生物源方铁锰矿吸附Cu（II）和Zn（II）的特性

利用从土壤中分离出来的Mn（II）氧化细菌Providencia sp. LLDRA6，制备和纯化生物锰氧化物。通过扫描电镜-能谱（SEM-EDS）、X射线衍射（XRD）、高分辨率透射电镜-选区电子衍射（HRTEM-SAED）、X射线光电子能谱（XPS）和比表面积测定（SSA）等手段，对生物锰氧化物进行了表征分析。研究结果表明：得到的生物锰氧化物是弱结晶的方铁锰矿（Mn2O3），比表面积为5.740 m2/g；生物源Mn2O3对Cu（II）和Zn（II）具有较强的吸附能力，吸附最适pH均为6，吸附容量分别为89.889 mg/g和70.595 mg/g；生物源Mn2O3吸附Cu（II）和Zn（II）的动力行为均符合伪二级动力学模型，表明生物源Mn2O3吸附Cu（II）和Zn（II）的速率受化学吸附的控制；生物源Mn2O3对Cu（II）和Zn（II）的吸附均符合Langmuir等温吸附模型，表明吸附类型属于单分子层吸附。

Characteristics of Adsorption of Cu(II) and Zn(II) by Biogenic Bixbyite

Biogenic Mn oxides were prepared and purified using the Mn(II) oxidizing bacterium Providencia sp. LLDRA6, which was isolated from soil. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), high-resolution transmission electron microscopy-selected area electron diffraction (HRTEM-SAED), X-ray photoelectron spectroscopy (XPS), and specific surface area (SSA) determination were used to characterize the biogenic manganese oxides. The biogenic manganese oxides were found to be poorly crystalline bixbiyte (Mn2O3) with a specific surface area of 5.740 m2/g. Biogenic Mn2O3 showed high adsorption capacity of Cu(II) and Zn(II), with an optimal pH of 6 and adsorption quantities of 89.889 mg/g and 70.595 mg/g, respectively. The adsorption curves of Cu(II) and Zn(II) by biogenic Mn2O3 were both consistent with the pseudo-second kinetic model, indicating that chemisorption influenced both Cu(II) and Zn(II) adsorption rates. Cu(II) and Zn(II) adsorption by biogenic Mn2O3 followed the Langmuir isothermal adsorption model, suggesting that the adsorption processes belonged to monomolecular layer adsorption.