UK

River Wye waste to be used in Aston University biochar study

Nicola Goodwin - BBC Hereford & Worcester
Wed, August 9, 2023

The status of the River Wye was downgraded by Natural England in May due to pollution


Centuries-old science could help to remove pollution from the River Wye and bring millions of pounds to the West Midlands economy, researchers say.

Biochar, a charcoal-like substance made from wood, leftover crops and agricultural waste, is being studied by a team at Aston University, Birmingham.

It could be used to treat chicken muck to turn it into items such as compost and building materials, they claim.

Sixteen biochar hubs are set to be built in the Wye Valley by a company.

The firm, Onnu, have purchased a site for their first hub in Madley, Herefordshire and said they plan to buy waste from poultry farmers to turn into biochar.

Biochar has been produced for centuries like charcoal, where material is heated without oxygen up to temperatures of 300C or higher.

The process, called pyrolysis, breaks down materials by heating them and turning them into a gas, before it is then condensed and cooled to produce solid or liquid substances.

Herefordshire Council said they hoped to find out more about the process soon.

In May, Natural England downgraded the status of the River Wye due to pollution.

In the catchment area, 24 million chickens are farmed and their waste is spread as fertiliser but some of it washes into the river when it rains.

The phosphorus from it causes prolonged algal blooms which suffocate plants and wildlife by sucking up all the oxygen and turning the water an opaque green.

A research team at Aston University's Energy and Bioproducts Research Institute (EBRI) believe the muck could be valuable if it is used in the right way.
Develop new products

They have been given a government grant of almost £2m to see how biochar can be used commercially.

"We are pulling together a lot of science to make it work for communities and the economy," said Tim Miller, director of engagement at EBRI.

"We are taking the material, such as chicken muck, processing it and then producing a range of new materials which then can be developed into new products."

The biochar has already been used as compost for the plants used in Birmingham's gold medal winning Chelsea Flower Show entry.

Tim Miller, from Aston University, said the waste could be processed and produced into "a range of new materials"

The team are also working on matting for chicken sheds to soak up smells and ammonia and to help prevent spillages from the farms.

They said it was a multi-million pound scheme which could create hundreds of jobs.

Michael Douglas, from Onnu, said their hubs could each potentially handle 10,000 tonnes of agricultural waste annually.

"None of these plants are massive. To minimize transport and by serving a relatively small catchment we'll be looking at ultra-local solutions," he added.

Chicken producer Avara processes two million chickens at its factory in Hereford every week and it is the county's largest employer.

The company said they have met with Onnu but there was a lot of research to be done.