Hansen M., Jonassen K., Feilberg A., 2014, Evaluation of Abatement Technologies for Pig Houses by Dynamic Olfactometry and On-site Mass Spectrometry, Chemical Engineering Transactions, 40, 253-258.
The aim of the present study was to evaluate the effect of abatement technologies for pig houses on odour based on 1) on-site measurements of dynamic olfactometry and chemical odorants and 2) dynamic olfactometry with storage of air samples in sampling bags. The study was conducted at two facilities with growing-finishing pigs with either biological air cleaning or slurry acidification. Five measurements days were carried out at the facility with biological air cleaning and six days at the facility with slurry acidification. A mobile laboratory containing proton-transfer-reaction mass spectrometry (PTR-MS) and an olfactometer was applied for the on-site measurements. The mobile laboratory was connected to the odour sources by insulated and heated Teflon tubes that were flushed continuously with sample air. The sampling bags for dynamic olfactometry were collected simultaneously with the on-site measurements and were analysed after ca. 24 h. At each measurement day three repetition were performed before and after the biological air cleaner and in the pig house with slurry acidification and in an identical control pig house. Odour threshold values for the individual chemical odorants were used to estimate the odour activity value for each sample. The results demonstrated that evaluation of the abatement technologies based on the on-site measurements of dynamic olfactometry and the odour activity value based on chemical odorants were in agreement and showed the same trend in data. However, if the effect of the abatement technologies was evaluated based on dynamic olfactometry with storage in sampling bags the effect of the biological air cleaner was in general underestimated and the effect of the slurry acidification system was overestimated. In conclusion, the storage in sampling bags seems to bias the measurements of odour and this may influence the estimated effect of abatement technologies. More research is needed to limit the bias of sampling bags used for dynamic olfactometry.
