改性纤维素的制备及分光光度法对Cu~(2+)吸附研究

针对日益严重的铜离子污染问题,以化学浆纤维素为原料,通过氨基酸接枝修饰2,2,6,6-四甲基哌啶氧自由基(TEMPO)氧化体系氧化的纤维素,制备出一种新型吸附剂,并采用灵敏简便的分光光度法研究改性对铜离子的吸附效果。结果表明,氨基酸修饰纤维素(AMC)与TEMPO氧化纤维素(TOC)相比,对铜离子的吸附效果有不同程度的提升,其中组氨酸改性的吸附效果最好,低浓度时吸附率可以高达97%。随着浓度增大,吸附率下降,但是吸附量增大,当吸附200 mg/L的Cu2+溶液时,吸附量可达47 mg/g。此外,研究了不同条件下AMC对Cu2+的吸附情况,包括AMC投加量、初始浓度、pH值等。结果表明,吸附过程的吸附模型符合Langmuir等温模型,吸附动力学可以用准二级吸附动力学方程拟合。

Novel Amino Acid Modified Cellulose for Copper(Ⅱ) Adsorption via Spectrophotometry

Copper is a highly toxic environmental pollutant,therefore,there is an urgent need to develop new materials for its removal from water.In the present study,new TEMPO oxidized cellulose-based materials were synthesized and investigated as an adsorbent for simple and rapid removal of copper ion Cu (Ⅱ)] via spectrophotometry.Cellulose was extracted from chemical pulp fiber,TEMPO oxidized,and modified by reaction with three different amino acids (Gly,Lys,His).Compared with TEMPO oxidizedcellulose (TOC),the amino acid modified cellulose (AMC) had better effect on the adsorption of copper ion,in which histidine modified cellulose achieved the best adsorption rate with 97 ％ in low copper concentration.In addition,the AMC dosing amount,initial copper concentration,pH on the adsorption effect were also investigated.The data were analyzed on the basis of variouskinetic and isotherm models,and pseudo-second-order kinetics and Langmuir isotherm were followed for Cu2+ adsorption.