Manta rays have filtration system that could improve water treatment

Filter feeders like Manta rays can provide important insight on more efficient filtration systems that could improve technology for wastewater treatment.

The Manta ray, in particular, is unique because its filtration system allows water to pass through, but tiny food particle ricochet off and can then be eaten. In other words, the Manta ray’s feeding mechanism repels particles instead of trapping them.

This makes the Manta ray’s filter feeding process resistant to clogging, unlike traditional solid-liquid separation systems.

Filtration systems like the sieve or cross-flow separation system commonly used in industrial and engineering processes today are prone to clogging and are difficult and costly to clean.

Researchers from California State University and Oregon State University set out to better understand how the separation mechanism in the feeding filter of the Manta ray worked.  

To do this, the researchers printed a 3D model of the Giant oceanic manta ray. The model was placed in a recirculating flow tank that was filled with colored water that had been dyed in order to show how the water flowed through the filter feeding system.

The researchers observed that flow separation occurred behind the leading edge of the ray’s filter lobes, and this caused a large vortex in each pore in the filtration system. Particles were naturally repelled away from the filters and were instead sucked into the mouth to be then eaten.  

“This solid-fluid separation mechanism may have interesting industrial applications, since it operates at high flow rates, effectively filters neutrally buoyant particles, and resists clogging,” the researchers wrote.

A study detailing the research efforts was published in the journal Science Advances.

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By Kay Vandette, Earth.com Staff Writer

Image Credit: Steve Kajiura