Mechanism and adsorptive performance of PANI/PTh copolymer as a novel and highly efficient adsorbent for the elimination of textile pollutants from aqueous solutions

Abstract

The use of conductive polymers as an adsorbent has gained attention as a potentially effective treatment for environmental issues owing to their high adsorption capacity, adjustable surface characteristics, sustainability, environmental stability, ease of application, low toxicity, and low cost. In this study, PANI/PTh was synthesized and its adsorption properties were investigated for the first time. The copolymer was utilized for the adsorption of the ARS and 2NSA. Langmuir isotherm was determined to be the most applicable for the sorption of ARS and 2NSA on the PANI/PTh. Maximum adsorption capacities from this isotherm were determined as 4629.6 and 3021.2 mg/g for ARS and 2NSA, respectively. Moreover, different kinetics were applied to the sorption data and it was found that both studies followed the PSO kinetic. Additionally, from the intraparticle diffusion and Avrami kinetic, the existence of more than one adsorption mechanism was determined. Thermodynamic parameters were calculated by adsorption studies performed at different temperatures. According to enthalpy values, it was determined that ARS (-7.22 kJ/mol) and 2NSA (-26.92 kJ/mol) adsorption were exothermic indicating both ARS and 2NSA adsorption occurred spontaneously. All of the results demonstrated that the PANI/PTh is a promising adsorbent for the removal of various contaminants from wastewater.