Bubble tech blows contaminants out of the water

Australian water treatment company Evocra has developed an innovative technology that uses bubbles to remove contaminants such as microplastics from water. The process — known as ozofractionative catalysed reagent addition (OCRA) — floats microplastic out of the water, where it is collected and sent for recycling.

Evocra Managing Director Mark Sykes said OCRA is a solution for many water-based environmental challenges.

“Microplastics are plastic items smaller than 5 mm that are found in everyday products such as sunscreen, shampoo and detergent. Too small to be filtered out in the treatment plants, they wash into waterways where they harm our aquatic wildlife,” he said.

“OCRA offers a positive solution to this complex environmental issue. The technology can be applied as a pre-treatment — that is, before the plastic enters the sewerage system — or at the treatment plant to remove the particles before discharge.”

In the OCRA process, chemicals or metals attach to tiny, charged microbubbles, each the size of a width of hair, which balloon out of the water.

Microplastics researcher Dr Thava Palanisami is working with Evocra and is supportive of its work in this area.

“Evocra was an early entrant into finding a solution for microplastics, which is a potential planetary boundary threat. OCRA has demonstrated it has a part to play in the solution of remediating the 12.7 million metric tonnes of plastic litter than enter the ocean each year,” he said.

Plastics can enter the human food chain and, when ingested by marine life, can potentially cause death from starvation.

Sykes said the applications for OCRA are vast, with capability to treat minerals and contaminants in mining, oil and gas extraction, agriculture and aquaculture, high-intensity industrial manufacturing, municipal water and wastewater treatment, and contaminated land remediation.

Environmental consulting firm Arcadis recently signed an exclusive licensing agreement to use OCRA to treat toxic PFAS (per- and poly-fluorinated alkyl substances), a component of products such as aqueous film-forming foams (AFFS), household chemicals, carpets and some clothes.

The technology was successfully used to help remediate a PFAS-impacted industrial sewer resulting from a firefighting foam spill at Brisbane Airport in 2017, removing greater than 99.9% of contaminants.

Sykes said OCRA is addressing old, new and future water contamination issues.

“Our first commercial application was in acid mining drainage, which has been an ongoing problem for the mining sector. PFAS is an international challenge we are facing right now and microplastics are certainly an emerging issue. Evocra are passionate about delivering technologies that have high social impact and that offer solutions across the spectrum in Australia and globally,” he concluded.

Image credit: ©stock.adobe.com/au/Chepko Danil