The UK press is full of stories about plastic pollution in general and the problem of microplastics building up in the water cycle. Several recent news items have caught my eye. Apparently, in the UK, we dispose of 100 billion pieces of plastic per year. According to the government we in the UK recycle 44% of our plastic. However, Greenpeace uses a higher bar for what counts as recycle and they reckon we only achieve 12%. Whichever, a lot of plastic is not recycled and eventually makes its way into the marine or freshwater environment as microplastics. It is clear from mounting evidence that plastic pollution continues to grow exponentially.
Membranes should be ideal as a technology to remove microplastics, whether it is in treating our wastewater discharges into the environment and/or for treating water that we abstract from the environment that has already been polluted. However, what would happen to the concentrate or reject from the membrane process? This would pose an even greater threat to the environment when we come to dispose of the waste.
But now, researchers at the University of Texas (UT) in Austin have announced the development of an AI engineered enzyme which seems to be able to address the problem. The UT research has been specifically targeted at PET, which is both ubiquitous and resistant to environmental breakdown, so an ideal research goal.
So where would membranes fit in? It strikes me that this would be an ideal opportunity for someone to develop a Microplastic Reactor (MPR). Its forerunner, the membrane bioreactor (MBR), was developed out of the idea of combining a membrane barrier with a biological reactor to provide a highly efficient single stage treatment for general wastewater. It was faced with multiple developmental challenges, but has now become of enormous importance and is by far the largest single application for membranes in water.
Perhaps the AI enzymes could be used on the membrane concentrate to break down the retained microplastics before disposal back to the environment in an MPR! The concentrate volumes would be a small fraction of the original feed and of course the microplastic concentration would be much higher. Both factors would have a major impact on treatability, potentially enabling enzyme treatment as a practical option. The MPR would combine known technologies which individually accomplish part of the required task. This is surely an opportunity for these technology solutions to get together and solve the most serious particulate pollution threat the planet has ever faced.