功能型纤维素纳米纤维膜的制备及其对重金属污水的净化

Preparation of Functional Cellulose Nanofiber Membrane and Its Application in Purification of Heavy Metal Wastewater

重金属离子污水对生态环境和人类健康造成严重危害。本文通过静电纺丝和化学改性工艺相耦合,在再生纤维素纳米纤维膜中键合引入对金属离子具有强配位作用的羧基基团。FTIR、XPS测试结果证明了羧基基团的存在和化学反应的完成;SEM测试表明改性过程导致纳米纤维出现部分卷曲,但没有破坏其典型的纤维结构和大比表面积吸附特性;水接触角(WCA)和机械性能测试结果表明羧基的引入赋予其超亲水特性和金属离子附着能力的同时,有利于膜产品综合机械性能的提升,从而赋予其良好应用特性;Cu2+离子吸附测试结果证明了改性膜优异的吸附特性,利用动力学对吸附作用机理进行探究,发现功能型纳米纤维膜主要通过化学吸附完成对重金属离子的净化去除,具有良好的高效性和稳定性。

Heavy metal ion wastewater causes serious harm to the ecological environment and human health.In this paper,carboxyl groups with strong coordination to metal ions were introduced into the regenerated cellulose nanofiber membrane through the coupling of electrospinning and chemical modification process.The results of FTIR and XPS prove the existence of carboxyl group and the completion of chemical reaction.SEM test shows that the nanofibers were partially crimped after modification without damaging the typical fiber structure and good adsorption characteristics from their large specific surface area.The results of water contact angle(WCA)and mechanical properties test show that the introduction of carboxyl group gives the functional nanofiber membrane not only super hydrophilicity and metal ion adhesion,but also improves comprehensive mechanical properties,thus giving it good application characteristics.The Cu2+ion adsorption test results prove the excellent adsorption characteristics of the modified membrane.The adsorption mechanism was explored by using kinetic analysis.It is found that the functional nanofiber membrane mainly used chemical adsorption to complete the removal of heavy metal ions,with good efficiency and stability.