Department of Chemical Engineering, State University of Maringá, Av. Colombo 5790, CEP, Maringá, PR, 47020-900, Brazil.
School of Chemical Engineering, State University of West Paraná, Rua da Faculdade 2550, CEP, Toledo, PR, 85903-000, Brazil.
Environ Sci Pollut Res Int. 2019 Apr;26(11):11100-11112. doi: 10.1007/s11356-019-04552-0. Epub 2019 Feb 21.
In this study, the alginate-based biosorbent produced from seaweed Sargassum sp. was used in biosorption of Ni and Cu ions from synthetic solutions and real electroplating effluents. Biosorption kinetics, isotherms, pH effect, thermodynamic parameters, and sorption/desorption cycles were also evaluated. Kinetic studies show the sorption equilibrium can be obtained within 180 min for Ni ions and 360 min for Cu ions, and the adsorption kinetics data are well described by the pseudo-second order and diffusion in spherical adsorbents. Langmuir model can be well used to describe the biosorption isotherm data. The maximum sorption capacity (q) and Langmuir constant (b) were up to 1.147 mmol g and 1.139 L mmol for Ni ions and 1.640 mmol g and 4.645 L mmol for Cu ions. The calculated thermodynamic parameters (ΔG°, ΔH°, and ΔS°) showed that the biosorption of Ni and Cu ions are predominantly a chemical phenomenon of endothermic nature, favorable, and spontaneous at the temperature ranges of 293-313 K. Partial desorption of the Ni and Cu ions on the biosorbent was achieved using acidic and saline eluents, allowing the biosorbent to be used in new sorption/desorption cycles. EDX analysis suggests an ion exchange mechanism between calcium ions on the biosorbent and target metals. Biosorption of Ni and Cu from real electroplating effluents with high concentrations of light metals becomes highly competitive, decreasing the amount of Ni and Cu ions biosorbed due to the ionic strength effect.
在这项研究中，使用了从海藻马尾藻中制备的基于海藻酸钠的生物吸附剂来从合成溶液和实际电镀废水中吸附 Ni 和 Cu 离子。还评估了生物吸附动力学、等温线、pH 效应、热力学参数和吸附/解吸循环。动力学研究表明，对于 Ni 离子，吸附平衡可在 180 分钟内获得，对于 Cu 离子，吸附平衡可在 360 分钟内获得，吸附动力学数据可以很好地用伪二级和球形吸附剂内扩散来描述。Langmuir 模型可以很好地描述生物吸附等温线数据。最大吸附容量（q）和 Langmuir 常数（b）分别高达 1.147 mmol g 和 1.139 L mmol 用于 Ni 离子和 1.640 mmol g 和 4.645 L mmol 用于 Cu 离子。计算得到的热力学参数（ΔG°、ΔH°和ΔS°）表明，Ni 和 Cu 离子的生物吸附主要是吸热的化学现象，在 293-313 K 的温度范围内是有利且自发的。使用酸性和盐水洗脱剂可实现 Ni 和 Cu 离子在生物吸附剂上的部分解吸，从而使生物吸附剂能够在新的吸附/解吸循环中使用。EDX 分析表明，生物吸附剂上的钙离子与目标金属之间存在离子交换机制。从高浓度轻金属的实际电镀废水中吸附 Ni 和 Cu 变得极具竞争力，由于离子强度效应，吸附的 Ni 和 Cu 离子数量减少。
