Manganese adsorption by iron impregnated pumice composite

Abstract

Manganese (Mn) is often present at high concentrations in ground and surface waters. Industrial discharges are also a major source of Mn pollution in the environment. Adsorption is a widely studied technique to abate Mn levels that various low cost adsorbents have attempted to for this purpose. Pumice is known to be effective adsorbent for removal of organics and heavy metals. Scientific efforts of modifying its surface were applied too, however, iron impregnated Pumice has not been applied to remove Mn yet. In this study the effect of initial Mn concentration and dose of adsorbents on adsorption efficiency of Mn were investigated. A detailed kinetic evaluation is given applyi,ng four isotherm models. Release of iron was monitored to evaluate the stability of new composite. The results of this study showed that Fe impregnated Pumice composite was more effective to remove Mn than Pumice adsorbent. Langmiur and Temkin Istorherms fitted adsorption data obtained in this study at higher correlation coefficients than other models. Relased Fe concentration was found to be much below than the limits of industrial discharges as well as than WHO guideline value for drinking water. These preliminary results indicate that Fe-Pumice composite is a promising and economical adsorbent and further studies are ongoing to enhance its stability and economical aspect by decreasing the dose of the composite to be used. (C) 2017 Elsevier B.V. All rights reserved.