2,5-Furandicarboxylic Acid-Based Porous Polyamides: Preparation and Adsorption Efficiency for Hg2+

From 2,5-furan dicarboxylic acid, a robust biomass platform molecule, furan-based porous polyamide (FPPA-1 and -2) was synthesized and applied for the removal of Hg2+ from water. FPPA-1 and -2 were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of pH, dosage, contact time, temperature and concentration on the adsorption of Hg2+ were systematically investigated. The pseudo-second-order kinetics and the Langmuir isotherm model are in the best agreement with the experimental data, and the maximum adsorption capacity is 462 mg g-1. Thermodynamically, the adsorption of Hg2+ is a spontaneous adsorption process. There was no significant loss of performance during five regeneration cycles. In combination with the experimental data and density functional theory (DFT) calculation, the chelation mechanism of Hg2+ was demonstrated. Our study offers new perspectives for the removal of Hg2+ from wastewater.