Microporous carbonaceous adsorbent prepared from a pyrolyzed polymer

Abstract

Emerging pollutants pose a significant health risk, and their presence in water has far-reaching consequences. Although there are several ways to decrease the levels of emerging contaminants, conventional water treatment processes are not designed for their removal. One of the more effective water treatment methods used for further micropollutant elimination is adsorption on carbonaceous materials. This work focuses on the preparation of a carbonaceous adsorbent using the pyrolysis of the polymer polyetheretherketone (PEEK). The polymer was pyrolyzed at 600 °C for 3 hours in an N₂ atmosphere. The prepared carbonaceous material is microporous and contains surface oxygen functional groups (ethers, ketones, and aldehydes). The adsorption properties of the prepared adsorbent were tested on two pharmaceuticals: the analgesic diclofenac and antibiotic ofloxacin. In this study, kinetic and equilibrium experiments were performed. The adsorption maximum was 2.25 mg g⁻¹ for diclofenac and 2.84 mg g⁻¹ for ofloxacin. The pseudo-second-order model and Redlich–Peterson model best fitted both diclofenac and ofloxacin. The prepared material did not show high adsorption capacity, but the potential of the polymers as a feedstock material for pyrolysis was successfully demonstrated. This research might serve as a stepping stone towards the preparation of tailor-made adsorbents that could be used for studying adsorption mechanisms.