An innovative Australian technology that uses bubbles to remove contaminants from water offers a solution to an emerging global pollution crisis – microplastics.
The technology belongs to EVOCRA, a water treatment company formed in Tasmania in 2011. The patented process, known as Ozofractionative Catalysed Reagent Addition (OCRA), literally floats the microplastic out of the water so it can be 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 5mm that are found in everyday products such as sunscreen, shampoo and detergent,” says Sykes. “Too small to be filtered out in the treatment plants, they wash into waterways where they harm our aquatic wildlife. 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 working with Evocra: “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 12.7m metric tonnes of plastic litter than enter the ocean each year.”
Plastics can enter the human food chain, and when ingested by marine life, can potentially cause death from starvation. According to Sykes, there are numerous applications for OCRA, with the potential to treat minerals and contaminants in mining, oil & gas extraction, agriculture and aquaculture, high-intensity industrial manufacturing, municipal water and wastewater treatment, and contaminated land remediation.
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 industrial sewer that had been polluted due to a fire-fighting foam spill at Brisbane Airport in 2017, removing more than 99.9% of contaminants.
Sykes believes OCRA can address 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.”