On the applicability of triazine-based covalent organic polymer as adsorbent for dye removal from aqueous solution

Triazine-based covalent organic polymer, TCOP, is synthesized via the reaction between cyanuric chloride and piperazine in 1,4-dioxane, and is characterized with FT-IR, EDX, elemental mapping, XRD, SEM, TEM and N-2 adsorption/desorption techniques. The capability of TCOP in the removal of different types of dye pollutants is studied and it was found that the removal efficiency is more than 70% for all of them. The kinetics and equilibrium adsorption of Rhodamine B (RhB) was studied at different conditions. Most of the adsorption takes place in less than 20 min and the maximum adsorption capacity is 153 mg/g. The adsorption isotherm can be well described by the modified Langmuir-Freundlich equation and the adsorption kinetics follows the fractal-like pseudo-first order kinetics model. Both of the fitted models reveal the heterogeneity of adsorbent. The adsorption thermodynamics parameters were calculated and interpreted. Finally, it was shown that the prepared TCOP can be used for the removal of dye mixture from aqueous solution.