Experimental and DFT studies of Congo red and AB 113 dyes removal by adsorption and disinfection using novel triazine-based porous organic polymer

Abstract

• Triazine-based adsorbent was developed by the reaction of cyanuric chloride and 4,4′-oxydianiline. • Anionic dyes such as Congo red and AB 113 in solution can be effectively removed using CC-ODA POP. • CC-ODA POP demonstrated reliable reusability for 3 adsorption/desorption cycles. • The adsorption studies were explained using DFT analysis. • The disinfection ability of the CC-ODA POP was evaluated using E. coli . Water pollution has become a widespread issue for both the environment and human health. The need for novel materials that can function as both adsorbent and disinfectant in wastewater treatment is vital. In this work, the porous organic polymer such as a triazine-based adsorbent (CC-ODA POP) was developed by the reaction among cyanuric chloride and 4,4′-oxydianiline. CC-ODA POP features a moderate surface area and a tunable porous structure, with a maximum adsorption capacity of 149 mg/g and 103 mg/g for Acid Blue 113 (AB 113) and Congo Red (CR) respectively. The adsorption of AB 113 and CR onto CC-ODA POP was effectively described by the Langmuir isotherm and pseudo-second-order kinetic models. The mechanism involves electrostatic attractions and hydrogen bonding and exhibits good recyclability. The interactions involving the polymer and dye molecules were explained using DFT studies based on the various quantum parameters, electrostatic potential diagram, and binding energy values. The calculated adsorption or complexation energy is more favorable for AB 113 (−19.68 kcal/mol) than CR (−18.17 kcal/mol). The CC-ODA POP demonstrated a disinfection efficiency of 99.64 % against E. coli . This triazine-based adsorbent, characterized by its high adsorption efficiency, excellent disinfection capabilities, and recyclability, holds significant potential for practical applications in wastewater treatment.

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