Singha A S, Guleria Ashish
Department of Chemistry, National Institute of Technology, Hamirpur HP, 177005, India.
Department of Chemistry, National Institute of Technology, Hamirpur HP, 177005, India.
Int J Biol Macromol. 2014 Jun;67:409-17. doi: 10.1016/j.ijbiomac.2014.03.046. Epub 2014 Apr 2.
Use of biological macromolecules for wastewater remediation process has become the topic of intense research mostly driven by growing concerns about the depletion of petroleum oil reserves and environmental problems. So in view of technological significance of cellulosic biopolymers in various fields, the present study is an attempt to synthesize cellulosic biopolymers based graft copolymers using free radical polymerization. The resulting cellulosic polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric (TGA) analysis. Furthermore, modified cellulosic biopolymer was used in removal of Cu(2+), Zn(2+), Cd(2+) and Pb(2+) toxic metal ions from wastewater. The effects of pH, contact time, temperature and metal ions concentration were studied in batch mode experiments. Langmuir and Dubinin-Radushkevich (D-R) models were used to show the adsorption isotherm. The maximum monolayer capacity qm calculated using Langmuir isotherm for Cu(2+), Zn(2+), Cd(2+), Pb(2+) metal ions were 1.209, 0.9623, 1.2609 and 1.295mmol/g, respectively. The thermodynamic parameters ΔH° and ΔG° values for metal ions adsorption on modified cellulosic biopolymer showed that adsorption process was spontaneous as well as exothermic in nature.
利用生物大分子进行废水修复处理已成为研究热点，这主要是由于人们对石油储备枯竭和环境问题的日益担忧。鉴于纤维素生物聚合物在各个领域的技术重要性，本研究试图通过自由基聚合反应合成基于纤维素生物聚合物的接枝共聚物。通过傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、X射线衍射（XRD）和热重分析（TGA）对所得纤维素聚合物进行了表征。此外，将改性纤维素生物聚合物用于去除废水中的Cu(2+)、Zn(2+)、Cd(2+)和Pb(2+)等有毒金属离子。在间歇模式实验中研究了pH值、接触时间、温度和金属离子浓度的影响。采用朗缪尔（Langmuir）和杜比宁-拉杜舍维奇（Dubinin-Radushkevich，D-R）模型来展示吸附等温线。使用朗缪尔等温线计算得出的Cu(2+)、Zn(2+)、Cd(2+)、Pb(2+)金属离子的最大单层吸附容量qm分别为1.209、0.9623、1.2609和1.295mmol/g。金属离子在改性纤维素生物聚合物上吸附的热力学参数ΔH°和ΔG°值表明，吸附过程是自发的且为放热过程。
