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- Bertling, Sofia, et al.
(författare)
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Occurrence and fate of corrosion-induced zinc in runoff water from external structures
- 2006
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 367:2-3, s. 908-923
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Tidskriftsartikel (refereegranskat)abstract
- This paper comprises data from an extensive cross-disciplinary research project aiming to elucidate the environmental fate of corrosion-induced zinc release from external structures. It includes an exposure assessment that provide long-term runoff rates, concentrations and chemical speciation of zinc, from 14 zinc-based materials exposed during 5 years in Stockholm, Sweden, and an effect assessment including bioavailability and ecotoxicity measurements, both at the immediate release situation and after soil interaction.Runoff rates of total zinc ranged from 0.07 to 2.5g Znm(-2) yr(-1) with zinc primarily released as the free ion for all materials investigated. The average effect concentration, causing a 50% growth reduction after 72h to the green algae Raphidocelis subcapitata, was at the immediate release situation 69 mu g ZnL-1. Upon interaction of runoff water with soil, which simulated 18 to 34years of exposure, the total zinc concentration was significantly reduced, from milligram per litre to microgram per litre levels. Simultaneously, the most bioavailable fraction of zinc in runoff, the hydrated zinc(II)-ion, decreased from more than 95% to about 30%. The major fraction, 98-99%, of the introduced total zinc concentration in the runoff water was retained within the soil. As long as the soil retention capacity was not reached, this resulted in zinc concentrations in the percolate water transported through the soil layer, close to background values and below growth inhibition concentrations for the green algae investigated. Zinc retained in soil was to a large extent (85-99.9%) extractable with EDTA, and available for plant uptake after 5 to 7months of ageing.
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- Fröberg, M, et al.
(författare)
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Dissolved Organic Carbon Leaching from a Coniferous Forest Floor - A Field Manipulation Experiment
- 2005
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 1573-515X .- 0168-2563. ; 75:2, s. 271-287
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Tidskriftsartikel (refereegranskat)abstract
- Leaching of dissolved organic carbon (DOC) from the O layer is important for the carbon cycling of forest soils. Here we study the role of the Oi, Oe and Oa horizons in DOC leaching from the forest floor in field manipulations carried out in a Norway spruce forest stand in southern Sweden. The manipulations involved the addition and removal of litter and the removal of Oi, Oe and Oa horizons. Our data suggest that both recent litter and humified organic matter contribute significantly to the leaching of dissolved organic matter from the O layer. An addition of litter corresponding to four times annual litterfall resulted in a 35% increase in DOC concentrations and fluxes although the specific UV absorbance remained unchanged. The removal of litterfall and the Oi horizon resulted in a decreased DOC concentration and in a significant increase in the molar UV absorptivity. The DOC concentration under the Oa horizon was not significantly different from that under the Oe horizon and there were no increase in DOC flux, but rather a decrease, from the bottom of the Oe horizon to the bottom of the Oa horizon, suggesting that there is no net release of DOC in the Oa horizon. However, significant leaching of DOC occurred from the Oa horizon when litterfall and the Oi and Oe horizons were removed. This indicates that there is both a removal of DOC from the Oi and Oe horizons and a substantial production of DOC in the Oa horizon. Quantitatively, we suggest that the Oi, Oe and Oa horizons contributed approximately 20, 30 and 50%, respectively, to the overall leaching of DOC from the O layer.
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- Olsson, Susanna, et al.
(författare)
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Metal leaching from MSWI bottom ash as affected by salt or dissolved organic matter
- 2009
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 29:2, s. 506-512
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Tidskriftsartikel (refereegranskat)abstract
- In order to manage municipal solid waste incineration (MSWI) bottom ash safely, risk assessments, including the prediction of leaching under different field conditions, are necessary. In this study, the influence of salt or dissolved organic matter (DOM) in the influent on metal leaching from MSWI bottom ash was investigated in a column experiment. The presence of salt (0.1 M NaCI) resulted in a small increase of As leaching, whereas no impact on leachate concentration was found when lakewater DOM (35.1 mg/I dissolved organic carbon) was added. Most of the added DOM was retained within the material. Further, X-ray spectroscopy revealed that Cu(II) was the dominating form of Cu and that it probably Occurred as a CuO-type mineral. The CU2+ activity in the MSWI bottom ash leachate was most likely determined by the dissolution of CuO together with the formation of Cu-DOM complexes and possibly also by adsorption to (hydr)oxide minerals. The addition of lake DOM in the influent resulted in lower saturation indices for CuO in the leachates. which may be due to slow CuO dissolution kinetics in combination with strong Cu-DOM complexation.
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