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

Scientific achievement

Tannin immobilized nanocellulose composite (TNCC) was pre-pared from black wattle tannin and dialdehyde nanocellulose(DANC) using a novel route. The black wattle tannin was suc-cessfully immobilized onto dialdehyde nanocellulose through thereaction between the aldehyde groups on DANC and reactivehydrogen on tannin molecules. The composite was fabricated byellipsoidal particles with lengths ranging from 100–400 nm. It canbe used to adsorb not only positively charged metal ions, Cu(II) andPb(II), but also negatively charged metal ion, Cr(VI), from aqueoussolutions.

Research details

In the present work, a nanocomposite biosorbent based onblack wattle tannin and nanocellulose was fabricated using a novelroute novelroute. Firstly, nanocrystalline cellulose was periodate oxidized toget dialdehyde nanocellulose (DANC), and then black wattle tanninwas covalently immobilized onto DANC by the reaction betweenthe aldehyde groups on DANC and reactive hydrogen on tanninmolecules. In this process, aldehyde nanocellulose was used as boththe matrix and cross linker. To our knowledge, tannin immobilizednanocellulose, which could be applied in contaminant removal,are not reported so far. The obtained tannin-nanocrystalline cellu-lose (TNCC) composite was characterized by using FT-IR, AFM andTGA. Subsequently, TNCC was applied to adsorb metal ions fromaqueous solutions, and the adsorption kinetics and isotherm wereinvestigated.