Heavy metals removal from synthetic and industrial wastewater using synthesized zinc oxide nanoparticles

With the advancement in wastewater treatment systems over conventional systems the application of nanotechnology has gained popularity in the past decade. The process can be applied by modifying the physico-chemical properties of metal oxides that increase their effectiveness in extracting heavy metals from wastewater. The present study has been carried out by synthesizing the Zinc oxide nanoparticles using green and chemical synthetic methods. Green-synthesized ZnO nanoparticles (GS-ZnO-NP) were discovered to exhibit a maximum removal effectiveness of 93% and 94% for heavy metals in industrial wastewater and synthetic wastewater, respectively. However, heavy metals removal efficiency from industrial and synthetic wastewater was observed to be 98% and 98% respectively using chemically synthesized ZnO nanoparticles (CS-ZnO-NP). The heavy metals removal efficiency for specific metal is observed to be Cr > Pb > Cu > Hg > As. The kinetics of adsorption was calculated using Freundlich and Langmuir isotherm models. Freundlich model is the best fit with the coefficient of correlation in the range of 0.71–1 for green synthesized and 0.82 to 0.95 for chemically synthesized ZnO nanoparticles.