title: Iron amendments to reduce bioaccessible arsenic.
abstract: Former sugarcane lands on the Island of Hawaii have elevated levels of soil arsenic (As) from historical use of arsenical pesticides. The bioaccessible fraction of total As (AsTOT), a measure of the potential for human As uptake by incidental ingestion of soil, is used in the assessment of human health risk and the determination of the need for remedial action. Ferric chloride plus lime and ferrous sulfate plus lime were applied to As-contaminated soils in a field plot setting to determine the potential for reducing in vitro bioaccessible As (AsIVBA) by increasing As sequestration by the formation of additional iron (Fe) oxyhydroxides. The two Fe sources performed similarly in reducing AsIVBA over a 2-year observation period, with 30-41% reduction in AsIVBA for 0.25wt% Fe dosing (dry soil basis) and 59-63% reduction for 0.5wt% Fe dosing. Addition of phosphate (PO4) to treated and untreated soils caused a significant increase in AsIVBA. Iron-treated and control soils showed more than twice the AsIVBA after the addition of 1500mgPkg(-1). The cost of in situ treatment of As-contaminated soil with ferrous sulfate plus lime to lower AsIVBA was estimated to be an order of magnitude less than excavation and landfill disposal on the Island of Hawaii, making the technology a viable alternative when remedial action objectives were based on AsIVBA levels.
authors.affiliation: Integral Consulting Inc., 285 Century Place, Suite 190, Louisville, CO 80027, USA; Department of Geology and Geophysics, University of Hawaii at Manoa, 1680 East-west Road, Honolulu, HI 96822, USA. Electronic address: wcutler@integral-corp.com.
authors.forename: William G
authors.initials: WG
authors.lastname: Cutler
authors.affiliation: Department of Geology and Geophysics, University of Hawaii at Manoa, 1680 East-west Road, Honolulu, HI 96822, USA. Electronic address: elkadi@hawaii.edu.
authors.forename: Aly
authors.initials: A
authors.lastname: El-Kadi
authors.affiliation: Department of Tropical Plant and Soil Sciences, University of Hawaii at Manoa, 3190 Maile Way, Honolulu, HI 96822, USA. Electronic address: nvhue@hawaii.edu.
authors.forename: Nguyen V
authors.initials: NV
authors.lastname: Hue
authors.affiliation: Hawaii Department of Health, 1582 Kamehameha Avenue, Hilo, HI 96720, USA. Electronic address: john.peard@doh.hawaii.gov.
authors.forename: John
authors.initials: J
authors.lastname: Peard
authors.affiliation: National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 5995 Center Hill Avenue, Cincinnati, OH 45224, USA. Electronic address: scheckel.kirk@epa.gov.
authors.forename: Kirk
authors.initials: K
authors.lastname: Scheckel
authors.affiliation: Robert B. Daugherty Water for Food Institute, University of Nebraska, 2200 Vine Street, Lincoln, NE 68583, USA. Electronic address: cray@nebraska.edu.
authors.forename: Chittaranjan
authors.initials: C
authors.lastname: Ray
mesh_terms: D000383:Agriculture; D001151:Arsenic / Q000737:chemistry*; D017610:Calcium Compounds; D002712:Chlorides / Q000737:chemistry; D004787:Environmental Pollution / Q000032:analysis*; D005290:Ferric Compounds / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D006254:Hawaii; D007501:Iron / Q000737:chemistry*; D010087:Oxides; D010710:Phosphates / Q000737:chemistry; D031786:Saccharum; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D017610:Calcium Compounds; D002712:Chlorides; D005290:Ferric Compounds; D005296:Ferrous Compounds; D010087:Oxides; D010710:Phosphates; D012989:Soil Pollutants; C020748:ferrous sulfate; C016538:lime; D007501:Iron; D001151:Arsenic; C024555:ferric chloride
keywords: Arsenic; Bioaccessibility; Hawaii; Iron amendments; Remediation