As I wait here at the airport, after an intense 3-day conference organized by the WEF I ask myself if it was the money of the olores.org advertisers worth, once the event has ended.

   Alright, I have met again all the colleagues and that is nice. I met Mike McGinley from St Croix and Thierry Pagé from Odotech. I spoke with the people of Ecometrika Chile and I met a lot of interesting people selling a bunch of different solutions like scrubbers, biofilters, ozoners, bioscrubbers, etc to manage“odors”…

   .. to manage odors? Is that right? Do they really treat odors? The answer comes plain from my point of view: No, none of the equipment shown at the event was specifically designed to treat odors, but to treat H₂S, which is not quite the same.

   Measuring H₂S instead of “odor” is like measuring vibration instead of noise, or measuring “sales” instead of “profit”. There is a very nice correlation between both parameters in many cases, but this correlation might get a bit uglier at lower H₂S concentrations ^{(1) (2)}.

   Every single equipment was designed to treat H₂S. None of the makers in the various booths at this conference has shown any data of efficiency in terms of odor units when asked about it. This is not a surprise if taken into account that there are just 3-4 olfactometric labs in USA^*. If every operator rely on H₂S measurement instead of a proper olfactometric measurement, no wonder there is no business for more olfactometry labs in the States!!

   During 2010 and 2011, the LUFA Nord-West Institute (Germany) in collaboration with the DLG has carried out the evaluation of the official measurements of 96 units of treatment equipment (3). Of these 96 measurements, 56 corresponded to initial audits and 40 were verifications following a period of time in operation. The key criteria for the odor evaluation performance were two:

• No detection of odor from the inlet in the outlet
• Odor emission limit value of 300 ou_E/m³

Here there are just a few examples.

   This is the difference and from my point of view, a very significant one.

   There is a need for data from the makers of  odor abatement equipments in the form of odor efficiency and not H₂S.

   Another interesting observation is that there is generally a trend towards the  comparison of odor measured in a lab by means of dynamic olfactometry and odors measured with a field olfactometer such as the Nasal Ranger or the newer Scentroid SM100.

   Dilution to threshold D/T is not an standardized “odor unit”. A D/T measurement has no correlation with a measurement made with a dynamic olfactometer ⁽⁴⁾⁽⁵⁾ according to the EN 13725.

   From my point of view, there is little use for a measurement of D/T in terms of proof of compliance for odour abatement equipments. Nor of H₂S measurement. Most of the operators that presented papers in this Odors and Air Pollutants 2012 organized by the Water Environment Federation (WEF) preferred to spend hundreds of thousands of dollars in expensive equipment for odor abatement but save a few thousands in the evaluation of these equipments with a repeatable and reproducible and thus standardized method named dynamic olfactometry. The fascinating presentation of Charles McGinley⁽⁶⁾ in this 2012 conference was quite refreshing and also clear about precision and accuracy of odor control system performance tests.

   The organization of the Odors and Air Pollutants 2012 Conference in Louisville was excellent and I would like to congratulate the organizers. This year and according to the list of participants, I was the only European there. This situation was a bit unusual as there was plenty of talks about the “European” norm.

   I would like to encourage to scientists and operators to come over to the next 2014 WEF conference. This year there were plenty of interesting talks and a very valuable contribution of scientists, technicians and plant operators. However if you did no come this time to Louisville, you have definitely lost the chance of enjoying a soothing glass of Kentucky bourbon.

   Notes

^* Just in a small country as Spain there are 6 olfactometric labs, 4 of them with the ISO 17025 and EN 13725 accreditation. In Germany, there are over 15 labs.

   References

⁽¹⁾ Gostelow, P., SA Parsons (2000). “Sewage treatment works odour measurements.” Wat. Sci.Technol. 41(6), 33-40.
⁽²⁾ Gostelow, P., SA Parsons, RM Stuetz (2001). “Odour Measurements for Sewage Treatment Works.” Water Research 35(3): 579-597.
⁽³⁾ Broer L. (2011): Geruchsminderung durch Abluftreinigung bei Tierhaltungsanlagen– Wie zuverlässig sind zertifizierte Anlagen in der Praxis. In: VDI Wissensforum GmbH (Hrsg.): Gerüche in der Umwelt. VDI-Berichte 2141.
⁽⁴⁾ Sheffield R., Thompson M., Dye B., Parker D. Evaluation of Field-based Odor Assessment Methods. WEF/A&WMA Odors and Air Emissions 2004
⁽⁵⁾ Bokowa A.,Ambient Odour Assessments: Comparison of Two Techniques Used for Assessing Ambient Odours.3rd IWA Odour Conference, October 2008.
⁽⁶⁾ McGinley C.Precision & Accuracy of Odor Control System Performance Tests. WEF Odors and Air Pollutants 2012.

If you find this article interesting, you might be also interested in these articles.

• Conference on Odors and Air Pollutants 15-18 April 2012 in Kentucky, USA.
• WEF/A&WMA Odors and Air Pollutants 2010, March 21 – 24, 2010 will be hold in Charlotte, North Carolin
• WEF Congress about odors and air emissions 2006
• Scentroid SM100 a New On Site Odour-measuring Device
• Odours in the Environment (Gerüche in der Umwelt), a different kind of conference organised by the Association of German Engineers VDI.