Feldspar/MnO2 composite as adsorbent for Pb2+ and Cd2+ removal from aqueous solution

Abstract

Increasing the adsorption efficiency of feldspar is the main target of this study. This was achieved by synthesizing new composite from feldspar and nanosized MnO₂ by immersion natural feldspar in green-synthesized MnO₂. This composite was characterized and confirmed by X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared (FTIR) and specific surface area by Brunauer–Emmett–Teller (BET). Rietveld XRD showed that the ratio percentage of feldspar, MnO₂, was 61.7 and 38.3 which is very close to the intended ratio of 60:40, respectively. TEM showed clearly that nanosized MnO₂ were distributed on and among big particles of feldspar and increased the surface area of the composite as estimated from BET measurements. The adsorption capacity of Pb²⁺ and Cd²⁺ ions by this unique composite of feldspar/MnO₂ (FLS/MnO₂) was carried out using batch adsorption experiments to explore the influence of contact time, initial metals concentrations, initial pH, temperature and adsorbent dose on the efficiency of removal of these ions. This study succeeded to synthesize unique composite of feldspar/MnO₂ and hence enrich the adsorption efficiency of natural feldspar by this simple technique to be 99% and 98%, for removal Pb²⁺ and Cd²⁺ ions, respectively.