改性纤维素接枝聚丙烯酸甲酯吸附重金属性能研究
发布时间：2018-11-09 09:00
【摘要】：水体重金属污染问题不仅威胁着人类的健康,而且对生态环境造成了严重的破坏,重金属废水的治理迫在眉睫。吸附法处理含重金属的废水具有操作简单、价格低廉、吸附性能好、可回收利用等优点,已成为一种实用可靠的水处理方法。吸附剂结构中需要存在能够吸附重金属离子的功能基团,其中羧基和氨基的吸附性能比较优秀。因此,研发出含羧基或多胺基团的高效吸附剂具有现实意义。丙烯酸甲酯(methyl acrylate, MA)是一种双官能团单体,常被用作于有机合成中间体,也可用来合成高分子聚合物。本课题以微晶纤维素为载体,MA为接枝聚合单体,通过硝酸铈铵(ceric ammonium nitrate, CAN)引发成功合成纤维素接枝聚丙烯酸甲酯(Cell-g-PMA)。随后使用氢氧化钠水解制备了吸附剂纤维素接枝聚丙烯酸钠(Cell-g-P(AA-Na)),并简易的表征了其在水溶液中对Pb(Ⅱ)和Cu(Ⅱ)重金属离子的吸附行为。四乙烯五胺(tetraethylenepentamine, TEPA)是一种具有高效重金属吸附功能的水溶性多胺,本研究通过Cell-g-PMA与TEPA的胺解反应成功制备了多胺类改性吸附剂四乙烯五胺改性纤维素接枝聚丙烯酸甲酯(Cell-g-PMA-TEPA),通过元素分析的表征手段确定了最优合成时间。随后,通过FTIR光谱、固态核磁碳谱、热失重TG/DTG分析和扫描电镜(SEM)对Cell-g-PMA-TEPA的结构和形貌进行了表征。为探究Cell-g-PMA-TEPA对水溶液中重金属离子的吸附性能,实验表征了其在水溶液中对Pb(Ⅱ)和Cu(Ⅱ)重金属离子的吸附行为,结果如下：静态吸附性能研究中,吸附剂Cell-g-PMA-TEPA对Pb(Ⅱ)和Cu(Ⅱ)的吸附过程分别在pH 5.0和pH 4.5时达到较好的效果,并均可在200min内达到吸附平衡,所得数据表明吸附过程符合准二级动力学吸附模型,即通过吸附剂与吸附质共享或交换电子所形成共价键的化学吸附。在对等温吸附模型的研究中发现：Langmuir等温吸附模型能更好的模拟实验过程,吸附剂对吸附质的吸附机理更趋于吸附剂均一表面的单层吸附,并且可推测出Cell-g-PMA-TEPA对Pb(Ⅱ)和Cu(Ⅱ)的最大吸附容量分别为444.4mg/g和168.35mg/g。动态吸附性能研究中,吸附剂Cell-g-PMA-TEPA在特定参数下对Pb(Ⅱ)和Cu(Ⅱ)的平衡吸附容量分别为440.4mg/g和170.6mg/g,由O.1M稀盐酸溶液淋洗后可再生吸附。经过五次吸附-洗脱循环后,平衡吸附容量都没有明显的下降,吸附容量损失均低于10%,吸附剂依然对Pb(Ⅱ)和Cu(Ⅱ)具有优秀的吸附性能。
[Abstract]:Heavy metal pollution not only threatens the health of human beings, but also causes serious damage to the ecological environment. The treatment of heavy metal wastewater is urgent. The treatment of wastewater containing heavy metals by adsorption method has many advantages, such as simple operation, low price, good adsorption performance and recyclability. It has become a practical and reliable water treatment method. In the structure of adsorbent, functional groups are needed to adsorb heavy metal ions, among which the adsorption properties of carboxyl group and amino group are excellent. Therefore, it is of practical significance to develop high-efficiency adsorbents containing carboxyl or polyamine groups. Methyl acrylate (methyl acrylate, MA) is a bifunctional monomer, which is often used as an intermediate in organic synthesis as well as in the synthesis of polymer. In this paper, cellulose grafted methyl acrylate (Cell-g-PMA) was successfully synthesized by cerium ammonium nitrate (ceric ammonium nitrate, CAN) with microcrystalline cellulose as carrier and MA as graft monomer. Then the adsorbent cellulose grafted sodium polyacrylate (Cell-g-P (AA-Na),) was prepared by hydrolysis of sodium hydroxide and the adsorption behavior of Pb (鈪，
本文编号：2319960
[Abstract]:Heavy metal pollution not only threatens the health of human beings, but also causes serious damage to the ecological environment. The treatment of heavy metal wastewater is urgent. The treatment of wastewater containing heavy metals by adsorption method has many advantages, such as simple operation, low price, good adsorption performance and recyclability. It has become a practical and reliable water treatment method. In the structure of adsorbent, functional groups are needed to adsorb heavy metal ions, among which the adsorption properties of carboxyl group and amino group are excellent. Therefore, it is of practical significance to develop high-efficiency adsorbents containing carboxyl or polyamine groups. Methyl acrylate (methyl acrylate, MA) is a bifunctional monomer, which is often used as an intermediate in organic synthesis as well as in the synthesis of polymer. In this paper, cellulose grafted methyl acrylate (Cell-g-PMA) was successfully synthesized by cerium ammonium nitrate (ceric ammonium nitrate, CAN) with microcrystalline cellulose as carrier and MA as graft monomer. Then the adsorbent cellulose grafted sodium polyacrylate (Cell-g-P (AA-Na),) was prepared by hydrolysis of sodium hydroxide and the adsorption behavior of Pb (鈪，
本文编号：2319960
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