Removal of Bacillus spores from stainless steel pipes by flow foam: Effect of the foam quality and velocity

Decontamination of Spores on Model Stainless-Steel Surface by Using Foams Based on Alkyl Polyglucosides

“…Based on the effect shown of SDS on spore removal under static conditions, we suppose that the effect of the SDS foam flow could be a combination of foam flow and/or SDS chemical action on spore surface proteins. It is important to point out also that in our previous studies, the foams based on SDS always had a stronger effect on the spores’ removal than the surfactant solution whatever the foam properties in terms of bubbles size and foam flow velocity [ 9 , 10 , 11 ].…”

“…The foam production device used in this study was the same as those used in previous works [ 9 , 10 ]. In brief, first, the surfactants were dissolved in osmotic water in the inlet tank of the foam production device.…”

“…Almost twenty years ago, foam circulation through pipes was described in the literature to be very efficient for radioactive surface decontamination of solid surfaces, because the amounts of chemicals involved and the volume of radioactive waste produced were much lower than with other processes [ 8 ]. Thus, one strategy described recently in the literature is the use of foam flows for cleaning in the food industry [ 9 , 10 , 11 ]. Due to foam wall friction and specific foam rheology properties in terms of viscous stress, foam bubbles could remove efficiently spores and biofilms [ 12 , 13 , 14 ].…”

“…In addition, foams enable the drastic reduction in the amount of water used because foams are mainly composed of air bubbles [ 15 ]. Therefore, the use of foams could have a direct positive impact on the environmental footprint of the cleaning process [ 9 , 10 , 11 ]. These first studies were based on the use of sodium dodecyl sulfate (SDS) as a surfactant at a concentration well below the CMC, leading to unstable foam [ 9 , 10 , 11 ].…”

“…Therefore, the use of foams could have a direct positive impact on the environmental footprint of the cleaning process [ 9 , 10 , 11 ]. These first studies were based on the use of sodium dodecyl sulfate (SDS) as a surfactant at a concentration well below the CMC, leading to unstable foam [ 9 , 10 , 11 ]. The aim of this study was to show that a decrease in the environmental footprint of foam flow cleaning was possible through the use of alkyl polyglucosides surfactants (APGs).…”