Chelating Polymer Bearing 2-(2-Diazolylazo)phenol Moiety for Adsorbent of Heavy Metal Ions

Abstract

Chelating polymer bearing 2-(2-diazolylazo)phenol moiety was synthesized and its metal adsorption properties for 6 divalent heavy metal ions (M²⁺): Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺ and Pb²⁺ were investigated. The polymer changed color from orange yellow to blue or to red violet with its chelation to Cu²⁺ or to Ni²⁺, respectively. The maximum capacity of the polymer for Cu²⁺ was found to be 1.35meq/g in pH 5.71 solution. The degrees of saturation of the capacity of the polymer after shaking for 30min were 71.3 and 83.6% for the adsorptions of Zn²⁺ and Cu²⁺, respectively. The capacity of the polymer for M²⁺ hardly varied with the presence of alkali or alkaline earth metal ions. The elimination of metals from the polymer-M²⁺ chelates was achieved with 4mol/l HCl or 4mol/l H₂SO₄ solution.