Resuspension is a process where deposited particles become airborne through entraining and then suspending in air. The high particle concentration can have adverse effect on health such as respiratory disease. Understanding the resuspension process can benefit the mitigation of particle concentration. In addition, the resuspension process can be found in many industrial applications. In this study, resuspension of solid particle and liquid droplet from a dusty surface is investigated, this is because dust is ubiquitous in our daily lives and it favors the resuspension process. To understand the resuspension from dusty surfaces, it is essential to study the properties of surface dust. The characterization of the dust deposit for different dust loadings and particle sizes were fi...[ Read more ]

Resuspension is a process where deposited particles become airborne through entraining and then suspending in air. The high particle concentration can have adverse effect on health such as respiratory disease. Understanding the resuspension process can benefit the mitigation of particle concentration. In addition, the resuspension process can be found in many industrial applications. In this study, resuspension of solid particle and liquid droplet from a dusty surface is investigated, this is because dust is ubiquitous in our daily lives and it favors the resuspension process. To understand the resuspension from dusty surfaces, it is essential to study the properties of surface dust. The characterization of the dust deposit for different dust loadings and particle sizes were first investigated. The mean and root-mean-square of the surface roughness were the characteristics of the dust deposit and the mean of the surface roughness was used to determine the type of deposit, such as monolayer, intermediate, and multilayer. After the classification of the deposit type, the solid particle resuspension from the dusty surface in a wind tunnel was studied. First, for a 2 g/m² dust loading surface, the dust particles resuspended significantly with increasing friction velocity compared to other dust loadings. With respect to particle resuspension, the remaining fraction decreased substantially with increasing dust loading. A log-normal adhesion force was utilized to analyse the experimental result. The detachment of glycerol droplet with different dust loadings was also investigated experimentally in the wind tunnel. It was found that the critical friction velocity of 0 g/m² dust loading was greater than the critical friction velocity of the surfaces with dust particles. The dust particles enable the resuspension process takes place more easily. Understanding the resuspension process can help to reduce indoor aerosol concentration and enhance the performance of industrial applications.