Adsorption of chromium (VI) ion using adsorbent derived from lignin extracted coir pith

Luong Huynh Vu Thanh, Cao Luu Ngoc Hanh, Tran Nguyen Phuong Lan, Tran Thi Bich Quyen, Ha Quoc Nam
2020 Can Tho University Journal of Science  
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 absorbent 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),
more » ... pzc analysis, Boehm titration and potentiometric titration were employed to characterize structure, specific surface area, functional groups and surface charge of the absorbent. Adsorption results showed that 95.23% of Cr(IV) was removed from solution of 100 mg.L-1 by using certain amount of absorbent at pH 2.0 within 20 min at room temperature. Kinetics of Cr(VI) adsorption from aqueous solution on absorbent fit to Pseudo-second-order kinetic equation and adsorption isotherm of Cr(IV) followed to Freundlich model.
doi:10.22144/ctu.jen.2020.024 fatcat:4nfsuldcxjfvbhc5ushc5vvyoi