Removal of Hg(II) ions from aqueous solution by poly(allylamine-co-methacrylamide-co-dimethylthiourea)

In this study, poly(allylamine-co-methacrylamide-co-dimethylthiourea), a chelating polymer containing amino groups and thiourea, was synthesized and tested for its capacity to remove mercury ions (Hg²⁺) from aqueous solutions. The structure of the prepared polymer was analyzed and characterized by FTIR and FE-SEM. The effects of various parameters such as pH, contact time, and initial Hg concentration on Hg(II) removal were studied. The Hg(II) adsorption reached maximum capacity at equilibrium within 1 h. The Hg ions were adsorbed for 4 h at pH 7. The highest Hg(II) adsorption was obtained at pH 7 and 400 mg L⁻¹. The experimental data were fitted to the pseudo-second-order model using kinetic modeling, indicating that the mechanism was chemisorption. In addition, the experimental data were fitted to the Langmuir isotherm model, thus demonstrating that the Hg(II) adsorption process occurred through the formation of a monolayer.