Zinc Oxide Nanoparticles Loaded on Activated Carbon and Its Application for Adsorption Removal of Uric Acid

Abstract

The work was devoted to the study of uric acid (UA) adsorption onto zinc oxide nanoparticles loaded on activated carbon (ZnO-NP-AC). This nontoxic and cheap material with high efficiency in a routine manner was synthesized in our laboratory and its surface properties such as surface area, pore volume and functional groups were characterized with different techniques such FT-IR, SEM, and BET analysis. Then, the its utilization for the removal of UA was investigated by optimization of the effects of variables such as solution pH, initial UA concentration, amount of adsorbent, temperature, and adsorption time. Fitting the equilibrium data to conventional isotherm models (Langmuir, Freundlich, and Tempkin) according to correlation coefficient and error analysis show the priority of the Langmuir model in term of higher correlation coefficient (0.995) and high adsorption capacity (345.8 mg g⁻¹) for data elucidation. The favorable adsorption data suggest its suitability for the fast and economic UA removal (more than 90% in time less than 15 min) using small amount of nanoparticle (<0.012 g). The result of removal of UA at various time was investigated and experimental data was analyzed by four kinetic models including pseudo first and second order Elovich and the intraparticle diffusion equations and subsequently their respective parameters such as rate constants, equilibrium adsorption capacities, and correlation coefficients were investigated and based on well known criterion their applicability was judged. The result show that adsorption of UA onto proposed adsorbent at all conditions such as versatile adsorbent dosage and initial UA concentrations sufficiently described by the pseudo second-order equation in addition to interparticle diffusion model.

Keywords:

• activated carbon
• AC
• adsorption
• kinetics and equilibrium study
• uric acid
• zinc oxide nanoparticle