Assessing the Bleaching Potential of Activated Sawdust on Soyabean and Goya Olive Oils (original) (raw)

The bleaching process is a crucial process in oil refining in which an adsorbent is majorly used to adsorb the unwanted colour pigments and a wide range of other impurities. This study aims to modify sawdust as an adsorbent and process it into powder form. Effects of three factors; temperature, mass and time, were investigated, while the experiment was performed using activation/carbonization, filtration, degumming, neutralization and bleaching methods. The adsorbent (sawdust) was prepared by chemical activation using phosphoric acid. Soyabean and goya olive oils were subjected to adsorption process utilizing the activated sawdust. The concentration of the adsorbent (activated sawdust), ranging from 0.5-3.0 g, enhanced the adsorption bleaching efficiency of the adsorbent. The absorbance and concentration of two neutralized oils were measured at 460 nm using ultra violet spectrophotometer. The values of equilibrium concentration, Ce/qc, Langmuir constant (b), and slopes for soybean and goya olive oils were obtained from Langmuir isotherm equation: Ce/Qc = 1. Ce/Q o + 1/ bQ o ; where Ce is the equilibrium concentration, Qc is the % absorption, 1/Q o is the slope, while Q o is the adsorption capacity and b is the Langmuir constant. The data obtained were fitted into Langmuir isotherm thereby indicating a monolayer adsorption, where the adsorption capacity (Q o ) for goya olive and soyabean oils were 0.54 and 0.02. The percentage (%) absorption values of goya olive oil were