Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environmental Science and Engineering, South China University of Technology, Guangzhou, 510006, China.
Environ Monit Assess. 2013 Aug;185(8):6713-8. doi: 10.1007/s10661-013-3059-9. Epub 2013 Jan 12.
Extracellular polymeric substances (EPS) were extracted from Aspergillus fumigatus using cationic exchange resin technique. The EPS were mainly composed of polysaccharide and low quantities of protein and nucleic acid. Biosorption of Cd(II), Pb(II), and Cu(II) of EPS was investigated as a function of pH using differential pulse polarography and the Ruzic model. Results showed that the EPS biosorption capacity determined using either the direct titration curves i = f(C M) or the method proposed by Ruzic (Analytica Chimica Acta 140:99-113, 1982) were coincident. Cu(II) had the highest affinity with EPS followed by Pb(II) and Cd(II). The total number of binding sites for Cu(II) and Cd(II) increased with pH in the range of 4.0-7.0. Similar trend was observed for Pb(II) at pH 4.0-5.0, while precipitates were observed at pH 6.0 and 7.0. The conditional binding constants of these three metals displayed low levels of fluctuation with pH and ranged from 4.02 ± 0.02 to 5.54 ± 0.05.
采用阳离子交换树脂技术从烟曲霉中提取胞外聚合物（EPS）。EPS 主要由多糖和少量蛋白质和核酸组成。采用差分脉冲极谱法和 Ruzic 模型研究了 EPS 对 Cd(II)、Pb(II)和 Cu(II)的生物吸附，作为 pH 的函数。结果表明，用直接滴定曲线 i=f（CM）或 Ruzic 提出的方法（Analytica Chimica Acta 140：99-113，1982）确定的 EPS 吸附容量是一致的。Cu(II)与 EPS 的亲和力最高，其次是 Pb(II)和 Cd(II)。在 4.0-7.0 的 pH 范围内，Cu(II)和 Cd(II)的总结合位点数量增加。在 pH 4.0-5.0 时，Pb(II)也观察到类似的趋势，而在 pH 6.0 和 7.0 时观察到沉淀。这三种金属的条件结合常数随 pH 的波动较小，范围为 4.02±0.02 至 5.54±0.05。
