Abstract
The rising presence of drug-related contaminants in water sources is a major environmental and public health concern. Several studies have addressed the hazardous influence of these pollutants on the lives of over 400 million people worldwide. In this study, we used molecular dynamics simulations to evaluate the efficacy of two promising composite materials for the removal of pharmaceutical contaminants by using the adsorption technique. Graphitic carbon nitride/graphene (g-C3N4/graphene) and metal-organic framework (MIL-101(Fe))/graphene have been simulated for the first time for the removal of three of the most common pollutants (acetaminophen, caffeine, and sulfamethoxazole). The nanocomposite structure has been created and optimized using the geometry optimization task in the DFTB Modules in the Amsterdam Modeling Suite. Our results reveal the remarkable ability of the g-C3N4/graphene and MIL-101(Fe)/graphene composites to adsorb acetaminophen, caffeine, and sulfamethoxazole. Using the Reactive Forcefield (ReaxFF) software, we reveal the mechanisms of the adsorption process, calculating van der Waals interactions, and the adsorption capacity. We found that the combination of MIL-101(Fe)/graphene had a higher adsorption capacity for the removal of pharmaceutical contaminants than g-C3N4/graphene. At 40 Ps (Picosecond), 80 molecules of each pharmaceutical contaminants (Acetaminophen, Caffeine and Sulfamethoxazole) have been adsorbed by MIL-101(Fe)/graphene with higher exothermic energy equated to (-1174, -1630, and − 2347) MJ/mol respectively. While for g-C3N4/graphene at 40 Ps, 70 molecules of each pharmaceutical contaminants have been adsorbed with exothermic energy equated to (-924, -966, and − 1268) MJ/mol respectively. Finally, we summarized the condition of the essential parameters (Temperature, pressure, and density) of the simulation box during the MD-simulation, and the adsorption kinetics using Pseudo-First Order (PFO) in order to ensure the accuracy of our MD-simulation results.