title: Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions.
abstract: Shredded card (SC) was assessed for use as a sorbent of potentially toxic elements (PTE) carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water). We further assessed SC for retention of PTE, using acidified water (pH 3.4). Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons) before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49) were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC). In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC). In water, only Pb showed high sorption (191x more Pb in leachate without SC). In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil), and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC). A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption). SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing.
authors.affiliation: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic.
authors.forename: Christopher
authors.initials: C
authors.lastname: Ash
authors.affiliation: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Drábek
authors.affiliation: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Tejnecký
authors.affiliation: Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Jehlička
authors.affiliation: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic.
authors.forename: Ninon
authors.initials: N
authors.lastname: Michon
authors.affiliation: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic.
authors.forename: Luboš
authors.initials: L
authors.lastname: Borůvka
mesh_terms: D001151:Arsenic / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000517:prevention & control; D005374:Filtration / Q000379:methods*; D007854:Lead / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry; D009930:Organic Chemicals; D012989:Soil Pollutants / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry*
chemical_list: D019216:Metals, Heavy; D009930:Organic Chemicals; D012989:Soil Pollutants; D012996:Solutions; D002104:Cadmium; D007854:Lead; D001151:Arsenic