Agriculture
Odour emission values in agriculture
How can we know exactly how much odour our operation emits?
How strong or disturbing an odour is depends largely on the odour concentration of the odour-laden air leaving the given emission sources.
The magnitude of the resulting odour emission depends on several factors:
the nature of the process (e.g. whether small-scale pig keeping on bedding or large-scale slurry-based technology is used),
the design of the process (e.g. in composting, whether the process is enclosed or open),
the nature of the raw materials and auxiliary materials used or processed (e.g. composting green waste produces different emissions from composting sewage sludge)
Even with the same technology, odour emission depends heavily on how the process is operated, on adherence to process discipline, and on the proper maintenance and periodic inspection of abatement equipment.
The strongest odour concentrations
First of all, let's clarify: what is odour concentration?
Odour concentration is simply the number of odour units in 1 cubic metre of gas containing odorous substances at standard conditions; its unit is the odour unit per cubic metre (OU/m3).
For the most common odour-emitting activities around us, odour concentration measurements taken at or right next to the source clearly show that the strongest odour concentrations generally arise in protein processing, near livestock farms and in composting plants.
In protein processing this value can reach an odour concentration of 100,000 OU/m3, as described in detail in the Odour Protection Handbook.
At wastewater treatment plants, at the typical odour-emitting point source, the odour-laden air leaving the sludge dewatering building typically shows odour concentrations of between 2,500 and 25,000 OU/m3.
Without odour control, a storage tank or wastewater at a slaughterhouse reaches 2,000-150,000 OU/m3.
Nuisance odours must therefore be addressed, not only because the basic questions of odour emission, the assessment of nuisance environmental odour impact and its prevention are laid down in Government Decree 306/2010 (XII. 23.) on the protection of air, but also because it is an important consideration and expectation that the surroundings of our plant remain liveable and that our activities do not place an unnecessary burden on the air.
