游离氨对硝化菌活性的抑制及可逆性影响

为考察游离氨(FA)对硝化菌(氨氧化菌AOB和亚硝酸盐氧化菌NOB)活性的抑制影响,采用SBR反应器,基于FA与过程控制协同作用在实现短程硝化的基础上,考察了不同FA浓度(1.0,5.3,16.6,13.4,9.9,5.2,1.0mg/L)梯度下,FA对AOB和NOB活性的抑制作用及可逆性.结果表明,当FA浓度达到13.4mg/L时,系统内亚硝态氮积累率(Ni AR)逐渐增加,硝态氮积累率(Na AR)逐渐减小,且Ni AR/Na AR1时,系统实现了稳定短程硝化.在此FA浓度条件下,FA对AOB和NOB活性均产生一定的抑制作用,但相对于AOB,NOB对FA的抑制作用更加敏感.当AOB活性被短暂抑制后,其活性又迅速恢复;而NOB活性被完全抑制.此后当FA浓度又逐渐降至1.0mg/L时,AOB活性始终维持较高水平,而NOB活性尚未恢复.也即是说,在本试验控制的FA浓度条件下,FA对AOB活性的抑制作用是可逆的,而对NOB活性的抑制作用不可逆.

Inhibitory effect of free ammonia on the activity of nitrifying bacteria and recoverability

In order to investigate the inhibition of free ammonia (FA) on nitrifying bacteria (ammonia-oxidizing bacteria, AOB and nitrite-oxidizing bacteria, NOB), after the nitrite pathway was stably achieved in an sequencing batch reactor (SBR) by synergetic interaction of FA and process control, the inhibitory effect of FA on AOB and NOB was investigated at different FA concentrations (1.0,5.3,16.6,13.4,9.9,5.2,1.0mg/L) levels. It demonstrated that, at FA concentration of 13.4mg/L, nitrite accumulation rate (NiAR) gradually increased, nitrate accumulation rate (NaAR) decreased, and chen the nitrite pathway was successfully established in the SBR. Further study showed that this level of FA had a certain inhibitory effect on the activity of AOB and NOB. Compared to AOB, NOB was more sensitive to FA. AOB activity could recovered quickly, while the NOB activity was completely inhibited all along. Thereafter, when the FA concentration was gradually decreased to 1.0mg/L (the lowest level in this study), AOB maintained good activity, however, the NOB activity had not recovered. Therefore, under the concentration of FA used in this experiment, AOB inhibition by FA was reversible, while NOB activity was non-reversible.