title: Alternating electric fields combined with activated carbon for disinfection of Gram negative and Gram positive bacteria in fluidized bed electrode system.
abstract: Strong electric fields for disinfection of wastewaters have been employed already for several decades. An innovative approach combining low strength (7 V/cm) alternating electric fields with a granular activated carbon fluidized bed electrode (FBE) for disinfection was presented recently. For disinfection performance of FBE several pure microbial cultures were tested: Bacillus subtilis, Bacillus subtilis subsp. subtilis, Enterococcus faecalis as representatives from Gram positive bacteria and Erwinia carotovora, Pseudomonas luteola, Pseudomonas fluorescens and Escherichia coli YMc10 as representatives from Gram negative bacteria. The alternating electric field amplitude and shape were kept constant. Only the effect of alternating electric field frequency on disinfection performance was investigated. From the bacteria tested, the Gram negative strains were more susceptible and the Gram positive microorganisms were more resistant to FBE disinfection. The collected data indicate that the efficiency of disinfection is frequency and strain dependent. During 6 h of disinfection, the decrease above 2 Log units was achieved with P. luteola and E. coli at 10 kHz and at dual frequency shift keying (FSK) modulated signal with frequencies of 10 kHz and 140 kHz. FBE technology appears to offer a new way for selective bacterial disinfection, however further optimizations are needed on treatment duration, and energy input, to improve effectiveness.
authors.affiliation: Wetsus, Centre of Excellence for Sustainable Water Technology, Agora 1, P.O. Box 1113, 8900 CC Leeuwarden, The Netherlands; Sub-Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands. Electronic address: justina.racyte@wur.nl.
authors.forename: Justina
authors.initials: J
authors.lastname: Racyte
authors.forename: Séverine
authors.initials: S
authors.lastname: Bernard
authors.forename: Astrid H
authors.initials: AH
authors.lastname: Paulitsch-Fuchs
authors.forename: Doekle R
authors.initials: DR
authors.lastname: Yntema
authors.forename: Harry
authors.initials: H
authors.lastname: Bruning
authors.forename: Huub H M
authors.initials: HH
authors.lastname: Rijnaarts
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002606:Charcoal / Q000494:pharmacology*; D055590:Electromagnetic Phenomena; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000528:radiation effects; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D002606:Charcoal
keywords: Alternating electric field; Disinfection; Frequency; Gram negative bacteria; Gram positive bacteria; Granular activated carbon