Abstract
The current knowledge of bacterial migration is mainly derived from work using bare or Fe-coated quartz sands as porous media. However, mineral coatings on quartz by phyllosilicates and Al-oxides prevail in natural soils, and their effect on bacterial transport remains unknown. Herein, we systematically explored the transport of two bacterial pathogens (Escherichia coli and Staphylococcus aureus) through saturated bare quartz and those coated by kaolinite (KaoQuartz), montmorillonite (MontQuartz) or Al-oxides (AlQuartz) under various solution ionic strength (IS) and pH levels. Elevating IS or decreasing pH discouraged bacterial mobility in all cases, with one exception for the migration of S. aureus through AlQuartz at various IS levels. E. coli showed a higher mobility than S. aureus in all cases. All the three coatings, especially the Al-oxides inhibited bacterial transport through quartz. Overall, the two phyllosilicates-coated sands showed transport behaviors (mobility trends with IS, pH, and cell type) similar to those for the bare quartz which could be explained by the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. Nevertheless, for transport within AlQuartz, there were deviations between the observations and the DLVO predictions, probably because of the existence of non-DLVO forces such as hydrophobic and chemical interactions. More importantly, the bacterial retention was found to correlate well with the adhesion regardless of the solution condition and the bacteria and media type, thereby revealing a central role of adhesion in mediating migration through mineral-coated sands. These findings highlight the significance of mineral coating and adhesion in pathogen dissemination in natural soils.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.