Removal of Some heavy metals Contaminants from Aqueous Solutions By Applying Biomass-Based Modified Activated Carbon

Abstract

Activated carbon (AC) has been prepared from rice husk (RH) as an agricultural by-product. Different analytical instruments characterized the prepared activated carbon. Fe 3+ and Mn 2+ were extracted from the aqueous solution. The effects of many different variables namely, pH effect, reaction time, adsorbent amount, starting concentration of metal ions, interfering ions and temperature on the adsorption of ions were evaluated. The optimal adsorption of Fe 3+ and Mn 2+ was 3 and 6, respectively. The optimal contact time was determined to be 2 hours for both Fe 3+ and Mn 2+ ions. The kinetic and thermodynamic of adsorption process was found to be a pseudo-second order for both Fe 3+ and Mn 2+ ions. The equilibrium data was applicable to Langmuir, and Freundlich isotherm. The correlation coefficient (R 2 ) of both isotherms were 0.99 & 0.89 for Fe 3+ , respectively and 0.99 & 0.77 for Mn 2+ , respectively. The obtained data predicted also that; the endothermic system governs the adsorption process. Furthermore, the maximum adsorption capacities for Fe 3+ and Mn 2+ were 72.2 & 49.6 mg/g, respectively and the removal of metal ions were 90.12 & 83.42 %, respectively. Finally, the results revealed that the adsorption process of the two metal ions is consistent with the pseudo-second-order kinetics.