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Organic waste facilities produce a variety of odours. Release of these air pollutants from the operations is often a cause for odour annoyance for people living in the surrounding area. Failure to control and manage odours is the single biggest cause of adverse publicity, regulatory pressure and facility closures in the organics recycling industry. The implementation of effective treatment solutions is therefore of key importance. Air Treatment systems are at the core of each organic waste treatment facility and our engineers know how to meet the most stringent odour abatement criteria.

With the support of WTT odour control at your facility is possible!

What causes these odours?

Composting and anaerobic digestion facilities have one thing in common: they manage the process of decomposition. This is a biological process whereby complex biochemical compounds are broken down into their constituent building blocks. Some odours are produced by biological changes in compounds by microorganisms, others are due to chemical changes in the composting pile. The major odour causing compounds are sulfur-, nitrogen-, and carbon-based. Ammonia is the most common odour that can be formed aerobically as well as anaerobically.

Odour Management

In our in-vessel composting system the feedstock is aerated and all process conditions are optimally controlled by our control system.

The composting process is managed in several phases, each of which are designed to shorten time-to-temperature and re-use and capture the available thermal energy. By running at thermophilic temperatures higher temperature heat can be captured. Depending on the type of feedstock up to 2600MJ per ton of feedstock can be captured.

The engineers of WTT design each odour abatement system specifically to
treat odour compounds and ensure ideal dispersion to the atmosphere.

State of the Art Solutions

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Two-stage Scrubber

This scrubber first removes dust from the air, and then removes ammonia. Thereby avoiding blockages caused by dust in regular wet-scrubbers. WTT’s two-stage acid scrubber reduces pressure losses, reduces maintenance costs and decreases energy consumption.


A biofilter uses moist organic materials to absorb and then biologically degrade odorous compounds. Based on our extensive experience with organic waste treatment in a variety of conditions, we know how to construct the biofilter, making sure it works for your facility.

State of the art

State of the art Air Treatment Systems

These are just two examples, our engineers are always looking for solutions that fit with your needs.

Greater than 98% odour removal

at WTT
at WTT

At WTT we strive to obtain the best, most cost effective results, while improving sustainability and reducing your overall carbon footprint.

View Past Client Projects


Odour abatement systems are at the core of each organic waste treatment facility. The buildings are ventilated to remove dust from the work environment. In addition, process air is treated with a wet-scrubbing process to remove ammonia. The dust containing air that is extracted from the work environment tends to cause blockage in the wet-scrubber. To solve this issue, WTT developed a two-stage acid scrubber. This scrubber reduces pressure losses and decreases energy consumption. In addition, maintenance costs can go down with 50% and downtime is reduced.


The buildings of a facility are ventilated to remove dust from the work environment. In addition, process air is treated to remove ammonia. Ammonia removal is achieved with a wet-scrubbing process, where ammonia is captured and discharged as a liquid fertilizer product. The dust containing air that is extracted from the work environments tends to cause blockage in the wet-scrubber.


WTT has developed a two-stage acid scrubber that first removes dust from the air, and then removes the ammonia. The dust removal section utilizes spray nozzles to trap the dust particles in the water. The air can now enter the ammonia section where the ammonia is removed by using a sulfuric acid solution, creating a fertilizer product: ammonium-sulphate.
The ammonium-sulphate is pumped from the ammonia section to the dust section, here it is recirculated to neutralize the solution. From the dust section the liquid fertilizer is pumped to a storage tank.

  • The two-stage acid scrubber developed by WTT leads to:
  • A reduction in pressure losses
  • Lower energy consumption
  • Maintenance costs can be reduced by 50%
  • Less downtime.

The new design was successfully implemented in Göttingen, Germany, with an in-process air stream of 50.000 m3/h and in London with two in-process air streams of 100.000 m3/h

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