title: Microbial removals by a novel biofilter water treatment system.
abstract: Two point-of-use drinking water treatment systems designed using a carbon filter and foam material as a possible alternative to traditional biosand systems were evaluated for removal of bacteria, protozoa, and viruses. Two configurations were tested: the foam material was positioned vertically around the carbon filter in the sleeve unit or horizontally in the disk unit. The filtration systems were challenged with Cryptosporidium parvum, Raoultella terrigena, and bacteriophages P22 and MS2 before and after biofilm development to determine average log reduction (ALR) for each organism and the role of the biofilm. There was no significant difference in performance between the two designs, and both designs showed significant levels of removal (at least 4 log10 reduction in viruses, 6 log10 for protozoa, and 8 log10 for bacteria). Removal levels meet or exceeded Environmental Protection Agency (EPA) standards for microbial purifiers. Exploratory test results suggested that mature biofilm formation contributed 1-2 log10 reductions. Future work is recommended to determine field viability.
authors.forename: Christopher
authors.initials: C
authors.lastname: Wendt
authors.forename: Rebecca
authors.initials: R
authors.lastname: Ives
authors.forename: Anne L
authors.initials: AL
authors.lastname: Hoyt
authors.forename: Ken E
authors.initials: KE
authors.lastname: Conrad
authors.forename: Stephanie
authors.initials: S
authors.lastname: Longstaff
authors.forename: Roy W
authors.initials: RW
authors.lastname: Kuennen
authors.forename: Joan B
authors.initials: JB
authors.lastname: Rose
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D001435:Bacteriophages / Q000302:isolation & purification; D018441:Biofilms; D002244:Carbon / Q000737:chemistry*; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D004755:Enterobacteriaceae / Q000302:isolation & purification; D005374:Filtration / Q000295:instrumentation*; D014780:Viruses / Q000302:isolation & purification*; D014871:Water Microbiology; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D002244:Carbon