Microplastic Removal from Drinking Water Using Point-of-Use Devices

Area of Science:

• Environmental Science
• Water Treatment Technology
• Public Health

Background:

• Microplastics (MPs) are increasingly detected in drinking water sources, posing potential human health risks.
• Conventional drinking water treatment plants (DWTPs) achieve high MP removal but do not eliminate them entirely.
• Point-of-use (POU) devices offer a potential secondary barrier for MP removal before consumption.

Purpose of the Study:

• To evaluate the efficacy of common pour-through POU water treatment devices in removing microplastics.
• To assess the performance of POU devices utilizing granular activated carbon (GAC), ion exchange (IX), and microfiltration (MF).
• To determine the impact of exceeding manufacturer-rated treatment capacity on MP removal efficiency.

Main Methods:

• Drinking water was spiked with polyethylene terephthalate (PET), polyvinyl chloride (PVC) fragments, and nylon fibers (30-1000 µm).
• Samples were analyzed from POU devices (GAC, IX, MF combinations) at increased treatment capacities (25-125%).
• Microscopic analysis was used to quantify MP removal efficiency.

Main Results:

• POU devices incorporating microfiltration (MF) membranes achieved high MP removal (78-100%).
• One POU device using only GAC and IX increased MP concentration in the effluent.
• POU devices with smaller MF pore sizes (0.2 µm) demonstrated superior MP removal compared to larger pore sizes (≥1 µm).

Conclusions:

• POU devices with physical barriers, particularly membrane filtration, are effective for reducing microplastics in drinking water.
• The choice of POU technology significantly impacts microplastic removal efficacy.
• MF-based POU systems show promise for enhanced microplastic reduction in household drinking water.