title: Effect of a new regeneration process by adsorption-coagulation and flocculation on the physicochemical properties and the detergent efficiency of regenerated cleaning solutions.
abstract: Reprocessing soiled cleaning-in-place (CIP) solutions has large economic and environmental costs, and it would be cheaper and greener to recycle them. In food industries, recycling of CIP solutions requires a suitable green process engineered to take into account the extreme physicochemical conditions of cleaning while not altering the process efficiency. To this end, an innovative treatment process combining adsorption-coagulation with flocculation was tested on multiple recycling of acid and basic cleaning solutions. In-depth analysis of time-course evolutions was carried out in the physicochemical properties (concentration, surface tension, viscosity, COD, total nitrogen) of these solutions over the course of successive regenerations. Cleaning and disinfection efficiencies were assessed based on both microbiological analyses and organic matter detachment and solubilization from fouled stainless steel surfaces. Microbiological analyses using a resistant bacterial strain (Bacillus subtilis spores) highlighted that solutions regenerated up to 20 times maintained the same bactericidal efficiency as de novo NaOH solutions. The cleanability of stainless steel surfaces showed that regenerated solutions allow better surface wettability, which goes to explain the improved detachment and solubilization found on different types of organic and inorganic fouling.
authors.affiliation: Université de Nantes, CNRS, GEPEA, UMR 6144, CRTT, 37 Boulevard de l'Université, BP 406, 44602 Saint-Nazaire Cedex, France. Electronic address: Walid.Blel@univ-nantes.fr.
authors.forename: Walid
authors.initials: W
authors.lastname: Blel
authors.affiliation: Elodys International, Allée du Lac Bleu ZI Carrières Beurrières, 49240 Avrillé, France; Université de Bretagne-Sud, LIMAT B (EA4250), Allée des Pommiers, 56300 Pontivy, France.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Dif
authors.affiliation: Université de Bretagne-Sud, LIMAT B (EA4250), Allée des Pommiers, 56300 Pontivy, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Sire
mesh_terms: D000327:Adsorption; D000818:Animals; D001412:Bacillus subtilis / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D003611:Dairy Products; D003612:Dairying; D003902:Detergents / Q000737:chemistry*; D004202:Disinfectants / Q000494:pharmacology*; D004866:Equipment Contamination; D005427:Flocculation; D005516:Food Microbiology; D006801:Humans; D012972:Sodium Hydroxide / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000187:drug effects; D013193:Stainless Steel
chemical_list: D003902:Detergents; D004202:Disinfectants; D013193:Stainless Steel; D012972:Sodium Hydroxide
keywords: Adsorption; Caustic soda; Cleaning-in-place; Green chemistry; Nitric acid; Regeneration