Filtration of Charged Aerosols

Theme: Aerosol Technology                Start date: Cohort 1: 2019

Supervisors: Dr Marc Stettler (Imperial) and Prof. Jonathan Reid (Bristol)

Conveying and generation of powders can lead to very high levels of charge on particles, affecting their transport agglomeration and ultimate removal from the environment. Through modelling and experiments this project seeks to optimize collection of particles in filtration processes accounting for and manipulating electrostatic charge.

Abstract:

The electrostatic charge on aerosols influences behaviour on both macro and micro scales, and have been identified as important factors ina wide variety of research areas, such as:outdoorand indoor air pollution; filtration; terrestrial and extra-terrestrial weather; material synthesis and processing; drug delivery to the lungs; bioactivity; and forensics. Understanding how charge is distributed across different aerosol sizes and compositions, and how aerosols obtain this charge distribution could therefore lead to improvements in these areas, i.e. more efficient pollution control technologies; more accurate weather predictions; identifying atmospheric compositions; the manufacture of new materials; more effective medicines and treatments; and more reliable criminal evidence.

Measurements of charge distributions of aerosols therefore have a wide and varied application and have the potential to aid the development of many areas of research. Charge characterisation measurement techniques are in their infancy, where thorough measurements are slow and expensive. Faster and cheaper measurements would enabledifferent research groups to conduct measurements to develop their fields.

This proposal starts with examining why indoor air quality is important to understand, what constituents are typically found in indoor air with a prime focus on domestic air in western countries, and what we know about how charge affects these constituents. There is a brief review on measurement techniques of electrical charge on aerosols and their measurement capabilities. Finally, a novel approach to measuring charge distributions more quickly than currently possible is proposed and some possible challenges addressed.