Adsorption of Citric Acid onto Calcium Peroxide Nanoparticles: Equilibrium, Kinetic, and Thermodynamic Data

Abstract

Recently, metal peroxide nanoparticles are becoming more significant as nano-adsorbents owing to their notable and improved features as well as their easy and economical synthesis. In the current investigation, calcium peroxide (CaO2) nanoparticles were evaluated as a new nano-adsorbent for the citric acid adsorption. For this purpose, calcium peroxide (CaO2) nanoparticles were synthesized utilizing an easy precipitation technique and characterized by various analyses (BET, FTIR, XRD, and SEM). The synthesized CaO2 nanoparticles were in nanoscale size with 34.77 nm, and the surface area was found to be 13.58 m(2).g(-1). The impacts of various adsorption conditions like adsorbent dosage (0.05-0.30 g), initial citric acid concentration (2-10% w/w), equilibrium time (30-240 min), and temperature (25-55 degrees C) were investigated. Moreover, thermodynamics and kinetic and isotherm modeling studies were theoretically computed to clarify citric acid adsorption process onto CaO2 nanoparticles. The highest CaO2 nanoparticle adsorption capacity for citric acid removal was obtained as 369.83 mg/g at the adsorbent dosage of 0.05 g, the initial concentration of citric acid of 10% (w/w), the equilibrium time of 180 min, and temperature of 25 degrees C. The outcomes demonstrated that calcium peroxide nanoparticles are effective adsorbents in removing citric acid from an aqueous solution.