INSIGHTS INTO THE NATURAL DEGRADATION RATE OF PLASTICS IN THE SEAWATER ENVIRONMENT AND THEIR DEGRADATION BY-PRODUCTS (PHTHALATES AND BISPHENOL A)

Abstract

Most plastics end up in the oceans. Their chemical additives that leach out into the ocean can be detrimental to humans and animals. This study investigates the degradation-fragmentation of different plastic types for 140 days in extreme environments, using fourier-transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray analysis along with weight loss and degradation rate calculations. Seawater samples used for the investigations were analysed using gas chromatography-mass spectrometry to examine three different phthalates and bisphenol A (BPA). Findings showed that microplastics degraded faster than macroplastics. The degradation behaviour of plastics varied depending on type and size. High-density polyethylene and polyethylene degraded faster under outdoor onshore conditions, while other types showed higher degradation under outdoor marine conditions. Dibutyl phthalate (DBP), Bis(2-ethylhexyl) phthalate (DEHP), and BPA were detected in seawater samples. Wave abrasion promoted the leaching of DEHP and DBP, while temperature and light promoted the leaching of DEHP.