ELECTROSTATIC PRECIPITATION OF NANOPARTICLES AND SUBMICRON PARTICLES: REVIEW OF TECHNOLOGICAL STRATEGIES

Very small particles dispersed in the atmosphere display complex dynamics, due to their characteristics of Brownian motion and low sedimentation rate, while chemical and physical transformations in the air can lead to the formation of compounds that present greater risk. In this context, one of the most efficient gas-solid separators is the electrostatic precipitator (ESP), based on electrical charging of the particles and their attraction to collection electrodes. Therefore, this work summarizes the technological strategies employing ESPs to collect nanoparticles and submicron particles. The physical phenomena involved in particle charging and collection are described, together with discussion of the geometrical and operating differences between industrial-scale ESPs and small-scale devices. Studies and innovations involving strategies of design and operation are presented. Aspects of the electro-fluid dynamics in the device are described, as well as methods used to mitigate ozone production in this process.