title: Virus inactivation in aluminum and polyaluminum coagulation.
abstract: Inorganic aluminum salts, such as aluminum sulfate, are coagulants that cause small particles, such as bacteria and viruses as well as inorganic particles, to destabilize and combine into larger aggregates. In this investigation, batch coagulation treatments of water samples spiked with Qbeta, MS2, T4, and P1 viruses were conducted with four different aluminum coagulants. The total infectious virus concentration in the suspension of floc particles that eventually formed by dosing with coagulant was measured after the floc particles were dissolved by raising the pH with an alkaline beef extract solution. The virus concentrations were extremely reduced after the water samples were dosed with aluminum coagulants. Viruses mixed with and adsorbed onto preformed aluminum hydroxide floc were, however, completely recovered after the floc dissolution. These results indicated that the aluminum coagulation process inactivates viruses. Virucidal activity was most prominent with the prehydrolyzed aluminum salt coagulant, polyaluminum chloride (PACl). Virucidal activity was lower in river water than in ultrapure water--natural organic matter in the river water depressed the virucidal activity. Mechanisms and kinetics of the virus inactivation were discussed. Our results suggest that intermediate polymers formed during hydrolysis of the aluminum coagulants sorbed strongly to viruses, either rendering them inactive or preventing infectivity.
authors.affiliation: Department of Civil Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. y-matsui@cc.gifu-u.ac.jp
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Matsui
authors.forename: Taku
authors.initials: T
authors.lastname: Matsushita
authors.forename: Satoru
authors.initials: S
authors.lastname: Sakuma
authors.forename: Takahito
authors.initials: T
authors.lastname: Gojo
authors.forename: Teppei
authors.initials: T
authors.lastname: Mamiya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuoki
authors.forename: Takanobu
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000327:Adsorption; D000534:Alum Compounds / Q000737:chemistry; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000737:chemistry*; D000536:Aluminum Hydroxide / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D005427:Flocculation; D007700:Kinetics; D013997:Time Factors; D014780:Viruses / Q000302:isolation & purification*; D014871:Water Microbiology / Q000592:standards*; D018508:Water Purification / Q000379:methods*
chemical_list: D000534:Alum Compounds; D017607:Aluminum Compounds; D002712:Chlorides; C016213:aluminum oxychloride; C041524:aluminum sulfate; D000077410:Aluminum Chloride; D000536:Aluminum Hydroxide