Effect of chemical treatment on adsorption characteristics of apricot stone biosorbent

Abstract

This paper deals with investigation of alkali treatment effect on structural changes of apricot stones lingo-cellulosic residue (KK) and on adsorption capacity based on adsorption of Cu(II) ions from wastewater. Characterization of natural and alkali treated biomaterial were done by FT-IR and SEM. SEM micrographs showed that the removal of the surface impurities after treatment, improves the surface roughness of KK thus opening more hydroxyl groups and other reactive functional groups on the surface. FT-IR spectrum showed that the peak at 1735 cm-1 from of untreated KK, which is assigned to aromatic carbonyl or carboxyl C=O stretching of carboxylic acids or their esters, was reduced after treatment. After treatment change of point of zero charge value of modified biomaterial was evident: from pHPzc=4.9 (KK) to pHPzc=6.0 (KKM). Overall, the changes made by alkali treatment of KK, resulted in five times higher adsorption capacity.