Digestate Treatment & Processing: Your Questions Answered

We previously posted articles about the benefits of using digestate for dewatered fertiliser alongside additional common uses for by-products of digestate treatment, and today, we want to answer some of your questions relating to digestate, its composition, treatment methods, and how to make the most of the by-products of digestate treatment. 

Firstly, what is digestate and how is it treated?

Digestate is the end product of anaerobic digestion – a biological process that relies on microorganisms to decompose organic matter without the presence of oxygen. This method is widely used across the agriculture, food, and beverage industries as this process provides an environmentally friendly method of disposing of waste materials such as animal skins, stomach contents, fats, dairy products, and various other organic residues. During digestate treatment, the treatment plant will remove all water content from the digestate, leaving only solids. The wastewater will then be treated further to extract useful minerals such as phosphates and remove harmful waste such as bacteria. The treated wastewater can then be purified further to make it suitable for additional uses, and the useful nutrients can be readded to the digestate solids as required to make crop fertiliser and more. 

Why is digestate treatment necessary?

Digestate in its untreated state can contain harmful pathogens and pollutants (such as heavy metals), as well as become a breeding ground for bacteria and disease. If not properly treated, digestate can pollute nearby water sources, damage the local environment, and disrupt ecosystems. Although untreated digestate may contain lots of useful nutrients, when these are in such excess it can have a negative impact on wildlife, crop growth, and local communities (as well as causing inflammatory diseases in humans, amongst other conditions).

What are the main components of digestate?

Digestate is typically composed of water, organic matter, nutrients (such as nitrogen and phosphorus), and residual contaminants (such as chemicals, heavy metals, and pathogens). The exact composition can vary depending on the industry and location as well as the anaerobic digestion process. A sample analysis can help determine the exact composition.

What are the common methods of digestate treatment?

The most common methods of digestate treatment include:

  • Dewatering: This involves separating the liquid and solid parts to reduce volume and extract nutrients.
  • Ammonia Stripping: This reduces the ammonia content to make the digestate more suitable for further applications such as soil conditions, fertilisers, and even animal feed.
  • Biological or Chemical Treatment: In some instances, the digestate may be treated to reduce contaminants and odours through biological or chemical processes. Odours can additionally be minimised using air biofilters (such as wood chips) or activated charcoal filters.

What are the challenges of digestate treatment?

The key challenges of digestate treatment include:

What are the opportunities associated with digestate treatment?

Digestate treatment and subsequent byproducts can not only help support the supply chain but can also provide additional sources of revenue for businesses. Biogas, for example, can be used as a sustainable fuel source; dewatered digestate can be used as soil conditioner; extracted minerals and nutrients can be used as supplements in soil condition; and lots more! Speak to our team to find out more about the opportunities for your business.

Can digestate be used as a fertiliser?

Digestate in its untreated form cannot be used as fertiliser, however, appropriately treated digestate can be used as fertiliser and is actually a more sustainable and eco-friendly way of creating fertiliser instead of relying on synthetic alternatives. As long as digestate meets local regulations for discharge and use on the land, it’s safe to use for agricultural purposes. 

How can I find the right digestate treatment solution for my specific needs?

When choosing the right digestate treatment solution, it’s important to ”shop around” and get a few different quotes from different companies who specialise in working with your industry. Check out our article on how to choose the right wastewater treatment company for your business for a detailed list of things to consider and contact our team for more information.

Contact The LAT Water Team

If you’re looking for a new industrial wastewater treatment provider with modern technology and around-the-clock support, contact our team on +44 (0)1635 635900 or by emailing info@latwater.com. Download our corporate brochure for more details about our sustainable wastewater treatment solutions and check out the rest of our blog for more insights into the work that we do.

Elias Elia
14th Sep 2023