Chemical and Pathogenic Cleanup of Wastewater Using Surface-Functionalized CeO₂ Nanoparticles

Abstract

In this paper, we report the simple synthesis, detailed characterization, and total wastewater cleanup by adsorption using bare and surfactant-functionalized cerium oxide (CeO2) nanoparticles. The synthesis of CeO2 nanoparticles was performed by a facile aqueous solution process and characterized by a diverse range of techniques, which confirmed that the nanoparticles are well-crystalline, possessing good structural and optical properties. The competence of the prepared nanoparticles was further explored to determine the dye removal efficiency. The developed nanoparticles have also provided chlorine-free disinfection of water. The observed results revealed that the synthesized nanoparticles efficiently lower the pollutant concentrations, reduced turbidity, and exhibited significant reductions in total dissolved solids, chemical and biochemical oxygen demands, and pathogenic load. Interestingly, the surfactant-functionalized nanoparticles revealed that they possess the ability to remove approximately 99% of dye (at a specific set of conditions) from a wastewater system. Further, the dye removal efficiencies of functionalized nanoparticles varied from 112.4 to 171.3 mg/g of dye, which is superior as compared to those of other nanoadsorbents studied for the same dye. The excellent dye adsorption performance was mainly due to the higher available surface area of the functionalized CeO2 nanoparticles. The regeneration of both dyes as well as nanoparticles further strengthens the importance of functionalized nanoparticles to utilize them for the next dye removal cycle. The in vitro antimicrobial and antimold activities of functionalized nanoparticles further revealed their disinfective nature, which is a crucial step in wastewater treatment. The presented work demonstrates that simply synthesized surface-functionalized CeO2 nanoparticles can be used efficiently for other potential environmental remediation applications.