Removing odours at mechanical-biological treatment facilities

With around 113 million tonnes of residual household waste produced in the EU each year, managing municipal waste sustainably is a huge ongoing concern. By 2025, there are expected to be almost 700 mechanical-biological treatment (MBT) plants in Europe with a combined treatment capacity of around 65 million tonnes. As air quality legislation becomes increasingly stringent, it’s essential to put reliable solutions for odour emissions in place at these MBTs. DESOTEC air filters are proving their value at several sites across Europe, including the following MBTs in France.

Purifying airflows

The term MBT covers a range of mechanical and biological technologies used to treat the waste that remains after recycling and garden waste have been separated out.

Treatment consists of mechanical operations (sorting) and biological steps (composting and anaerobic digestion).

In most of Europe, the focus is on solid recovered fuel (SRF) production. However, in France, the preferred option is anaerobic digestion: turning the natural gas into biogas and biomethane and using the composted digestate to spread on fields as a fertiliser or to make compost.

At anaerobic digestion installations, air flows must be purified of odours before they are emitted into the atmosphere. Operators spend around 15% of their investment in an MBT system on odour control.

How can activated carbon help?

As it is almost impossible to design biofilters for the treatment of very high air flows, activated carbon filtration is generally the best solution.

DESOTEC activated carbon filtration systems are safe, compact, very efficient, and require little day-to-day operation. As well as odour control, they capture volatile organic compounds (VOCs) and hydrogen sulfide (H₂S).

DESOTEC supplies mobile filters on a rental basis, requiring no upfront investment. As they are mobile, they can be delivered rapidly in situations where odour complaints have arisen.

They are also modular, so filtration set-ups may be expanded or reduced to meet changing requirements or legislation.

Our full-service solutions include the safe and sustainable handling of waste carbon. Once filters are saturated, we transport the closed filter units away from customers’ sites and take them to our facilities. All adsorbed molecules are destroyed in our furnaces, and the carbon reactivated wherever possible. This circular system boosts sustainability and brings down clients’ costs.

Real-life case studies: DESOTEC’s solutions in action

  • Improving air quality for workers at an anaerobic digestion facility

At one anaerobic digestion site in the Vendée (France), DESOTEC has installed two Aircon V-XL filters, which both process a flow rate of 55 000 m³.

One is sited in the reception hall, while the other is in the building where the compost matures. A biofilter and an H₂SO₄ scrubber on a separate circuit treat the damp air in the building, while the Aircon V-XL filters speed up the process, improving air quality for workers at the site.

  • Purifying air emissions at an MBT plant

This MBT site in the Morbihan region of France processes 45 000 tonnes of residual household waste each year.

Two DESOTEC Aircon-V filters were in place for several years, purifying air emissions and removing odours successfully.

To modernise the system, it was replaced in 2021 by a new installation comprising four Aircon V-XL filters. These continue to purify air emissions at the site, ensuring an odour-free environment for workers and neighbours.