title: Influence of Phytoplankton on Fate and Effects of Modified Zerovalent Iron Nanoparticles.
abstract: Nanoscale zerovalent iron (nZVI) and its derivatives hold promise for remediation of several pollutants but their environmental implications are not completely clear. In this study, the physicochemical properties and aggregation kinetics of sulfide/silica-modified nZVI (FeSSi) were compared in algal media in which Chlamydomonas reinhardtii had been cultured for 1, 2, or 11 days in order to elicit the effects of organic matter produced by the freshwater algae. Furthermore, transformation of FeSSi particles were investigated in C. reinhardtii cultures in exponential (1-d) and slowing growth (11-d) phases while monitoring the response of algae. We found evidence for steric stabilization of FeSSi by algal organic matter, which led to a decrease in the particles' attachment efficiency. Transformation of FeSSi was slower in 11-d cultures as determined via inductively coupled plasma and X-ray analyses. High concentrations of FeSSi caused a lag in algal growth, and reduction in steady state population size, especially in cultures in exponential phase. The different outcomes are well described by a dynamic model describing algal growth, organic carbon production, and FeSSi transformations. This study shows that feedback from algae may play important roles in the environmental implications of engineered nanomaterials.
authors.affiliation: Bren School of Environmental Science & Management, University of California , Santa Barbara, California 93106-5131, United States.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106-5131, United States.
authors.forename: Adeyemi S
authors.initials: AS
authors.lastname: Adeleye
authors.affiliation: Department of Ecology, Evolution and Marine Biology, University of California , Santa Barbara, California 93106-5131, United States.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106-5131, United States.
authors.forename: Louise M
authors.initials: LM
authors.lastname: Stevenson
authors.affiliation: Bren School of Environmental Science & Management, University of California , Santa Barbara, California 93106-5131, United States.|State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai 200092, China.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106-5131, United States.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Su
authors.affiliation: Department of Ecology, Evolution and Marine Biology, University of California , Santa Barbara, California 93106-5131, United States.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106-5131, United States.
authors.forename: Roger M
authors.initials: RM
authors.lastname: Nisbet
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai 200092, China.
authors.forename: Yalei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Bren School of Environmental Science & Management, University of California , Santa Barbara, California 93106-5131, United States.|University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, California 93106-5131, United States.
authors.forename: Arturo A
authors.initials: AA
authors.lastname: Keller
mesh_terms: D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry; D010839:Phytoplankton; D013440:Sulfides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D013440:Sulfides; D014874:Water Pollutants, Chemical; D007501:Iron