Occurrence, characterization, and removal efficiency of microplastics in point-of-use drinking water systems: A case study in Dogonbadan, Iran

The presence of microplastic in drinking water has garnered increasing attention due to their widespread occurrence. This study aimed to assess the presence, characteristics, and removal efficiency of MPs in point-of-use water treatment systems (POU-WTS) in Dogonbadan, Iran. A total of 90 samples were collected from the inlets and outlets of various POU-WTS. These samples were analyzed using μ-Raman spectroscopy to quantify and identify MPs based on their abundance, morphological characteristics, and polymer types. Additionally, physicochemical and microbial parameters were evaluated using standard reference methods. The average MPs abundance in the inlet and outlet water of POU-WTS was 11.66 ± 4.30 MPs/L and 20 ± 9.43 MPs/L, respectively. The results showed that polycarbonate and polypropylene were the most abundant polymers identified among the MPs. Physicochemical parameters in the inlet water of the POU-WTS were within the permissible limits established by the World Health Organization (WHO). However, the outlet water from the POU-WTS exhibited reductions in beneficial ions such as fluoride, calcium, magnesium, and residual free chlorine. Furthermore, the increase in MPs at the outlet of the POU-WTS, along with adverse effects such as softened water, fluoride deficiency, and wastage of drinking water, suggests that the use of POU-WTS in Dogonbadan is not recommended. • A higher abundance of microplastics in the outlet water compared to the inlet water of the POU-WTS. • The most predominant type of polymer was polycarbonate. • Fibers were the dominant types of microplastic. • Estimated daily intakes are range from 0.84 to 1.37 (Items/kg-BW/day)