School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, 541004, China.
School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, 541004, China.
J Environ Manage. 2018 Jul 1;217:305-314. doi: 10.1016/j.jenvman.2018.03.107. Epub 2018 Apr 5.
A novel and recyclable bioadsorbent (PTP) has been prepared by the cationization of persimmon tannin (PT) using polyethyleneimine (PEI) for application in the removal of the anionic dye methyl orange (MO) from aqueous solution. The physicochemical properties of the prepared PTP were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, Zeta potential measurements, Brunauer-Emmett-Teller and thermogravimetric analysis. Systematic batch adsorption experiments were carried out with pH, bioadsorbent dosage, initial MO concentration and contact time. Kinetic regression analysis indicated that the adsorption processes followed the pseudo-second order model. The equilibrium isotherm was in good fit with the Freundlich model with a maximum adsorption capacity of 225.74 mg/g. Thermodynamics data revealed that the adsorption of MO onto PTP was feasible, spontaneous and endothermic. A possible biosorption mechanism was presented where electrostatic interactions, hydrogen bonding, and π-π interactions dominated the adsorption of MO onto PTP. Moreover, the regeneration of the PTP was easily achieved and MO removal efficiency remained high (81.47%) after six cycles. The actual sewage treatment simulation was evaluated and the PTP had a good preference to adsorption MO. All these results indicated that PTP could be considered a high performance and promising candidate for the effective removal of anionic dyes from aqueous solutions.
一种新型可回收生物吸附剂（PTP）已通过使用聚乙烯亚胺（PEI）对柿子单宁（PT）进行阳离子化制备而成，可用于从水溶液中去除阴离子染料甲基橙（MO）。通过傅里叶变换红外光谱、扫描电子显微镜、Zeta 电位测量、BET 和热重分析对制备的 PTP 的物理化学性质进行了表征。系统地进行了 pH 值、生物吸附剂用量、初始 MO 浓度和接触时间的批量吸附实验。动力学回归分析表明，吸附过程遵循拟二级模型。平衡等温线与 Freundlich 模型拟合良好，最大吸附容量为 225.74mg/g。热力学数据表明，MO 吸附到 PTP 上是可行的、自发的和吸热的。提出了一种可能的生物吸附机制，其中静电相互作用、氢键和π-π相互作用主导 MO 吸附到 PTP 上。此外，PTP 易于再生，经过六次循环后 MO 的去除效率仍保持在 81.47%。还评估了实际污水处理模拟，PTP 对吸附 MO 具有很好的偏好。所有这些结果表明，PTP 可以被认为是一种从水溶液中有效去除阴离子染料的高性能、有前途的候选材料。
