高岭土对Fe2+的吸附及其对高岭土中Fe3+生物还原的影响研究

Adsorption of Fe2+ on Kaolin and Its Effect on Fe3+ Bioreduction in Kaolin

利用异化铁还原微生物可将高岭土中不溶性的Fe^3＋还原成可溶性的Fe^2＋,但是此过程中产生的Fe^2＋能够被高岭土以及异化铁还原微生物吸附,从而影响高岭土中铁的异化还原。本文研究了pH、高岭土量、Fe^2＋浓度、温度4个因素对高岭土吸附Fe^2＋的影响;并采用Logistic方程拟合,研究Fe^2＋及温度对高岭土中Fe^3＋的生物还原特征。结果表明：pH、高岭土量、浓度、温度4个因素均会影响高岭土吸附Fe^2＋,当Fe^2＋吸附在高岭土和微生物菌体表面时,微生物的活性下降,同时高岭土表面Fe^3＋的生物可利用性也降低,Fe^3＋生物还原的最大速率减小。

Insoluble Fe^ 3＋ in kaolin can be leached out as soluble Fe ^2＋ with dissimilation iron-reducing microorganism. However, the produced Fe^ 2＋ would affect iron reduction because of its adsorbing on kaolin and dissimilation iron-reducing microorganisms. Hence, the effects of pH, amount of kaolin, initial concentration of Fe^ 2＋ and temperature on adsorption of Fe^ 2＋ on kaolin were investigated. The bioreduction of Fe ^2＋ and the effect of temperature on the reduction of Fe ^3＋ in kaolin with Logistic equation were found. The results showed that pH, amount of kaolin, initial concentration of Fe^ 2＋ and temperature had an impact on the adsorption of Fe^2＋ . When the Fe^2＋ adsorbed on kaolin and microbial, it would reduce the maximum rate of iron reduction due to the reduction of microbial activity and bioavailability of Fe3＋ on kaolin surface.