Occurrence and removal of microplastics by advanced and conventional drinking water treatment facilities

Potential health risks associated with microplastic ingestion via drinking water cannot be appropriately addressed until their occurrence and removal during treatment has been quantified. For most drinking water providers, monitoring of microplastics is not economically or practically feasible as it requires analytical expertise, lengthy sample processing, and costly instrumentation to quantify size, concentration, as well as to identify polymer types. These parameters must be appropriately determined such that potential human exposure and related health risks may be quantified. This study incorporated the use of in-line on-site sampling equipment such that small microplastics (¿2 µm) known to be associated with human health impacts could be readily captured. Following filtration of up to 50 L, background organic and inorganic material was removed via an optimized oxidation and enzymatic digestion method. Raman spectroscopy was subsequently employed for particle characterization. It is anticipated that the protocols developed during this study could easily be incorporated into standardized methods for the analysis of microplastics in drinking water. Results were used to compare the performance of a range of conventional treatment processes as well as technologies including ozone, UV, ultrafiltration, and advanced oxidation. Small microplastics (range 2-20 µm) were predominant in both raw and treated drinking waters. Both conventional and advanced treatment facilities were observed to typically remove ¿98 Also see: https://micro2024.sciencesconf.org/566845/document