Isotherm and thermodynamic studies on the removal of gelatin-stabilized silver nanoparticles from water by activated carbon

Authors : Ayşenur CERYAN, Nurettin ELTUĞRAL

Pages : 919-938

Doi:10.18596/jotcsa.1098891

View : 19 | Download : 8

Publication Date : 2022-08-31

Article Type : Research Paper

Abstract :Gelatin-stabilized silver nanoparticles insert ignore into journalissuearticles values(AgNPs); with a particle size of 6.9 insert ignore into journalissuearticles values(±3.2); nm were synthesized and employed in nanoparticle adsorption onto activated carbon insert ignore into journalissuearticles values(AC);. Subsequently, the synthesized AgNPs and the adsorbed nanoparticles onto the AC insert ignore into journalissuearticles values(AgNP@AC); were characterized by various techniques including UV–Vis spectrophotometry, transmission electron microscopy insert ignore into journalissuearticles values(TEM);, scanning electron microscopy insert ignore into journalissuearticles values(SEM);, Fourier transform infrared spectroscopy insert ignore into journalissuearticles values(FT–IR); and X–ray diffraction insert ignore into journalissuearticles values(XRD);. AgNPs possessed colloidal stability at a wide pH interval ranging between 4 and 13. Adsorption was studied batch-wise as a function of initial nanoparticle concentration insert ignore into journalissuearticles values(4–14 mg L-1);, temperature insert ignore into journalissuearticles values(298–323 K);, pH insert ignore into journalissuearticles values(4–13); and adsorbent dosage insert ignore into journalissuearticles values(0.01–0.05 g);. Adsorption isotherms were investigated by fitting the data to different isotherm models including Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich insert ignore into journalissuearticles values(D–R);. Error analysis indicated that the adsorption is well described by the Langmuir model with a monolayer adsorption capacity of 10.36 mg g-1 for 0.05 g AC at pH 7 and 323 K. Thermodynamic parameters such as enthalpy insert ignore into journalissuearticles values(66.77 kJ mol-1);, entropy insert ignore into journalissuearticles values(232.92 J mol-1 K-1);, and Gibbs free energy insert ignore into journalissuearticles values(–8.31 kJ mol-1); indicated that the process is endothermic, favorable and spontaneous through physical interactions.
Keywords : Silver nanoparticles, gelatin, activated carbon, adsorption, thermodynamic parameters