| dc.description.abstract | Adsorption of Cadmium and Lead in aqueous solutions by Spent coffee grounds/chitosan/PVA composite beads was studied.
An adsorption Batch experimental model was used to determine the Isotherms and kinetics of 4 different compositions of beads, it was developed according to the individual adsorption capacity of the constituents stated in the literature and assigned in 4 groups: Control bead (BC; containing only 4% chitosan), Bead 1 (B1; 1 gr of SCG, 4% chitosan and 7,5% of PVA), Bead 2 (B2; 2 gr of SCG, 4% chitosan and 7,5% PVA) and Bead 3 (B3; 3 gr of SCG, 4% chitosan, 10% PVA).
Morphological variables were measured using TGA, FTIR, BET, and SEM, and the adsorption capacity and removal efficiency were calculated.
The adsorption behavior was studied through non-linear and linear Isotherms and pseudo-first and second order kinetic modeling. All beads presented a non-linear Langmuir and Temkin and a pseudo-second-order fit only for cadmium adsorption according to the R2 correlation coefficients. Maximum values for adsorption capacity (qmax) were obtained for the adsorption of cadmium using the non-linear Langmuir model (B2 199,61 mg/g, B1 with 176,619 mg/g and B3 103,587 mg/g). B1 shown the highest value for lead adsorption among both approaches (263,16 mg/g).
These results could become a good contribution to the current knowledge along with a strong incentive to further research, about the valorization of waste and its important utilization in the synthesis of composites as remediators of contaminated water. | |
