Fe2+和Fe3+对厌氧氨氧化污泥活性的影响

通过接种厌氧氨氧化污泥研究了Fe离子浓度及价态变化对厌氧氨氧化污泥活性的影响.短期浓度影响结果表明,当进水铁离子浓度由0升高到5 mg·L-1时,厌氧氨氧化污泥活性因受刺激而逐渐增强;当进水铁离子浓度大于5 mg·L-1时,因厌氧氨氧化反应产碱,铁离子形成氢氧化物沉淀,生物活性未受到影响.不同价态铁离子浓度变化对厌氧氨氧化污泥活性的影响无明显区别.长期价态影响结果表明,经过71个周期培养,含Fe2+进水的厌氧氨氧化反应器R1脱氮效能(以氮计)由0.28 kg·(m3·d)-1升高到0.65 kg·(m3·d)-1,是含Fe3+进水反应器R2的1.28倍.因此Fe2+更适合厌氧氨氧化菌生长的需求.实验结果进一步表明,Fe3+易导致厌氧氨氧化反应器R2内氨氮过量转化,亚硝氮与氨氮转化比(1.17)明显低于含Fe2+进水的反应器R1内亚硝氮与氨氮转化比(1.24).

Effect of Fe2+and Fe3+ on the Activity of ANAMMOX

The effect of the change in concentration and valence of iron ion on the ANAMMOX sludge activity was studied by inoculating ANAMMOX sludge. The concentration experimental results showed that the ANAMMOX sludge activity was stimulated and gradually increased when the influent iron ion concentration increased from 0 to 5 mg·L^-1. Iron hydroxide precipitate was formed with the pH value increased due to the alkalinity of the ANAMMOX product when the influent iron ion concentration was higher than 5 mg·L^-1, while the biological activity was not inhibited. There was no significant difference in the effects of the concentration change of iron ions with different valence effects on the ANAMMOX sludge activity. The long-term experimental results showed that the nitrogen removal rate (as N) of anammox reactor R1 was increased from 0.28 kg·(m³·d)^-1 to 0.65 kg·(m³·d)^-1 with Fe²⁺ in influent, which was 1.28 times as high as that in the ANAMMOX reactor R2 containing Fe³⁺ in influent, after 71 cycles of cultivation. Therefore, Fe²⁺ could better meet the growth needs of ANAMMOX bacteria. The results also showed that Fe³⁺ easily led to the excessive conversion of ammonia in the ANAMMOX reactor. The conversion ratio between nitrate and ammonia was 1.17 in reactor R2, which was significantly lower than that in the reactor R1, with a conversion ratio between nitrate and ammonia of 1.24.