect of the pH value on the configuration of the nitrifying bacteria and by the inhibition of NOB to free ammonia.