Cadmium biosorption using Aloe. barbadensis Miller leaves waste powder treated with sodium bicarbonate

Abstract

The research on Aloe.barbadensis Miller leaves powder use which is related to environmental application such as clean water technology/wastewater treatment process has been focused on the removal of cadmium, Cd(II). The present investigation describes the use of Aloe. Barbadensis Miller leaves powder treated with chemical Na 2 CO 3 as bio-adsorbent, ( MABL ) for Cadmium removal from aqueous solutions. Batch experiments were performed to study the effects of various parameters, such as pH, dosage, contact time, initial metal concentration on the removal behavior of Cd (II) from aqueous solutions. The kinetic data fitted well to the pseudo-second order model, with a calculated adsorption capacity (q e ) value of 17.54 mg/g at 20 ppm. The biosorption data conformed best to the Freundlich isotherm as revealed by a lower non-linear Chi-square (x 2 ) value of 0.32 and a higher correlation value of 0.99 at 293 K.The maximum biosorption capacity for the leaves powder was 23.86 mg/ g at 313 K. The thermodynamic parameters values vary with concentration. The negative ΔG value indicates the reaction to be spontaneous, the negative ΔH at different concentrations indicates the reaction to be exothermic, less than 1 value of S*sticking probability showed that biosorption process was feasible and bioadsorbent was suitable to the removal of Cd (II) from aqueous solutions. Fourier transform infrared (FTIR) spectroscopy confirmed the involvement of OH, C=C, and C-O groups on the removal of Cd (II) from aqueous solutions. Scanning electron microscopy, Zeta potential, BET characterizations of the bioadsorbent were also performed. This study indicated that Modified Aloe. barbadensis Miller leaves powder ( MABL ) can be used very effectively to remove Cd (II) from aqueous solutions as well as real wastewater. • Modified A. barbadensis Miller Leaves powder as low cost efficient Biosorbent • Effect of process parameters such pH, concentration, biosorbent doses, temperature • To determine the isotherms and kinetic models • Thermodynamic study of the biosorbent-Cd(II) aqueous system