An Australian technology that uses bubbles to remove contaminants may offer a solution to the emerging global pollution crisis of microplastics.
The technology belongs to EVOCRA, an Australian water treatment company formed in Tasmania in 2011. The patented process, known as Ozofractionative Catalysed Reagent Addition or OCRA, literally floats the microplastic out of the water where it is collected and sent for recycling.
EVOCRA’s managing director Mark Sykes says OCRA is a solution for many water-based environmental challenges.
“Microplastics are plastic items smaller than five millimetres 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 says. “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.”
Dr Thava Palanisami, a world leader in microplastics research, is supporting Evocra 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 says.
Plastics can enter the human food chain and, when ingested by marine life, can potentially cause death from starvation. Sykes says the applications for OCRA were 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.
The world’s largest 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 fire-fighting foams (AFFS), household chemicals, carpets and some clothes.
In the OCRA process, chemicals or metals attach to tiny, charged micro-bubbles, each the size of a width of hair, and balloon out of the water. In a world first, the technology was successfully used to help remediate a PFAS impacted industrial sewer resulting from a fire-fighting foam spill at the Brisbane Airport in 2017, removing more than 99.9 percent of contaminants.
Sykes says 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 is passionate about delivering technologies that have high social impact and that offer solutions across the spectrum in Australia and globally.”