Copper Removal by Acid-Conditioned Zeolite, Part I: Equilibrium, and Numerical Simulations

Abstract

Heavy metal water pollution is one of the most pressing environmental problems of the last decades. Wastewater from many industrial processes contain high concentrations of metals and have very acid pH. Thus, technologies to remove heavy metals from aqueous solutions are costly or suffer deterioration when in contact with substances with acid pH. Natural zeolites have demonstrated to be a low-cost heavy metal adsorbent. This study aimed to determine basic parameters for efficient copper removal by aluminosilicates. A Zeolite was conditioned with concentrated H₂SO₄ to further develop the experiments to test 12 equilibrium isotherms (Freundlich, Redlich-Paterson, Sips, Halsey, Dubinin-Radushkevich, Flory-Huggins, Langmuir, Temkin, Elovich, Fowler-Guggenheim, Henry's and Kiselev) and pHpzc. Maximum removal was obtained with neutral pH values; the Freundlich model had the best performance. The removal efficiency increased as the initial concentration of the solution increased. The pH value at the point of zero charge was 2.9.

Keywords: Isotherms; Aluminosilicates, Metals, Freundlich, Numerical Simulations

DOI: 10.7176/JEES/9-3-03

Publication date:March 31^st 2019