Comparison of nickel doped Zinc Sulfide and/or palladium nanoparticle loaded on activated carbon as efficient adsorbents for kinetic and equilibrium study of removal of Congo Red dye.

In this study, the efficiency of nickel doped Zinc Sulfide nanoparticle loaded on activated carbon (Ni-ZnS-NP-AC) and palladium nanoparticles loaded on activated carbon (Pd-NP-AC) for the removal of Congo Red (CR) from aqueous solution was investigated. These materials were fully identified and characterized in term of structure, surface area and pore volume with different techniques such XRD, FE-SEM and TEM analysis. The dependency of CR removal percentage to variables such as pH, contact time, amount of adsorbents, CR concentration was examined and optimum values were set as: 0.03g Ni-ZnS-NP-AC and 0.04g of Pd-NP-AC at pH of 3 and 2 after mixing for 22 and 26min for Ni-ZnS-NP-AC and Pd-NP-AC, respectively. Subsequently, it was revealed that isotherm data efficiency can be correlated Langmuir with maximum monolayer adsorption capacities of 286 and 126.6mgg(-1) at room temperature for Ni-ZnS-NP-AC and Pd-NP-AC, respectively. Investigation of correlation between time and rate of adsorption reveal that the CR adsorption onto both adsorbents followed pseudo second order and interparticle diffusion simultaneously.