Evocra home

The OCRA Process

Ozofractionative Catalysed Reagent Addition (OCRA) is a resilient treatment process that treats complex contaminated waters and is able to be modified to suit many diverse requirements.

The OCRA Process has many benefits and can be applied to many different processes for many different objectives. Overall the OCRA process is able to reduce operating costs of other process units by efficient removal of contaminants and addition of reagents or oxidisation beneficial to downstream processes.

The resilience of the process is due to foam fractionation underpinning the technology, allowing for treatment rate to be independent of sediment load while also removing the sediment from contaminated water, simplifying and reducing any upstream pre-treatment requirements compared to other treatment or resource recovery processes.

The foam fractionation mechanics are also improved with the efficient generation of microbubbles (0.5μm - 10μm in diameter), maximising the surface area of the working gas to capture to the desired contaminants or resources. The production of these microbubbles provides a very large area for the removal of contaminants that are hydrophobic, exploiting physical phenomena without intensive energy usage for treatment.

The ionic charge of the working gas also provides an additional removal function while also providing a heavily oxidising environment to also convert contaminants to a less reactive and benign material overall.

Reagent addition adds an extra optimisation step that can be targeted for both removal within the OCRA process or for downstream process performance after treatment by the OCRA process.

Typical volume reduction in wastewaters are approximately 1% of influent volume, reducing disposal or waste management by a significant amount. Further reduction is possible with an extra retreatment step to concentrate the generated waste volume, which has been demonstrated to produce approx. 10% volume of the 1% influent waste volume as the final concentrated waste volume. The treated water from the retreatment stage is then treated by the initial waste treatment process as a recycle wastewater stream.

For removal of contaminants, the OCRA process is flexible and scalable during design to either be in parallel operations or series operations or a combination of both providing the following:

  • Parallel operation to scale overall throughput capacity and minimising area requirements
  • Series operation to increase removal efficiency with each stage reducing contaminant load, magnifying the removal by the last stage

The OCRA process runs well for bulk removal of contaminants and can increase the efficiency of any downstream filtration or polishing processes by removing contaminant load upstream. Typically reduction in change out frequency of polishing media or filtration cartridges/membranes is observed and overall sizing requirements of polishing or filtration processes are reduced.

The OCRA process can be utilised to recover targeted mineral resources for further refining or as a solid metal oxide, generating additional revenue streams for your project. The process’s modular design can easily be adapted to target multiple mineral extractions or specific contaminant removal and in the case of many organic compounds, destruction.


For specific applications of the OCRA process please see the following:

Acid Mine Drainage
To contact us for further information or for a solution to a problem you have, please click here.