Paper Title
Application of Nano-Composite Solid Phase Adsorbent for Abatement of Pb(Ii) from Aqueous Solution

Abstract
The present study reports the synthesis, characterization and utilization of polyaniline-metaloxidenano composite material for the adsorption of Pb(II) from aqueous solution. The adsorbent was characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Atomic force microscopy (AFM). For obtaining the optimum conditions for maximum Pb(II) removal, various physico-chemical parameters such as effect of contact time, initial metal ion concentration, adsorbent dose and solution pH were evaluated. Adsorption of metal ion on to the nanocomposite material was found to be quite fast. The time to reach equilibrium was 30 min for initial metal concentration of 50 mg L-1 and below while it was 60 min. for concentration 80 mg L-1 and above. Effect of pH was studied by varying solution’s pH from 2-10 and optimum pH was found to be 4 where percent removal of Pb(II) was 92%. Equilibrium Isotherm and kinetic data were evaluated by non-linear curve fitting of experimental data using Origin 9.1 data analysis and graphing software. Maximum monolayer adsorption capacity based on Langmuir isotherm was 66.7 mg g-1. Kinetic analysis showed that Pseudo-second-order kinetic model was well obeyed indicating that chemisorption was rate limiting step. In order to stablish practical utility and economic feasibility of the nanocomposite material, regeneration was carried out using 0.1N HCl as desorbing eluent. Regeneration was done up to six adsorption-desorption cycles and the adsorbent exhibited excellent regeneration capability. Keywords - Nano composite; Pb(II); Adsorption; Isotherm; Regeneration.