title: As(V)/Cr(VI) pollution control in soils, hemp waste, and other by-products: competitive sorption trials.
abstract: We study As(V)/Cr(VI) competitive sorption on a forest soil, a vineyard soil, pyritic material, mussel shell, pine bark, oak ash, and hemp waste, adding variable As(V) and Cr(VI) concentrations or displacing each pollutant with the same concentration of the other. When using variable concentrations, As(V) showed more affinity than Cr(VI) for sorption sites on most materials (sorption up to >84 % on oak ash and pyritic material). The only exception was pine bark, with clearly higher Cr(VI) sorption (>90 %) for any Cr(VI)/As(V) concentration added. Regarding the displacement experiments, when As(V) was added and reached sorption equilibrium, the subsequent addition of equal Cr(VI) concentration did not cause relevant As displacement from oak ash and pyritic material, indicating strong As bindings, and/or low competitive effects. When Cr(VI) was added and reached sorption equilibrium, the subsequent addition of equal As(V) concentration caused Cr(VI) displacement from all materials except pine bark, indicating weak Cr bindings. In view of these results, oak ash and the pyritic material could be used to remove As(V) in concentrations as high as 6 mmol L(-1), even in the presence of a wide range of Cr(VI) concentrations, whereas pine bark could be used to remove Cr(VI) concentrations as high as 6 mmol L(-1). The other materials assayed (including hemp waste, studied for the first time as As(V) and Cr(VI) bio-sorbent) cannot be considered appropriate to remove As(V) and/or Cr(VI) from polluted media.
authors.affiliation: Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, University of Santiago de Compostela, Lugo, 27002, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Quintáns-Fondo
authors.affiliation: State University of West Paraná, Center for Agricultural Sciences, Marechal Cândido Rondon, Paraná, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Ferreira-Coelho
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Sciences, Campus Ourense, University of Vigo, Ourense, 32004, Spain.
authors.forename: Remigio
authors.initials: R
authors.lastname: Paradelo-Núñez
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Sciences, Campus Ourense, University of Vigo, Ourense, 32004, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Nóvoa-Muñoz
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Sciences, Campus Ourense, University of Vigo, Ourense, 32004, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Arias-Estévez
authors.affiliation: Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, University of Santiago de Compostela, Lugo, 27002, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Fernández-Sanjurjo
authors.affiliation: Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, University of Santiago de Compostela, Lugo, 27002, Spain.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Álvarez-Rodríguez
authors.affiliation: Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, University of Santiago de Compostela, Lugo, 27002, Spain. avelino.nunez@usc.es.
authors.forename: Avelino
authors.identifier: http://orcid.org/0000-0001-5373-1606
authors.initials: A
authors.lastname: Núñez-Delgado
mesh_terms: D000327:Adsorption; D000818:Animals; D001151:Arsenic / Q000032:analysis / Q000737:chemistry*; D049872:Bivalvia; D002188:Cannabis; D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring; D004787:Environmental Pollution; D065928:Forests; D028223:Pinus; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis; D014866:Waste Products / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014866:Waste Products; D002857:Chromium; C074702:chromium hexavalent ion; D001151:Arsenic
keywords: Competitive As(V)/Cr(VI) sorption; Hemp waste; Mussel shell; Oak ash; Pine bark; Pyritic material