Pb^(2+)、Cd^(2+)、Ni^(2+)在改性纳米纤维素上的竞争吸附  

Competitive adsorption of Pb^(2+),Cd^(2+)and Ni^(2+)on modified nano-cellulose

作　　者：韩校 唐婧[1] 张驰[1] 苏杨[1] HAN Xiao;TANG Jing;ZHANG Chi;SU Yang(School of Municipal and Environmental Engineering,Shenyang Jianzhu University,Shenyang,110168,China)

机构地区：[1]沈阳建筑大学市政与环境工程学院,沈阳110168

出　　处：《环境工程学报》2025年第1期126-134,共9页Chinese Journal of Environmental Engineering

基　　金：辽宁省教育厅重点攻关项目(LJKZZ20220081)。

摘　　要：为研究改性纳米纤维素(RCA-NC)对水溶液中Pb^(2+)、Cd^(2+)、Ni^(2+)的单一吸附效果及其竞争吸附特性,以稻草为原料制备纳米纤维素(NFC)并通过丙烯酸接枝改性得到RCA-NC。应用SEM、XRD和FTIR对RCA-NC微观结构进行了表征分析。结果表明,引入羧酸基团的RCA-NC表观纤维分布更密集,束状结构更规则,并未彻底改变NFC的内部结晶结构。单一吸附实验结果表明,在最佳实验条件下,20 mg·L^(−1)的Pb^(2+)、Cd^(2+)、Ni^(2+)在RCA-NC中的去除率分别为93.88%、90.41%、91.28%;在阳离子(Ca^(2+)、Mg^(2+)、Na^(+)、K^(+))、阴离子(Cl^(−)、CO_(3)^(2−))、有机物以及3种重金属离子混合体系中,竞争吸附能力均为Pb^(2+)>Cd^(2+)>Ni^(2+)。Pb^(2+)去除率在71.7%~93.88%。Pb^(2+)、Cd^(2+)、Ni^(2+)在RCA-NC上的吸附符合Langmuir等温吸附和准二级动力学,吸附机理主要为离子交换、表面官能团络合及静电吸附。To investigate the adsorption effect of Pb^(2+),Cd^(2+),or Ni^(2+)alone in aqueous solutions as well as their competitive adsorption by acrylic acid modified rice nano-cellulose(RCA-NC),the nanofiber-cellulose(NFC)was prepared from rice straw,then the graft modification with acrylic acid was implemented for the RCA-NC preparation.The microstructure of RCA-NC was characterized by means of scanning electron microscopy(SEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR).The results showed that the carboxyl group introduction to RCA-NC led to denser apparent-distribution of fiber,more regular bundle structure and not complete alteration in the crystal structure of NFC.The adsorption tests of Pb^(2+),Cd^(2+),or Ni^(2+)alone demonstrated that their removal rates at an initial concentration of 20 mg·L^(−1)by RCA-NC were 93.88%,90.41%,and 91.28%,respectively.In the mixed system containing cations(Ca^(2+),Mg^(2+),Na^(+),K^(+)),anions(Cl^(−),CO_(3)^(2−)),organic matter,and the three heavy metal ions,the competitive adsorption ability followed the order of Pb^(2+)>Cd^(2+)>Ni^(2+),and Pb^(2+)removal rate ranged from 71.7%to 93.88%.The adsorption of Pb^(2+),Cd^(2+),and Ni^(2+)onto RCA-NC conformed to the Langmuir isothermal adsorption and quasi-second-order kinetics.The predominant adsorption mechanisms were identified as ion exchange,surface functional group complexation and electrostatic adsorption.

关 键 词：改性纳米纤维素 竞争吸附 重金属离子 

分 类 号：X703[环境科学与工程—环境工程]