Ionothermal synthesis of activated carbon from waste pet bottles for dye waste water treatment

Abstract

The production and use of poly-ethylene terephthalate (PET) bottles in packaging have increased significantly. Thus, PET bottles have become a significant plastic waste with environmental problems. Currently, the conventional methods for producing activated carbons (ACs) from waste PET are unsustainable, complex, and unfeasible. As a result, ionothermal synthesis (IS) of waste PET bottles impregnated with choline chloride-urea (CU) deep eutectic solvent (DES) was carried out in order to prepare ACs. The obtained ACs were characterized using XRD, CHNS Elemental analysis and FTIR. The as-prepared ACs were effective as adsorbents for dye adsorption from dye waste water. Specifically, the AC obtained from pristine waste PET bottles (956 mgg−1 at 100 ppm) displayed higher adsorptive capacity compared to the ACs obtained from CU-DES impregnated PET flakes (550mgg−1 at 100ppm). Even though it was expected that the use of CU-DES required no post-synthesis washing or higher temperature treatments might be required to improve the adsorptive capacity of the ACs obtained from IS.This research work established that the synthesis of AC from abundant waste PET bottles using a sustainable and facile method could facilitate its commercial application. Also, this work represents the first attempt to produce activated carbons from PET using low temperature annealing in the presence of limited air, instead of the usual pyrolysis.