Water-to-air transfer of nano/micro-sized particulates: enrichment effect in bubble bursting jet drops

TL;DR

This study investigates how nano/micro-sized particles are enriched in jet drops during bubble bursting, revealing hydrodynamic mechanisms and proposing scaling laws to predict enrichment factors, with implications for climate and health.

Contribution

It provides the first detailed experimental analysis of particle enrichment in bubble bursting jet drops and introduces scaling laws for predicting enrichment factors.

Findings

Enrichment of particles is significantly influenced by bubble dynamics.

Scaling laws accurately predict enrichment factors across different conditions.

Hydrodynamic mechanisms like bubble scavenge and bursting govern particle transport.

Abstract

Bubbles dispersed in liquids are widely present in many natural and industrial processes, and play a key role in mediating mass transfer during their lifetime from formation to rising to bursting. In particular, nano/micro-sized particulates and organisms, present in the bulk water can be highly enriched in the jet drops ejected during bubble bursting, impacting global climate and public health. However, the detailed mechanism of this enrichment remains obscure, with the enrichment factor being difficult to predict. Here, we experimentally investigate the enrichment of nano/micro-sized particles in bubble bursting jet drops and highlight the underlying hydrodynamic mechanism, combining the effects of bubble scavenge and bursting on the transport of particles. Scaling laws for the enrichment factor are subsequently proposed that describe both our and prior experimental results reasonably well. Our study may provide new insights for water-to-air transfer of microbes related to bubble bursting.