x Abu Dhabi, UAEFriday 21 July 2017

Abu Dhabi's Masdar seeks to harvest dwindling phosphorous

Scientists are desperately hunting alternatives to fossil fuels but there is another natural resource even more depleted whose absence would be no less grave: phosphorus.

As mankind continues to mine the Earth's natural resources, scientists are desperately hunting alternatives.

Sustainable and renewable fuels are part of that. But there is another natural resource that is even more depleted and whose absence would have repercussions at least as grave for modern life: phosphorus.

The element is critical to all forms of life. It helps living things turn nutrients into energy, and is an essential component of DNA. It is in our electronics, our matchsticks and our shampoo.

Perhaps most crucially, it is a key component of agricultural fertiliser, making up for deficiencies in soil quality to turn barren land into productive land and increase the yield of a wide range of crops.

And yet it is estimated that our reserves of the phosphate rocks that comprise the main raw material from which fertiliser is made may last only 50 years.

And as these reserves dwindle, the price will increase - it has already risen by about 800 per cent in recent decades - potentially making food prohibitively costly in many countries, particularly those where the soil is poor.

To counter this grave situation, researchers at the Masdar Institute are working to harvest phosphorus from other sources.

They are exploring ways of recovering and recycling phosphorus, from sources such as household waste or domestic waste water.

Abu Dhabi is currently among the world's highest per-capita producers of municipal solid waste, generating more than 5kg per person a day, about three quarters of which is organic matter. It generates a lot of waste water, too.

At present, household waste goes to landfill, and no phosphorus is recycled from domestic waste water.

As things stand, the phosphorus content of that waste is hazardous. It can all too easily end up being discharged into rivers, lakes or the Arabian Gulf.

There, it can cause eutrophication, a sudden bloom of aquatic plant life caused by a surfeit of nutrient, which in turn can suffocate fish and make the water toxic to human beings. But it can be removed, not only making waste-water outflows more benign, but also, potentially, providing a new source of biofuel and fertilisers.

The Masdar team is trying to develop a UAE-specific method for this removal. It would use microbes to convert the waste into biofuel, producing a phosphorus-rich residue.

The biogas produced through this method is similar to natural gas and can be used in its place, and bioethanol can be added to regular petrol. Meanwhile the phosphorus residue could be used as a cheap, secure and locally-manufactured source of fertiliser.

And on top of this triple benefit - fuel, fertiliser, and safer waste - this research will also contribute to Abu Dhabi's leadership in the development of technologies based on renewable and sustainable resources. That's quite a result from something we currently throw away.

 

Dr Jens Ejbye Schmidt is a professor in the chemical engineering programme at the Masdar Institute of Science Technology.