CHARACTERIZATION OF SORGHUM AGRICULTURAL WASTE FOR USE AS COLORING MATERIAL BIOSORBENT

Abstract

This paper presents an agricultural residues of sorghum (RAS) characterization with the objective of its evaluation as biosorbent of contaminants present in aqueous solutions. The material is collected from the producers and treated by washing, drying and sizing. For characterization its physicochemical, thermal and structural properties were studied. Thermal properties were determined by thermogravimetric analysis and structural properties by Fourier Transform Infrared Spectroscopy (FTIR). It was found that 7.5 is the zero loading point; and that 0.750 meq/g and 0.525 meq/g are the values for acid and basic sites respectively and that particle sizes of 0.342 mm and those between 0.63 and 0.83 mm predominate. The elemental composition reflects that it is mainly carbon and oxygen. Infrared analysis shows that it is highly complex in nature due to the number of surface functional groups present. Thermogravimetric analysis identifies four fundamental thermal zones associated with losses of mass through dehydration, pyrolysis of hemicellulose and cellulose, cellulose and lignin, and residual H+. The results obtained allow the identification of this low cost agricultural waste as a possible biosorbent material for dyes.