Experimental study of mass transfer by volatilization inside a portable wind tunnel used to estimate emission rates for odorous compounds

Wastewater treatment plants are sources of hydrogen sulfide in urban environments. This compound, at certain concentrations, may be associated with compromising the health and well-being of populations living near such sources, characterized by diffuse emission, which makes it difficult to quantify. The portable wind tunnel is one of the devices used to measure this type of emission; however, this equipment is not capable of simulating all significant mass transport phenomena. Thus, this study investigated mass transfer at the liquid-gas interface of hydrogen sulfide by estimating the global mass transfer coefficient within the portable wind tunnel. The inlet flow rate into the system ranged from 600 to 1,800 , and the analysis of concentration decay in the liquid phase was performed using spectrophotometry. The observed exponential decay is consistent with the adopted hypotheses; however, no significant variation in the mass transfer coefficient was observed for different system operation flow rates. The average value found was 2.70×10 -5 ±2.99×10 -6 . In summary, this study contributed to understanding the mass transfer of hydrogen sulfide in wastewater treatment environments using a portable wind tunnel as an experimental tool.