REMOVAL OF MICROPLASTICS IN FULL-CYCLE WATER TREATMENT PLANTS

Microplastic (MP) pollution has become a global concern due to its environmental impacts and risks to human health. Recent studies have confirmed the ubiquitous presence of MPs in aquatic ecosystems, groundwater, freshwater bodies, and even in food and human organisms.

This study evaluated MP removal in full-cycle Water Treatment Plants (WTPs), which operate through coagulation, flocculation, sedimentation, filtration, and disinfection. Samples of 2 L of raw water and 2 L of treated water were collected in glass bottles from two WTPs in Goiânia, Brazil (Meia Ponte and Mauro Borges) over three consecutive days, considering the 4-hour hydraulic detention time from influent to effluent. The samples were filtered using 5 µm membranes (microplastics) and 0.5 µm membranes (nanoplastics) with a vacuum pump, Büchner funnel, and Kitasato flask. Particle identification was performed by optical scanning with a Stemi 508 Zeiss stereomicroscope.

The results revealed the persistence of MPs in both raw and treated water. The Meia Ponte WTP presented higher particle concentrations compared to the Mauro Borges WTP, possibly due to differences in their watershed characteristics. The detection of MPs in treated water highlights the limitations of conventional full-cycle treatment and raises concerns about continuous human exposure.

These findings emphasize the urgent need to improve removal technologies and advance research to identify the composition and morphology of MPs. Alternative strategies, such as slow sand filtration, appear promising to mitigate contamination and ensure safer drinking water.