Development of Physical and Chemical Characterization Methodology for Microplastics Utilized in Personal Care Products for Potential Impact in Wastewaters and the Environment
Open Access
- Author:
- Ghetu, Christine C
- Area of Honors:
- Forensic Science
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Frank Dorman, Thesis Supervisor
Dr. Mitchell Mark Holland, Thesis Honors Advisor - Keywords:
- microplastics
persistent organic pollutants
surface analysis
environmental
FTIR
FESEM - Abstract:
- Environmental contamination related to microplastics is a growing concern across the globe. In addition to the primary concern of microplastic levels in the environment, they have also been known to absorb a variety of organic materials, potentially facilitating transport through wastewater systems and eventually to the environment. The focus of this study was to observe qualitative differences in surface characteristics and composition of neat polyethylene microplastic standards relative to polyethylene samples extracted from personal care products and collected field samples. Microplastics were first characterized using Fourier Transform Infrared Spectroscopy (FTIR) with Attenuated Total Reflectance (ATR) for chemical composition, then imaged using Field Emission Scanning Electron Microscopy (FESEM) and Optical Profilometry (OP). Under FESEM and OP imaging, neat polyethylene microplastic standards appeared uniform in spherical shape with a smooth surface displaying shallow pitting. Using the boiling water and sieve stack method, microplastics were successfully extracted from personal care products, and characterized as polyethylene using FTIR. Under FESEM and OP, many of these samples displayed a distortion from the spherical shape of the neat standards with crevices ranging at various depths. Microplastics were successfully extracted using isolation and wet peroxidation methods. Field samples collected from the Penn State Waste Water Treatment Facility (WWTF) effluent tank and living filter spray field were characterized to be polyethylene and unknown polymers. Using OP, these samples displayed similar distortion to personal care product microplastics. Extracted microplastics from personal care products displayed larger average surface roughness values and an overall sharper surface characteristics compared to neat polyethylene standards, while extracted field samples displayed a smaller average surface roughness but significantly sharper surface characteristics. These modifications in surface morphology suggest that the extracted microplastics may have dissimilar sorption capabilities relative to neat standards, due to the increased surface area and pore size, demonstrating a need for future studies to better define laboratory procedures that would more consistently reflect actual environmental conditions.