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

Qinghua Xu; Yulu Wang; Liqiang Jin; Yu Wang; Menghua Qin

doi:10.1016/j.jhazmat.2017.06.005

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

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

Authors

Qinghua Xu¹, Yulu Wang², Liqiang Jin², Yu Wang³, Menghua Qin⁴

Affiliations

¹ Key Laboratory of Paper Science & Technology of Ministry of Education, Qilu University of Technology, Jinan 250353,China. Electronic address: xqh@qlu.edu.cn.
² College of Leather Chemical and Engineering, Qilu University of Technology, Jinan 250353,China.
³ Key Laboratory of Paper Science & Technology of Ministry of Education, Qilu University of Technology, Jinan 250353,China.
⁴ Taishan University, Tai'an 271000, China.

PMID: 28633083
DOI: 10.1016/j.jhazmat.2017.06.005

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 FeCl₃ 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^-1, 53.371mgg^-1 and 104.592mgg^-1 for Cu(II), Pb(II) and Cr (VI), respectively.

Keywords: Adsorption; Black wattle tannin; Heavy metal ions; Nanocellulose; Nanocomposite.