Biosorption of copper(II) and cadmium(II) by a novel exopolysaccharide secreted from deep-sea mesophilic bacterium.
Biosorption of copper(II) and cadmium(II) by a novel exopolysaccharide secreted from deep-sea mesophilic bacterium.
复制标题
DOI：
10.1016/j.colsurfb.2009.04.018
复制
发表时间：
2009-09
期刊：
影响因子：
--
通讯作者：
Weizhi Zhou;Jing Wang;Boling Shen;W. Hou;Yuzhong Zhang
中科院分区：
文献类型：
--
作者：
Weizhi Zhou;Jing Wang;Boling Shen;W. Hou;Yuzhong Zhang
研究了从深海沉积物中分离到的一种新型胞外多糖(EPS)对重金属Cu(II)和Cd(II)的吸附行为及其机理。采用间歇吸附技术研究了SM-A87 EPS浓度、溶液pH和离子强度对金属吸附的影响。对Cu2+和Cd(II)的最佳吸附容量分别为48.0 mg/g、39.75 mg/g和48.0 mg/g。盐的添加降低了土壤对铜(II)或镉(II)的吸收，其顺序为K+<；Na+<；吸附平衡数据符合Langmuir和Freundlich模型，表明生物对Cu2+有良好的吸附，且对Cu2+的吸附容量和吸附强度大于对Cd(II)的吸附。与准一级动力学模型和颗粒内扩散动力学模型相比，两种金属的生物吸附动力学均可用准二级动力学模型较好地描述。在不同金属比的双组分溶液中，SM-A87 EPS对铜(II)的选择性吸附远高于对Cd(II)的选择性吸附。傅里叶变换红外光谱(FT-IR)分析表明，SM-A87 EPS可能存在参与金属生物吸附的官能团(如OH、COO和COC)，这表明SM-A87 EPS有可能成为去除水中铜(II)或镉(II)的有效吸附剂。
The biosorption behaviors and mechanisms of a novel exopolysaccharide (EPS), which is secreted by a mesophilic bacterium (namely Wangia profunda (SM-A87)) isolated from deep-sea sediment, for heavy metals Cu(II) and Cd(II) have been studied in this paper. The effects of SM-A87 EPS concentration, solution pH and ionic strength on the metal uptake were investigated by employing batch adsorption techniques, respectively. The optimum biosorption capacities were observed at pH 5.0 for Cu(II) with 48.0mg/g and pH 6.0 for Cd(II) with 39.75mg/g, respectively. Addition of salts decreased Cu(II) or Cd(II) uptake in the order of K+<Na+<Ca2+. Langmuir and Freundlich models were employed to describe the biosorption equilibrium data, indicating the favorable biosorption occurs and larger biosorption capacity and intensity for Cu(II) than for Cd(II). The biosorption kinetics for both metals can be well described by pseudo-second-order kinetic model, compared with pseudo-first-order and intraparticle diffusion kinetic models. The competitive biosorption was also studied, indicating that in two-component solution with different metal ratios, the selective biosorption of SM-A87 EPS for Cu(II) was much higher than for Cd(II). The Fourier transform infrared spectroscopy (FT-IR) analysis indicated possible functional groups (e.g., OH, COO and COC) of SM-A87 EPS involved in metal biosorption process, which indicated the potential of using SM-A87 EPS as an effective sorbent for Cu(II) or Cd(II) removal from water.