Functionalized Ni–Co MOFs for Pharmaceutical Pollutant Removal: Adsorption Performance and Kinetic Study

With the continuous rise in global population and technological progress particularly in the pharmaceutical sector, the contamination of water bodies by pharmaceutical residues has emerged as a critical environmental concern. These pollutants, even at trace levels, can pose significant risks to aquatic life and human well-being. As access to clean water becomes increasingly urgent, there is a pressing need to devise highly effective strategies for the elimination of such contaminants. In this research, a novel composite adsorbent derived from a nickel–cobalt metal–organic framework (Ni–Co MOF) was fabricated via a solvothermal approach and tested for its capacity to remove diclofenac sodium (DCF) and ibuprofen (IBU) from water. The significance of targeting these pollutants lies in their chemical persistence and harmful ecological impacts. To enhance adsorption efficiency, the material's surface was functionalized using cetyltrimethylammonium bromide (CTAB). Experimental findings showed that under optimized conditions (100 mg/L initial concentration of DCF and IBU, 50 mL solution volume, 60 min contact time, pH 6.5, and temperature of 25 °C), the material achieved removal efficiencies of 87.48% for DCF and 74.37% for IBU. The corresponding maximum adsorption capacities were 380.34 and 297.65 mg/g, respectively. Isothermal modeling confirmed that the adsorption conformed to the Langmuir model, which is indicative of monolayer adsorption on a homogeneous surface. Additionally, kinetic studies revealed a better fit with the pseudo-second-order model, pointing to the dominance of chemisorption mechanisms. Overall, the findings suggest that the CTAB-functionalized Ni–Co MOF holds considerable potential as a high-performance adsorbent for pharmaceutical pollutant removal and represents a promising solution for next-generation water purification technologies.