Methodology of Key Odorants Selection from Wastewater Treatment Plants Based on Their Kinetics with Selected Atmospheric Oxidants

Abstract

Nowadays, wastewater treatment plants (WWTPs) are considered significant contributors to odour emissions, which can have a sensorineural impact on surrounding communities. In this study, calculations of the half-lives of selected odorants commonly found in wastewater treatment plants were carried out, considering varying concentrations of atmospheric oxidants that exhibit diurnal and geographical fluctuations. Odorants displaying quick reactivity and brief half-lives, which were deemed less significant contributors to odour nuisances, reacted with nitrate radicals (NO₃•) during nighttime and chlorine atoms (Cl^*) with T½ ranging from 1.23 to 2.77×10⁵ minutes and from 6.57×10^-4 to 3.14x10³ minutes, respectively. On the other hand, extended half-lives were observed during reactions with ozone (O₃), ranging between 1.81×10³ and 1.61x10¹¹ minutes, suggesting a potentially smaller role in the degradability of odorants in the atmosphere. These insights into odorant-oxidant kinetics may aid in predicting atmospheric lifetimes and their contribution to secondary aerosol formation, thus informing regulatory and mitigation strategies to improve air quality.