Fe(Ⅲ)对Anammox污泥脱氮效能长短期影响

The long-term and short-term effect of Fe(Ⅲ)on nitrogen removal efficiency of Anammox sludge

通过接种厌氧氨氧化(Anammox)污泥,研究了Fe(Ⅲ)对Anammox污泥脱氮效能长短期影响.结果表明,适量提升Fe(Ⅲ)浓度可以提升Anammox菌的活性.当进水Fe(Ⅲ)浓度达到0.09mol/L时,反应器氮去除速率最高为0.238kg/(L·d),较对照组提升了14.2%.继续提高进水Fe(Ⅲ)浓度,氮去除速率逐步下降,当Fe(Ⅲ)浓度升至0.18mol/L时,氮去除速率降至0.215kg/(L·d),与最高氮去除速率相比下降10.75%.采用Haldane抑制动力学模型拟合得到Fe(Ⅲ)对Anammox半速率常数(KFe)为0.012mol/L,半抑制常数(KI)为0.449mol/L.长期结果表明,在0.09mol/L Fe(Ⅲ)浓度下,Anammox氮去除速率增幅最快,并且随着Fe(Ⅲ)浓度增加而逐步降低.由于Fe(Ⅲ)代替了NO_(2)^(-)-N作为电子受体发生厌氧铁氨氧化反应,在含有Fe(Ⅲ)的反应器中NO_(2)^(-)-N与NH_(4)^(+)-N的转化比在1.108~1.227之间波动,明显低于理论值1.32,并随Fe(Ⅲ)浓度的提升而降低.扫描电镜结果表明,添加Fe(Ⅲ)可使Anammox菌细胞结构更加稳定.

The effects of Fe(Ⅲ)concentration on nitrogen removal efficiency in Anammox sludge were studied in short-term and long-term.The proper amount of Fe(Ⅲ)could enhance the nitrogen removal efficiency of Anammox bacteria,0.09mol/L was the most suitable concentration,the nitrogen removal rate was 0.238kg/(L·d),compared with the control group increased by 14.2%.The nitrogen removal rate was decreased gradually with the influent Fe(Ⅲ)concentration increased constantly.When the Fe(Ⅲ)concentration increased to 0.18mol/L,the nitrogen removal rate dropped to 0.215kg/(L·d)decreased by 10.75%compare with 0.09mol/L.The half-saturation constant(KFe)was 0.012mol/L,the inhibiting kinetic constant(KI)was 0.449mol/L obtained by Haldane inhibition kinetic model fitting.The long-term experiment results showed that at 0.09mol/L Fe(Ⅲ)concentration,the nitrogen removal rate of Anammox increased the fastest,and gradually decreased with the increase of Fe(Ⅲ)concentration.the conversion ratio of NO_(2)^(-)-N and NH_(4)^(+)-N was significantly lower than the theoretical value of 1.32,fluctuate between 1.108 and 1.227,and decreased with the increase of concentration of Fe(Ⅲ),presumably due to the addition of Fe(Ⅲ)instead of NO_(2)^(-)-N as electron acceptor.Scanning electron microscope results showed that the addition of Fe(Ⅲ)could make the Anammox bacteria cell structure more stable.