Tiny water fleas help tackle wastewater pollution

Newborn Daphnia magna

Tiny water fleas, known as Daphnia, could be a cost-effective and eco-friendly solution for filtering harmful chemicals from wastewater, say scientists from the University of Birmingham, UK.

Scientists have discovered that these water fleas have the ability to absorb and remove various pollutants, such as pharmaceutical compounds, pesticides, heavy metals, and industrial chemicals, with promising results in the lab and actual treatment facility settings.

The tiny water fleas were found to filter drugs, pesticides, and industrial chemicals from wastewater. These pollutants often end up in rivers, streams, and irrigation systems, harming ecosystems and contaminating food and water.

Using water fleas as a natural filter is eco-friendly, low-cost, and scalable, say researchers.

“We’ve developed our bioequivalent of a Dyson vacuum cleaner for wastewater, which is very, very exciting.”

Karl Dearn, University of Birmingham.

The researchers selected water fleas that consume four types of pollutants: diclofenac, atrazine, arsenic, and PFOS (perfluorooctane sulfonate) - often used to make clothes waterproof. In laboratory tests, the water fleas could remove a significant percentage of these pollutants.

In the laboratory, the water fleas could remove 90% of diclofenac pollutants, 60% of arsenic, 59% of atrazine and 50% of PFOS.

Daphnia-based wastewater technology prototype. Image: University of Birmingham

Luisa Orsini, an environment professor at the University of Birmingham and co-author of the study published in the journal Science of the Total Environment said, "I had my ‘A-ha!’ moment, and I thought, ‘Wait a second, they can absorb chemicals’.

"Removing 50% of PFOS is excellent compared to whatever exists now because nothing removes or metabolises PFOS like this, and [other approaches are] extremely costly, producing a lot of toxic byproducts.”

The fleas are self-sustaining as they reproduce by cloning and can adapt to various environmental conditions, meaning this filtering method could be a game-changer, especially in areas with limited infrastructure. According to researchers, this technology has the potential to contribute to clean growth, water reuse, and the prevention of environmental pollution by preventing persistent chemicals from entering waterways.