Boiling and Straining Can Eliminate Up to 90% of Nano- and Microplastics from Drinking Water, Study Finds

Breakthrough from Chinese Scientists

According to НВ — Техно: Researchers in China have discovered that simply boiling water and then filtering it through a common household strainer can remove up to 90% of nano- and microplastic particles from drinking water. Published in Environmental Science & Technology Letters, this finding offers a promising, accessible approach to improving water safety worldwide.

How Water Hardness Influences Plastic Removal

The study, conducted at Guangzhou Medical University, revealed that water hardness-particularly the concentration of calcium carbonate-plays a crucial role in the purification effectiveness. When calcium carbonate levels were 80 mg/L, about 34% of plastic particles were eliminated. This removal rate rose to 84% at 180 mg/L and reached a peak of 90% at 300 mg/L, the highest tested water hardness.

Calcium carbonate, which forms as scale when hard water is heated, crystallizes on plastic particles, causing them to clump together. These larger clusters are easier to capture using fine mesh filters such as tea strainers. Even in softer water, boiling alone can bind roughly 25% of plastic particles.

Over recent decades, humanity has produced nearly 9 billion metric tons of plastic. Tiny plastic particles enter water supplies through sources like:

• wearing synthetic clothing,
• using kitchen utensils,
• applying cosmetic products.

Unfortunately, municipal water treatment plants are unable to fully filter out these microscopic plastics, highlighting the urgent need for alternative purification methods.

While boiling water is a common practice in some parts of the world, this research suggests it could be more widely adopted as a simple and effective way to reduce microplastic contamination in drinking water.

This discovery marks a significant advance in addressing the global challenge of water pollution caused by microplastics.

Given that conventional water treatment systems struggle to remove such fine particles, the availability of a straightforward technique like boiling offers a practical solution, especially for regions with hard water. Future investigations may optimize this process and explore its use in varied environments.