Ändra sökning
Avgränsa sökresultatet
4567 301 - 330 av 330
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 301. Westerlund, Camilla
    et al.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Bäckström, Magnus
    Seasonal variations in road runoff quality in Lulea, Sweden2003Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 48, nr 9, s. 93-101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In regions with cold climate the urban drainage and highway runoff processes become much more complex, compared to temperate regions. Therefore, climatic conditions should be taken into account in planning and design of BMPs and snow handling strategies. In order to increase the knowledge of road runoff quality during melt and rain periods, respectively, measurements were carried out at a field site during a two-month period. The field site was situated at Sodra Hamnleden, a road with 7,400 vehicles/day, in the central part of Lulea. Runoff samples were analysed for suspended solids and heavy metals (Pb, Cu, Cd, Ni and Zn). The results showed that the concentrations of suspended solids, lead, copper and cadmium were higher for the melt period, compared to rain generated runoff on the catchment without snow, and the highest concentrations were found during the rain-on-snow events. The results indicate a flow dependent increase in the concentration of suspended solids during the melt period. A comparison of the total mass of suspended solids over a one-month period showed that the melt period produced about 3 times more suspended solids. Metal elements during melt period were more particulate bound as compared to the rain period characterised by a higher percentage of the dissolved fraction

  • 302.
    Viklander, Maria
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Marsalek, J.
    National Water Research Institute, Burlington, Ontario.
    Malmquist, P-A
    Chalmers University of Technology, Urban Water.
    Watt, W.E.
    Queen's University, Department of Civil Engineering, Kingston, ON.
    Urban drainage and highway runoff in cold climates: conference overview2003Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 48, nr 9, s. 1-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This overview of research findings presented at the conference on urban drainage and highway runoff in cold climates starts with generation of urban runoff and snowmelt, followed by snowmelt and winter runoff quality, best management practices for urban snowmelt and winter runoff, and snow management in urban areas. Research on the urban hydrological cycle is lagging behind the needs in this field, particularly in terms of data availability. The current studies of winter urban runoff quality focus on road salts in the urban environment and their environmental effects. The needs for better source controls in salt applications, improved management of chloride-laden runoff, and selective adoption of environmentally safer alternative de-icers were reported. Adaptation of the conventional stormwater best management practices (BMPs) for winter operation remains a challenge. The first step in refining the existing BMPs for winter operation is to advance the understanding of their operation, as reported for some cases at the conference. Finally, snow management in urban areas may require local storage of fresh (unpolluted) snow and disposal of more polluted snow at central snow disposal sites.

  • 303.
    Viklander, Maria
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Marsalek, J.National Water Research Institute.Malmquist, P-AChalmers University of Technology, Urban Water.Watts, W.E.Queen's University, Department of Civil Engineering, Kingston, ON.
    Urban drainage and highway run-off in cold climates: selected proceedings of the International Conference on Urban Drainage and Highway Run-off in Cold Climates, held in Luleå, Sweden, 25-27 March, 20032003Samlingsverk (redaktörskap) (Övrigt vetenskapligt)
  • 304. Bäckström, Magnus
    et al.
    Malmqvist, Per-Arne
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Stormwater management in a catchbasin perspective - best practices or sustainable strategies?2002Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 46, nr 6-7, s. 159-166Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A strategy for sustainable stormwater management is needed. This study has focused on the relative importance of stormwater as a pollutant source in a catchbasin, if Best Management Practices (BMPs) result in pollutant removal or pollutant redistribution, and methods for screening of stormwater strategies. Stormwater is most likely an important pathway for pollutants in a catchbasin perspective. True pollutant removal can only be achieved if the pollutant sources are eliminated. Until that is reached, we should have the best possible control of the pollutant fluxes in the watershed. This study indicates that the search for a sustainable stormwater strategy could be easier to handle if different "screens" could be used. The Swedish environmental objectives, which try to encapsulate all aspects of sustainability, may be used as a foundation for a "sustainability screen". By using this screen, the "unsustainable" features of different stormwater strategies could be pointed out. A "standards and legislation screen" will be based on the EU Water Framework Directive. As this study has shown, it is doubtful whether the conventional BMPs, such as stormwater ponds and infiltration facilities, produce a sufficient pollutant control.

  • 305.
    Miikkelsen, P.S.
    et al.
    Environment and Resources DTU, Technical University of Denmark.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Linde, J.J.
    Environment and Resources DTU, Technical University of Denmark.
    BMPs in urban stormwater management in Denmark and Sweden2001Ingår i: Linking stormwater BMP designs and performance to receiving water impact mitigation: proceedings of an Engineering Foundation conference, August 19 - 24, 2001, Snowmass Village, Colorado / [ed] Ben R. Urbonas, American Society of Civil Engineers (ASCE), 2001, s. 354-368Konferensbidrag (Refereegranskat)
    Abstract [en]

    Best Management Practices (BMPs) for control of stormwater runoff include structural elements (structural BMPs) that can be applied on the local scale (e.g. infiltration), the drainage catchment scale (e.g. ponds and treatment, or wetlands) and the receiving water scale (e.g. retrofitting of river reaches), and non-structural BMPs, such as controls of chemicals or building materials, and street sweeping. The available knowledge of stormwater BMPs performance in pollution control is inconsistent and the effect of various BMPs on receiving water quality is either poorly understood, or not known. A review of recent experiences with selected stormwater BMPs in Denmark and Sweden is presented and discussed with respect to the current issues related to legislation and the forces driving future development in stormwater management

  • 306.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Ion exchange of ammonium in zeolites: a literature review2001Ingår i: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 127, nr 8, s. 673-681Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective of this review was to acquire knowledge concerning the ammonium ion exchange technique within the field of wastewater treatment. General concepts as well as details concerning the loading and the regeneration phases were included. Both chemical and biological regeneration processes were reviewed. Concerning ion exchangers, the study focused on different kinds of zeolites. The possibilities of employing the ion exchange technique for the recovery of nitrogen was also discussed. The study was carried out as a literature review. Conclusions from this study are that full-scale wastewater treatment plants that employ the ammonium ion exchange technique are scarce and few applications have been developed to recover ammonia nitrogen, for example, for agricultural purposes. Zeolites are somewhat heterogeneous because of natural variations of the minerals. Factors that influence the ammonium adsorption during the loading phase are well known. Biological regeneration has primarily been developed to decrease the brine consumption at regeneration or to improve the conventional nitrification-denitrification process. If the ion exchange technique is to be used to recover ammonium, both chemical and biological regeneration might be employed.

  • 307.
    Andersson-Chan, Anneli
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    A rockwool biofilter for the treatment of restaurant emissions2000Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Over the past 20 years, the use of biological air pollution control has become a popular treatment alternative for contaminated gas streams. The objective of this licentiate thesis was to investigate the feasibility of a compact rockwool biofilter to treat emissions from a restaurant, to identify an appropriate microbial population for the inoculation of the biofilter, and suitable environmental conditions for this culture. Rockwool mats with pre-set structures were shown to have a good structural stability, developed low pressure drop, did not compact, and seemed to be a appropriate habitat for microorganisms. Bacteria from different environments were enriched in batch cultures; it was found that all cultures were able to oxidize rape-seed oil. Nutrients, mainly phosphorus and nitrogen, must be added occasionally to the bacterial culture. Clogging due to high depositions of grease could be prevented by using a mechanical collector installed upstream of the biofilter. The off-gas from the fryer consisted of a complex mixture of partially oxidized hydrocarbons and the short residence times (<10 s) provided in the filter were not sufficient to achieve a significant reduction of aldehydes or fatty acids.

  • 308.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Adsorption and reclamation of wastewater nitrogen and the value of human urine as a nitrogen fertiliser2000Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Ammonium adsorption and ammonium ion exchange technique are possible alternatives for ammonium reclamation at conventional wastewater treatment plants. There are a few ion exchange applications that have been suggested for nitrogen reclamation, which can be further developed. It was indicated that a small amount of ammonium was adsorbed to sand due to a low adsorption capacity. It seemed, however, as the adsorption capacity was not completely utilised during the warm seasons when employing wastewater infiltration systems. An increased adsorption would, therefore, not automatically have a significant impact on the nitrogen retention; this due to the weak binding between the ammonium ions and sand grains. When comparing human urine with commercial fertilisers and green manure crops as nitrogen fertilisers, it was indicated that utilising human urine regenerated the lowest net exergy consumption. The distance of the urine transports had a great impact on the exergy consumption.

  • 309. Bäckström, Magnus
    et al.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Integrated stormwater management in cold climates2000Ingår i: Journal of Environmental Science and Health. Part A: Toxic/Hazardous Substances and Environmental Engineering, ISSN 1093-4529, E-ISSN 1532-4117, Vol. 35, nr 8, s. 1237-1249Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Integrated stormwater management is based on the natural processes in the water cycle and the criteria for sustainable development. The aim of this paper was to investigate which integrated stormwater system components might be suitable in cold climate regions. The evaluation was based on literature reviews and studies made in Lulea, Northern Sweden. It was found that porous pavement, grassed waterways (swales, ditches), wet pond, and percolation basin were the most suitable integrated stormwater system components in cold regions whereas dry basin, stormwater infiltration surfaces, and stormwater reuse seemed to be the less suitable. Polluted snow may be treated at a central (large-scale) snow deposit; cleaner snow may be placed in many local snow depots.

  • 310.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Nitrogen conversion processes when treating wastewater in soil systems: the importance of ammonium adsorption2000Ingår i: Vatten, ISSN 0042-2886, Vol. 56, nr 2, s. 85-95Artikel i tidskrift (Övrigt vetenskapligt)
  • 311. Sundin, E.
    et al.
    Lundberg, Angela
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Semadeni-Davies, A.F.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Nordell, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Urban Snow Research at Luleå University of Technology2000Ingår i: Nordic Hydrological Conference 2000: Uppsala, Sweden 26-30 June 2000 / [ed] Torbjörn Nilsson, Uppsala: Sveriges Lantbruksuniversitet, 2000, s. 608-615Konferensbidrag (Refereegranskat)
  • 312.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Dissolved and particle-bound substances in urban snow1999Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 39, nr 12, s. 27-32Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to create a picture of the pollutant pathways for snow in urban areas, snow samples were collected in the city of Lulea, northern Sweden. Sampling sites were chosen in the city centre and in a housing area three different sites in each area. Snow samples were collected during the whole winter of 1995. The results showed that the amounts of dissolved substances as percentages of the total amounts varied according to time, site and the type of substance. For the sites along the roadsides in the city centre, the amounts that were in solution were less than 1% of the lead, 2.5% of the phosphorus, 11% of the copper, and 18% of the zinc. For the site with no-traffic, the dissolved fractions were considerably higher.In order to create a picture of the pollutant pathways for snow in urban areas, snow samples were collected in the city of Lulea northern Sweden. Sampling sites were chosen in the city centre and in a housing area - three different sites in each area. Snow samples were collected during the whole winter of 1995. The results showed that the amounts of dissolved substances as percentages of the total amounts varied according to time, site and the type of substance. For the sites along the roadsides in the city centre, the amounts that were in solution were less than 1% of the lead, 2.5% of the phosphorus, 11% of the copper, and 18% of the zinc. For the site with no-traffic, the dissolved fractions were considerably higher

  • 313.
    Sundin, Eva
    et al.
    Luleå tekniska universitet.
    Andreasson, Patrik
    Luleå tekniska universitet.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Energy budget approach to urban snow deposit melt1999Ingår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 30, nr 1, s. 39-56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In urban areas in cold regions snow handling is a significant part of municipal activity. The snow is usually ploughed off the streets and then transported to a snow deposit. As a consequence the snow is mechanically blended, packed, polluted and piled up, giving it a characteristic texture, shape, and size. To predict snow deposit melt an energy budget model that uses general meteorological data has been derived. The model is a synthesis of available energy balance terms developed for natural snow covers, and general mass and heat transfer considerations. This approach was found applicable for estimating snow deposit melt. Only geometry, radiation, sensible and latent heat are included to the model. Radiation was found to be the major source of snow deposit melt. Very little difference was found between top and side energy fluxes. Model predictions were compared with measurements of two pilot snow deposits which were constructed with snow collected from the streets of Lulea, Sweden. The degree day approach also seems to be an applicable method to estimate snow deposit melt

  • 314.
    Hedström, Annelie
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hanaeus, Jörgen
    Natural freezing, drying, and composting for treatment of septic sludge1999Ingår i: Journal of cold regions engineering, ISSN 0887-381X, E-ISSN 1943-5495, Vol. 13, nr 4, s. 167-179Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A full-scale experimental plant intended for local treatment of septic sludge, situated in northern Sweden, is presented in this paper. The concept investigated included natural freezing, thawing, and drying in combination with composting. The experimental plant consisted of an undrained freezing-thawing-drying bed and a heat-insulated composter. About 500 L of fresh sludge, with a dry matter (DM) content of 4–5%, collected from a septic tank employed by one family, was transferred to the freezing-thawing-drying bed in the beginning of November 1996. During the winter months, the sludge froze and then thawed in the middle of May 1997. During a drying period of three weeks, the DM content increased from 10.6–21.3 to 25–95%. The final sludge volume and weight were 180 L and 54 kg, respectively. Approximate concentrations of nitrogen, phosphorus and total organic carbon of the dried sludge were determined to be 23, 5.9, and 346 g/kg DM. From June until the end of August, the sludge was cocomposted with kitchen refuse. Within two weeks, the composting temperature exceeded 65°C. The measured composting temperature indicated a high pathogen die-off, but before this concept can be suggested as an alternative to conventional septic sludge treatment, further studies should be conducted, including direct measurements of pathogens. The concept, however, has proved to be of interest in cold regions due to its simple construction and operation

  • 315.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Substances in Urban Snow: A comparison of the contamination of snow in different parts of the city of Luleå, Sweden1999Ingår i: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 114, nr 3-4, s. 377-394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of the study was to investigate how the quality of snow varies within a city. The study area is situated in the Luleå municipality, in northern Sweden (lat. 65°35'N and long. 22°10'E). For this study, the city was divided into three different types of areas: housing areas, city centre and outskirts. In one area of each type, sampling sites were selected. Snow samples were taken at nine occasions, once every fourteenth day in the city centre and in the housing area. Analyses were carried out for pH, conductivity, suspended solids and both the total and dissolved concentration of phosphorus and selected metals. It was concluded that traffic or activities related to traffic were a major source of heavy metals and phosphorus in urban snow, both in the city centre and in the housing area. Also, the type of area and the design of the street were important for the quality of snow. A clear relation was found between the pH and the quantity of suspended solids in the snow. Higher pH values were found in snow samples from sites with higher traffic loads, and lower pH values at sites, which were the no-traffic sites, with small quantities of particles. The particulate and dissolved substances in the snow behaved in different ways.

  • 316.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Particle size distribution and metal content in street sediments1998Ingår i: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 124, nr 8, s. 761-766Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sediments that had accumulated during the winter season, and which were left at the surface when the snow had melted, were studied with regard to physical and chemical characteristics. The investigation was carried out in the city of Luleå, which is located in northern Sweden. Sediment samples were collected in the city center and in a housing area at streets with different traffic loads. The results showed that the amount of the sediments at a street surface was evidently affected by the presence of a sidewalk. The street with a sidewalk accumulated much more sediment than the street without a sidewalk did. Both of these streets had approximately the same traffic load. The sidewalk also affected the particle size distribution. The content of heavy metals in the sediments varied with the traffic load and the area type. The highest concentration of cadmium, lead, and zinc was found in the street with the highest traffic load.

  • 317.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Snow quality in the city of Lulea, Sweden: time-variation of lead, zinc, copper and phosphorus1998Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 216, nr 1-2, s. 103-112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The quality of urban snow was studied with regard to how the concentrations of selected metals and phosphorus vary over time. The area studied is situated in northern Sweden (65°36 prime N; 22°13 prime E). Snow samples were taken at three different locations in the city centre, approximately every second week, throughout winter. This study has clearly shown the importance of local conditions and snow clearance operations on snow quality. The study also shows that it is difficult to interpret and predict the concentrations of lead, zinc, copper and phosphorus in the snow. However, it should be possible to predict the mass loads of these substances from the deposition velocities, if the snow handling methods and routines, as well as the local circumstances are known.

  • 318.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Snow quality in urban areas1997Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The studies reported on this thesis aim to provide information and increase knowledge about the quality of urban snow and the path of pollutants. The results develop a basis for decisions regarding the prevention of environmental damage. A number of projects have been carried out to provide more detailed knowledge about: snow quality in cities, sediments that had accumulated during the winter, and that were left at the surface when the snow had melted, and the paths of pollutants at urban snow deposit. For these purposes studies have been performed in laboratory, pilot and full scale. The snow quality was studied in the city of Luleå with regard to variation with time and area. The aim was to investigate urban snow in its actual environment, throughout an entire winter season. Snow samples were taken in a housing area and in the city centre, at sites with different traffic load. It was found that traffic or activities related to traffic was a major source of heavy metals and phosphorus in urban snow, both in the city centre and the housing area. Also the type of area and the design of the street were important for the snow quality. A clear relation between the pH and the quantity of suspended solids in the snow was found. Higher pH values were found in snow from sites with higher traffic loads, compared to sites with small quantities of particles which were the no-traffic sites. The dissolved fractions showed more complicated results. The concentration of the studied substances in the snow was affected by the precipitation at the site with no traffic. At the street where the snow was left beside the street, the concentration of substances increased with time, while the precipitation was of less importance. The mass loads of substances increased with time for both the streets, where the snow stayed in the vicinity of the street, and for the non-traffic site. For the site with traffic the snow handling operations evidently affected the mass loads. This was especially the case for particle-connected substances. As a result of the increased interest in reuse of friction material the sediment which remained along the streets after snow melt was studied with regard to physical and chemical characteristics. The side walk affected the amount of substances on the street more than the traffic load. For the streets without sidewalk an increased traffic load increased the amounts of sediment. The particle size distribution of the sediments swept from the street with a sidewalk differed from the distribution at the streets without a sidewalk. With two exceptions the smallest size fraction (>75 µm) had the largest concentration of heavy metals. For composite samples the concentration increased with traffic load. The pathways of pollutants in urban snow deposits have been studied in three different scales; laboratory, pilot, and full-scale. The initial snow, melt water and sediment were analysed with regard to chemical content. It was found that the dissolved substances to a great extent folowed with the melt water while for the particle bounded substances as much as 90-99% stayed in the sediment below the deposit. The dissolved substances left the snow in the beginning of the melt period, while the substances connected to particles showed a uniform release. The laboratory study showed that melt- freeze cycles delayed the release of substances. Almost all substances were attached to particles in the snow, while in the melt water a large part was in solution. It should be noted that a so-called acid shock was not found during these studies.

  • 319.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Urban snow deposits: pathways of pollutants1996Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 189-190, s. 379-384Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The pathways of pollutants in urban snow deposits have been studied in the laboratory, in a pilot study and at an actual deposit. The fractions of dissolved and particle-bound substances in the snow and melt water were studied. The results showed that almost all substances in the snow were attached to particles, while in the melt water more than 50% of most substances were dissolved. A large part of the substances which were attached to particles stayed in the sediment below the deposit, while the dissolved substances were mainly removed with the melt water.

  • 320.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Melting of urban snow deposits: a water quality study1994Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 321.
    Viklander, Maria
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Malmqvist, Per-Arne
    Luleå tekniska universitet.
    The composition of melt water from urban snow1994Ingår i: Proceedings: International Conference on Development and Commercial Utilization of Technologies in Polar Regions, March 22-25, 1994 Luleå, Sweden, Högskolan i Luleå , 1994, s. 285-295Konferensbidrag (Refereegranskat)
  • 322.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Snöhantering och snötippar: en enkätundersökning1991Rapport (Övrigt vetenskapligt)
  • 323.
    Nordell, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Förstudie av isenergins användningsområden1989Rapport (Övrigt vetenskapligt)
  • 324. Hanaeus, Jörgen
    et al.
    Sellgren, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Ledningsteknik i kallt klimat: förslag till ramprogram 1983-19861983Rapport (Övrigt vetenskapligt)
  • 325.
    Vidal, Brenda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering. Urban Water Engineering group.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Barraud, Sylvie
    Department of Civil Engineering and Urban Planning, National Institute of Applied Sciences of Lyon.
    Kärrman, Erik
    Division of the Built Environment, Research Institutes of Sweden.
    Herrmann, Inga
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Assessing the sustainability of on-site sanitation systems using multi-criteria analysisManuskript (preprint) (Övrigt vetenskapligt)
  • 326.
    Nyström, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Nordqvist, Kerstin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Herrmann, Inga
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Laboratory evaluation of coagulants for treatment of urban snowmeltManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The treatment effect and process characteristics of coagulation were investigated in urban snow at laboratory scale using jar tests. An initial screening of twelve coagulants and flocculant aids was carried out to find a selection of chemicals that efficiently reduced turbidity and suspended solids. Five coagulants were then further investigated and additional parameters measured (conductivity, alkalinity and ζ-potential). The urban snowmelt mixture was characterized by high, but variable, particle content and low alkalinity. In the jar tests, high treatment efficiency (>90% reduction of both turbidity and suspended solids) was achieved for all coagulants. For very low alkalinity waters, the use of a biopolymer such as chitosan may be advantageous due to minimal alkalinity consumption. Based on the occurrence of charge reversal for all chemicals investigated, the mechanism for coagulation was likely charge neutralization. Treatment effect occurred in the ζ-potential range of -14 to +1 mV depending on the coagulant used. Initial turbidity and the ζ-potential are interesting parameter candidates for dosing control in stormwater treatment applications.

  • 327.
    Broekhuizen, Ico
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. Luleå Tekniska Universitet.
    Muthanna, Tone Merete
    Norwegian University of Science and Technology.
    Leonhardt, Günther
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Model structure uncertainty in green urban drainage modelsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Mathematical storm water models are often used as tools for planning and analysis of urban drainage systems, but the models’ inherent uncertainties need to be understood to make optimal use of them. One source of uncertainty that has received relatively little attention, especially for the increasingly popular green areas as part of urban drainage systems, is the choice of the mathematical model structure. This paper analyses the differences between three different widely-used models (SWMM, MIKE MOUSE and MIKE SHE) when simulating green areas over a 26 year period. A wide range of eleven different soil types and six different soil depths was used to investigate sensitivity of the models to changes in both. Important hydrological factors such as seasonal runoff and evapotranspiration, the number of events that generated runoff, and the initial conditions for rainfall events, varied strongly between the three models. MOUSE generated the highest runoff and was insensitive to changes in soil type and depth, while SHE was sensitive mainly to changes in soil type, and SWMM, which generated the least runoff, was sensitive to changes in both soil type and depth. Explanations for the observed differences were found in the descriptions of the mathematical models. The differences in model outputs could significantly impact the conclusions from design or analysis studies of urban drainage systems. The amount and frequency of runoff from green areas in all three models indicates that green areas cannot be simply ignored in urban drainage modelling studies.

  • 328.
    Nyström, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Nordqvist, Kerstin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Herrmann, Inga
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Removal of metals and hydrocarbons from urban snowmelt by coagulation and flocculationManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The treatment efficiency of a coagulation/flocculation and sedimentation process was investigated in urban snowmelt. Five different coagulants were evaluated for their effectiveness in reduction of particle content, organic carbon, total and dissolved metals, hydrocarbon oil index, PAHs and if any changes occurred in the particle size distribution. The pollutants in the snow melt were mostly in the particulate phase, and for both oil index and PAHs characterized by the larger sized molecules. An iron chloride coagulant was the only coagulant that had an effect on the particle size distribution post-treatment, where the distribution was shifted towards larger particles. In terms of total metal removal, the performance for the coagulants were similar with above 90% removal on average. Dissolved Cu, was one of the metals found in the dissolved phase, and it was reduced by 40% by coagulation treatment. The iron chloride coagulant did increase the dissolved Zn, attributed to a larger drop in pH resulting in a higher ion mobility. Similarly, the reduction in organic content, both TOC/oil/PAH were above 90% for most coagulants.

  • 329.
    Pericault, Youen
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Risberg, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Temperature performance of a heat-traced utilidor for sewer and water pipes in seasonally frozen groundManuskript (preprint) (Övrigt vetenskapligt)
  • 330.
    Müller, Alexandra
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Helene
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Marsalek, Jiri
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    The pollution conveyed by urban runoff: A review of sourcesIngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026Artikel i tidskrift (Refereegranskat)
4567 301 - 330 av 330
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf