Adsorption Studies of Trimethoprim Antibiotic on Powdered and Granular Activated Carbon in Distilled and Natural Water

Contamination of drinking water sources by Pharmaceuticals and Personal Care Products (PPCPs) has raised concerns due to associated negative effects on the ecosystem, which include reproductive and hormonal malfunctions in some living organisms. In addition, occurrence of antibiotics in aquatic environment has been associated with development of antimicrobial resistance. However, the conventional water and wastewater treatment technologies are not effective at removing such organic micro-pollutants from the source waters, hence most of such contaminants find their way through the systems with minimal restrain. Hence accelerated effort to find technologies to enhance removal of recalcitrant organic micro-pollutants from the water and wastewater. The objective of this study was to investigate the removal of Trimethoprim (TMP) from natural water using Powdered Activated Carbon (PAC) and Granular Activated Carbon (GAC). Adsorption experiments were conducted following batch process using natural water and distilled water. We also investigated the effect of pH changes on adsorption of TMP from the water. We obtained better performance for PAC in the removal of TMP compared to GAC. The removal efficiency decreased as a function of TMP concentrations in the aqueous solution. The optimal pH for adsorption was found to be 7, whereas pH values below or above 7 exhibited decreased adsorption of the antibiotic. There was no significant difference in the adsorption of TMP in both natural water and distilled water, which was attributed to limited organic matter in the natural water that was used.