Hybrid inorganic/organic alumina adsorbents-functionalized-purpurogallin for removal and preconcentration of Cr(III), Fe(III), Cu(II), Cd(II) and Pb(II) from underground water

Abstract

Metal pollution is well recognized as one of the major environmental problems that must be imperatively addressed and solved. In this study, three types of alumina adsorbents (I–III) were physically immobilized with purporogallin as a chelating ion exchangers. These were found to exhibit strong capability and selectivity characters for a series of heavy metal ions. Surface modification of hybrid alumina was characterized and identified from the determination of surface coverage and infrared analysis. Hybrid alumina adsorbents were identified for their strong resistivity to acid leaching in pH > 2–7 as well as their high thermal stability up to 350 °C. The ability of newly synthesized hybrid inorganic/organic alumina adsorbents (I–III) to bind and extract various metal ions was examined and evaluated in various buffer solutions (pH 1.0–7.0) via determination of the metal adsorption capacity values. These were identified as high as 420–560, 500–580 and 500–590 μmol g −1 for alumina adsorbents (I), (II) and (III), respectively in the case of high concentration levels of Cr(III), Fe(III) and Cu(II). The influence of alumina matrices were highly characterized when low concentration levels (μg ml −1 and ng ml −1) of metal ions were used. Hybrid alumina adsorbents were successfully applied for selective extraction, removal and preconcentration of various heavy metals from underground water samples with percentage recovery values of 92–100 ± 1–3%.