Enhancing breakdown of microplastics by hydrothermal Fenton reaction

초록

Microplastics(MPs) are frequently traced in almost all environmental matrices (soil, water, air). Developing relevant technology for the detection and degradation of microplastics in them are in a very early stage.. In the present work, the oxidation of conventional microplastics (Polyethylene: PE, Polypropylene: PP, Polystyrene: PS) along with the actual plastic wastes (plastic bottles, micropipette tips, centrifuge tubes, nitrile gloves, packaging plastics) were examined by employing the coalescence of thermal-Fenton reaction carried out in a hydrothermal autoclave reactor. Typical parameters such as time, temperature, MPs dose, H2O2 dose, Fe+2 concentration, and solution pH were optimized. Medium density polyethylene showed almost ~82% weight loss at the optimum conditions (temperature = 140°C, time = 16 h, MP dose = 1 g L?1, H2O2 dose = 200 mM, Fe+2 concentration = 15 mL of 1000 mg L?1, solution pH = 1?0.1). The microplastic samples before and after the reactions were analyzed by SEM, FTIR, and XPS to track down the physical and chemical changes. The Carbonyl indices (CI) for samples were evaluated at 0.30, 0.31, 0.51, 0.68, and 0.69 from the FTIR spectra for 4 , 8 , 12h, 16, and 20 h of reaction , respectively. In this regard, the morphological changes were observed confirming that cracks on the surface of the plastics generated have grown bigger with the reaction time.