Synthesizing metal-organic UiO-66 framework in microwave fields based on polyethylene terephthalate waste for adsorptive removal of tartrazine food dye from aqueous solutions

The sample of metal-organic UiO-66 framework (Zr6O4(OH)4bdc, bdc = benzene-1,4-dicarboxylate/terephthalate), which is a promising adsorbent of persistent organic pollutants from aqueous medium, is obtained by the original method in the medium of unconventional “green” solvent, triethylene glycol (TEG), under conditions of microwave activation of reaction mass at atmospheric pressure according to one-step approach. PET-UiO-66 material is synthesized using polymer waste, viz. recycled polyethylene terephthalate (PET), as a source of organic linker (terephthalic or benzene-1,4-dicarboxylic acid, H2bdc) for framework formation. Its adsorption activity is first studied in the adsorption removal of tartrazine food dye (E-102) from aqueous solutions. It is found that the kinetics of the adsorption process obeys the pseudo-second-order model, and its thermodynamics corresponds to the Langmuir model.