title: Utilisation of chemically stabilized arsenic-contaminated soil in a landfill cover.
abstract: The aim of the study was to determine if an As-contaminated soil, stabilized using zerovalent iron (Fe(0)) and its combination with gypsum waste, coal fly ash, peat, or sewage sludge, could be used as a construction material at the top layer of the landfill cover. A reproduction of 2 m thick protection/vegetation layer of a landfill cover using a column setup was used to determine the ability of the amendments to reduce As solubility and stimulate soil functionality along the soil profile. Soil amendment with Fe(0) was highly efficient in reducing As in soil porewater reaching 99 % reduction, but only at the soil surface. In the deeper soil layers (below 0.5 m), the Fe treatment had a reverse effect, As solubility increased dramatically exceeding that of the untreated soil or any other treatment by one to two orders of magnitude. A slight bioluminescence inhibition of Vibrio fischeri was detected in the Fe(0) treatment. Soil amendment with iron and peat showed no toxicity to bacteria and was the most efficient in reducing dissolved As in soil porewater throughout the 2 m soil profile followed by iron and gypsum treatment, most likely resulting from a low soil density and a good air diffusion to the soil. The least suitable combination of soil amendments for As immobilization was a mixture of iron with coal fly ash. An increase in all measured enzyme activities was observed in all treatments, particularly those receiving organic matter. For As to be stable in soil, a combination of amendments that can keep the soil porous and ensure the air diffusion through the entire soil layer of the landfill cover is required.
authors.affiliation: Waste Science and Technology, Luleå University of Technology, 971 87, Luleå, Sweden, juku@ltu.se.
authors.forename: Jurate
authors.initials: J
authors.lastname: Kumpiene
authors.forename: Paolo
authors.initials: P
authors.lastname: Desogus
authors.forename: Sven
authors.initials: S
authors.lastname: Schulenburg
authors.forename: Mariarita
authors.initials: M
authors.lastname: Arenella
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Renella
authors.forename: Evelina
authors.initials: E
authors.lastname: Brännvall
authors.forename: Anders
authors.initials: A
authors.lastname: Lagerkvist
authors.forename: Lale
authors.initials: L
authors.lastname: Andreas
authors.forename: Rolf
authors.initials: R
authors.lastname: Sjöblom
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D060729:Coal Ash / Q000737:chemistry; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation / Q000379:methods; D007220:Industrial Waste; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D064091:Waste Disposal Facilities
chemical_list: D060729:Coal Ash; D007220:Industrial Waste; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic