Benzoic acid removal from aqueous solutions by activated charcoal

Abstract

Benzoic acid has a wide use primarily in food but it is also used in cosmetic, pharmaceutical and other products. Because of noted carcinogenic and toxic characteristics under certain concentration it is considered a pollutant that becomes an important environmental problem. In this study, commercial activated charcoal was tested for the removal of benzoic acid from aqueous solutions. Removal of benzoic acid was investigated in a batch and column system under various values of pH, temperature, activated charcoal granulation and mass. The analysis of all samples was performed by visible absorption spectrometry. The optimum conditions for benzoic acid removal in a batch system were found to be pH 3, contact time of 60 min, the temperature of 273.65 K and adsorbent dose of 10 g L-1. The benzoic acid removal can be performed in a column system as well in which the highest quantity of benzoic acid is removed during the first 20 min (70%) and saturation occurs after 70 min. The used benzoic acid removing methods can be characterized as simple, economical and fast and requiring no chemical treatment.