Detection and Removal of Microplastics in Water Treatment: a Laboratory Evaluation

Abstract

Plastic production has significantly increased over the past 50 years due to its low cost, ease of production, versatility, and durability. Plastic materials take decades to degrade and could remain in the environment indefinitely. Once plastic is disposed of, it encounters several environmental elements that ultimately will break down these plastics into smaller fragments known as microplastics. These plastics may eventually find their way into a water treatment plant via numerous channels. Once these plastics enter the treatment system, a facility's ability to remove them relies on the treatment used. This thesis investigates the presence of microplastic pollution in drinking water and wastewater treatment facilities and the efficiency of these facilities in removing microplastics using conventional treatment under varying influent turbidities. This study found that as raw water's turbidity increased, microplastic removal increased, indicating that influent turbidity may be an essential factor in removing microplastics in treatment facilities. Additionally, the thesis explores using a UV-LED collimated beam to rapidly age microplastics in a lab setting. This method was validated through FTIR spectra comparison to environmental samples and SEM imaging, demonstrating its efficacy in aging microplastics for further study. These findings are significant because they contribute to a better understanding of the challenges of removing microplastics from water treatment facilities and provide insight into potential solutions for more effective removal. Moreover, aged plastics performed better under conventional treatment than unaged plastics, indicating that the aging process may enhance the removal of microplastics from water treatment facilities. In addition, aged plastics were found to absorb more heavy metals than unaged plastics, suggesting that aged microplastics may play a role in transporting heavy metals in aquatic environments. The study also underscores the importance of continued research in this area to ensure drinking water's safety and quality and protect the environment from the negative impacts of microplastic pollution.