Chelating Solid-Phase Polymeric Adsorbent for the Removal of Hg2+ Ions from Aqueous Solutions: Preparation, Characterization and Adsorption Optimization Studies

In this article, preparation, characterization and application of a chelating amino-grafted solid-phase polymeric adsorbent for the removal of Hg2+ ions from contaminated aqueous solutions were discussed. Functional groups identification and surface morphology studies were carried out using FTIR, XRD, and SEM techniques. Batch adsorption methodology was used to explore the influence of solution’s pH, shaking time, adsorbent dose, Hg2+ ions initial concentration, and temperature on the adsorption capacity of the prepared adsorbent. A maximum adsorption capacity of 120 mg Hg2+/g adsorbent was achieved at pH 7.0, shaking time 120 min and adsorbent dose of 0.4 g/L. Based on non-linear modeling and error functions analysis, the current adsorption process is well described by Langmuir isotherm and pseudo-second order models; suggesting a chemisorption reaction between the Hg2+ ions and the amino groups on the adsorbent surface via complexation. Moreover, the adsorption process is carrying out spontaneously with a negative enthalpy change. Finally, the adsorbent regeneration and reusability were studied and an accumulative uptake capacity of 464 mg Hg2+/g adsorbent was achieved.