Equilibrium studies for copper removal from aqueous solution using nanoadsorbent synthesized from rice husk

Abstract

Nanomaterials have gained utmost attention in the field of science and technology due to magnetic, catalytic, thermal and adsorption properties. This study reports the incisiveness of preparation and characterization of nanoadsorbent synthesized from rice husk an agricultural waste by chemo-mechanical method and its ease in the removal of copper from aqueous solution. Nanoadsorbent was individuated by different techniques viz. Force-emission scanning electron microscopy, Fourier Transform Infrared spectroscopy technique and Atomic force microscopy. Adsorbent to metal interaction by adsorption process was accomplished in batch mode to optimize different parameters viz., pH, adsorbent dose, contact time, metal ion concentration, temperature. Thermodynamic parameters Gibb’s free energy change, enthalpy change and entropy change implied that Cu (II) adsorption is spontaneous and endothermic. The experimental data of Cu (II) adsorption rate was well accounted by pseudo second order kinetic model with R2 value 0.998. The adsorption of copper on the nanoadsorbent surface was modeled with Freundlich, Langmuir and Temkin isotherm models with R2 values 0.993, 0.968 and 0.960 respectively. The results confided that Cu (II) is substantially adsorbed on the nanoadsorbent and turned up to be economically viable approach for copper removal from aqueous solution.