Department of Chemistry, Government College University, Faisalabad, Pakistan.
Water Res. 2013 Sep 1;47(13):4238-46. doi: 10.1016/j.watres.2013.04.051. Epub 2013 May 9.
Zinc biosorption characteristic of locally isolated Aspergillus flavus NA9 were examined as a function of pH, temperature, pulp density, contact time and initial metal ion concentration. The maximum zinc uptake was found to be 287.8 ± 11.1 mg g(-1) with initial metal concentration 600 mg L(-1) at initial pH 5.0 and temperature 30 °C. The equilibrium data gave good fits to Freundlich and Florry models with correlation coefficient value of 0.98. The contribution of the functional groups and lipids to zinc biosorption as identified by chemical pretreatment was in the order: carboxylic acids > hydroxyl > amines > lipids. The mechanism of biosorption was also studied using Fourier transform infrared (FTIR) spectrometry, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The biosorbent was regenerated using 0.01 M HCl with 83.3% elution efficiency and was reused for five sorption-desorption cycles with 23.5% loss in biosorption capacity. The order of co-cations showing increased inhibitions of zinc uptake by A. flavus NA9 was Pb > Cu > Mn > Ni. The biosorption assays conducted with actual paint industry effluents revealed efficiency of 88.7% for Zn (II) removal by candidate biomass.
考察了当地分离的黄曲霉 NA9 的锌生物吸附特性，研究了 pH 值、温度、纸浆密度、接触时间和初始金属离子浓度对其的影响。在初始金属浓度为 600mg/L、初始 pH 值为 5.0 和温度为 30°C 的条件下，最大锌吸附量为 287.8±11.1mg/g。平衡数据与 Freundlich 和 Florry 模型拟合良好，相关系数值为 0.98。通过化学预处理鉴定了功能基团和脂质对锌生物吸附的贡献，其顺序为：羧酸 > 羟基 > 胺 > 脂质。还使用傅里叶变换红外 (FTIR) 光谱、扫描电子显微镜 (SEM) 和能量色散 X 射线分析 (EDX) 研究了生物吸附的机理。使用 0.01 M HCl 再生生物吸附剂，洗脱效率为 83.3%，在五个吸附-解吸循环中，生物吸附容量损失了 23.5%。对 A. flavus NA9 中锌摄取的抑制作用依次为 Pb > Cu > Mn > Ni。在实际的油漆工业废水中进行的生物吸附试验表明，候选生物质对 Zn(II)的去除效率为 88.7%。
