Comparison of nickel and/or zinc selenide nanoparticle loaded on activated carbon as efficient adsorbents for kinetic and equilibrium study of removal of Arsenazo (ΙΙΙ) dye

Nickel nanoparticles (Ni–NP) and zinc selenide nanoparticles (Zn–Se–NP) were synthesized and characterized. Synthesized Ni–NP and Zn–Se–NP were loaded on activated carbon and were successfully used for the removal of Arsenazo (III) dye from aqueous medium. Adsorbents were characterized using VSM, XRD and SEM analyses and reported well. The influence of various experimental parameters like initial pH, contact time, amount of adsorbents and initial dye concentration on its removal percentage was investigated. The experimental equilibrium data was fitted and evaluated by various adsorption isotherms like Langmuir, Freundlich, Tempkin and Dubinin–Radushkevich models. It was found that Langmuir isotherm model fitted well. The kinetic study was carried out by analyzing the time dependency kinetic data to various models. It was found that both adsorbents followed pseudo second order kinetics and intra-particle diffusion mechanism for Arsenazo (III) removal. Performance of Ni–NP–AC in dye adsorption was found to be better than that of Zn–Se–NP–AC. It was found that the maximum dye adsorption capacity of Ni–NP–AC was 168 mg g− 1 whereas, the extent of dye adsorption capacity was 162.74 mg g− 1 for Zn–Se–NP–AC.