Bioreactor promises low cost sterilisation

A low cost means of sterilising waste water has been developed by researchers at Plymouth Marine Laboratory (PML), the work being published in the journal Nature Scientific Reports in late May. It could have a big impact in the developing work, according to the group.
The work was undertaken in collaboration with UK-based contract research specialist Protein Technologies, and received support from the Bill and Melinda Gates Foundation. It is described as a simple technology involving some basic plumbing parts, a household drill and a model boat propeller, re- alising a low cost means of sterilising waste water.

The system is said to be scalable, from the toilet block up to large scale treatment plants

“What started out as a technology to help convert microalgae into biofuels spun off ‘quite literally’ in the direction of global waste water sanitation”, commented PML Microbial Biochemist Dr Mike Allen, as the researchers recognised the broader implications of the work they were undertaking. Based on the straightforward notion of exploiting a continuous vortex contained within a pipe to bring pathogens into contact with a biocidal agent, the team now hope to launch the technology so that it can be deployed around the world to sterilise waters contaminated with faecal matter.
The system currently uses cop- per powder embedded in a sea- weed extract as the anti-bacterial agent. “We see total destruction of bugs like E.coli after only a few minutes, and we haven’t even optiised the system yet: we’ve been
focused on proving it could work first.”
The PML team sent prototype vortex bioreactors as far afield as South America, North America, South Africa and India to gather data on performance. “Every locale is different with different cultures and infrastructure to deal with. We are fortunate that we have such a simple technology that is versatile enough to easily fit right in to a diverse set of situations”.
Scalable promise
The team of researchers believe the vortex bioreactor has the potential to revolutionise the treatment of waste water in the developing world. “The beauty of the system is it’s completely scalable: we can design and build systems that work at the toilet block, village or city scale depending on the requirement.
Depending on the size of the system, it can be driven by hand, bicycle or by motor. It’s a low cost, low energy, low tech, but high performance alternative to UV sterilisation” says Dr Allen.
Furthermore, the team aim to make the technology freely avail- able for humanitarian applications. Paul Goddard, Chief Executive of PTL commented: “The vortex bio- reactor is an incredibly powerful technology, one that could revolutionise high throughput liquid processing in many industries. However, in this instance, we felt we had a moral obligation to provide this technology freely to vulnerable people who really need it.”