Acidithiobacillus ferrooxidans去除水中Ni^(2+)、Mn^(2+)、Cd^(2+)机理的研究

Study on Mechanism of Ni^(2+),Mn^(2+) and Cd^(2+) Removal by Acidithiobacillus ferrooxidans in Water

以从粤北大宝山酸性矿山废水(AMD)分离出具有的Acidithiobacillus ferrooxidans(A.f菌)为研究对象,采用原子吸收分光光度法和X射线衍射分析技术,研究A.f菌对水中Ni^(2+)、Mn^(2+)、Cd^(2+)的去除和钝化机理。实验结果显示,A.f菌与重金属离子共培养7 d后,其对Ni^(2+)、Mn^(2+)、Cd^(2+)的去除率分别为18.52%、31.63%、36.05%,X射线衍射分析显示Ni^(2+)、Mn^(2+)、Cd^(2+)与次生矿物晶体内的构晶离子Fe^(3+)间的类质同象作用不明显;A.f菌成因次生矿物对Ni^(2+)、Mn^(2+)、Cd^(2+)的吸附容量分别达130.26、74.99、78.36 mg/kg,可能与A.f菌次生高铁矿物纳米颗粒表面富含OH^-、SO_4^(2-)等高吸附能位点的强静电相互作用密切相关。

A strain of Acidithiobacillus ferrooxidans （A.f） was isolated from the acid mine drainage of Dabaoshan Mine in North Guangdong.The atomic absorption spectrophotometry and XRD method were used to explore the mechanism for Ni（2＋） ,Mn（2＋） and Cd（2＋） removal and inactivation in water by Acidithiobacillus ferrooxidans.After A.f was co-cultured with heavy metal irons for 7 d,the removal rate of Ni（2＋） ,Mn（2＋） and Cd（2＋） reached 18.52%,31.63% and 36.05%,respectively.The results of XRD showed that Ni（2＋） ,Mn（2＋） and Cd（2＋） could not obviously isomorphously replaced Fe3＋,which existed in the secondary mineral crystal as crystal structural ion.The Ni（2＋） ,Mn（2＋） and Cd（2＋） adsorption capacity of biogenic secondary iron minerals were 130.26,74.99 and 78.36 mg/kg,respectively.The mechanism of Ni（2＋） ,Mn（2＋） and Cd（2＋） removal may be closely related with strong electrostatic force between heavy metal irons and high adsorption-energy sites of OH- and SO4（2-） located at the surface of secondary iron mineral nanoparticles.