How these researchers developed a test to improve water and soil quality

2 Oct 2019

From left: Dr Panagiotis Manesiotis and Federica Pessagno. Image: TechWatch

P-Sense is one of 12 finalists in the upcoming Invent 2019 competition. TechWatch’s Emily McDaid spoke to founders Dr Panagiotis Manesiotis and Federica Pessagno to find out more.

Here is a fact that I bet you didn’t know: rivers and lakes age over time.

That ageing process is due to the fact that plants grow faster than they die and decompose so, over time, a natural body of water becomes filled up with nutrients and plant matter. The matter collects at the bottom, making the water more shallow over time. This natural process is known as eutrophication.

However, like many natural processes, human activity is disrupting it. Fertilizers used for agriculture (containing phosphates) are speeding up eutrophication.

Two scientists at QUB are hoping to slow these human-made impacts, by creating a field-ready test for phosphates in soil and water. Their test will signal to farmers and environmentalists where to focus action on removing some phosphates.

The process goes like this: fertilizers run off into water systems, causing high concentrations of phosphates, which cause algae blooms.

“As the algae grow, they are consuming oxygen – at the expense of all other organisms in the surrounding ecosystem,” says P-Sense co-founder Dr Panagiotis Manesiotis.

“Also, phosphorous is a useful element that is largely non-renewable. Once phosphorous is mined from the ground and used up, it disappears into places where it’s really hard to get, where it taints water sources.

“There are very few technologies out there to recover phosphorus, but our test can help mitigate wasteful use and identify hotspots where remedial intervention can recover useful quantities of phosphorus.”

Bringing the idea out of the lab

Manesiotis is originally from Greece, but he has been a senior lecturer in analytical chemistry at QUB for the past seven years. He has joined forces with Federica Pessagno, a PhD researcher from Italy, to create P-Sense’s testing strips.

“Satellite imagery will show an unnatural green colour in rivers, lakes and sometimes even near river mouths in salt water,” says Manesiotis.

“That green colour is caused by the algae, which are consuming the oxygen and other nutrients, choking the fragile ecology of that body of water.”

He says that testing for phosphates can assist farmers as well as the environment.

“This is an expensive global problem – farmers may be spraying slurry or other fertilizer when they already have enough phosphate in the soil. Because our finite supply of phosphorous is running out, this becomes more expensive year after year.”

P-Sense will be incorporated and spun out from the university later this year. A patent application is underway for the unique technology.

Of his move to Northern Ireland, Manesiotis says: “Greece can be too warm – and that can be distracting because you often have to put down your pencil and go for a swim.

“I have been living on the island of Ireland for about 10 years, and I’ve had a great time both north and south – the ethos of the country, engagement with industry and the research opportunities are great here.”

Pessagno agreed, adding: “The opportunities and the support that I received over the years in Northern Ireland have allowed us to bring our idea out of the laboratory.

“We started an amazing journey that will hopefully end up making a really positive environmental impact by improving water and soil quality.”

About P-Sense:

  • Levels of phosphate in soil and water are tested instantly using a dipstick that changes colour with increasing levels of phosphate
  • The testing strips do not require samples to be sent to the lab, as is traditionally the case, leading to a huge cost savings
  • P-Sense says its strips cost 50p each, whereas a lab-based test costs between £50 and £100 – and results are instant, as opposed to taking several days
  • It assists with two problems in agriculture: wasting expensive phosphorous-based fertilizers, and run-off of those fertilizers into the water system

P-Sense is a finalist in the annual Invent competition run by Catalyst, aiming to showcase the best and brightest innovators that Northern Ireland has to offer. Invent 2019 will take place on Thursday 10 October in Belfast, where 12 finalists will battle it out for a £33,000 prize fund.

TechWatch by Catalyst covered tech developments in Northern Ireland