| 1. |
- Andersson, Camilla, 1979-, et al.
(författare)
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Inter-annual variations of ozone and nitrogen dioxide over Europe during 1958-2003 simulated with a regional CTM
- 2007
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Ingår i: Water, Air and Soil Pollution. - Netherlands : Springer. - 0049-6979 .- 1573-2932 .- 1567-7230 .- 1573-2940. ; 7, s. 15-23
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Inter-annual variability of surface ozone(O3) and nitrogen dioxide (NO2) over Europe hasbeen studied over the period 1958-2003 using athree-dimensional Chemistry-Transport Model coupledto meteorological data from the ERA40 data setproduced at the European Centre of Medium-rangeWeather Forecasts (ECMWF). Emissions and boundaryconditions were kept at present levels throughoutthe simulation period. It was found that the annualmean NO2 concentration varies between ±50% andthe summer mean O3 concentration varies between-10 and +20 percent (%) compared to the 46-yearaverage over the model domain. There is alsovariation in ozone and NO2 over longer time scales.The last 22 years display high concentrations ofozone in central and south-western Europe and lowconcentrations in north-eastern Europe. The first22 years display very high concentrations of NO2over the North Sea. There is indication of trends inozone and nitrogen dioxide but this has to beinvestigated further. Such information is one factorthat should be taken into account when consideringfuture control strategies.
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| 2. |
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| 3. |
- Abbas, Mazhar, et al.
(författare)
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Biosorption of chromium (III) and chromium (VI) by untreated and pretreated Cassia fistula biomass from aqueous solutions
- 2008
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 1573-2932 .- 0049-6979. ; 191:1-4, s. 139-148
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Tidskriftsartikel (refereegranskat)abstract
- The present study explained the effect of pretreatments on the biosorption of Cr (III) and Cr (VI) by Cassia fistula biomass from aqueous solutions. For this purpose Cassia fistula biomass was pretreated physically by heating, autoclaving, boiling and chemically with sodium hydroxide, formaldehyde, gluteraldehyde, acetic acid, hydrogen peroxide, commercial laundry detergent, orthophosphoric, sulphuric acid, nitric acid, and hydrochloric acid. The adsorption capacity of biomass for Cr (III) and Cr (VI) was found to be significantly improved by the treatments of gluteraldehyde (95.41 and 96.21 mg/g) and benzene (85.71 and 90.81 mg/g) respectively. The adsorption capacity was found to depend on pH, initial metal concentration, dose, size, kinetics, and temperature. Maximum adsorption of both the Cr (III) and Cr (VI) was observed at pH 5 and 2. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The kinetic studies showed that the sorption rates could be described better by a second order expression than by a more commonly applied Lagergren equation.
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| 4. |
- Abdalla, M., et al.
(författare)
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Simulation of CO2 and Attribution Analysis at Six European Peatland Sites Using the ECOSSE Model
- 2014
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 1573-2932 .- 0049-6979. ; 225:11, s. 2182-2182
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we simulated heterotrophic CO2 (Rh) fluxes at six European peatland sites using the ECOSSE model and compared them to estimates of Rh made from eddy covariance (EC) measurements. The sites are spread over four countries with different climates, vegetation and management. Annual Rh from the different sites ranged from 110 to 540 g C m(-2). The maximum annual Rh occurred when the water table (WT) level was between -10 and -25 cm and the air temperature was above 6.2 degrees C. The model successfully simulated seasonal trends for the majority of the sites. Regression relationships (r(2)) between the EC-derived and simulated Rh ranged from 0.28 to 0.76, and the root mean square error and relative error were small, revealing an acceptable fit. The overall relative deviation value between annual EC-derived and simulated Rh was small (-1 %) and model efficiency ranges across sites from -0.25 to +0.41. Sensitivity analysis highlighted that increasing temperature, decreasing precipitation and lowering WT depth could significantly increase Rh from soils. Thus, management which lowers the WT could significantly increase anthropogenic CO2, so from a carbon emissions perspective, it should be avoided. The results presented here demonstrate a robust basis for further application of the ECOSSE model to assess the impacts of future land management interventions on peatland carbon emissions and to help guide best practice land management decisions.
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| 5. |
- Abed, S. N., et al.
(författare)
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Impact of Storage Time on Characteristics of Synthetic Greywater for Two Different Pollutant Strengths to Be Treated or Recycled
- 2020
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Ingår i: Water, Air, and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 231:5
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Tidskriftsartikel (refereegranskat)abstract
- Storage of greywater is controversial for environmental and health reasons. Artificial greywater was assessed after 2 and 7 days of storage time. Two different greywater pollutant strengths were statistically compared at each storage time. A negative significant (p < 0.05) correlation was evident with increasing storage time for the 5-day biochemical oxygen demand for more than 2 days. However, the concentrations of 5-day biochemical oxygen and chemical oxygen demands reduced significantly at 2 days of storage when compared with freshly prepared greywater. Biodegradability (5-day biochemical oxygen demand/chemical oxygen demand ratio) decreased significantly after storage to between 0.14 and 0.39. The nitrification process was improved significantly with increasing storage time concerning low strength greywater with a significant increase in the removal of ammonia-nitrogen and a non-significant decrease in the removal of nitrate-nitrogen. The correlation was significantly positive between ammonia-nitrogen and 5-day biochemical oxygen demand for stored greywater, while it was significantly negative between total suspended solids and both 5-day biochemical oxygen demand and dissolved oxygen. Significant reductions in colour, total suspended solids and turbidity were correlated positively with storage time. Precipitation of dissolved metals was suspected to occur in storing greywater by binding the inorganic components with the sediment and collide surfaces through adsorption, allowing a significant drop in concentrations of dissolved and undissolved metals with increasing storage time through sedimentation. Synthetic greywater of low mineral pollution had significantly higher removals for almost all concentrations compared with those for high concentrations. More advanced technologies for high trace element removal are required.
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| 6. |
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| 7. |
- Al-Khafaji, Mahmoud, et al.
(författare)
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The Interactive Impact of Land Cover and DEM Resolution on the Accuracy of Computed Streamflow Using the SWAT Model
- 2020
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Ingår i: Water, Air and Soil Pollution. - Germany : Springer. - 0049-6979 .- 1573-2932. ; 231:8
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Tidskriftsartikel (refereegranskat)abstract
- Twenty daily time step–based SWAT simulation models for the Duhok, Adhaim and Dokan dam watersheds, in Iraq, were implemented using five land cover (LC) and digital elevation model (DEM) of different resolutions. The optimal LC and DEM for computing the most accurate streamflow for each watershed were specified. Results indicated that delineation of the flat watersheds is significantly affected by the DEM resolution and there was no evident trend on the computation of watersheds’ total areas, boundaries, number of subbasins and stream networks. Moreover, there is no significant trend between the increase in LC and DEM resolutions and accuracy of the computed streamflow. The most accurate streamflows for the Duhok, Adhaim and Dokan watersheds were computed using LC (DEM) of 30 m, 1000 m and 1000 m.
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| 8. |
- Alkaradaghi, Karwan, et al.
(författare)
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Geospatial Technique Integrated with MCDM Models for Selecting Potential Sites for Harvesting Rainwater in the Semi-arid Region
- 2022
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Ingår i: Water, Air and Soil Pollution. - : Springer Nature. - 0049-6979 .- 1573-2932. ; 233:8
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Tidskriftsartikel (refereegranskat)abstract
- Severe droughts and mismanagement of water resources during the last decades have propelled authorities in the Kurdistan Region to be concerned about better management of precipitation which is considered the primary source of recharging surface and groundwater in the area of interest. The drought cycles in the last decades have stimulated water stakeholders to drill more wells and store uncontrolled runoff in suitable structures during rainy times to fulfill the increased water demands. The optimum sites for rainwater harvesting sites in the Qaradaqh basin, which is considered a water-scarce area, were determined using the analytical hierarchy process (AHP), sum average weighted method (SAWM), and fuzzy-based index (FBI) techniques. The essential thematic layers within the natural and artificial factors were rated, weighted, and integrated via GIS and multi-criteria decision-making (MCDM) approaches. As a consequence of the model results, three farm ponds and four small dams were proposed as future prospective sites for implementing rainwater harvesting structures. The current work shows that the unsuitable ratio over the study area in all methods AHP, SAWM, and FBI occupied 12.6%, 12.7%, and 14.2% respectively. The area under the curve (AUC) and receiver operating characteristics were used to validate the model outcomes. The AUC values range from 0.5 to 1, meaning that all MCDM results are good or are correctly selected. Based on the prediction rate curve for the suitability index map, the prediction accuracy was 72%, 57%, and 59% for AHP, SAWM, and fuzzy overlay, respectively. The final map shows that the potential sites for rainwater harvesting or suitable sites are clustered mainly in the northern and around the basin’s boundary, while unsuitable areas cover northeastern and some scatter zones in the middle due to restrictions of geology, distance to stream with the villages, and slope criteria. The total harvested runoff was 377,260 m3 from all the suggested structures. The proposed sites may provide a scientific and reasonable basis for utilizing this natural resource and minimize the impacts of future drought cycles.
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| 9. |
- Alveteg, Mattias, et al.
(författare)
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Developing a kinetic alternative in modeling soil aluminium.
- 1995
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Ingår i: Water, Air and Soil Pollution. - 1573-2932. ; 79:1-4, s. 377-389
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Tidskriftsartikel (refereegranskat)abstract
- Soil chemistry models often use gibbsite solubility and similar equilibrium models to predict Al concentrations in soil solution. A kinetic alternative was developed with the goal of finding universal rate constants instead of the site- and depth-specific solubility constants usually associated with the equilibrium approach. The behavior of the two approaches was studied within the framework of the steady-state soil chemistry model PROFILE using data from Solling, Germany and Gårdsjön, Sweden, two sites with different mineralogy and land use history. The kinetic alternative uses a mass balance to predict Al concentrations. The sources of Al in soil water are deposition, weathering and mineralization. The sinks are leaching and the formation of an aluminosilicate precursor. The precursor slowly transforms into an ordinary clay mineral. Both formation and transformation of the precursor are treated as irreversible processes. The kinetic model introduces a new relationship between pH and Al and produces a systematic pattern of different apparent gibbsite equilibrium constants at different depths. Results show that the kinetic model systematically underestimates Al concentration in the upper horizons, which indicates that there may be additional sources of Al in the upper horizons not accounted for in the model. Predicted values of pH and Al concentrations are comparable with field observations.
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| 10. |
- Alveteg, Mattias, et al.
(författare)
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Integrated assessment of soil chemical status. 1. Integration of existing models and derivation of a regional database for Switzerland
- 1998
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Ingår i: Water, Air and Soil Pollution. - 1573-2932. ; 105:1-2, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- A regional soil acidification model was developed by integration and adaptation of existing models. The regional model consists of the dynamic multi-layer soil chemistry model SAFE, its steady-state version INITSAFE, the atmospheric deposition and nutrient uptake reconstruction model MAKEDEP, and a routine with empirical relations concerning depth-dependent parameters. A scheme for the extraction of input to the regional model from available information of different geographical detail also was developed. Basic data sources considered were: 1) national surveys such as the National Forest Inventory, covering site specific information, 2) available point measurements of parameter values, and 3) literature sources. Not all parameters were available on a regional scale with sufficient resolution. Input required for the model calculations therefore was derived from the available data sources by means of transfer algorithms including spatial interpolation. Interpolation was done allocating parameter values determined at reference sites to conventionally mapped entities such as geological units, soil type, and other kinds of geographical information. The exercise resulted in a data base of the required 68 site-specific parameter values covering climatic, deposition and land use parameters, as well as stand characteristics and soil properties.
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