A Thermal Analysis-Based Approach to Identify Different Waste Macroplastics in Beach Litter: The Case Study of Aquatina di Frigole NATURA 2000 Site (IT9150003, Italy)

Mariaenrica Frigione,Gabriele Marini,Maurizio Pinna

doi:10.3390/su13063186

Abstract

The dispersion of commercial plastics in the marine environments is a major threat to biodiversity and ecosystem services of the last decades. The lower density of the plastics with respect to marine water density determines their floating, transferring, and accumulation in sandy beaches. Sandy beaches represent a natural sink ecosystem for marine plastics, where the latter are fragmented and photo-degraded in relation to the kind of polymer. Here, we propose an accurate and cost-effective method, the differential scanning calorimetry (DSC), to identify different polymers from plastic samples collected on the Aquatina di Frigole beach (Apulia Region, Southeast of Italy), included in the NATURA 2000 Site coded as IT9150003. Our results reveal the exclusive presence of thermoplastic polymers in the beach plastic samples, mostly belonging to the polyolefin family. They appear to be remnants of larger plastic fragments, which could impact biodiversity and ecosystem services such as beach recreation activities and tourism.

Highlights

Commercial commodity plastics consist of a large variety of polymers, mostly belonging to thermoplastic family, including polypropylene (PP), polyethylene (PE), polystyrene (PS), polyvinylchloride (PVC), polyethylene terephthalate (PET), and polyamide (PA).The majority of them are based on synthetic polymers, produced starting from fossil oil and designed to meet the different requirements of a wide variety of end products
Analytical methods such as Fourier transform infrared (FT-IR) spectroscopy and micro-Raman spectroscopy have proven to be effective in identifying the polymer types of microplastics in environmental samples [22]. These techniques are based on the well-known infrared absorption bands that represent distinct chemical functionalities in the material analysed. The applicability of such common techniques has shown several drawbacks: (1) they require the extraction of the microplastics from environmental matrices including density separation, clean up steps and biomass removal; (2) large-sized samples must be analysed to confirm the composition of a plastic item composed of different polymers [23]; (3) these techniques are time consuming and laborious [24]; and (4) FT-IR
A total of 1168 plastic items for a total weight of 535.6 g were gathered from 18 sampling plots/replicates (30 cm ×30 cm ×10 cm) on the Aquatina di Frigole beach along two transects in which three sampling stations were identified with respect to the distance from the sea, such as: A = intertidal zone; B = medium beach; C = base of the dune

Summary

Introduction

Commercial commodity plastics consist of a large variety of polymers, mostly belonging to thermoplastic family, including polypropylene (PP), polyethylene (PE), polystyrene (PS), polyvinylchloride (PVC), polyethylene terephthalate (PET), and polyamide (PA). The majority of them are based on synthetic polymers, produced starting from fossil oil and designed to meet the different requirements of a wide variety of end products. Thanks to their versatility, durable nature, and high cost-effectiveness, plastics have played a crucial role in many strategic sectors in the last decades, such as packaging, the building and construction industry, transportation, electrical and electronic devices, agriculture, medical applications, and sport equipment [1,2].

Methods

Results

Discussion

Conclusion