Probing young drinking water biofilms with hard and soft particles.
The aim of our study was to investigate, through the use of soft (Escherichia coli) and hard (polystyrene microspheres) particles, the distribution and persistence of allochthonous particles inoculated in drinking water flow chambers. Biofilms were allowed to grow for 7-10 months in tap water from Nancy's drinking water network and were composed of bacterial aggregates and filamentous fungi. Both model particles adhered almost exclusively on the biofilms (i.e. on the bacterial aggregates and on the filamentous structures) and not directly on the uncolonized walls (glass or Plexiglas). Biofilm age (i.e. bacterial density and biofilm properties) and convective-diffusion were found to govern particle accumulation: older biofilms and higher wall shear rates both increased the velocity and the amount of particle deposition on the biofilm. Persistence of the polystyrene particles was measured over a two-month period after inoculation. Accumulation amounts were found to be very different between hard and soft particles as only 0.03 per thousand of the soft particles inoculated accumulated in the biofilm against 0.3-0.8% for hard particles.
Paris
Tony
T
Laboratoire d'Energétique et de Mécanique Théorique et Appliquée (LEMTA), UMR 7563, Nancy-University, CNRS, 2 avenue de la Forêt de Haye, BP 160, 54504 Vandoeuvre-lès-Nancy, France.
Skali-Lami
Salaheddine
S
Block
Jean-Claude
JC
D018441:Biofilms / Q000254:growth & development*; D004926:Escherichia coli / Q000166:cytology / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006244:Hardness; D008863:Microspheres; D011137:Polystyrenes / Q000378:metabolism*; D033081:Shear Strength; D013997:Time Factors; D014881:Water Supply
D011137:Polystyrenes; D049452:Green Fluorescent Proteins