title: In Situ Fixation of Metal(loid)s in Contaminated Soils: A Comparison of Conventional, Opportunistic, and Engineered Soil Amendments.
abstract: This study aimed to assess and compare the in vitro and in vivo bioaccessibility/bioavailability of As and Pb in a mining contaminated soil (As, 2267 mg kg(-1); Pb, 1126 mg kg(-1)), after the addition of conventional (phosphoric acid), opportunistic [water treatment residues (WTRs)], and engineered [nano- and microscale zero valent iron (ZVI)] amendments. Phosphoric acid was the only amendment that could significantly decrease Pb bioaccessibility with respect to untreated soil (41 and 47% in the gastric phase and 2.1 and 8.1% in the intestinal phases, respectively), giving treatment effect ratios (TERs, the bioaccessibility in the amended soil divided by the bioaccessibility in the untreated soil) of 0.25 and 0.87 in the gastric and intestinal phase, respectively. The in vivo bioavailability of Pb decreased in the phosphate treatment relative to the untreated soil (6 and 24%, respectively), and also in the Fe WTR 2% (12%) and nZVI-2 (13%) treatments. The ZVI amendments caused a decrease in As bioaccessibility, with the greatest decrease in the nZVI2-treated soil (TERs of 0.59 and 0.64 in the gastric and intestinal phases, respectively). Arsenic X-ray absorption near-edge spectroscopy analysis indicated that most of the As in the untreated soil was present as As(V) associated with Fe mineral phases, whereas in the treated soil, the proportion of arsenosiderite increased. Arsenite was present only as a minor species (3-5%) in the treated soils, with the exception of an nZVI treatment [∼14% of As(III)], suggesting a partial reduction of As(V) to As(III) caused by nZVI oxidation.
authors.affiliation: Dipartimento di Agraria, Sezione di Scienze e Tecnologie Ambientali e Alimentari, University of Sassari , Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Mele
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia , Building X, Mawson Lakes Campus, Adelaide, South Australia 5095, Australia.|Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) , P.O. Box 486, Salisbury, South Australia 5106, Australia.
authors.forename: Erica
authors.initials: E
authors.lastname: Donner
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia , Building X, Mawson Lakes Campus, Adelaide, South Australia 5095, Australia.|Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) , P.O. Box 486, Salisbury, South Australia 5106, Australia.
authors.forename: Albert L
authors.initials: AL
authors.lastname: Juhasz
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia , Building X, Mawson Lakes Campus, Adelaide, South Australia 5095, Australia.|Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) , P.O. Box 486, Salisbury, South Australia 5106, Australia.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Brunetti
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia , Building X, Mawson Lakes Campus, Adelaide, South Australia 5095, Australia.|Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) , P.O. Box 486, Salisbury, South Australia 5106, Australia.
authors.forename: Euan
authors.initials: E
authors.lastname: Smith
authors.affiliation: Office of Research and Development, National Risk Management Research Laboratory, United States Environmental Protection Agency , 26 West Martin Luther King Drive, Cincinnati, Ohio 45268, United States.|Oak Ridge Institute for Science and Education , P.O. Box 117, Oak Ridge, Tennessee 37831, United States.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Betts
authors.affiliation: Dipartimento di Agraria, Sezione di Scienze e Tecnologie Ambientali e Alimentari, University of Sassari , Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Castaldi
authors.affiliation: Dipartimento di Agraria, Sezione di Scienze e Tecnologie Ambientali e Alimentari, University of Sassari , Viale Italia 39, 07100 Sassari, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Deiana
authors.affiliation: National Risk Management Research Laboratory, United States Environmental Protection Agency , 5995 Centre Hill Avenue, Cincinnati, Ohio 45224, United States.
authors.forename: Kirk G
authors.initials: KG
authors.lastname: Scheckel
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia , Building X, Mawson Lakes Campus, Adelaide, South Australia 5095, Australia.
authors.forename: Enzo
authors.initials: E
authors.lastname: Lombi
mesh_terms: D000818:Animals; D001151:Arsenic / Q000032:analysis / Q000493:pharmacokinetics*; D001682:Biological Availability; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007501:Iron / Q000737:chemistry / Q000493:pharmacokinetics; D007558:Italy; D007854:Lead / Q000032:analysis / Q000493:pharmacokinetics*; D008297:Male; D008807:Mice, Inbred BALB C; D008903:Minerals / Q000737:chemistry; D008906:Mining; D010710:Phosphates / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000493:pharmacokinetics*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D008903:Minerals; D010710:Phosphates; D012987:Soil; D012989:Soil Pollutants; D007854:Lead; D007501:Iron; D001151:Arsenic