羟氨对CANON工艺中短程硝化及脱氮性能的影响

作为全程自养脱氮(completely autotrophic nitrogen removal over nitrite, CANON)工艺中间产物，羟氨(hydroxylamine, NH₂OH)可能对CANON工艺产生重要影响。为研究NH₂OH对于CANON工艺中短程硝化及脱氮性能的影响，利用稳定运行的移动床式生物膜反应器(moving-bed biofilm reactor, MBBR)进行批次实验，控制进水${{\rm{NH}}_4^ +} $-N质量浓度为230 mg·L⁻¹，添加NH₂OH质量浓度分别为0、5、20、80 mg·L⁻¹，研究了添加不同质量浓度的NH₂OH对CANON工艺的影响。结果表明，NH₂OH质量浓度越高，越有利于CANON工艺中亚硝酸盐氧化菌(nitrite oxidizing bacteria, NOB)的抑制。当NH₂OH质量浓度≤20 mg·L⁻¹时，提高NH₂OH质量浓度，有利于提高${{\rm{NH}}_4^ +} $-N的降解速率；当NH₂OH质量浓度为20 mg·L⁻¹，${{\rm{NH}}_4^ +} $-N降解速率可以提高29.4%。从总体脱氮效果来看，NH₂OH的添加会提高CANON的脱氮性能，建议将NH₂OH投加质量浓度控制在5 mg·L⁻¹为宜。

Effect of NH2OH on the short-cut nitrification and nitrogen removal performance of CANON process

As an intermediate product in completely autotrophic nitrogen removal over nitrite (CANON) process, hydroxylamine (NH2OH) may have a great effect on CANON process. A batch experiment was carried out by using a moving-bed biofilm reactor (MBBR) with stable operation to study the effect of NH2OH concentration on the short-cut nitrification and nitrogen removal performance of CANON process. The influent ${\rm{NH}}_4^ + $-N concentration was controlled at 230 mg·L−1, and the concentrations of NH2OH addition were 0, 5, 20, and 80 mg·L−1, respectively. The results showed that the higher the concentration of NH2OH, the more beneficial to the inhibition of nitrite oxidizing bacteria (NOB) in CANON process. When the NH2OH concentration was less than or equal to 20 mg·L−1, the increase of the concentration of NH2OH was beneficial to the increase of ${\rm{NH}}_4^ + $-N degradation rate. When the NH2OH concentration was 20 mg·L−1, the degradation rate of ${\rm{NH}}_4^ + $-N increased by 29.4 %. In the view of the total nitrogen removal effect, the addition of NH2OH could increase the nitrogen removal performance of CANON process, and the concentration of NH2OH addition could be controlled at 5 mg·L−1.