Biosolids

Biosolids recycling

A cost-effective and environmentally sustainable fertiliser for your farm. 

Every year, we recycle just under 600,000 tonnes of biosolids as a fertilsier in a safe and sustainable way out to agriculture. The fertiliser we produce is used on approximately 30,000 hectares of land, and we complete around 7,000 soil samples to ensure our fertiliser is right for that land. 

This fertiliser, known as biosolids, play a vital role in enhancing soil health and supplying crop nutrients.

Our biosolids are a fantastic source of organic matter, phosphate and a range of other nutrients to help improve soil health. It also acts as a high-quality alternative to manufactured fertilisers, at a competitive and cost-effective price.

Recycling biosolids from the wastewater treatment process to use in agriculture is one of the most sustainable ways we can support the United Kingdom’s goal of achieving a regenerative, circular economy that that eliminates waste.

You can watch a short video showcasing how the Bioresources team operates (or skip to 04:20 to see the Biosolids Recycling process).

Our products

We have over 1000 sewage treatment works across our region that treat our captured wastewater. 

At these sites we clean the wastewater and return it to the environment. The organic material we recover from the wastewater is commonly referred to as “sludge”. 

This sludge is then treated at large, strategically located treatment centres. Here we remove the excess water from the waste to create a dry product known as biosolids, also referred to as “biosolids cake” or “treated sludge cake”. 

Biosolids provide a sustainable source of nutrient-rich fertiliser for farmers. 

We continuously improve our processes and currently we produce biosolids with limited odour and an improved ability to stack in fields.

You should CONTACT YOUR FARM LIAISON OFFICER to discuss your farm’s needs, the fertilsier produced in your area and the best option for you.

Harnessing biomethane for our sites and the national grid

More than 20 of our sites use anerobic digestion to conventionally treat sewage sludge.

This involves storing the sludge in a container, without oxygen, for a set period and temperature – usually 15 days at 37.5 0C. 

This produces methane gas. We convert this methane into a renewable source of energy and use it to power our sites. 

We put any surplus energy back into the national grid where it’s used by people all over the region. 

On occasion we blend the sludge with quicklime. This raises the pH value of the sludge to a neutral level.

Enhanced treated biosolids using a thermal hydrolysis process.

At some of our larger sites we optimise sludge treatment thorugh the use of a thermal hydrolysis plant, which cooks our sludge at high temperature and pressure. 

This makes the sludge more biodegradable, results in a higher production of biogas and the final biosolids product is also dryer than those created using conventional digestion.

We’re working to constantly improve this process and bring to more of our sites in the future. 

As well as selling just around 550,000 tonnes of biosolid products each year, we also produce around 60,000 tonnes of clean water sludge from our water treatment processes.

Clean water sludges are made up of the soil dragged in from reservoirs and rivers and filtered out during the production of clean drinking water.

The clean water sludge is free and can be used as a soil-conditioner.

Biosolid product prices and cost benefits

There is a fantastic cost benefit of using biosolids in comparison to manufactured fertilisers. 

The actual saving depends on a wide variety of factors, but typical applications will save your business well over £200 per hectare on nitrogen, phosphate, potash and sulphur. 

The organic matter, trace elements and other nutrients supplied with the biosolids adds further value and savings.

How we calculate prices

Our biosolids are charged on a price per hectare basis, dependent on the distance of your farm from our sludge treatment centres.

And you’re paying for more than just the fertiliser. When you buy from us, you get: