title: Phytofiltration of arsenic and cadmium by using an aquatic plant, Micranthemum umbrosum: phytotoxicity, uptake kinetics, and mechanism.
abstract: Arsenic (As) and cadmium (Cd) are noxious and carcinogenic pollutants that can be removed from water by using emerging, ecofriendly, phytofiltration technology that employs Micranthemum umbrosum. After culturing M. umbrosum for 7 days in a hydroponic experiment, accumulation of 1219±44.11 µg As g(-1) and 799.40±30.95 µg Cd g(-1) were observed in the leaves, from 1000 µg As L(-1) and 1000 µg Cd L(-1) of water, respectively. Plant and water samples were analyzed for assessing the As and Cd accumulations, translocations, phytotoxic effects, uptake mechanisms and kinetics, and for evaluating the potential of M. umbrosum in As and Cd phytofiltration. The uptake pattern was leaf>stem>root for both pollutants. The plant showed higher resistance to As than to that to Cd. Uptake of inorganic As species was much greater than that of organic As and was found at above the substrate concentration. However, Cd showed similar uptake pattern to that of inorganic As species, and the data was better fit to a non-linear than a linear model. Low molecular weight substances that have thiol group(s) may be responsible for the binding of As in plants whereas Cd showed a different mechanism to that of As. M. umbrosum showed good As phytofiltration capabilities without any phytotoxic effects, but it was found to be a moderate accumulator of Cd with some phytotoxic effect compare to some other previously studied plant.
authors.affiliation: Environmental Adaptation Science, Division of Environmental Science Development, Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
authors.forename: Md Shariful
authors.initials: MS
authors.lastname: Islam
authors.affiliation: Laboratory of Environmental Health Sciences, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saito
authors.affiliation: Environmental Adaptation Science, Division of Environmental Science Development, Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan; Group of Environmental Adaptation Science, Faculty of Environmental Earth Science, Hokkaido University, Kita 10 Nishi 5, Kita-ku, Sapporo 060-0810, Japan. Electronic address: kura@ees.hokudai.ac.jp.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kurasaki
mesh_terms: D001151:Arsenic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007700:Kinetics; D028083:Scrophulariaceae / Q000378:metabolism*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D001151:Arsenic; D002104:Cadmium; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Arsenic; Cadmium; Micranthemum umbrosum; Phytofiltration; Phytotoxic; Uptake