Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran.
Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran.
Int J Biol Macromol. 2019 Jun 1;130:1025-1045. doi: 10.1016/j.ijbiomac.2019.02.033. Epub 2019 Mar 1.
Poly aniline modified chitosan embedded with ZnO/FeO nanocomposites were synthesized using a precipitation method and applied to the removal of Cu(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, FESEM, TEM, EDS, TGA, BET and zeta-potential analyses. The adsorption batch experiments were conducted as a function of five effective parameters including pH, contact time, initial concentration of copper, temperature, and adsorbent dosage using a central composite design (CCD) in response surface methodology (RSM). Contour and surface plots were used to determine the interaction effects of main factors and optimum conditions of process. The regression equation coefficients were calculated and the data confirmed the validity of second-order polynomial equation for the removal of Cu(II) with novel absorbent. Analysis of variance (ANOVA) showed a high coefficient of determination value (R) for copper removal being 0.99. The optimum level of the pH, temperature, initial concentration of copper, adsorbent dosage and contact time for maximum Cu(II) removal (94.51%) were found to be 6.5, 31 °C, 82 mg L, 0.81 g L, and 51 min, respectively. It was confirmed from XPS and EDS analyses that heavy metal ions were present on the surface of nanocomposite after adsorption. The adsorption equilibrium data fitted well with the Langmuir isotherm model and the adsorption process followed the pseudo-second-order and intra-particle diffusion kinetic model. The saturated adsorption capacity is found to be 328.4 mg/g. Thermodynamics analysis suggests that the adsorption process is endothermic, with increasing entropy and spontaneous in nature. Further recycling experiments show that nanocomposite still retains 95% of the original adsorption following the 5th adsorption-desorption cycle. The effects of coexist cation ions on the adsorption of Cu(II) was also investigated under optimal condition. All the results demonstrate that nanocomposite is a potential recyclable adsorbent for hazardous metal ions in wastewater.
聚苯胺改性壳聚糖嵌入 ZnO/FeO 纳米复合材料是通过沉淀法合成的，并应用于从水溶液中去除 Cu(II)。合成的纳米复合材料通过傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）、能谱分析（EDS）、热重分析（TGA）、比表面积和孔径分布（BET）和 Zeta 电位分析进行了表征。吸附批实验作为功能的五个有效参数包括 pH 值、接触时间、铜的初始浓度、温度和吸附剂用量的响应面法（RSM）中的中心复合设计（CCD）进行。使用等高线和表面图确定主要因素的相互作用效应和过程的最佳条件。计算回归方程系数，数据验证了用于去除 Cu(II)的新型吸附剂的二次多项式方程的有效性。方差分析（ANOVA）表明，铜去除的高决定系数值（R）为 0.99。最大 Cu(II)去除率（94.51%）的最佳 pH 值、温度、铜初始浓度、吸附剂用量和接触时间水平分别为 6.5、31°C、82mg/L、0.81g/L 和 51min。XPS 和 EDS 分析证实，重金属离子在吸附后存在于纳米复合材料的表面上。吸附平衡数据很好地符合 Langmuir 等温模型，吸附过程遵循准二级和内扩散动力学模型。饱和吸附容量为 328.4mg/g。热力学分析表明，吸附过程是吸热的，熵增加，本质上是自发的。进一步的回收实验表明，纳米复合材料在第 5 次吸附-解吸循环后仍保留 95%的原始吸附能力。还在最佳条件下研究了共存阳离子离子对 Cu(II)吸附的影响。所有结果表明，纳米复合材料是废水中危险金属离子的一种有潜力的可回收吸附剂。
