Affinity Augmentation of ZnFe2O4 Nanoparticles Toward Hexavalent Chromium Through a Facile Bi3+ Doping Process.

A facile method to prepare activated ZnFe2O4 nanoparticles through novel metal ion doping using Bi3+ is demonstrated. The enhanced activity of the Bi3+-doped ZnFe2O4 nanoparticle was evaluated through Cr(VI) ions adsorption capability analysis from aqueous samples since industrial effluents have the metal ion as a major source of concern. ZnFe2-xBixO4 (x = 0.0, 0.05, 0.10, 0.15, 0.2) were synthesized using sol gel method, and a comparative adsorption efficiency study of Bi3+-doped and undoped ZnFe2O4 was performed. To understand the variation in adsorption efficiency and mechanism of adsorption on the Bi3+-doped ZnFe2O4, the adsorption study was conducted under varying adsorption conditions including pH, adsorbent dosage, contact time, initial ion concentration, and temperature. All the quantification studies regarding the adsorption were done using atomic adsorption spectroscopy (AAS). The studies suggested enhanced adsorption capability via Bi3+ doping as it can enhance the effective surface area and electrostatic charge density on the surface. Adsorption equilibrium information from this study was modeled using prominent adsorption kinetics and isotherm models, for extracting information regarding the performance of the adsorbent, rate of the adsorption and adsorption mechanism, which are imperative in the design and operation of adsorption systems. Scope of regeneration and reusability of the spent adsorbents in water treatment, which is also investigated in this work, addresses the ecological and economic demands for sustainability and also makes the wastewater treatment process cost effective. [ABSTRACT FROM AUTHOR]