Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia.
Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia.
Sci Total Environ. 2016 Jan 15;542(Pt A):603-11. doi: 10.1016/j.scitotenv.2015.10.095. Epub 2015 Nov 3.
A breakthrough biosorbent namely multi-metal binding biosorbent (MMBB) made from a combination of tea wastes, maple leaves and mandarin peels, was prepared to evaluate their biosorptive potential for removal of Cd(II), Cu(II), Pb(II) and Zn(II) from multi-metal aqueous solutions. FTIR and SEM were conducted, before and after biosorption, to explore the intensity and position of the available functional groups and changes in adsorbent surface morphology. Carboxylic, hydroxyl and amine groups were found to be the principal functional groups for the sorption of metals. MMBB exhibited best performance at pH 5.5 with maximum sorption capacities of 31.73, 41.06, 76.25 and 26.63 mg/g for Cd(II), Cu(II), Pb(II) and Zn(II), respectively. Pseudo-first and pseudo-second-order models represented the kinetic experimental data in different initial metal concentrations very well. Among two-parameter adsorption isotherm models, the Langmuir equation gave a better fit of the equilibrium data. For Cu(II) and Zn(II), the Khan isotherm describes better biosorption conditions while for Cd(II) and Pb(II), the Sips model was found to provide the best correlation of the biosorption equilibrium data. The calculated thermodynamic parameters indicated feasible, spontaneous and exothermic biosorption process. Overall, this novel MMBB can effectively be utilized as an adsorbent to remove heavy metal ions from aqueous solutions.
一种突破性的生物吸附剂，即由茶渣、枫叶和蜜桔皮组合而成的多金属结合生物吸附剂（MMBB），被制备出来以评估其从多金属水溶液中去除 Cd(II)、Cu(II)、Pb(II)和 Zn(II)的生物吸附潜力。在吸附前后进行了 FTIR 和 SEM 分析，以探究可用官能团的强度和位置以及吸附剂表面形貌的变化。发现羧酸、羟基和胺基是吸附金属的主要官能团。MMBB 在 pH 5.5 时表现出最佳性能，对 Cd(II)、Cu(II)、Pb(II)和 Zn(II)的最大吸附容量分别为 31.73、41.06、76.25 和 26.63 mg/g。拟一级和拟二级动力学模型很好地描述了不同初始金属浓度下的动力学实验数据。在两种参数吸附等温线模型中，Langmuir 方程对平衡数据的拟合更好。对于 Cu(II)和 Zn(II)，Khan 等温线描述了更好的生物吸附条件，而对于 Cd(II)和 Pb(II)，Sips 模型被发现提供了生物吸附平衡数据的最佳相关性。计算得到的热力学参数表明生物吸附过程是可行的、自发的和放热的。总的来说，这种新型 MMBB 可以有效地用作吸附剂，从水溶液中去除重金属离子。
