| 21. |
- Hynes, M.J., et al.
(författare)
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Element migration from glass compositions containing no added lead
- 2004
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 319:1, s. 39-52
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Tidskriftsartikel (refereegranskat)abstract
- Six crystal glass compositions without added lead were used to prepare standard beakers having a volume of ca. 240 ml. The experimentally determined concentrations of the elements in the glass beakers were in satisfactory agreement with the theoretically predicted values. The degree of leaching of selected elements from these beakers was determined using 4% acetic acid as described in the ISO 7086-1:2000 standard test. In addition, to the degree of leaching by 4% acetic acid, migration into cola, red wine, 40% ethanol and 0.3% citric acid was also determined. Elements tested included antimony, barium, bismuth and zinc as these were considered to be of most interest. The results show that it is possible to produce durable glass containing no added lead. The overall quality of the glasses was good and the concentrations of the various elements migrating (leaching) into the various test solutions used was very small and it is clear that they would not present a hazard to consumers in the event that they were to use glasses of any of these compositions for consumption of either alcoholic or non-alcoholic beverages. The original ISO7086-1:2000 test using a 4% acetic acid leaching solution was developed to test for lead migration from crystal containing added lead and ceramic ware containing lead glazes or colouring. This work also shows that it is an excellent leaching agent for assessing the safety of crystal containing no added lead as it gave the highest degree of migration for all the glass compositions and all the elements tested. In the case of glasses containing ZnO, it was shown that the degree of zinc migration was linearly related to the mole-% of ZnO in the glass. With respect to the durability of glasses, it was shown that the degree of attack increases when the degree of silica depolymerisation increases. © 2003 Elsevier B.V. All rights reserved.
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| 22. |
- Johansson, H., et al.
(författare)
-
Retention of conservative and sorptive solutes in streams - simultaneous tracer experiments
- 2001
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 266:03-jan, s. 229-238
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Tidskriftsartikel (refereegranskat)abstract
- The effective transport velocity of solutes in rivers and streams is governed by transient storage in hyporheic zones in which the longitudinal advection velocity is small relative to the main stream flow velocity. Results from a simultaneous tracer experiment using a non-reactive (tritium, (H2O)-H-3) and a sorptive tracer [chromium, Cr-51(III)] have formed the basis of a more accurate interpretation of the retention characteristics of solutes in streams than previously has been possible. By using a simultaneous injection of these two tracers, it was possible to distinguish between their different behaviours. Based on estimations of fluxes, the retained mass of chromium in the storage zones along the 30-km-long study-reach was 76% after 150 h. Independent observations in the bed sediment indicated that the loss of chromium observed in the water was mainly a result of uptake into the bed sediment. To describe the transport in the stream, a model concept including solute sorption kinetics in the bed sediment was proposed. Evaluation of parameters in the model, indicated that the uptake of chromium in the bed sediment is controlled by sorption kinetics.
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| 23. |
- Johansson, Inger, et al.
(författare)
-
Levels and patterns of polycyclic aromatic hydrocarbons in incineration ashes
- 2003
-
Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 311:1-3, s. 221-231
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Tidskriftsartikel (refereegranskat)abstract
- Polycyclic aromatic hydrocarbons were analysed in weathered bottom ash from municipal solid waste incineration, fly ash from a mixed heating plant and an ash mixture from different kinds of biofuels. Although of different origin and age, all three ashes are evaluated in different small-scale fill applications. The ultimate goal is the usage of these ashes on a larger scale. The samples were Soxhlet extracted and analysed using GC/MS in the full scan mode. The sum of the 16 US EPA PAHs was found to vary from 140 mug/kg up to more than 77 000 mug/kg. Total amounts of PAHs were similar in bottom ash and in fly ash. The concentration in the mixed biofuel ash was more than 10 times higher, and exceeded the generic guidelines for PAHs in soil set by the Swedish Environmental Protection Agency. The patterns of the individual PAHs normalised to the total concentration of PAHs were found to be very similar for all the three ashes. Naphthalene and phenanthrene were the dominating PAHs for all ash samples, but the mixed biofuel ash also contained high levels of fluoranthene and pyrene. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 24. |
- Johansson, Lena, 1967-
(författare)
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Blast furnace slag as phosphorus sorbents - column studies
- 1999
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 229:1-2, s. 89-97
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Tidskriftsartikel (refereegranskat)abstract
- Filter substrates that efficiently remove phosphorus (P) from wastewater can be used to optimise the nutrient removal by on-site wastewater treatment systems. A number of filter substrates have been investigated and the industrial by-product blast furnace slag has attracted attention as a promising substrate. To further evaluate the sorption and attenuation of PO(4)(3-), a column experiment was carried out under conditions of intermittent P loading. Two types of slag were used; crystalline slag (CS) and amorphous slag (AS). The slags were available in two particle sizes; 0-0.125 mm and 0.25-4 mm, respectively. The slags were mixed with inert sand to improve the hydraulic conductivity. In addition to the column experiment, a P fractionation experiment was conducted. The sorption experiment indicated that the removal of P by the CS (0.25-4 mm), the AS (0.25-4 mm) and the AS (0-0.125 mm) columns at the end of the experiment exceeded 95%. In the other columns, the P sorption had decreased remarkably indicating a beginning saturation of the substrates. The P fractionation experiment showed that the P sorption was largest in the uppermost layers. Clear gradients of the P sorption in the downward direction could also be observed. It was concluded that the P sorption by the coarser slags was high at the end of the experiment indicating that saturation had not been achieved.
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| 25. |
- Johansson Thunqvist, Eva-Lotta, et al.
(författare)
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Airborne spreading and deposition of de-icing salt : A case study
- 1999
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 235:1-3, s. 161-168
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Tidskriftsartikel (refereegranskat)abstract
- In this study it was concluded that between 20 and 63% of the de-icing salt applied on the road was transported by air and deposited on the ground 2-40 m from the road. The reason for the higher percentages is suggested to be intense snowfall, which leads to more splash generation and ploughing. Ninety percent or more of the total deposition occurs within 20 m at all transects. For all periods and both localities the deposition was greater on the east side of the road, which reflects the prevailing westerly winds in relation to the de-icing action occasions.
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| 26. |
- Jonsson, Arne, et al.
(författare)
-
Phasing out cadmium and lead : Emissions and sediment loads in an urban area
- 2002
-
Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 292:1-2, s. 91-100
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines how fluxes in the aquatic environment reflect the reduced use of cadmium (Cd) and lead (Pb) in Stockholm, Sweden, between 1975 and 1995. The sediment deposition of Cd and Pb in the waters around Stockholm was investigated using laminated sediment cores, which facilitated reconstructions of historical annual metal deposition to the sediments. The resulting reconstructions were compared to independent estimations of the emissions to the aquatic environment during the phase-out period. The loads of Cd and Pb from sewage treatment plants, storm water and in atmospheric deposition were studied using literature data. The data set indicates a reduced load of Cd and Pb on the aquatic surroundings of Stockholm. The reduction is, however, not as pronounced in the sediment deposition as in the calculated emissions. This indicates that emissions may be delayed on their way to the sediments or that there are other sources, e.g. resuspension of older sediments. It is therefore argued that sediment investigations are an essential component in environmental monitoring, in order to get a complete picture of the metal fluxes to and in the environment in urban areas. © 2002 Elsevier Science B.V. All rights reserved.
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| 27. |
- Jonsson, K., et al.
(författare)
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Effect of sorption kinetics on the transport of solutes in streams
- 2001
-
Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 266:03-jan, s. 239-247
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Tidskriftsartikel (refereegranskat)abstract
- To provide an appropriate description of the transport of a reactive substance in a stream, it is important to include a kinetic description of sorption in a transport model. In this study, first-order sorption kinetics was taken into account in both the transient storage zone and the stream water, and analytical expressions for relative error in statistical moments of the residence time PDF, resulting from disregarding sorption kinetics, were derived. The sorption rate coefficient in the water was found to influence the error in the expected value, and the error was found to approach infinity as the travel distance or sorption rate coefficient approaches zero. The sorption rate coefficient in the storage zone influences only higher-order moments. For sufficiently long distances, the error in the variance was found to be more pronounced when sorption kinetics in the storage zone was disregarded, than when sorption kinetics in the stream water was disregarded. Parameter values from a tracer experiment with Cr-51 revealed that the relative error in the variance could be more than 100%, if sorption kinetics in the storage zone is disregarded.
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| 28. |
- Karlén, Camilla, et al.
(författare)
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Runoff rates and ecotoxicity of zinc induced by atmospheric corrosion
- 2001
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 277:1-3, s. 169-180
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Tidskriftsartikel (refereegranskat)abstract
- Initiated by regulatory restrictions on the use of zinc for various building and construction applications, together with a lack of knowledge related to the release of zinc induced by atmospheric corrosion, a major interdisciplinary research project was implemented to generate data to be used in future risk assessment. Runoff rates from a large number of commercially available zinc-based materials have been determined on panels inclined 45 degrees from the horizon, facing south, during a 1-year atmospheric exposure in an urban environment in Sweden. Possible environmental effects of runoff water immediately after leaving the surface of the various materials have been evaluated during two different sampling periods of varying season and zinc concentration, using the standard growth inhibition test with algae, Raphidocelis subcapitata (formerly Selenastnim capricornutum), Zinc-specific biosensors with the bacterial strain of Alcaligenes cutrophus. and computer modeling using the water-ligand model MINTEQA2 and the humic aquatic model WHAM, have been used to assess the bioavailability and chemical speciation of zinc in the runoff water. An excellent consistency between the different methods was observed. The results show considerably lower runoff rates of zinc (0.07-3.5 gm(-2) year(-1)) than previously being used for regulatory restrictions, and the concentration of zinc to be predominantly responsible for the observed toxicity of the runoff water towards the green algae. The majority of the released zinc quantity was found to be present as free hydrated zinc ions and, hence, bioavailable. The data do not consider changes in bioavailability and chemical speciation or dilution effects during entry into the environment. and should therefore only be used as an initial assessment of the potential environmental effect of zinc runoff from building applications. This interdisciplinary approach has the potential for studies on the environmental fate of zinc in soil or aquatic systems.
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| 29. |
- Lindgren, Åsa
(författare)
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Asphalt wear and pollution transport
- 1996
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 189-190, s. 281-286
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Tidskriftsartikel (refereegranskat)abstract
- Studded tires cause extensive wear of road surfaces during winter producing small particles. Besides transporting different adsorbed pollutants these particles also discharge metal ions by their own natural content. The major part (95%) of the asphalt is composed of stone fractions. The rest consists mainly of bitumen, which contains trace quantities of metals. Laboratory studies in this study have demonstrated different adsorbing properties of metal ions, as well as differences in adsorption when comparing stone materials. Two stone materials, a gabbro and a porphyry, have been tested for their adsorption properties concerning Pb, Cu, Zn and Cd. The gabbro showed better adsorption capacity than the porphyry. Gabbro has coarser grains, it is softer, and also has a higher content of most metals compared to the porphyry. In all tests lead and copper are more adsorbed than zinc and cadmium. All metal ions are released at about the same pH ({approx}4)
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| 30. |
- Müller, Barbara, et al.
(författare)
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Adsorption of trace elements on pyrite surfaces in sulfidic mine tailings from Kristineberg (Sweden) : a few years after remediation
- 2002
-
Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 298:1-3, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) has been used to determine the elemental composition of the surface and interior layers of pyrite grains from the mine tailings from Kristineberg (northern Sweden) in order to determine concentration gradients between these two layers. The pyrite grains were collected from oxidized and unoxidized zones within the tailings. The aim of this study was to assess the role of pyrite surfaces as sites for the attenuation of solutes from the mine-tailings porewater. The normalized intensities of Cu, Zn, Ag, Sb, Ce, Pb and Bi are highest at the surface of each grain (within the surface layer drilled by the LA) and decrease towards the interior. The surface adsorption of Cu, Zn and Pb is more pronounced within the unoxidized than within the oxidized zone of the tailings. Copper exhibits a distinct concentration peak at the surface of the pyrite grains below the pre-remediation oxidation front. Silver, Sb, Bi, As and Au are preferably adsorbed within the uppermost layer of the oxidized zone in the tailings, where the pH is as high as 6.2. The conversion of intensity signals of the elements to concentration values in ppm was accomplished using an external calibration against an in-house pyrite standard.
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