Abstract
The adsorptive nature of calcium oxide nanoparticles in aqueous sample of naphthalene in presence of Ca2+ ions was estimated. Enhanced efficiency of calcium oxide regeneration (90%) with the aid of calcium chloride in the solution concentration of 0.002–0.1 M was depicted. The less degree of toxic naphthalene desorption merged with SEM, FTIR and XRD characterization data portrays the importance of naphthalene adsorption onto calcium oxide using calcium chloride for regeneration. Batch adsorption studies were performed to evaluate the operating parameters such as pH, naphthalene concentration, contact time and impact of Ca2+ on naphthalene study. The adsorption isotherm of naphthalene on calcium oxide nanoparticle was described by Langmuir, Freundlich, Temkin and Dubinin Radushkevich and theoretical maximum monolayer adsorption capacity was found to be 63.81 mg/g at 303 K. The adsorption kinetic best fitted with pseudo second order kinetic model. The positive influence of making the addition of Ca2+ ions into naphthalene solution for its rapid adsorption was elucidated which is leaded by a probable increase in sorption capacity for naphthalene molecules at lower concentrations. The stable nature of crystallinity of calcium oxide and a less degree of naphthalene molecules leaching during consecutive cycles of adsorptive process and nanoparticle regeneration was also scrutinized.
•Naphthalene removal was made using Calcium Oxide nanoparticle.•Calcium oxide nanoparticles were obtained from waste crab shell.•Linear isotherm and kinetic mechanism was tested.•Freundlich isotherm and Pseudo II order kinetic mechanisms were favourable to present adsorption process.•Effect of Ca2+ and OH− ions on naphthalene adsorption was revealed.