Oxfiniti OxBox

The 10 billion litres of sewage processed daily in England & Wales is becoming more concentrated as people try to save water. Processors are struggling to meet legal discharge limits without further expensive offsite treatment. Activated Sludge Processing (ASP), the UKs most widely used treatment process, uses beneficial micro-organisms to digest waste in water, but they need oxygen to eat, digest, grow and breed. Aeration systems provide this by injecting air bubbles into the water, they consume 60%+ of the energy used in sewage treatment. Traditional aeration uses large air bubbles (79% Nitrogen, of no benefit for ASP), which surface and burst within seconds, wasting 90%+ of the energy used.

Recent studies prove ultrafine bubbles (UFB) have a larger surface area than an equivalent volume of large bubbles and have a longer dwell time in water - in some cases weeks. This increases oxygen availability 10 fold, greatly improving the effectiveness of sewage treatment. However, UFB can currently only be generated by lab devices at around 5% of the volume required to treat sewage.

OxBox is a unique, patented process that generates ultrafine bubbles using a shear jet venturi system based on advanced aerospace fuel injection systems. It can oxygenate 6814 litres of flow p/h with a 30% reduction in energy compared to current aeration systems. If deployed in every UK ASP plant it would save 139 GWh each year - enough to power all the homes in Cambridge.

We have developed a proof of concept prototype, which has generated great industry interest. However, the range of applications for OxBox means it must be highly scalable, from small-scale 'top-up' systems to high throughput emergency treatment. Scaling our prototype is extremely challenging as the key components are highly bespoke and any change in the dimensions of components will lead to unpredictable changes in bubble size and hence oxygenation performance.

This project will use computer modelling to compare simulated bubble generation to empirical data from our existing prototype. We will then "virtually" rescale OxBox using the model before a physical, scaled prototype is produced. This will be used to demonstrate the accuracy of the virtual model and validate the significant improvements in efficiency and energy reduction OxBox can provide.

Successful exploitation of OxBox will generate 5 year sales & service returns to the UK of £65 million, reduce sewage waste, make treatment lest costly and reduce energy consumption.