Kinetic study of the simultaneous removal of ibuprofen, carbamazepine, sulfamethoxazole, and diclofenac from water using biochar and activated carbon adsorption, and TiO2 photocatalysis
Klaudia Całus-Makowska, Anna Grosser, Anna Grobelak, Hanna Białek, Ewa Maria Siedlecka
Abstract
The growing number of pharmaceuticals released into the environment poses a threat not only to the aquatic environment but also to human health. This work introduces a novel approach for the simultaneous analysis of four pharmaceuticals—ibuprofen, carbamazepine, sulfamethoxazole, and diclofenac—each with distinct chemical structures. The study explores the kinetic behavior of these compounds during their removal from water, employing biochar and activated carbon as adsorbents, as well as titanium dioxide (TiO 2 ) for photocatalytic degradation. This utilizes two distinct approaches incorporating adsorption mechanisms. The concentrations of pharmaceuticals were simultaneously measured using High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD). In addition to adsorption, photocatalysis with varying dosages of TiO 2 was investigated as an alternative method for pharmaceutical removal. The HPLC- DAD analysis enabled the simultaneous monitoring of all four pharmaceuticals in a single analysis. The Langmuir-Hinshelwood model was applied to the photocatalysis data to assess reaction kinetics. The results demonstrate the efficacy of both adsorption methods in removing pharmaceutical contaminants from water. Integrating both adsorption and photocatalysis experiments in one manuscript allows for a comprehensive evaluation of these methods' individual strengths in water treatment applications, providing insights into their combined potential for addressing pharmaceutical contamination in water resources. The calculated removal efficiencies, Langmuir-Hinshelwood kinetics, half-life values, and equilibrium adsorption capacities provide a comprehensive understanding of the efficiency and mechanisms involved in the removal processes, emphasizing the importance of addressing pharmaceutical contamination in water treatment strategies. • Simultaneous removal of carbamazepine, diclofenac, ibuprofen, and sulfamethoxazole was studied. • Pharmaceuticals removal was conducted by adsorption and photocatalysis with TiO 2 . • Photocatalysis with TiO 2 showed higher removal efficiency than adsorption methods. • Competitive effects reduced pharmaceutical removal in multicomponent solutions.