Biosorption of cadmium (II) in aqueous solutions using green alga biomass modified by calcium

Abstract

Green algae biomass modified by Calcium has been used as a sorbent to study the uptake of Cadmium(II) from aqueous solution. The study was conducted at the Laboratory scale. The main aims of the study were to know the level of Biosorbent-Ca content and Langmuir as well as Freundlich sorption capacities at optimum condition. Initially the study began by testing the sorption capacity and optimum efficiency of the Biosorbent-Ca for Cd(II). Then continued by testing their sorption isotherm models, capacity, and followed by FTIR spectra analysis. The performed Cd(II) concentration was between 50 to 200 mg/L at pH 5 for each 1.0 g Biosorben-Ca/L. The results shown that the optimum Cd(II) sorption capacity was obtained at 73.48 mg/g Biosorbent-Ca, while the efficiencies reached before holding sorption equilibrium was 79.06%. Furthermore, the maximum Langmuir qm constants for Cd(II) was 76.92 mg/g while KL levels=0.167 L /mg. Subsequently, the Freundlich constants: KF = 12.27 mg/g and n=1.59 g/L. The value of 1/n <1 strongly supporting the suitability of Freundlich models in sorption process. The results of FTIR spectra showed that the functional groups of amines, carbonyl and hydroxyl were playing major roles as active sites in the biosorption process of Cd(II) by biosorbent of green algae modified Calcium.