Li Xiaojuan, Wang Zhongmin, Liang Haijun, Ning Jingliang, Li Guiyin, Zhou Zhide
a School of Materials Science and Engineering , Guilin University of Electronic Technology , Guilin , People's Republic of China.
b School of Life and Environmental Sciences , Guilin University of Electronic Technology , Guilin , People's Republic of China.
Environ Technol. 2019 Jan;40(1):112-124. doi: 10.1080/09593330.2017.1380712. Epub 2017 Oct 4.
Lead (Pb) pollution has triggered a great threat to ecological system as well as public health due to its highly toxic and mutagenic properties. In this study, chitosan surface modified persimmon tannin (PT-CS) biomass composite as an environmental-friendly bioadsorbent for highly efficient removal of Pb(II) from aqueous solutions was investigated. Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy and Zeta potential were used to elucidate the adsorption mechanism. Combining oxidation reaction, electrostatic interaction and chelation reaction, PT-CS exhibited fine adsorption to Pb(II). The maximum adsorption capacity was 179.3 mg/g. Equilibrium isotherm for the adsorption of Pb(II) was analyzed by the Langmuir, Freundlich and Temkin models, and the Langmuir isotherm (R > 0.99) was the best. The pseudo-first-order, pseudo-second-order and intraparticle diffusion equations were used to analyze the kinetic data of the adsorption process and the pseudo-second-order kinetic (R > 0.98) model was fitted well. Moreover, thermodynamic parameters including ΔG< 0, ΔH (150.57 KJ/mol) > 0 and ΔS (456.13 J/mol K) > 0 showed that the process of Pb(II) adsorption by PT-CS was spontaneous and endothermic. All these results illustrated that PT-CS would be a promising and low-cost alternative bioadsorbent of Pb(II) in wastewater treatment.
铅（Pb）污染因其高毒性和致突变性，已对生态系统和公众健康构成巨大威胁。本研究考察了壳聚糖表面改性柿单宁（PT-CS）生物质复合材料作为一种环境友好型生物吸附剂，用于高效去除水溶液中的Pb(II)。采用傅里叶变换红外光谱、X射线衍射、扫描电子显微镜、布鲁诺尔-埃米特-泰勒法、X射线光电子能谱和Zeta电位来阐明吸附机理。结合氧化反应、静电相互作用和螯合反应，PT-CS对Pb(II)表现出良好的吸附性能。最大吸附容量为179.3 mg/g。用朗缪尔、弗伦德里希和坦金模型分析了Pb(II)吸附的平衡等温线，其中朗缪尔等温线（R > 0.99）拟合效果最佳。用伪一级、伪二级和颗粒内扩散方程分析了吸附过程的动力学数据，伪二级动力学（R > 0.98）模型拟合良好。此外，热力学参数ΔG< 0、ΔH（150.57 KJ/mol） > 0和ΔS（456.13 J/mol K） > 0表明，PT-CS吸附Pb(II)的过程是自发的且吸热的。所有这些结果表明，PT-CS将是废水处理中一种有前景的低成本替代生物吸附剂。
