Enhanced Adsorption of Ketoprofen and Reactive Yellow 15 from Aqueous Solutions Using Silver Nanoparticle-Modified Luffa: Characterization, Optimization, and Reusability Studies

Abstract

Abstract In the current work, luffa was modified with silver nanoparticles to prepare LF/AgNPs adsorbent for the elimination of ketoprofen and reactive yellow 15 (RY15) from aqueous media. Various characterization techniques, including FTIR, XRD, and SEM-EDS analyses, were employed to confirm the successful modification of LF/AgNPs. Several key parameters such as contact time, adsorbent dosage, concentration, pH, and agitation technique were fine-tuned to optimize the adsorption process. Ketoprofen removal was found to be most effective in weakly acidic conditions (pH=5), while reactive yellow 15 adsorption was enhanced in an acidic environment (pH=2). At 298 K, the highest adsorption capacities reached 56.88 mg/g for ketoprofen and 97.76 mg/g for reactive yellow 15. The adsorption of ketoprofen followed the Temkin isotherm model, indicating a chemisorption process (R2=0.997). Reactive yellow 15, however, adhered to the Freundlich isotherm model, suggesting multilayer adsorption due to uneven distribution of active sites (R2=0.987). Additionally, the kinetics of ketoprofen adsorption were best described by the Pseudo-first order model (R2=0.989), whereas the Pseudo-second order model provided the most accurate fit for reactive yellow 15 adsorption (R2=0.997). Importantly, the LF/AgNPs adsorbent displayed consistent performance over five consecutive reuse cycles, affirming its stability and efficacy in removing both contaminants. These findings underscore the exceptional potential of LF/AgNPs as a reliable adsorbent for the removal of reactive yellow 15 and ketoprofen from aqueous solutions.