利用黑荆树单宁固定化纳米纤维素从水溶液中吸附 Cu（II）、Pb（II）和 Cr（VI）。

Adsorption of Cu (II), Pb (II) and Cr (VI) from aqueous solutions using black wattle tannin-immobilized nanocellulose.

机构信息

Key Laboratory of Paper Science & Technology of Ministry of Education, Qilu University of Technology, Jinan 250353,China.

College of Leather Chemical and Engineering, Qilu University of Technology, Jinan 250353,China.

出版信息

J Hazard Mater. 2017 Oct 5;339:91-99. doi: 10.1016/j.jhazmat.2017.06.005.

DOI:10.1016/j.jhazmat.2017.06.005

PMID:28633083

Abstract

A novel nanocomposite based on black wattle (BW) tannin and nanocellulose was prepared and applied in heavy metal ions adsorptive removal from aqueous solutions. Firstly, nanocrystalline cellulose was oxidized by sodium periodate to get dialdehyde nanocellulose (DANC). BW tannin was then covalently immobilized onto DANC, which was used as both the matrix and crosslinker, to obtain tannin-nanocellulose (TNCC) composite. The resulting nanocomposite was characterized using FTIR, AFM, and TG. The successful immobilization was confirmed by the chromogenic reaction between FeCl and TNCC and FT-IR analysis. AFM images revealed that TNCC was ellipsoidal particles with lengths ranging from 100-400nm. Zeta potential measurement showed that TNCC was negative charged at a pH range from 1-12. Compared to the original tannin, the thermal stability of TNCC was slightly increased by the addition of nanocellulose. TNCC demonstrated the maximum adsorption efficiency at pH2 for Cr(VI) and pH 6 for Cu(II) and Pb(II), respectively. The adsorption for these three metal ions followed pseudo second-order kinetics, indicating the chemisorption nature. The adsorption isotherms all fitted well with the Sips model, and the calculated maximum adsorption capacities were 51.846mgg, 53.371mgg and 104.592mgg for Cu(II), Pb(II) and Cr (VI), respectively.

摘要

一种基于黑荆树单宁和纳米纤维素的新型纳米复合材料被制备出来，并应用于从水溶液中吸附去除重金属离子。首先，纳米纤维素被高碘酸钠氧化得到二醛纳米纤维素（DANC）。然后，黑荆树单宁通过共价键固定在 DANC 上，DANC 既作为基质又作为交联剂，得到单宁纳米纤维素（TNCC）复合材料。采用 FTIR、AFM 和 TG 对所得纳米复合材料进行了表征。通过 TNCC 与 FeCl 的显色反应和 FT-IR 分析证实了单宁的成功固定。AFM 图像显示 TNCC 是长度在 100-400nm 之间的椭圆形颗粒。Zeta 电位测量表明，TNCC 在 pH 值为 1-12 的范围内带负电荷。与原始单宁相比，纳米纤维素的加入略微提高了 TNCC 的热稳定性。TNCC 对 Cr(VI)的最大吸附效率在 pH 2 时达到，对 Cu(II)和 Pb(II)的最大吸附效率在 pH 6 时达到。这三种金属离子的吸附均符合准二级动力学模型，表明为化学吸附。吸附等温线均很好地符合 Sips 模型，计算得到的最大吸附容量分别为 51.846mgg、53.371mgg 和 104.592mgg 用于 Cu(II)、Pb(II)和 Cr(VI)。