Biosolids are a by-product of the treatment of waste water from domestic and industrial sources. Bacteria and other microorganisms
purify the waste water to create digested liquid. The liquid is drained out, purified and returned to rivers or the sea. What remains is a dried up substance called digested cake
Biosolids contain huge quantities of nutrients, phosphate, nitrogen, sulphur, magnesium and organic matter which helps farmers to meet
the requirements for crop nutrients and soil fertility without the need for fertilisers and other chemicals. It is highly regulated which ensures the safety of the crops, as well as minimising any
potential risk to humans and livestock, and reduces the amount of waste product which would have to be disposed of.
Typical total values for nutrients are:
- Nitrogen: 10.5 Kg N/tonne
- Phosphate: 13 Kg P2O5/tonne
- Potash: 0.6 Kg K2O/tonne
- Sulphur: 6 Kg SO3/tonne
- Magnesium: 1.6 Kg MgO/tonne
P.A. Wright & Sons Limited work closely with water treatment companies and local farmers in the delivery and distribution of
Biosolids to farms all over the Midlands. Each year, we recycle more than 600,000 tonnes of Biosolids from Severn Trent Water sewage treatment works. We have a dedicated team of Farm Liaison officers
(FLO’s) each with their dedicated regions to talk through each farmer's requirements.
Once ordered, P.A. Wright & Sons Limited provide the delivery of the Biosolids to the field location, in which we will
stockpile come rain or shine. We are able to do this using our specialist trackway which is put down by our bespoke hiab vehicles.
Our skilled machine operators will stockpile the Biosolids to the farmers’ requirements, leaving the field site in a clean and neat
manner. Once the field has been harvested we will send one of our experienced spreading teams to get the Biosolids spread at the required rates.
Digestate is a nutrient-rich substance produced by anaerobic digestion that can be used as a fertiliser. It consists of left over
indigestible material and dead micro-organisms - the volume of digestate will be around 90-95% of what was fed into the digester.
All the nitrogen, phosphorous and potassium present in the feedstock will remain in the digestate as none is present in the
biogas. Typical values for nutrients are:
- Nitrogen: 2.3 - 4.2 kg/tonne
- Phosphorous: 0.2 - 1.5 kg/tonne
- Potassium: 1.3 - 5.2 kg/tonne
However, the nutrients are considerably more bioavailable than in raw slurry, meaning it is easier for plants to make use of the
nutrients. This can be particularly valuable for land within Nitrate Vulnerable Zones (NVZ) where applications of organic nitrogen are restricted.
We have a dedicated team who are happy to answer any questions you have about Biosolids. Please call us on 01827 880472.