Removal of Heavy Metals Cadmium and Chromium from Synthetic Water by Using Zinc Oxide Nanoparticles

Abstract

The research focuses on addressing the significant issues of water pollution caused by heavy metals like cadmium and chromium. To tackle this problem nanotechnology is being applied to develop a solution using zinc oxide nanoparticles as a Nano adsorbent for water treatment. The primary objective of this study is to synthesize zinc oxide nanoparticles and their subsequent characterization through FTIR, SEM and EDX analyses. The research also aims to assess various parameters that affect the removal efficiency of cadmium and chromium from synthetic water by using zinc oxide nanoparticles. These parameters include the contact time, heavy metal solution, adsorbent dosage and levels. The synthesis of zinc oxide nanoparticles was done by controlled precipitation method with zinc sulfate as a precursor followed by calcination at 600 C. Additionally desorption and desorption studies are conducted to understand the efficiency of zinc oxide in removing heavy metals from water. After the removal of heavy metals, the samples were sent for analysis under atomic adsorption spectroscopy. After this adsorption kinetics data were fitted by pseudo-second-order kinetics with high regression coefficients. The FTIR peaks show zinc oxide nanoparticles at a wavenumber of 405 to 450nm.The confirmation of the process of adsorption of metal ions was done by EDX analysis. Morphology and size of nanoparticles was shown by SEM. Nanoparticles are larger in size and lead to agglomeration before calcination After calcination nanoparticles are reduced in number. For chromium and cadmium maximum adsorption by nanoparticle dosage takes place at 1g and 2g, the ideal contact time for maximum adsorption are 30 ,60 ,150 and 120 minutes, for heavy metal solution maximum adsorption takes place at 150ppm and pH level of 2 and 9 has been identified as most effective condition for adsorption process. All the experimental data was best suited by a pseudo –second-order kinetics model.