Study On Bubble Adsorption Characteristics Of Electric Field:Based On Molecular Simulations

Air flotation is widely used in the field of oily wastewater treatment and mineral flotation.It is an efficient way to separate water pollutants and hydrophobic solid particles.In order to further improve the separation efficiency of air flotation,the combination of external electric field and air flotation technology provides a new idea.Some scholars have proved that the external electric field can promote the separation efficiency of air flotation,but its mechanism and influencing factors are still not clear.Therefore,the molecular dynamics simulation was performed to investigate gas-liquid interface properties of bubbles,the changes in the shape of the bubbles and the changes in the properties of hydrophobic surfaces in the salt solution when there is an external electric field applied.The effect mechanism of the external electric field on the adsorption of air bubbles in the air floatation process was studied from the micro level,which may provide useful guidance for the combination of electric field and air flotation technology.The main research contents of this paper are listed below:To investigate the effect of an external electric field on the gas-liquid interface of bubbles during the separation of toluene by air flotation.The molecular dynamics simulation was used to study the angle between the dipole moment of the water molecules and the normal phase of the gas phase of the bubble,the viscosity of the liquid phase under an external electric field,the surface tension of the bubble,and the probability of hydrogen bonding at the interface.The above parameters were used to represent the bubble Adsorption capacity for oil pollutants.To investigate the effect of the applied electric field on the micro-nano bubbles adsorbed on the surface of hydrophobic particles during air flotation.Molecular dynamics simulations were used to study the bubble size,gas diffusion coefficient,viscosity of the system,and hydrogen bonding characteristics of water molecules in the system.The above parameters were used to characterize the effect of the applied electric field on the adsorption characteristics of micro-nano bubbles on the surface of hydrophobic particles.Based on the above research,the purpose of this study was to investigate the effect of an external electric field on the surface properties of hydrophobic particles during air flotation in a salt solution environment.Through molecular dynamics simulation,the thickness change of the hydrophobic layer and the radial distribution of graphene-CO₂,which symbolize the attractiveness of the hydrophobic surface to the micro-nano bubbles.The coordination number and the residence time of water moleculesthe in first layer of Na⁺,which has a major impact on the thickness of the hydrophobic layer were studied.