In 2006 the WG27 of CEN TC264 started with the normalisation of the different methods for determi... more In 2006 the WG27 of CEN TC264 started with the normalisation of the different methods for determination of odour in ambient air. Existing VDI standards for the grid method and the stationary plume method were used as a starting point in this standardization committee. In Belgium however, there is since the early nineties a lot of experience with a slightly different method. This method, called the dynamic plume method, is since then widely used for determination of odour downwind of a source. The method itself is very easy to execute, doesn't require special instruments and gives a very comprehensible output. The results of these observations are used in modelling exercises to determine the emission strength of a source and hence the odour impact on the surroundings. Emission is expressed as a number of sniffing units per second (su/s). The Flemish odour legislation is based on this methodology. This paper gives an overview of the advantages and drawbacks of this method and indi...
In this study the influence of sampling and storage of samples was studied focusing on a number o... more In this study the influence of sampling and storage of samples was studied focusing on a number of mercaptans. First the influence of the sampling material on the composition of the sampled gas was studied and secondly the stability of the mercaptans in the different sampling materials is followed over time.Stainless steel, Teflon and deactivated stainless steel were tested as inlet material for a Nalofane bag. These were compared with sampling using both stainless steel or Silonite treated canisters. As a last sampling strategy, active sampling on sorbent tubes was considered.The tests indicate the composition during sampling can be changed in presence of untreated stainless steel as this gives rise to the formation of disulfides. Furthermore, the stability over time of the mercaptans after sampling is very limited for the sorbent tubes with great loss of certain mercaptans over a very short period of time (>2 hours). Also in bags the stability is rather limited and the best sta...
This paper presents the methodologies to determine odour in ambient air by field inspection that ... more This paper presents the methodologies to determine odour in ambient air by field inspection that will be a new European standard. The objective is to characterise the odour in a defined area. Without making a link with potential annoyance due to the presence of odours, the described methods propose the way to characterise an exposed environment. Two approaches are defined in the new standard: the grid method and the plume method. The grid method can be used to determine the exposure to ambient odours in a defined area of study, using direct observation of recognisable odours in the field by human panel members. This method must be applied over a sufficiently long period of time (6 or 12 months) to be representative of the meteorological conditions of that location. The result is the distribution of the frequency of exposure to odours within the assessment area. The plume method can be used to determine the extent of detectable and recognisable odours from a specific source using dir...
The treatment of poorly water soluble waste gas compounds, such as ethene, is associated with low... more The treatment of poorly water soluble waste gas compounds, such as ethene, is associated with low substrate concentration levels in the liquid phase. This low concentration level might hamper the optimal development of a microbial population. In this respect, the possible benefit of introducing nitrifying activity in the heterotrophic removal of ethene at moderate concentrations (< 1000 ppm) from a waste gas was investigated. Nitrifying activity is known to be associated with (i) the production of soluble microbial products, which can act as (co-)substrates for heterotrophic micro-organisms and (ii) the co-oxidation of ethene. The used reactor configuration was a packed granular activated carbon biobed inoculated with the heterotrophic strain Mycobacterium E3. The nitrifying activity was introduced by regular submersion in a nitrifying medium prepared from (i) compost or (ii) activated sludge. In both cases a clear enhancement of the volumetric removal rate of ethene could be obs...
In 2006 the WG27 of CEN TC264 started with the normalisation of the different methods for determi... more In 2006 the WG27 of CEN TC264 started with the normalisation of the different methods for determination of odour in ambient air. Existing VDI standards for the grid method and the stationary plume method were used as a starting point in this standardization committee. In Belgium however, there is since the early nineties a lot of experience with a slightly different method. This method, called the dynamic plume method, is since then widely used for determination of odour downwind of a source. The method itself is very easy to execute, doesn't require special instruments and gives a very comprehensible output. The results of these observations are used in modelling exercises to determine the emission strength of a source and hence the odour impact on the surroundings. Emission is expressed as a number of sniffing units per second (su/s). The Flemish odour legislation is based on this methodology. This paper gives an overview of the advantages and drawbacks of this method and indi...
In this study the influence of sampling and storage of samples was studied focusing on a number o... more In this study the influence of sampling and storage of samples was studied focusing on a number of mercaptans. First the influence of the sampling material on the composition of the sampled gas was studied and secondly the stability of the mercaptans in the different sampling materials is followed over time.Stainless steel, Teflon and deactivated stainless steel were tested as inlet material for a Nalofane bag. These were compared with sampling using both stainless steel or Silonite treated canisters. As a last sampling strategy, active sampling on sorbent tubes was considered.The tests indicate the composition during sampling can be changed in presence of untreated stainless steel as this gives rise to the formation of disulfides. Furthermore, the stability over time of the mercaptans after sampling is very limited for the sorbent tubes with great loss of certain mercaptans over a very short period of time (>2 hours). Also in bags the stability is rather limited and the best sta...
This paper presents the methodologies to determine odour in ambient air by field inspection that ... more This paper presents the methodologies to determine odour in ambient air by field inspection that will be a new European standard. The objective is to characterise the odour in a defined area. Without making a link with potential annoyance due to the presence of odours, the described methods propose the way to characterise an exposed environment. Two approaches are defined in the new standard: the grid method and the plume method. The grid method can be used to determine the exposure to ambient odours in a defined area of study, using direct observation of recognisable odours in the field by human panel members. This method must be applied over a sufficiently long period of time (6 or 12 months) to be representative of the meteorological conditions of that location. The result is the distribution of the frequency of exposure to odours within the assessment area. The plume method can be used to determine the extent of detectable and recognisable odours from a specific source using dir...
The treatment of poorly water soluble waste gas compounds, such as ethene, is associated with low... more The treatment of poorly water soluble waste gas compounds, such as ethene, is associated with low substrate concentration levels in the liquid phase. This low concentration level might hamper the optimal development of a microbial population. In this respect, the possible benefit of introducing nitrifying activity in the heterotrophic removal of ethene at moderate concentrations (< 1000 ppm) from a waste gas was investigated. Nitrifying activity is known to be associated with (i) the production of soluble microbial products, which can act as (co-)substrates for heterotrophic micro-organisms and (ii) the co-oxidation of ethene. The used reactor configuration was a packed granular activated carbon biobed inoculated with the heterotrophic strain Mycobacterium E3. The nitrifying activity was introduced by regular submersion in a nitrifying medium prepared from (i) compost or (ii) activated sludge. In both cases a clear enhancement of the volumetric removal rate of ethene could be obs...
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