Phosphorylated cellulose triacetate–silica composite adsorbent for recovery of heavy metal ion.

Phosphorylated cellulose triacetate (CTA)/silica composite adsorbent was prepared by acid catalyzed sol–gel method using an inorganic precursor (3-aminopropyl triethoxysilane (APTEOS)). Reported composite adsorbent showed comparatively high adsorption capacity for Ni(II) in compare with different heavy metal ions (Cu 2+ , Ni 2+ , Cd 2+ and Pb 2+ ). For Ni(II) adsorption, effect of time, temperature, pH, adsorbent dose and adsorbate concentration were investigated; different kinetic models were also evaluated. Thermodynamic parameters such as ΔG °, ΔH ° and ΔS ° were also estimated and equilibrium adsorption obeyed Langmuir and Freundlich isotherms. Developed adsorbent exhibited about 78.8% Ni(II) adsorption at pH: 6 and a suitable candidate for the removal of Ni(II) ions from wastewater. Further, about 65.5% recovery of adsorbed Ni(II) using EDTA solution was demonstrated, which suggested effective recycling of the functionalized beads would enable it to be used in the treatment of contaminated water in industry. [ABSTRACT FROM AUTHOR]