Article info.

ABSTRACT

Received 11 Aug 2020
Revised 08 Oct 2020

Accepted 30 Nov 2020

In this study, coconut coir pith (cellulose-lignin compound) was first treated with water and sodium hydroxide solution to remove lignin and impurities, then lignin-extracted coir pith was calcined at 200°C for 6 h. The obtained adsorbent was applied to remove Cr(IV) ions by using adsorption method. Some analytical methods such as thermal gravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR), Brunauer–Emmett–Teller analysis (BET), X-ray powder diffraction analysis (XRD), pH_pzc analysis, Boehm titration, and potentiometric titration were employed to characterize structure, specific surface area, functional groups, and surface charge of the adsorbent. Adsorption results showed that 95.23% of Cr(IV) was removed from solution of 100 mg.L^-1 by using a certain amount of adsorbent at pH 2.0 within 20 min at room temperature. Kinetics of Cr(VI) adsorption from aqueous solution on adsorbent fit to Pseudo-second-order kinetic equation and adsorption isotherm of Cr(IV) followed to the Freundlich model.

Keywords

Adsorbent, adsorption, Cr(VI) ion, coir pith

Cited as: Thanh, L.H.V., Lan, T.N.P., Quyen, T.T.B., Nam, H.Q. and Hanh, C.L.N., 2020. Adsorption of chromium (VI) ion using adsorbent derived from lignin extracted coir pith. Can Tho University Journal of Science. 12(3): 54-65.