Modeling odour dispersion from composting plants: comparison with electronic nose measurements

The dispersion of odour from a composting plant was calculated with the CALPUFF modeling system, where site specific meteorological and geophysical informations were taken into account. The odour emissions, both from forced and free-convection sources, were measured by means of dynamic olfactometry and implemented in the model employing mass-transfer considerations. The results obtained from the model were compared with measurements from a MOS sensor based Electronic Nose equipped with a preconcentrator (to augment its sensitivity to low concentrations) placed in two locations (at 150 m and 230 m far from the plant in two different directions), for a period of two weeks for each location. Comparisons were made both on a global level (2D maps of percentiles of hourly averages) and on an “instantaneous” point of view (time series correlation); results advocate the need for a truly site-specific meteorology to obtain satisfying predictions, and give some hints for tuning model parameters for odour applications.