腐殖酸-重金属对ANAMMOX菌脱氮性能的影响及其动力学分析

Effect of HumicAcid-Heavy Metals on the Nitrogen Removal Performance of ANAMMOX Bacteria and Its Kinetic Analysis

通过批次实验研究了两种典型重金属离子[Cu(Ⅱ)和Ni(Ⅱ)]与腐殖酸对厌氧氨氧化(ANAMMOX)脱氮效果(SAA)的影响并进行了动力学模型分析,同时探讨了腐殖酸-重金属对ANAMMOX脱氮的影响.结果表明,在投加ρ[Cu(Ⅱ)]和ρ[Ni(Ⅱ)]均为3 mg·L^(-1)时,对ANAMMOX有促进作用,SAA分别提高了8.64%和7.78%;当ρ[Cu(Ⅱ)]和ρ[Ni(Ⅱ)]分别为20 mg·L^(-1)和5 mg·L^(-1)时则对ANAMMOX有抑制作用,抑制效果随重金属离子浓度增加而越发显著,指数拟合表明Cu(Ⅱ)和Ni(Ⅱ)对ANAMMOX的IC50分别为29.67 mg·L^(-1)和28.75 mg·L^(-1).在投加ρ(腐殖酸)为1 mg·L^(-1)时SAA提高了7.37%,40 mg·L^(-1)时抑制率即达到36.80%,线性拟合表明腐殖酸对ANAMMOX菌的IC50为58.36 mg·L^(-1).修正的Michaelis-Menten模型能较好地描述重金属和腐殖酸对ANAMMOX的抑制动力学行为,拟合获得的Cu(Ⅱ)、Ni(Ⅱ)和腐殖酸对ANAMMOX菌活性完全抑制时的浓度(I)分别为49.59、74.46和84.27 mg·L^(-1).适量的腐殖酸有利于改善重金属对ANAMMOX菌活性的抑制,过量的腐殖酸又会重新对ANAMMOX菌形成抑制.

The effects of two typical heavy metal ions[Cu(Ⅱ)and Ni(Ⅱ)]and humic acid on ANAMMOX nitrogen removal(SAA)were studied through batch experiments,and the kinetic model was analyzed.At the same time,the effects of humic acid-heavy metal on ANAMMOX nitrogen removal were discussed.The results showed that ANAMMOX was promoted whenρ[Cu(Ⅱ)]andρ[Ni(Ⅱ)]were 3 mg·L^(-1),and SAA was increased by 8.64%and 7.78%,respectively;ANAMMOX was inhibited when theρ[Cu(Ⅱ)]andρ[Ni(Ⅱ)]were 20 mg·L^(-1)and 5 mg·L^(-1),respectively,and the inhibition effect was more significant with the increase in heavy metal ion concentration.The index fitting showed that the IC50 of Cu(Ⅱ)and Ni(Ⅱ)on ANAMMOX were 29.67 mg·L^(-1)and 28.75 mg·L^(-1),respectively.SAA was increased by 7.37%when theρ(humic acid)was 1 mg·L^(-1),and the inhibition rate reached 36.80%when the humic acid concentration was 40 mg·L^(-1).The linear fitting showed that the IC50 of humic acid on ANAMMOX was 58.36 mg·L^(-1).The modified Michaelis-Menten model could better describe the inhibitory kinetic behavior of heavy metals and humic acid on ANAMMOX.The model fitting showed that the complete inhibition concentrations(I)of Cu(Ⅱ),Ni(Ⅱ),and humic acid on ANAMMOX were 49.59,74.46,and 84.27 mg·L^(-1),respectively.An appropriate amount of humic acid was beneficial to improve the inhibition of heavy metals on ANAMMOX bacteria activity,and excessive humic acid would cause inhibition on ANAMMOX bacteria again.