Mercury(II) decontamination using a newly synthesized poly(acrylonitrile-acrylic acid)/ammonium molybdophosphate composite exchanger

Abstract

Mercury is a high priority pollutant because of its fatal effects on the ecosystem. This manuscript demonstrates the preparation of a new organic-inorganic composite exchanger resin for the removal of divalent mercury (Hg(II)) by adsorption from aqueous solution. The preparation was based on binding polymer poly(acrylonitrile-acrylic acid) [P(AN-AA)] with ammonium molybdophosphate (AMP). The prepared adsorbents (P(AN-AA)/AMP and P(AN-AA)) were characterized using FTIR, SEM, BET, and TGA for assigning their physicochemical properties. The conditions controlling the adsorption process were optimized. The removal by P(AN-AA)/AMP and P(AN-AA) reached 96.5 and 77.5%, respectively. The isotherm and kinetics studies showed that the experimental results fit well with the Langmuir isotherm model and the pseudo-second-order kinetic model with a maximum adsorption capacity of 221.23 and 202.43 mg/g for P(AN-AA)/AMP and P(AN-AA), respectively. The thermodynamic study showed that the adsorption process is endothermic in nature with an enthalpy of 88.38 and 9.33 kJ/mol for P(AN-AA)/AMP and P(AN-AA), respectively. The obtained results suggest that strong chemical adsorption mechanism highly participated in the adsorption process.