title: Disinfection of ballast water with iron activated persulfate.
abstract: The treatment of ballast water carried onboard ships is critical to reduce the spread of nonindigenous aquatic organisms that potentially include noxious and harmful taxa. We tested the efficacy of persulfate (peroxydisulfate, S2O8(2-), PS) activated with zerovalent iron (Fe(0)) as a chemical biocide against two taxa of marine phytoplankton grown in bench-scale, batch cultures: the diatom, Pseudonitzshia delicatissima and the green alga, Dunaliella tertiolecta . After testing a range of PS concentrations (0-4 mM activated PS) and exposure times (1-7 days), we determined that a dosage of 4 mM of activated PS was required to inactivate cells from both species, as indicated by reduced or halted growth and a reduction in photosynthetic performance. Longer exposure times were required to fully inactivate D. tertiolecta (7 days) compared to P. delicatissima (5 days). Under these conditions, no recovery was observed upon placing cells from the exposed cultures into fresh media lacking biocide. The results demonstrate that activated PS is an effective chemical biocide against species of marine phytoplankton. The lack of harmful byproducts produced during application makes PS an attractive alternative to other biocides currently in use for ballast water treatments and merits further testing at a larger scale.
authors.affiliation: Institute of Environmental Health, Division of Environmental and Biomolecular Systems, Oregon Health & Science University , 3181 SW Sam Jackson Park Road, Portland, Oregon 97239-3098, United States.
authors.forename: Samyoung
authors.initials: S
authors.lastname: Ahn
authors.forename: Tawnya D
authors.initials: TD
authors.lastname: Peterson
authors.forename: Jason
authors.initials: J
authors.lastname: Righter
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Miles
authors.forename: Paul G
authors.initials: PG
authors.lastname: Tratnyek
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D004203:Disinfection / Q000379:methods*; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D010839:Phytoplankton / Q000187:drug effects / Q000254:growth & development; D012767:Ships; D013431:Sulfates / Q000737:chemistry* / Q000494:pharmacology; D013997:Time Factors; D018508:Water Purification
chemical_list: D013431:Sulfates; D002734:Chlorophyll; D007501:Iron