Removal of terephthalic acid, derived from polyethylene terephthalate plastics, using an advanced oxidation process based on a KrCl excimer photoreactor

Title : Removal of terephthalic acid, derived from polyethylene terephthalate plastics, using an advanced oxidation process based on a KrCl excimer photoreactor

Abstract:

The presence of plastics in the marine environment is currently a serious environmental problem and, ultimately, for human health. In particular, in recent years, there has been a growing concern around microplastics which, given their small size, pose a greater challenge from the point of view of their correct management. In this sense, it is essential to develop more effective processes for the treatment and disposal of plastics in wastewater treatment plants, in order to prevent their subsequent passage into natural water bodies.

Polyethylene terephthalate (PET) is one of the most widely used plastics due to its excellent properties and diversity of applications, and due to its overconsumption and the difficulty of its disposal, it is present in large quantities in all water bodies. In its natural degradation, a series of secondary compounds are formed, including terephthalic acid (TPA), one of its key monomers and the object of study of this work.

For the correct elimination of PET and its degradation products, new treatments have been proposed in recent years, highlighting advanced oxidation processes (AOPs). In this work, an advanced oxidation treatment is used with a KrCl excimer lamp acting as a plug flow photoreator with complete recirculation, and with H₂O₂ as an oxidant, for the degradation of TPA.

Different experimental series have been carried out to optimize the process, varying the H₂O₂:TPA mass ratio, the initial concentration of TPA and the reaction volume. With standard conditions of initial concentration of TPA 100 mg/L and reaction volume 250 ml, the 3:1 mass ratio has been shown to be optimal, achieving 100% TPA conversions in about 80 minutes and obtaining the lowest values of chemical oxygen demand (COD). With this optimum mass ratio, decreasing the initial concentration of TPA to 50 mg/L, or the reaction volume to 125 ml, total conversion is reached in around 40 minutes.

This research is an initial approach for the treatment of PET and its degradation products using lamps of excimer technology, with promising results that support the effectiveness of this technique

Biography:

Dr. Maria Gomez finished the Degree in Chemical Engineering at Murcia University in 2003 obtaining the Extraordinary End of Degree Award. She joined the Research Group "Analysis and Simulation of Chemical, Biochemical and Membrane Processes" to carry out her Doctoral Thesis, receiving the PhD degree in 2007. In 2018 she took the position of Associate Professor. She has collaborated in 2 main research lines: "Removal of persistent organic pollutants through enzymatic treatments, membrane processes and photodegradation" and "Enzymatic synthesis of polymeric esters for application in industry". She has published more than 90 research papers and has an h-index of 23.