| 1. |
- Björklund, Karin, 1979, et al.
(författare)
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Best Management Practices to Reduce Phthalate and Nonylphenol Loads in Urban Runoff
- 2008
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Ingår i: Proceedings of the International Conference on Urban Drainage, 1-5 September, Edinburgh, UK.
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Konferensbidrag (refereegranskat)abstract
- Phthalates and nonylphenols, organic substances of widespread use, are believed to be ubiquitous in Swedish stormwater and urban sediments. Due to their reported hazardous properties, it is of great interest to identify effective best management practices (BMPs) to reduce the release of these substances to recipient waters. The stormwater-quality model SEWSYS was used to identify sources and quantify loads of phthalates and nonylphenols in two urban catchment areas. Based on the modelling results, BMPs were proposed, and their efficiencies evaluated. The SEWSYS simulations showed that discharges of phthalates and nonylphenols depend on catchment area characteristics: pollutants in a residential area originate mainly from building materials, whereas vehicles are the dominant source in a high-density traffic area. By replacing traditional building materials by phthalate and nonylphenol-free alternatives and by implementing congestion taxes to reduce traffic, the simulated pollutant loads could be reduced by more than 20% in the high-density traffic area. However, discharges from many diffuse sources cannot entirely be stopped, and a structural BMP, e.g. a sedimentation pond, is essential to further decrease pollutant loads in urban runoff. This study shows that SEWSYS can be a useful tool for selecting and evaluating adequate BMPs to reduce stormwater contamination.
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| 2. |
- Björklund, Karin, 1979, et al.
(författare)
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Källor till och flöden av ftalater och nonylfenoler i Stockholms dagvatten
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SEWSYS is a computer model designed for simulating fluxes of pollutants from its’ sources to the urban stormwater system. The model is able to simulate concentrations of substances in stormwater – thereby reducing the need for sampling and analyses of stormwater – as well as establishing the major sources of the pollutants in the urban environment. The aim of this work has been to identify the sources of some selected organic pollutants, adjusting SEWSYS to these new substances and simulating their fluxes in urban stormwater. The simulation results have then been used to investigate proper barriers to prevent these substances to reach the environment.The prioritised pollutants chosen to be studied were four phthalates – DBP, DEHP, DINP and DIDP – nonylphenols (NP) and their ethoxylates (NPE). Phthalates are plasticisers used in PVC (often as coil coating), paint and sealants. NP/E:s are surfactants used in a range of materials, such as concrete, paint and plastics. In order to add these pollutants into the SEWSYS model, the emission of each substance from each of the identified sources was scrutinised. Depending on the overall lack of data, assumptions and estimations were necessary to be made for the emission calculations.Two housing areas and one area dominated by traffic were selected for the modelling. Information on the prevalence of the different sources together with rainfall data were used for the simulation of stormwater runoff and pollution load. The model was calibrated with measured stormwater flows and volumes, as well as analysed concentrations of the pollutants in stormwater from the chosen housing and traffic areas. The traffic area showed high concentrations of phthalates in the stormwater samples. DIDP, and particularly DINP, showed the highest concentrations in most samples, both from the traffic area and the housing areas. The NP and NPE concentrations in most samples were close to or under the detection limits for the analytical methods used.The calibration of the model showed that the runoff module in SEWSYS is able to predict the runoff volume well. After recalculating and adjusting some of the emission factors, the concentrations of the pollutants were in the same magnitude as the measured values. The simulations showed that vehicles are the dominating source of the phthalates in the traffic area. Parking spaces and concrete are indicated to emit significant amounts of NP/E:s. In the housing areas the construction materials – such as plastic coated steel for roofing and cladding – were the most important sources of phthalates. Parking spaces tend to cause high pollution loads of NP/E:s.To reduce the load of organic pollutants in the environment a combination of barriers can be used – these barriers may include legislative measures to prohibit the use of a substance, recommendations to the consumers (not) to use specific construction materials or installing technical measures such as sedimentation facilities. A preliminary simulation show that by using construction materials free from phthalates or NP/E:s or reducing the traffic load, combined with a technical barrier such as a sedimentation pond, the pollution load from housing or traffic area is considerably decreased.
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| 3. |
- Björklund, Karin, 1979, et al.
(författare)
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Phthalates and nonylphenols in urban runoff: Occurrence, distribution and area emission factors
- 2009
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 407:16, s. 4665-4672
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Tidskriftsartikel (refereegranskat)abstract
- The urban water system is believed to be an important sink for the nonpoint-source pollutants nonylphenols and phthalates. The presence of nonylphenols (NPs), nonylphenol ethoxylates (NPEOs), and eight phthalates was analyzed in urban stormwater and sediment from three catchment areas in Sweden. Emission loads for these substances were then calculated for a specific urban catchment area. In addition, substance distribution in road runoff passing through a sedimentation facility was modeled using a modified QWASI-model for chemical fate. High concentrations of DEHP, DIDP and DINP (≤ 48, 66 and 200 µg/g dw, respectively) as well as nonylphenol mono- and di-ethoxylate (6.6 and 20 µg/g dw, respectively) were found in the sediment. Aqueous concentrations of the pollutants varied considerably; branched NP was detected in concentrations up to 1.2 µg/L, whereas di(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), and diisononyl phthalate (DINP) were the most frequently detected phthalates in concentrations up to 5.0, 17 and 85 µg/L, respectively. The fate modeling demonstrated that predicted substance levels in water agreed well with measured levels, whereas the modeled sediment levels were underestimated. Calculation of catchment area emission factors from an urban highway environment revealed that as much as 2.1 kg of total phthalates and 200 g of NP and NPEOs may be emitted per hectare and year. The results indicate that all monitored phthalates, branched NPs and lower NPEOs are present in Swedish urban water systems. The long-chain phthalates DIDP and DINP are believed to occur at higher concentrations than other phthalates because of their higher environmental persistence and their increasing use in Sweden.
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| 4. |
- Björklund, Karin, 1979, et al.
(författare)
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Screening of Organic Contaminants in Urban Snow
- 2011
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 64:1, s. 206-213
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Tidskriftsartikel (refereegranskat)abstract
- Snowmelt is known to cause peak concentrations of pollutants, which may adversely affectreceiving water quality. High concentrations of metals and suspended solids in snow have beenreported, whereas studies on organic pollutants are rare. This study aims at investigating theoccurrence of anthropogenic organic compounds in urban snow in Gothenburg (Sweden). The mostfrequently detected organic pollutants in the collected snow samples were polycyclic aromatichydrocarbons (PAHs), high molecular-weight phthalates, 4-nonylphenol and 4-t-octylphenol.Brominated flame retardants and chlorinated paraffins were only sporadically detected. In severalsnow samples, the concentrations of specific PAHs, alkylphenols and phthalates were higher thanreported stormwater concentrations and European water quality standards. Pollutant sourceidentification and sustainable management of snow are important instruments for the mitigation oforganic contaminants in the urban environment.
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| 5. |
- Björklund, Karin, 1979, et al.
(författare)
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Screening of organic contaminants in urban snow
- 2010
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Ingår i: Proceedings, 14th International Conference, IWA Diffuse Pollution Specialist Group: Diffuse Pollution and Eutrophication. ; , s. 270-275
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Konferensbidrag (refereegranskat)abstract
- Snowmelt is known to cause peak concentrations of pollutants which may adversely affect receiving water quality. High concentrations in snow have been shown for e.g. metals and suspended solids, whereas studies on organic pollutants are rarely reported. This study aimsat investigating the occurrence of anthropogenic organic compounds in urban snow, and at identifying sources of the pollutants. Snow from sites in Gothenburg, Sweden, was sampled and a range of organic substances was analysed. The most frequently detected organic pollutants in urban snow were polycyclic aromatic hydrocarbons, high molecular-weightphthalates, 4-nonylphenol and 4-octylphenol. Brominated flame retardants and chlorinated paraffins were only sporadically detected. In several snow samples, the concentrations of specific PAHs, alkylphenols and phthalates were higher than reported stormwater concentrations and European water quality standards. Pollutant source identification and sustainable management of snow are important instruments for the mitigation of organic contaminants in the urban environment.
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| 6. |
- Björklund, Karin, 1979, et al.
(författare)
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Simulating organic pollutant flows in urban stormwater: development and evaluation of a model for nonylphenols and phthalates
- 2011
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 65:3, s. 508-515
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Tidskriftsartikel (refereegranskat)abstract
- Stormwater-quality models can be useful tools for predicting pollutant loads and identifying sources of contamination. Most models in current use handle pollutants such as metals, nutrients and suspended solids, whereas models including emerging organic contaminants are rare.This study aims at developing and evaluating a model for simulating stormwater flows of two groups of organic pollutants; nonylphenols and phthalates. Sources, emission patterns and environmental fate were examined to create a model framework for the organic contaminants. The model was calibrated using field data from three urban catchments. The results show that the simulated pollutant concentrations are overestimated compared to the measured concentrations, which are often close to or below the analytical detection limit. The high uncertainty and the lowpredictive power of the model may be explained by factors such as incorrect catchment data, lack of knowledge on buildup, washoff and other processes involved in substance fate, and an underreporting of pollutant concentrations in stormwater. More data on release patterns and sewer fate are needed to adequately simulate stormwater concentrations of nonylphenols and phthalates. A conventional substance flow analysis based on bookkeeping, evaluated in parallel to the computer model, has proven to be useful for calculating fluxes of nonylphenols and phthalates in urban catchments.
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| 7. |
- Björklund, Karin, 1979, et al.
(författare)
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Using the stormwater-quality model SEWSYS to identify sources and fluxes of hazardous organic substances
- 2008
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Ingår i: Book of abstracts. 9th Highway and Urban Environment Symposium, 9-11 June 2008, Madrid, Spain. ; , s. 21-
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Konferensbidrag (refereegranskat)abstract
- Stormwater-quality models simulating pollutant pathways in urban catchments are proven to be valuable means when planning and evaluating appropriate strategies to reduce the detrimental impacts of urban runoff [Zoppou, 2001]. SEWSYS, a substance flow model simulating pollutant concentrations in stormwater, is an effective instrument for predicting pollution loads from non-point sources and can therefore be used for proposing measures to reduce the release of contaminants into the environment [Ahlman, 2006]. SEWSYS is now being expanded from operating with nutrients and metals, to include also a few organic substances. In this study, two groups of organic compounds – phthalates and nonylphenols (NPs) – were selected for an initial flow analysis. These compounds, classified as “very toxic to aquatic organisms” [KEMI, 2007a], are high volume chemicals used as additives in a variety of products [KEMI, 2007b]. To incorporate phthalates and NPs into SEWSYS, an extensive literature study was accomplished. The study included identification of potential pollutant sources in urban areas, e.g. building materials and vehicles, and analysis of emission patterns and rates. Also, model input data such as source distribution and authentic rain series were collected from three urban catchment areas. Simulated pollutant concentrations were then compared with measured and analysed concentrations in stormwater from the investigated catchments. Preliminary model simulations showed that pollutant loadings and major contributing sources are catchment dependent: e.g. vehicles are the dominant sources of phthalates in traffic areas whereas construction materials are the most important sources in residential areas. These simulation results were then used for proposing adequate measures in order to mitigate phthalate and NP loads in stormwater. Calculations showed that by using phthalate- or NP-free construction materials, and by reducing the traffic load, the pollution load from residential and traffic areas was considerably decreased. These findings illustrate the use of SEWSYS as a tool for improving urban runoff quality, and corresponding simulations could easily be performed by local authorities for planning of effective abatement strategies. ReferencesAhlman S (2006) Modelling of Substance Flows in Urban Drainage Systems. Doctoral Thesis, Department of Civil and Environmental Engineering, Chalmers University of Technology, Göteborg, Sweden.KEMI (Swedish Chemicals Agency). (2007a) Classification List. http://apps.kemi.se/klassificeringslistan/default.cfmKEMI (Swedish Chemicals Agency). (2007b) KemI-Stat. http://apps.kemi.se/kemistat/start.aspx?sprak=eZoppou C (2001) Review of urban storm water models. Environmental Modelling & Software 16 (3), 195-231.
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