Validating a Turbulence Transfer Based Approach to Quantify Odor Emissions from waste Water Treatment Plants

摘要

Quantifying odour emissions from water surfaces is conventionally done using the flux chamber technique. However, field measurements indicate that the flux chamber technique underestimates the odour emissions because the odour emissions are highly dependent on environmental variables such as atmospheric turbulence. The transfer of odour between the air and water is governed by turbulent and molecular transport processes. Both transport processes can be characterized by diffusion coefficients and the concentration gradient between air and water surface. Away from the water surface, the turbulent transfer is typically orders of magnitude higher than the molecular transfer. We developed an approach by combining flux chamber measurements with turbulence flux for estimating odour emissions from water surfaces based on turbulence transfer. We applied this approach to a waste water treatment plant (WWTP) to quantify its odour emission rates. We validated this approach by using air dispersion modeling and downwind ambient odour measurements and found this approach plausible, which was presented at the A&WMA 2015 Annual Conference. However, the validation did not allow us to pinpoint individual sources because all sources are located very close to each other. Following this, more validations have been performed at other WWTPs. Additionally, we also evaluated the impact of aeration process on the turbulence flux and odour emission rates. Furthermore, the odour impacts from a WWTP will be quantified using air dispersion modelling based on the odour emissions derived using both the flux chamber and the proposed approach. All results will be presented in this paper.