Sugar palm Arenga pinnata Merr (Magnoliophyta) fruit shell as biomaterial to remove Cr(III), Cr(VI), Cd(II) and Zn(II) from aqueous solution

The removal of toxic heavy metals Cr(III), Cr(VI), Cd(II) and Zn(II) from aqueous solution by sugar palm (Arenga pinnata) fruit shell has been examined. Adsorption factors consisted of solution of pH, mass of biosorbent as well as initial metal concentration. The Langmuir isotherm was used to study the adsorption mechanism. Moreover, characterization of sugar palm fruit shell was investigated using Fourier transform infrared spectroscopy and surface morphology was checked using scanning electron microscope. The removal percentage at maximum conditions were: 0.28, 0.52, 0.43 and 0.58 mg g⁻¹ for Cr(III), Cr(VI), Cd(II) and Zn(II), respectively. Desorption study was carried out by using nitric acid at a range of pH 1–4. This work shows that the performance of biosorption of metals by A. pinnata has many advantages, such as good removal and deremoval efficiencies.