Facile synthesis of anthranilic acid based dual functionalized novel hyper cross-linked polymer for promising CO(2) capture and efficient Cr(3+) adsorption.

A novel hyper cross-linked polymer of 2-Aminobenzoic acid (HCP-AA) is synthesized for the adsorption of Cr(3+) and CO(2). The Brunauer-Emmett-Teller surface area of HCP-AA is 615 m(2) g(-1). HCP-AA of particle size 0.5 nm showed maximum adsorption of Cr(3+) for lab prepared wastewater (93%) while it was 88% for real industrial wastewater. It is might be due to electrostatic interactions, cation-π interactions, lone pair interactions and cation exchange at pH 7; contact time of 8 min; adsorbent dose 0.8 g. The adsorption capacity was calculated 52.63 mg g(-1) for chromium metal ions at optimum conditions. Freundlich isotherm studies R(2) = 0.9273 value is the best fit and follows pseudo second order kinetic model (R(2) = 0.979). The adsorption is found non-spontaneous and exothermic through thermodynamic calculations like Gibbs free energy (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were 6.58 kJ mol(-1), - 60.91 kJ mol(-1) and - 45.79 kJ mol(-1) K(-1), respectively. The CO(2) adsorption capacity of HCP-AA is 1.39 mmol/g with quantity of 31.1 cm(3)/g (6.1 wt%) at 273Kwhile at 298 K adsorption capacity is 1.12 mmol/g with quantity 25.2 cm(3)/g (5 wt%). Overall, study suggests that carboxyl (-COOH) and amino (-NH(2)) groups may be actively enhancing the adsorption capacity of HCP-AA for Cr(3+) and CO(2).