Zhou Shun-gui, Zhou Li-xiang, Chen Fu-xing
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Feb;27(2):367-70.
An amorphous ferric hydroxysulfate named schwertmannite was synthesized by using bacterial oxidation of ferrous iron by resting A. ferrooxidans cells in acid ferrous sulfate solution (pH 2.5). The identification of the bacterially oxidized iron precipitate was carried out by SEM, XRD, FTIR and chemical analysis. Results showed that resting cells of A. ferrooxidans LX5 could completely oxidize ferrous ions to ferric ions in the FeSO4-H2O system after 2 days of incubation. The solution pH decreased from an initial 2.5 to 2.10, and about 15% of the ferrous iron was transformed into the red-brown precipitates. The subsequent characterization of the precipitates showed that the biotic, synthetic ferric hydroxysulfate was schwertmannite. Sorption edge measurement showed that the adsorption behavior of metal cations (e. g., Cu2+, Zn2+ and Cr3+) was pH-dependent. The adsorption increased with an increase in pH, and the maximum was found in a pH range of 6.0-7.0. For solution concentration of 50 mg x L(-1), the maximum adsorption efficiencies of Cu2+, Zn2+ and Cr3+ were 99.3%, 99.4% and 87.6%, respectively.
通过在酸性硫酸亚铁溶液（pH 2.5）中利用静止的氧化亚铁硫杆菌细胞对亚铁进行细菌氧化，合成了一种名为施韦特曼石的无定形羟基硫酸铁。通过扫描电子显微镜（SEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和化学分析对细菌氧化产生的铁沉淀物进行了鉴定。结果表明，在FeSO₄-H₂O体系中培养2天后，氧化亚铁硫杆菌LX5的静止细胞能够将亚铁离子完全氧化为铁离子。溶液pH从初始的2.5降至2.10，约15%的亚铁转化为红棕色沉淀物。对沉淀物的后续表征表明，生物合成的羟基硫酸铁是施韦特曼石。吸附边界测量表明，金属阳离子（如Cu²⁺、Zn²⁺和Cr³⁺）的吸附行为与pH有关。吸附量随pH升高而增加，在pH 6.0-7.0范围内达到最大值。对于50 mg·L⁻¹的溶液浓度，Cu²⁺、Zn²⁺和Cr³⁺的最大吸附效率分别为99.3%、99.4%和87.6%。
