Particulate characteristics and emission rates during the injection of class B biosolids into an agricultural field

A field study was conducted during the summer of 2009 to collect airborne particulate matter emitted during the agricultural activities. The activities surrounding the injection application of class B biosolids were targeted for the sampling. The sampling was carried out before (pre-application), during (application), and after (post-application) the application. This study characterized the particulate emissions deposited on the aerosols spectrometer. The effect of different biosolids related activities was significant on the mass concentration, the number concentration, and the size distribution. The mass concentration of fine (PM2.5) and ultrafine (PM1.0) was highest during the pre-application. The mass concentration of thoracic fraction (PM2.5-10) increased significantly during the application. A bimodal size distribution was observed throughout the sampling. Nuclei mode formation was predominant during the pre-application and the post-application, whereas the accumulation mode was distinctive during the application. The number concentration of ultrafine particles was highest during the entire sampling period. The application of biosolids resulted into a higher number of coarse particle emission. It was also observed that the ultrafine and fine particles traveled longer downwind distances. The emission rates were determined for pre-application, application, and post-application activities.

► The particle characteristics and emission rates during the injection of class B biosolids are determined. ► Different agricultural activities (pre-application, application, and post-application) affect the particle characteristics. ► The modal distribution, number concentration, and mass concentration of the particles are affected by the application.