Abstract:
In the present work, the removal of metals ions such as Pb(II), Cd(II), Cr(III) from industrial effluent by batch adsorption technique using different bio-adsorbents were investigated. Standard solutions of the metal ions of different concentrations were prepared and their adsorption properties onto neem leaf powder (NLP), nut shell powder (NSP) and jute stick powder (JSP) were studied. The influence of initial metal ion concentration, contact time, pH, adsorbent dose, free energy and desorption studies were investigated. Experimental data for all the adsorbents were found to fit well to both Langmuir and Freundlich adsorption isotherm models. The experimental data revealed that these adsorbents are highly effective for the removal of Pb(II) and Cd(II) but a little bit less potential for the removal of Cr(III) from industrial effluents at pH 6-7. The data obtained were interpreted kinetically by using pseudo first order, and pseudo second order kinetic models. In all the cases, the adsorption kinetics followed pseudo second order rate equation.
NLP, NSP and JSP are very effective adsorbent for the removal of Pb(II), Cd(II) and Cr(III) even when their concentration is as low as 4 ppm. The main advantage of using NLP, NSP and JSP for the adsorptive removal of metal ions from wastewater lies in the fact that these adsorbents are most effective when the pH of the medium is about 6.5. So, NLP, NSP and JSP may be used as cost-effective and environment-friendly adsorbents for the removal and recovery of Pb(II), Cd(II) and Cr(III) ions from industrial wastewater.
