NEW CONCEPTION OF DYNAMIC FLUX CHAMBERS TO FOLLOW ODOR EMISSION FROM AREA SOURCES

If exhausts (industrial chimneys,…) largely contribute to air pollutant emission, area sources (open tanks, evaporation or oxidation lagoons, storages, wastes…) present also an impact on pollution and especially on annoyance. This last aspect due to odorous compound emission is present in many cases because area sources are difficult to manage particularly because of very large surfaces. Comparatively to exhausts (with channelized flow) that can be characterized and treated more easily, the emission from area source is still difficult to measure and the air cannot be treated if the surface is too large. Several objectives are linked to the development of such chambers. The characterization of emission from area sources is necessary to quantify the pollution and then to estimate the annoyance or the toxicity. It allows also the acquisition of data for modeling development and impact prediction.In order to follow emitted pollutants, their concentration and their odor from area sources, several chambers were developed in our laboratory during the last eight years. If our works were based on dynamic chambers (preferred to static chambers), it was to recreate inside the chamber, the external wind conditions (with some limits). Chambers were both tested in a wind tunnel for laboratory development and on real sites. The wind tunnel was 9 m long and contains an area source (surfaceof 0.75 m2 and tank volume of 150 L where synthetic solutions or real effluent can be put).The evolution of chambers is shown but describing results with a simple device that do not give precise results and with two types (I and II) of chambers (tangential and modular respectively). With these two new types of chambers, odor flow emitted by liquid sources can be measured. These devices are able to simulate external conditions for low wind velocities and then to realize a measurement corresponding to conditions of emissions. Laboratory studies and applications on industrial sites are given for both types of chambers