Green Synthesis of Cost-Effective and Efficient Nanoadsorbents Based On Zero and Two Dimensional Nanomaterials for Zn2+ and Cr3+ Removal from Aqueous Solutions

Abstract

Novel, efficient and cost-effective heavy metals nanoadsorbents were developed. Polyaniline nanofibers were prepared at ambient conditions and their nanocomposites based on zero and two dimensional nanomaterials were developed. Polyaniline nanofibers chains were polymerized on the surface of clay layers and silica nanoparticles originated from rice husk individually using facile synthesis approach. Polyaniline nanofibers and their nanocomposites were used as efficient adsorbents for removal of Zn2+ and Cr3+ ions. The developed nanocomposites achieved superior adsorption uptake efficiency for removal of Zn2+ and Cr3+ ions compared to polyaniline nanofibers alone. The new adsorbents achieved excellent uptake efficiency for removal of Zn2+ and Cr3+ of 95 and 92% respectively. Effect of nanomaterial shape on the adsorption efficiency of metal ions was investigated. Also, effect of adsorbent dose, initial metal ions concentrations, pH of solution and contact time on the adsorption efficiency of Zn2+ and Cr3+ were investigated and tuned. Additionally, the adsorption of Zn2+ and Cr3+ ions on the nanocomposites were further analyzed using Langmuir and Freundlich models and the adsorption isotherms of Zn2+ and Cr3+ were found to be fit well with Langmuir model. This study presents a new approach for development of cost-effective and efficient adsorbents from abundance precursors for removal of heavy metal ions from industrial wastewater.