From Microbubbles to Nanobubbles: Effect on Flotation

George Z Kyzas,Kostas A Matis,Athanasios C Mitropoulos

doi:10.3390/pr9081287

George Z Kyzas, Kostas A Matis + Show 1 more

Open Access

https://doi.org/10.3390/pr9081287

Copy DOI

Abstract

Attachment of particles and droplets to bubbles—the latter being of various fine sizes and created by different techniques (as described in detail)—forms the basis of flotation, a process which indeed was originated from mineral processing. Nevertheless, chemistry often plays a significant role in this area, in order for separation to be effective, as stressed. This (brief) review particularly discusses wastewater treatment applications and the effect of bubble size (from nano- to micro-) on the flotation process.

Highlights

Attachment of particles and droplets to bubbles—the latter being of various fine sizes and created by different techniques—forms the basis of flotation, a process which was originated from mineral processing
“Particle” attachment to air bubbles is the basis of the flotation process
Solutions containing low concentrations of heavy metal could be produced from any industrial processes and it is important to remove these ions from aqueous solution due to environmental regulations [6,7]

Summary

Flotation—Introduction

Flotation, depending on the method used to generate the bubbles, is classified as follows: dispersed-air flotation (DispAF), dissolved-air flotation (DAF), and electroflotation [2,3,4]. “Particle” attachment to air bubbles is the basis of the flotation process These flotation applications mainly include the treatment of wastewater, and bacteria, coal, clays, corn, resins, proteins, fats, rubber, dyes, glass, plastics, fruit juices, cane sugar, etc. Solutions containing low concentrations of heavy metal could be produced from any industrial processes and it is important to remove these ions from aqueous solution due to environmental regulations [6,7] For many of these applications, the process is best carried out by the dissolved-air generation method, rather than the dispersed-air one (typically in machines/cells or columns) used for minerals.

Fundamentals

Zeta-potential

Wastewater Treatment

Findings

Nanobubbles