Si Rongrong, Chen Yehong, Wang Daiqi, Yu Dongmei, Ding Qijun, Li Ronggang, Wu Chaojun
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Nanomaterials (Basel). 2022 Jan 3;12(1):160. doi: 10.3390/nano12010160.
In the present study, carboxymethyl cellulose nanofibrils (CMCNFs) with different carboxyl content (0.99-2.01 mmol/g) were prepared via controlling the ratio of monochloroacetic acid (MCA) and sodium hydroxide to Eucalyptus bleached pulp (EBP). CMCFs-PEI aerogels were obtained using the crosslinking reaction of polyethyleneimine (PEI) and CMCNFs with the aid of glutaraldehyde (GA). The effects of pH, contact time, temperature, and initial Cu concentration on the Cu removal performance of CMCNFs-PEI aerogels was highlighted. Experimental data showed that the maximum adsorption capacity of CMCNF30-PEI for Cu was 380.03 ± 23 mg/g, and the adsorption results were consistent with Langmuir isotherm (R > 0.99). The theoretical maximum adsorption capacity was 616.48 mg/g. After being treated with 0.05 M EDTA solution, the aerogel retained an 85% removal performance after three adsorption-desorption cycles. X-ray photoelectron spectroscopy (XPS) results demonstrated that complexation was the main Cu adsorption mechanism. The excellent Cu adsorption capacity of CMCNFs-PEI aerogels provided another avenue for the utilization of cellulose nanofibrils in the wastewater treatment field.
在本研究中，通过控制一氯乙酸（MCA）与氢氧化钠和桉木漂白浆（EBP）的比例，制备了具有不同羧基含量（0.99 - 2.01 mmol/g）的羧甲基纤维素纳米纤维（CMCNFs）。借助戊二醛（GA），利用聚乙烯亚胺（PEI）与CMCNFs的交联反应获得了CMCFs-PEI气凝胶。重点研究了pH值、接触时间、温度和初始铜浓度对CMCFs-PEI气凝胶去除铜性能的影响。实验数据表明，CMCNF30-PEI对铜的最大吸附容量为380.03±23 mg/g，吸附结果符合朗缪尔等温线（R>0.99）。理论最大吸附容量为616.48 mg/g。用0.05 M乙二胺四乙酸（EDTA）溶液处理后，气凝胶在三个吸附-解吸循环后仍保持85%的去除性能。X射线光电子能谱（XPS）结果表明，络合是主要的铜吸附机制。CMCFs-PEI气凝胶优异的铜吸附容量为纤维素纳米纤维在废水处理领域的应用提供了另一条途径。
