OXIDATIVE DEGRADATION OF POLYSTYRENE MICROPLASTIC BY THE FENTON PROCESS

The buildup of plastic microparticles in water is a serious problem that requires new, faster ways to break them down. Polystyrene is one of the toughest pollutants to destroy. Because of its large phenyl groups, microbes can hardly break it down, making the material very stable. In this study, we looked at how to decompose polystyrene particles in water using the Fenton process (FeSO4 * 7H2O/H2O2). We ran the experiments at a stable temperature of 35-40°C and a pH level of 2-3. Keeping the pH in this narrow range is vital; it keeps the iron active and stops it from settling out as a solid. Under these conditions, the system starts producing hydroxyl radicals (•OH). These radicals are powerful oxidizers that pull hydrogen atoms from the polymer frame, which breaks the carbon-carbon bonds and cuts the size of the molecules. To see how the surface changed before and after the reaction, we used optical and scanning electron microscopy (SEM). The images clearly show the plastic wearing away, with deep cracks, chips, and small pits (cavities) appearing. We also checked the particle sizes using dynamic light scattering (DLS). The data confirmed that the particles became significantly smaller after the treatment.Our results prove that the Fenton reaction effectively starts the breakdown of strong aromatic polymers. Therefore, this method is a promising step for industrial wastewater treatment systems.

1. Plastic waste inputs from land into the ocean / J.R. Jambeck et al // Science. – 2015. – Vol. 347, № 6223. – P. 768-771.

2. Lost at sea: where is all the plastic? / R.C. Thompson et al. // Science. – 2004. – Vol. 304, № 5672. – P. 838-838.

3. Geyer R. Production, use, and fate of all plastics ever made / R. Geyer, J.R. Jambeck, K.L. Law // Science Advances. – 2017. – Vol. 3, № 7. – e1700782.

4. Degradation of polystyrene microplastics by Fenton-like process: Mechanism and pathways / Y. Zhang et al // Journal of Hazardous Materials. – 2020. – Vol. 384. – P. 121151.

5. Fenton’s reagent for the rapid and efficient isolation of microplastics from environmental samples / A.S. Tagg et al // Analytical Methods. – 2017. – Vol. 9, № 9. – P. 1432-1440.

6. Pignatello J.J. Advanced oxidation processes for organic contaminant destruction based on the Fenton reaction and related chemistry / J.J. Pignatello, E. Oliveros, A. MacKay // Critical Reviews in Environmental Science and Technology. – 2006. – Vol. 36, № 1. – P. 1-84.

7. Neyens E. A critical review of Fenton’s reagent applications / E. Neyens, J. Baeyens // Journal of Hazardous Materials. – 2003. – Vol. 98, № 1-3. – P. 33-50.

8. Oxidative degradation of polystyrene microplastics by advanced oxidation processes / J.H. Kang et al // Chemosphere. – 2022. – Vol. 287. – P. 132320.

9. Microplastics in the marine environment: A review of their sources, distribution, effects and management / D. He et al // Engineering. – 2019. – Vol. 5, № 3. – P. 538-550.

10. Effect of Fenton-like oxidation on surface characteristics and adsorption properties of microplastics / P. Liu et al // Chemosphere. – 2019. – Vol. 234. – P. 151-159.

11. Using scanning electron microscopy for the identification of marine microplastic debris / J. Brandon et al // Marine Pollution Bulletin. – 2016. – Vol. 110, № 1. – P. 556-561.

12. Characterization of microplastics in water using dynamic light scattering / J. Li et al // Environmental Pollution. – 2018. – Vol. 237. – P. 557-563.

13. Degradation of microplastics in the environment: Processes, mechanisms, and influencing factors / J. Wang et al // Environmental Pollution. – 2021. – Vol. 270. – P. 116023.

14. Advanced oxidation processes for microplastics degradation: A recent update / S.S. Ali et al // Journal of Environmental Management. – 2023. – Vol. 326. – P. 116742.