Change search
Refine search result
1 - 31 of 31
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Søberg, Laila
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Dataset on stormwater bioretention column studies: Impact of temperature, salt and a submerged zone on the removal of metals, nutrients and suspended solids2022Data set
    Abstract [en]

    This data set presents the full raw data from bioretention column studies conducted at Luleå University of Technology in 2010-2014. The pilot scale columns were watered with synthetic stormwater. Influent and effluent samples were collected and analysed for pollutants including total and dissolved metals, nutrients, pathogens and suspended sediment. Further, supporting parameters (e.g. pH, conductivity) are included. The data enables quantifying the impact of bioretention design factors (submerged zone) and ambient factors (salinity in stormwater inflow, temperature) on the removal of these pollutants by bioretention. All filters utilised the same general column design and filter material as well as stormwater preparation. This enables inter-comparability between the different studies. Synthetic stormwater inflow concentrations and bioretention effluent concentrations are presented in the data set. Further, metal concentrations in the filter material and plant tissue have been analysed. The data set enables further analyses of bioretention performance, comparison with similar work performed elsewhere and can be used in modelling of bioretention removal performance and processes. Scientific papers describing the data have been published (see Publications)

  • 2.
    Flanagan, Kelsey
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Heléne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Contamination of Urban Stormwater Pond Sediments: A Study of 259 Legacy and Contemporary Organic Substances2021In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 55, no 5, p. 3009-3020Article in journal (Refereed)
    Abstract [en]

    Stormwater ponds improve water quality by facilitating the sedimentation of particles and particulate contaminants from urban runoff. Over time, this function entails the accumulation of contaminated sediments, which must be removed periodically to maintain a pond’s hydraulic and treatment capacity. In this study, sediments from 17 stormwater sedimentation facilities from four Swedish municipalities were analyzed for 259 organic substances likely to be found in the urban environment. A total of 92 substances were detected in at least one sample, while as many as 52 substances were detected in a single sample. A typical profile of urban contamination was identified, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, organotins, aliphatic hydrocarbons, phthalates, aldehydes, polybrominated diphenyl ethers, perfluorinated substances, and alkylphenols. However, levels of contamination varied greatly between ponds, influenced heavily by the dilution of urban pollutants and wear particles from other sources of particles such as eroded soil, sand, or natural organic matter. For 22 of 32 samples, the observed concentrations of at least one organic substance exceeded the regulatory threshold values derived from toxicity data for both sediment and soil.

  • 3.
    Galfi, Helen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Haapala, Jenny
    Water Östersund, Östersund Municipality, Krondikesvägen 60, 83182 Östersund, Sweden.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Westerlund, Camilla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Indicator bacteria variation in separate sewersystems in Östersund, Sweden - Preliminary results: [La variation des indicateurs bactériens et des flux de MES dans les systèmes séparatifs d'eaux pluviales à Östersund, en Suède - Résultats préliminaires]2013Conference paper (Refereed)
    Abstract [en]

    Faecal bacteria are a major pollution threat of water bodies designated for multipurpose use including drinking water sources or recreational purposes. Even though stormwater discharges may contribute significantly to microbiological pollution, they have not been fully investigated in the European context. We have studied the presence of indicator bacteria and total suspended solids (TSS) in stormwater discharged from four urban catchments, with areas between 5 and 40 ha, in Östersund, Sweden. The aim was to determine local variation of standard bacteria strains and TSS in Swedish urban catchments with specific land uses. Further, intra event variations were investigated. During dry weather, indicator bacteria concentrations in sewers conveying baseflow did not exceed 100 CFU/100 mL. During storm runoff, total coliform and int. enterococci concentrations increased 102 to 103 times, compared to those in baseflow. Compared to these two parameters, considerably lower concentrations were observed for E. coli and C. perfringens. Bacteria concentrations differed significantly among the sampling sites and partly, a first flush phenomenon was observed. Partly, significant correlations between TSS and indicator bacteria were observed. These were catchment specific and need a more detailed assessment. Further research will focus on seasonal variations and influential factors.

    Download full text (pdf)
    fulltext
  • 4.
    Galfi, Helen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Haapala, Jenny
    Water Engineering, Water Dept. Östersund, Östersund Municipality, Krondikesvägen 60, 83182 Östersund, Sweden.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Westerlund, Camilla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Inter-Event and Intra-Event Variations of Indicator Bacteria Concentrations in the Storm Sewer System of the City of Östersund, Sweden2016In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 142, no 7, article id 6016003Article in journal (Refereed)
    Abstract [en]

    An episode of microbiological contamination of the drinking water supply of the City of Östersund, Sweden (63°10′45″N; 14°38′09″E) prompted a study of fecal pollution in four storm drainage catchments discharging in the vicinity of the water treatment plant intake, with the overall aim of determining the presence and variation of standard fecal indicator bacteria strains and total suspended solids (TSS) in stormwater from urban catchments with specific land uses and sizes varying from 5 to 40 ha. Four bacteria strains used as indicators of fecal pollution in Sweden were studied: total coliforms, enterococci, Escherichia coli (E. coli) and Clostridium perfringens (C. perfringens). In dry weather, indicator bacteria concentrations in storm sewers conveying baseflow did not exceed 100  colony forming units (CFU)/100  mL 100  colony forming units (CFU)/100  mL, but during wet weather, total coliform and enterococci concentrations increased 10 2 102 to 10 3 103 times, compared to those in baseflow, and considerably less in the case of E. coli and C. perfringens. Bacteria concentrations differed significantly among the sampling sites and in the majority of events observed in the four catchments; higher bacteria concentrations were observed during the early phases of runoff. Only in one catchment, positive correlations were observed between TSS and total coliforms, E. coli, and enterococci, suggesting similar sources; in the remaining catchments, no such correlations were observed. The collected indicator bacteria data represent a useful addition to the available data on indicator bacteria in stormwater in cold-climate regions.

  • 5.
    Galfi, Helen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Influence of sampling methods on the measurements of urban stormwater quality constituents - Preliminary results: [Influence des méthodes d'échantillonnage pour la mesure de la qualité des eaux pluviales urbaines - Résultats préliminaires]2013Conference paper (Refereed)
    Abstract [en]

    The choice between automatic and manual sampling of urban stormwater quality has been addressed in the past as an issue of economic efficiency, field safety, and practicality. Nevertheless, there is experimental evidence that both types of sampling may yield statistically different stormwater quality data. While the past attention focused on differences in sampled solids, a new issue was addressed in this study, the potential impacts of sampling methods on concentrations of indicator bacteria. Towards this end, four indicator bacteria (coliforms, E. coli, enterococci and C. perfringens) were sampled in storm sewers of two urban catchments in Östersund, Sweden, using both automatic samplers and manual sampling. Such data were further supplemented by measurements of total suspended solids (TSS) and turbidity, recognizing that bacteria are mostly transported in the attachment to solids. Preliminary results indicate that there may be large differences between indicator bacteria in automatic and manual samples, with E. coli measurements yielding the least differences, and turbidity readings were correlated well with all the indicator bacteria and particularly E. coli. These findings will be used in the continuation of this study for refining the existing experimental design and developing practical guidance for surveys of municipal storm sewers for faecal pollution.

    Download full text (pdf)
    fulltext
  • 6.
    Galfi, Helen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Sundelin, Monica
    Hjortens Laboratorium, Fagerbacken 28, 831 46, Östersund, Sweden.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Comparison of indicator bacteria concentrations obtained by automated and manual sampling of urban stormwater runoff2014In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 225, no 9, article id 2065Article in journal (Refereed)
    Abstract [en]

    A comparative study of indicator bacteria concentrations obtained by laboratory analysis of grab samples of storm water, which were collected manually or by automatic samplers, was carried out in two urban catchments. Samples were analyzed for four types of indicator bacteria, total coliforms, Escherichia coli (E. coli), enterococci, and Clostridium perfringens and further documented by measurements of total suspended solids (TSS) and turbidity. Analysis of complete data sets (N=198) indicated no statistically significant differences in the geometric means of all the constituent samples collected automatically or manually, but there were some small differences between the results produced by the two sampling methods applied. Total coliform concentrations were positively biased in samples collected by automatic samplers, but for the three remaining indicator bacteria (E. coli, enterococci, and C. perfringens), the opposite was true. Risk of sample cross-contamination in automatic samplers was assessed in the laboratory by sampling consecutively synthetic storm water with high and low concentrations of E. coli and enterococci. The first low-concentration samples preceded by high-concentration samples were cross-contaminated and the measured concentrations were positively biased. This cross-contamination was explained by storm-water residue in the sampling line. Such a residue remained in place even after line purging by compressed air, and its mass depended on the sampling line length (tested up to 5 m), as verified by measurements in the laboratory. The study findings should be helpful for improving field protocols for indicator bacteria sampling.

  • 7.
    Herrmann, Inga
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Effect of temperature on the performance of laboratory-scale phosphorus-removing filter beds in on-site wastewater treatment2014In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 117, p. 360-366Article in journal (Refereed)
    Abstract [en]

    P-sorbing filter beds appear to be viable options for treating wastewater to reduce P discharges and recover this non-renewable resource. However, greater knowledge of filters’ responses to temperature variations is required to assess their likely performance in full-scale applications and facilitate the transfer of laboratory results to the field. Thus, in the present study two filter materials (Top16 and Polonite) were characterized physicochemically and effects of temperature on their performance were investigated under controlled laboratory conditions. Using a 22 factorial design and secondary wastewater eight filter columns were tested at temperatures of 4.3 °C and 16.5 °C. Temperature significantly (α = 0.05) and strongly affected the P binding capacity of both materials, as it was 1.2- and 1.5-fold higher at 16.5 °C than at 4.3 °C for Top16 and Polonite, respectively. This is probably due to the enhanced precipitation of calcium phosphates at higher temperature. Observed reductions in total organic carbon content in the wastewater were also positively correlated with temperature, while the pH and reduction of dissolved organic carbon remained unaffected. The physicochemical analyses indicated that several calcium phases dissolved from the filter materials, primarily gypsum and bassanite from Top16 and Portlandite from Polonite. No clear evidence of any crystalline calcium phosphates was observed in the used materials. The results clearly show that temperature strongly influences the retention of P in filters and its effects should be carefully considered before using candidate filters in full-scale applications.

  • 8.
    Kaykhaii, Saida
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Heidfors, Ingemar
    Purac AB, Malmö, Skåne, Sweden.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Enhancing stormwater treatment through ultrafiltration: impact of cleaning chemicals and backwash duration on membrane efficiency2023In: Water Reuse, ISSN 2709-6092Article in journal (Refereed)
    Abstract [en]

    The effect of chemical cleaning and regular backwashing on the efficiency of an ultrafiltration membrane fouled during stormwater treatment was studied. Increasing backwash time from 30 to 60 s resulted in an increase in productivity by 20%. However, the productivity was highest when a backwash time of 45 s was used (3% higher than using 60 s). Chemical cleaning was carried out using an alkaline solution (NaOH with or without NaOCl) followed by acid washing with HCl. The addition of NaOCl to the cleaning chemical did not significantly increase the efficiency of chemical cleaning, and the average pure water permeability increase was 97 ± 13 LMH bar−1 after chemical cleaning with NaOH followed by HCl and 117 ± 15 LMH bar−1 after chemical cleaning with NaOH + NaOCl followed by HCl, on average. In addition, reversibility after chemical cleaning was 96 ± 67%, on average. The result from scanning electron microscopy showed that at the end of the experiments, inorganic foulants existed in both the inner layer (feed side) and the outer layer (permeate side) of the membrane.

    Download full text (pdf)
    epub
  • 9.
    Kaykhaii, Saida
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Stormwater treatment using an ultrafiltration membrane and pulsatile fluid flow2023In: Urban Water Journal, ISSN 1573-062X, E-ISSN 1744-9006Article in journal (Refereed)
    Abstract [en]

    A polymeric ultrafiltration (UF) membrane was used for stormwater treatment, with the focus on evaluating the increase in the membrane process productivity by adding pulsatile fluid flow to UF membrane treatment. Sedimentation and sieving were used as pre-treatment. The result showed that increasing the pulse frequency from 0 to 4 Hz increased productivity from -6.6 to 82 LMH. UF membrane removed suspended solids, oil and turbidity below detection limit. The UF membrane also separated total coliforms, E. coli and P. aeruginosa below detection limit. Total organic carbon (TOC) was reduced by between 70 and 91%. In addition, the UF membrane was able to reduce BOD7 and COD to below 7 mg/L in the permeate. According to the US EPA, WHO, and national regulations in Canada,  Japan, and South Korea, treated stormwater can be used for flushing toilets and streets irrigation and agricultural use. 

    Download full text (pdf)
    fulltext
  • 10.
    Kaykhaii, Saida
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Stormwater treatment using ultrafiltration – Effect of cleaning chemical and backwash time on membrane efficiency2022Conference paper (Refereed)
    Abstract [en]

    Stormwater runoff is known as one of the main contributors of pollutants which is often discharged untreated to the water bodies and causes environmental risk [1]. Membrane treatment may be a good option for treatment of heavily polluted stormwater as it can also remove small particles and colloids that are not normally captured in typical stormwater facilities such as ponds, wetlands, etc. However, fouling in membranes is challenging to control. Application of a pre-treatment prior to the membrane process might help to postpone fouling [2]. In addition, a proper combination of backwash and chemical cleaning for the membrane is essential but this has not yet been studied specifically for stormwater runoff treatment with membranes. In this study, a combination of ultrafiltration PVP/PES membrane with pulsatile fluid flow was used for separation of pollutants from stormwater. Sieving was considered as pre-treatment. In addition, a combination of backwash and chemical cleaning was used to assess reversibility, flux recovery and productivity of the membrane. The results showed that by increasing backwash time from 30 to 60 s, the reversibility and flux recovery increased from 26% to 75% and 55% to 87%, on average and also resulted in 20% increase in productivity. Cleaning chemically with alkaline solution (NaOH, pH=12), followed by acidic solution (HCl, pH=2), had a good impact on removing foulants from membrane surface. According to the experiments, addition of NaOCl to the alkaline solution did not have significant effect on pure water flux recovery. From environmental point of view, using NaOCl is not recommended [3].

    Download full text (pdf)
    fulltext
  • 11.
    Kaykhaii, Saida
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Stormwater treatment with ultrafiltration: Characterisation of backwash water: [Traitement des eaux pluviales par ultrafiltration: Caractérisation deseaux de rétrolavage]2023Conference paper (Other academic)
    Abstract [en]

    Backwash water is an integral part of membrane treatment, normally making up between 2 and 10 % of the clean water production which constitutes a large volume on an industrial scale. To identify suitable treatment or disposal methods for backwash water, it is important to understand the characteristics of the backwash water and what contaminants it contains. In this study, the backwash water from an ultrafiltration membrane process for stormwater treatment was analysed. Concentrations of TSS and TOC were 2.4 and 24 times higher in the backwash water than the influent stormwater. The concentration of particulate and dissolved (<0.45µm) metals in the backwash water was high, for example, the average concentration of total Cu and Cr was 742 ± 215 and 737 ± 243 µg/L. In addition, the average concentration factors for Cu and Cr were 29 ± 9 and 41 ± 15.9. Methods such as coagulation, electrocoagulation and evaporation could be used to further treat backwash water. The residue fraction would contain high concentrations of metals that need to be disposed or could potentially be a good resource for metal recovery in the future.

    Download full text (pdf)
    fulltext
  • 12.
    Kaykhaii, Saida
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Stormwater treatment using membrane filtration with pulsatile fluid flow2021Conference paper (Refereed)
    Abstract [en]

    Stormwater runoff is one of the most important contributor of pollutants to natural waters. Therefore, separation of pollutants from stormwater runoff before entering the receiving waters is an important issue. Nitrogen (ammonium, nitrite, nitrate, total nitrogen), phosphorus (organic and inorganic), metals (Fe, Cd, Zn, Pb, As, Al, metalloid As, Cr, Cu, Ni in total, dissolved and truly dissolved form) are main compounds that are contained in various concentrations in the runoff and should be separated. Various methods have been used for stormwater treatment. Membrane technology is applied in water and wastewater industries1, but is not yet used for treatment of stormwater. Ceramic, polymeric and metallic membranes have been used in other research studies in order to optimise removal efficiency for separation of particulate, colloidal and dissolved substances in runoff. To prevent fouling, which is the major problem in membranes and to decrease the operational cost, use of a proper pre-treatment is helpful 2–4, as is periodical cleaning of the membrane surface 5,6. This process can be further assisted by using membranes with larger pore size (microfiltration, ultrafiltration) than nanofiltration and reverse osmosis membranes which have smaller pore size but higher removal efficiency. In this study, sedimentation was used as a pre-treatment method and an ultrafiltration membrane process and pulsatile flow were evaluated with respect to separation of pollutants from snowmelt mixture. A bench-scale membrane unit was used with a polyether sulfone ultrafiltration membrane (PES/PVP UF membrane) to assess the efficiency of the process and to evaluate if pulsatile flow at different pulse frequencies (0 and 4 Hz) can postpone fouling. The feed and permeate was sampled and analysed on the concentration of TSS, pH, total and dissolved metals and chloride content, as well as the particle size distribution, TOC, turbidity and oil index. The volume of permeate achieved in each experimental run was monitored. The results from these experiments showed that by increasing pulse frequency from 0 to 4 Hz, the productivity of membrane increased from 13.5% to 65.5%. In addition, TOC removal increased from 70% to 87%. Regardless of pulse frequency the ultrafiltration membrane set-up removed TSS, particles and oil fractions completely. Dissolved As, Cd, Cu, Cr, Ni, Pb and P were reduced by 16, 12.6, 11.8, 23.5, 21, 44 and 73.1%, respectively.

    Download full text (pdf)
    fulltext
  • 13.
    Lange, Katharina
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Furén, Robert
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water. NCC Sverige AB, Department of Research and Innovation, Herrjärva Torg 4, 170 80, Solna, Sweden.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Winston, Ryan
    Department of Food, Agricultural, and Biological Engineering, Ohio State University, Agricultural Engineering Building AE, Building 298, 590 Woody Hayes Dr, Columbus, OH 43210, USA; Department of Civil, Environmental, and Geodetic Engineering, Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210, USA; Core Faculty, Sustainability Institute, Ohio State University, 3018 Smith Lab 174 W, 18th Avenue Columbus, OH 43210, USA.
    Tirpak, R. Andrew
    Department of Food, Agricultural, and Biological Engineering, Ohio State University, Agricultural Engineering Building AE, Building 298, 590 Woody Hayes Dr, Columbus, OH 43210, USA.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Smith, Joseph
    Department of Food, Agricultural, and Biological Engineering, Ohio State University, Agricultural Engineering Building AE, Building 298, 590 Woody Hayes Dr, Columbus, OH 43210, USA.
    Dorsey, Jay
    Department of Food, Agricultural, and Biological Engineering, Ohio State University, Agricultural Engineering Building AE, Building 298, 590 Woody Hayes Dr, Columbus, OH 43210, USA.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Abundance, distribution, and composition of microplastics in the filter media of nine aged stormwater bioretention systems2023In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 320, article id 138103Article in journal (Refereed)
    Abstract [en]

    Bioretention systems are designed for quality treatment of stormwater. Particulate contaminants are commonly treated efficiently and accumulate mainly in the surface layer of the bioretention filter material. However, concerns exist that microplastic particles may not show equal accumulation behavior as other sediment particles. So far only two field and two laboratory studies are available on the fate of microplastics in few relatively newly built bioretention systems. Therefore, this study investigated the abundance and distribution of microplastics in nine 7–12 years old stormwater bioretention systems. It was found that microplastics generally accumulate on the surface of bioretention systems. Microplastic median particle concentrations decreased significantly from the surface layer (0–5 cm) of the filter material to the 10–15 cm depth layer from 448 to 136 particles/100 g, respectively. The distance to the inlet did not significantly affect the surface accumulation of microplastic particles, suggesting modest spatial variability in microplastics accumulation in older bioretention systems. Further, this study investigated the polymer composition in bioretention systems. It was shown that PP, EVA, PS and EPDM rubber are the most abundant polymer types in bioretention systems. Also, it was found that large percentages of microplastic particles are black particles (median percentage of black particles: 39%) which were found in 28 of the 33 investigated samples. This underlines the importance of including black particles in microplastic studies on stormwater, which has been overlooked in most previous studies.

    Download full text (pdf)
    fulltext
  • 14.
    Milovanovic, Ivan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Müller, Alexandra
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Synthetic stormwater for laboratory testing of filter materials2023In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 44, no 11, p. 1600-1612Article in journal (Refereed)
    Abstract [en]

    Synthetic stormwater was tested to determine the ageing effects on dissolved metal concentrations and used in a column experiment to determine efficiency of four different filter materials (milkweed, bark, peat, polypropylene) in removing total and dissolved metals. Synthetic stormwater was created by adding metal salts, oil and collected stormwater sediment to tap water. Two ageing experiments were performed to determine the change of synthetic stormwater quality over time. One experiment lasted for 11 days and another focused on rapid concentration changes one day after preparation. The one-day ageing experiment showed rapid decrease in dissolved concentration of certain metals, specifically Cu. To consider this change, correction coefficients for each metal were developed and used to estimate the average dissolved metal concentration in the synthetic stormwater during the experiment to determine filter treatment efficiency. During the 11-day experiment on metal concentrations, no noticeable quality changes were observed for at least six days after the preparation of synthetic stormwater. Furthermore, a column experiment was run with duplicate filter columns. Inflow and outflow samples were analysed for total and dissolved metals, turbidity, particle size distribution, and pH. High removal of total metal concentrations was noticed in all tested filter media (58-94%). Dissolved metal concentration removal varied among different filter media. In general, columns with bark and peat media were able to treat dissolved metals better than polypropylene and milkweed. The level of treatment of dissolved metals between the different filter media columns were bark > peat > milkweed > polypropylene.

    Download full text (pdf)
    fulltext
  • 15.
    Müller, Alexandra
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Building surface materials as sources of micropollutants in building runoff: A pilot study2019In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 680, p. 190-197Article in journal (Refereed)
    Abstract [en]

    Control of diffuse pollution is critical for achieving good surface water quality status. In this context, pollutant contributions from building materials have received increased attention in recent decades. This study examined the releases of metals, nonylphenols and phthalates from ten common building surface materials (installed in triplicates) into rainwater runoff from six rain events. The highest releases of metals were from copper and zinc sheets (average concentrations of 3090 μg/L Cu and 7770 μg/L Zn respectively), while other metal materials, e.g., Corten weathering steel, exhibited lower releases. PVC roofing released high concentrations of nonylphenols and phthalates (average concentrations of up to 26 μg/L nonylphenols and 455 μg/L Diisononyl phthalate, DINP) which have not been investigated in the earlier studies. Pollutant releases varied between events, likely because of weather conditions and rainfall characteristics. Study findings should be valuable for environmentally responsible applications of the existing building materials and the development of new ones, as well as the investigations and risk assessment of specific pollutants in stormwater.

  • 16.
    Müller, Alexandra
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Heléne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Lindfors, Sarah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Organic micropollutants in stormwater runoff from three urban catchments in Sweden: [Micropolluants organiques dans les eaux de ruissellement de trois bassins versants urbains en Suède]2023Conference paper (Refereed)
    Abstract [en]

    Urban runoff is recognised to contribute to the deterioration of surface water quality and previous research pointed out a need to focus on organic micropollutants. This study presents measurements of stormwater quality with respect to polycyclic aromatic hydrocarbons, oil, phthalates, alkylphenols, organotin compounds (OTC), polyfluoroalkyl substances (PFAS) and polychlorinated biphenyls (PCBs) from three Swedish catchments (two industrial parks and one parking lot). The results showed that all the studied groups of organic micropollutants except for PFAS and PCBs were present in the stormwater. The oil levels were similar in base flow compared to runoff, while other substances had higher concentrations during runoff events compared to base flow. Among the analysed phthalates, DEHP and DINP were those that were detected in concentrations above the analytical reporting limits, of which DINP was the most abundant, with a maximum concentration of 140 μg/L. Among the OTCs, monobutyltin was the most abundant, which was detected in all samples and present in the highest concentrations (up to 270 ng/L). Regarding the different types of runoff studied (rain, snowmelt and rain on snow) no clear differences could be identified by the available body of data.

    Download full text (pdf)
    fulltext
  • 17.
    Müller, Alexandra
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Heléne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Releases of micropollutants from building surface materials into rainwater and snowmelt induced runoff2023In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 330, article id 138730Article in journal (Refereed)
    Abstract [en]

    Building surface materials, exposed to wash-off by rainwater or snowmelt, are recognised as one of the significant urban diffuse pollution sources contributing to the impairment of stormwater quality. The pollution conveyed by roof runoff originates from two potential sources, migration of surface material constituents, or wash-off of pollutants deposited on the surface by atmospheric deposition. This study investigated the releases of metals and several groups of contaminants of emerging concern: alkylphenols, alkylphenol ethoxylates, and phthalates, from commercially available materials, which are commonly used on buildings and structure surfaces in the urban environment. The materials tested included the following: metal sheets of stainless steel, copper, zinc, galvanised steel, corten steel, corrugated and coated steel, coated zinc; and bitumen-based roofing felt and shingles, as well as polyvinyl chloride (PVC) from two manufacturers. The stainless steel was considered a control material serving to estimate pollutant contributions deposited on the pilot panels from the surrounding environment. Moreover, this study presents novel data on roof snowmelt induced runoff quality, not reported in the previous literature. The experimental setup consisted of 2-m2 rectangular panels mounted in triplicates of each material and placed in an open-air setting on the campus of Luleå University of Technology, Sweden. Runoff leaving the gently sloping material panels was collected during 11 rain and three snowmelt driven runoff events occurring over a five-year period. The results showed that, in general, the micropollutant concentrations and loads were lower in snowmelt than rain induced runoff, and no decreasing trend was detected in the releases of phthalates or metals during the study period. Moreover, on a yearly basis, copper sheets were estimated to release 0.6 g/m2 Cu to runoff, zinc and galvanised sheets 1.3 and 0.7 g/m2 Zn, respectively, and, PVC sheets were estimated to release up to 78 mg/m2 of diisononyl phthalate (DINP).

    Download full text (pdf)
    fulltext
  • 18.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Particle concentrations: analysis methods for urban runoff2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Urban runoff often contains high concentrations of particles. Pollutants that adsorbs to surfaces of particulate material will be transported to receiving waters or a sewage treatment plant. For the recipient, the particles in the runoff are a significant cause of water quality impairment. The particles are associated with impacts of surface waters such as increased turbidity, and effects on water-living organisms and fish. The particle concentration is one of the most common parameters to measure in urban runoff.The main objective was to investigate and compare the accuracy of analysis methods for measuring total particle concentration in urban runoff. The methods to be compared are total suspended solids (TSS), suspended sediment concentration (SSC-A, SSC-B and SSC-C), and one new method; multiple filter method (MFM). General differences between the analysis methods:Handling of sample: * SSC and MFM – analysis of entire sample * TSS –aliquot analysisFilter pore size: * TSS and SSC – 1.6 μm * MFM – 0.45 μmThe studies were performed with artificial and natural runoff samples. Three studies with artificial samples were performed a) high amount of small particles, b) high amount of large particles and c) different particle intervals. The study with natural runoff samples, were performed with rainfall runoff, undisturbed snow and snowmelt runoff. The result for artificial samples showed that SSC and MFM gave comparable result irrespective of particle concentration or size, approximately 100 % of the initial concentration. TSS which measures the suspended solids underestimates the particle concentration with 55-90 %. Measured concentrations for samples with particles larger than 0.063 mm were underestimated. The underestimation increased with increased particle size.For rainfall runoff samples a statistical analysis, ANOVA test, showed that MFM gave a significantly higher result than SSC-B and TSS at a confidence level of 95 %. These result implied that small particles of size 0.45 – 1.6 μm influence the results. The ANOVA test showed no significant difference between SSC-B and TSS. The results from this study show that the particle size distribution has importance for the result and the particle concentrations showed to have no influence.

    Download full text (pdf)
    FULLTEXT01
  • 19.
    Nordqvist, Kerstin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Galfi, Helen
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Westerlund, Camilla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Measuring solid concentrations in urban stormwater and snowmelt: a new operational procedure2014In: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 16, no 9, p. 2172-2183Article in journal (Refereed)
    Abstract [en]

    A comparative study of five methods measuring suspended sediment or solid concentrations in water–sediment mixtures indicated that, depending on the method used, broadly varying results can be obtained. For water–sediment mixtures containing sand size particles, the standard TSS method produced negatively biased results, accounting for 0 to 90% of the present solids; the negative bias directly depended on the magnitude of the sand fraction in the water–sediment mixture. The main reason for the differences between the TSS and the rest of the methods laid in the handling of samples; in the former methods, whole samples were analysed, whereas the TSS analysis was performed on sub-samples withdrawn from the water sample, the withdrawal process tending to exclude large particles. The methods using whole water–solid samples, rather than aliquots withdrawn from such samples, produced accurate estimates of solid concentrations, with a fairly good precision. Two whole-sample methods were studied in detail, a slightly modified standard SSC-B method and the newly proposed operational procedure referred to as the Multiple Filter Procedure (MFP), using three filters arranged in a series with decreasing pore sizes (25, 1.6 and 0.45 µm). Both methods assessed accurately concentrations of solids in a broad range of concentrations (200–8000 mg L−1) and particle sizes (0.063–4.0 mm). The newly introduced MFP was in good agreement with the SSC procedure, the differences between the two procedures not exceeding the standard bias defined for the SSC-B method. The precision of both SSC and MFP was generally better than ±10%. Consequently, these methods should be used when the total mass of transported solids is of interest.

  • 20.
    Nordqvist, Kerstin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Westerlund, Camilla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Measuring solids concentrations in urban runoff: methods of analysis2011Conference paper (Refereed)
    Abstract [en]

    Various types of solids conveyed with rainfall and snowmelt runoff into receiving waters cause numerous environmental impacts, including reduced sunlight penetration, blanketing of fish spawning substrates, and transport of pollutants contributing to aquatic pollution. For the assessment of such impacts, it is important to measure solids concentrations in both runoff and snowmelt. In this study, accuracies of three analytical methods used to measure solids were assessed: (a) A TSS (total suspended solids) method, (b) Suspended sediment method (SSC-B), and (c) a multiple filter method (MFM). For rainfall runoff samples containing 90% of particles smaller than 5 μm, the MFM measurements produced concentrations significantly higher than those obtained with SSC-B and TSS methods, at a 95% confidence level. In the case of snowmelt runoff, the SSC-B and MFM methods yielded similar concentrations, which were 10-20% higher than those measured by the TSS method, and the coefficient of variation of repeated TSS readings was up to three times higher than that of the former methods. The results indicate the importance of choosing the “best” analytical method for assessing the operational and environmental impacts of solids conveyed by urban runoff and snowmelt.

    Download full text (pdf)
    FULLTEXT01
  • 21.
    Nyström, Fredrik
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Flocculation and membrane filtration of stormwater: laboratory experiments2016Conference paper (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 22.
    Nyström, Fredrik
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Laboratory scale evaluation of coagulants for treatment of stormwater2020In: Journal of Water Process Engineering, E-ISSN 2214-7144, Vol. 36, article id 101271Article in journal (Refereed)
    Abstract [en]

    The treatment effect and process characteristics of coagulation were investigated in semi-synthetic stormwater in 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 with additional parameters measured (conductivity, alkalinity, and ζ-potential). The semi-synthetic stormwater was characterized by a high but variable, particle content, and low alkalinity. In the jar tests, a 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 span 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.

  • 23.
    Nyström, Fredrik
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Removal of metals and hydrocarbons from stormwater using coagulation and flocculation2020In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 182, article id 115919Article in journal (Refereed)
    Abstract [en]

    As the understanding of how stormwater pollutants are fractioned and need for mitigation has increased, so has the investigation into more advanced treatment techniques. The present study investigated the treatment efficiency of coagulation/flocculation and sedimentation in semi-synthetic stormwater. Five coagulants were evaluated in terms of reducing particle content, organic carbon, total and dissolved metals, hydrocarbon oil index, and polycyclic aromatic hydrocarbons (PAHs). Changes in the resulting particle size distribution as a consequence of the coagulation treatment were also investigated. The pollutants in the semi-synthetic stormwater were predominantly in the particulate phase. The medium and longer chained hydrocarbons dominated the hydrocarbon oil index, while medium to high molecular weight PAHs were most abundant. Iron chloride was the only coagulant that affected particle size distribution post-treatment, shifting the distribution toward larger particles. In terms of total metal removal, the performance of the coagulants was similar, with over 90% removal on average. Concentration of zdissolved copper, one of the metals found in the dissolved phase, was reduced by 40% via coagulation treatment. The iron chloride coagulant increased dissolved Zn, a change attributed to a considerable drop in pH resulting in higher ion mobility. Similarly, the reduction in organic content (total organic carbon, oil, and PAHs) was over 90% for most coagulants.

  • 24.
    Nyström, Fredrik
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Removal of small particles from urban snow melt mixture by coagulation/flocculation and sedimentation2017In: 14th IWA/IAHR International Conference on Urban Drainage: Conference Proceedings, 2017, 2017Conference paper (Other academic)
    Abstract [en]

    This abstract presents a laboratory study of a coagulation/flocculation process on an urban snow melt mixture. Coagulation/flocculation is ubiquitous in water treatment, but has seen little use in the stormwater context. Using a jar-test procedure five different chemicals are evaluated as primary coagulants and their treatment performance on urban snow melt with respect to solids removal and metal content. Particle-size distribution measurements will indicate the process effect on different size fractions in the urban snow melt. Analysis for metal content will show the extent of metal reduction that occurs, either by separating out the particulate fraction or due to precipitation reactions.

    Download full text (pdf)
    fulltext
  • 25.
    Sami, Mashreki
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Kvarnström, Elisabeth
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    On-site greywater treatment systems - influent and effluent quality2023Data set
    Abstract [en]

    The dataset presented here consists of raw data on the quality of influent and effluent greywater from eight on-site greywater treatment systems situated in Södertälje municipality, Sweden. These on-site treatment systems included three types of commercially available package plants and one sand filter. The influent and effluent samples were taken as grab samples between August 2020 and December 2021 and analysed for organic material, nutrients, pathogens, anionic surfactants, salt and (for two of the eight on-site systems) microplastics. Supporting parameters, e.g. suspended solids and pH, are also included. Further, for microplastics, results from blank samples are included.

    This dataset was used to evaluate the treatment efficiency of the on-site greywater treatment systems and to assess the suitability of the treated water for reuse.

  • 26.
    Sami, Mashreki
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Kvarnström, Elisabeth
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Quality of greywater from a city district before and after treatment in a green wall2023Data set
    Abstract [en]

    The dataset presented here consists of raw data on the quality of influent greywater generated from a city district with 800 PE (population equivalent) and the effluent quality of greywater after treatment using a green wall. Five natural filter materials (pumice, biochar, hemp fiber, spent coffee ground, and composted fiber soil) were used in the green wall and tested for three hydraulic loading rates (54, 108 and 216 l/m2/d). The influent and effluent samples were taken manually between November 2021 and March 2022 and were analyzed for organic material, nutrients, pathogens, anionic surfactants, salt and microplastics. Supporting parameters e.g. suspended solids and pH, are also included in the dataset. Further, for microplastics, results from blank samples are included. This dataset was used to evaluate the treatment efficiency of the filter materials at different hydraulic loading rates.

  • 27.
    Sami, Mashreki
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Kvarnström, Elisabeth
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Removal of Microplastics from Greywater Using a Green Wall Treatment System2022In: 17th International Conference on Wetland Systems for Water Pollution Control: Conference Proceedings, 2022, p. 505-508Conference paper (Refereed)
    Abstract [en]

    A green wall with four filter media - pumice, biochar, hemp, and compost soil - was investigated with regard to the removal of microplastics from real greywater. Nine polymers were analysed using thermal extraction desorption gas chromatography-mass spectrometry (TED-GC/MS). The results showed the presence of polyvinylchloride (PVC), polystyrene (PS), poly-ethylene-terephthalate (PET), polypropylene (PP), and polyamide (PA) in the influents and effluents. High concentration of PS (22 μg/l) and PET (73 μg/l) were observed in the influent but were removed efficiently in the green wall with effluent concentrations of <2 μg/l from all filter materials except for hemp. The effluent from one hemp replicate showed higher concentrations of PVC (58 μg/l) and PET (114 μg/l) than the influent. During the sampling period, all filter materials removed TSS, BOD and TOC by >90%.

    Download full text (pdf)
    fulltext
  • 28.
    Westerlund, Camilla
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Galfi, Helen
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Particle pathways during urban snowmelt and mass balance of selected pollutants2011Conference paper (Refereed)
    Abstract [en]

    The pathways and mass balance of selected pollutants, released during the snowmelt process, were investigated for urban bulk snow placed in small, intermediate, and large-scale lysimeters. The results showed that low percentages of TSS (total suspended solids) and heavy metal (Cu, Zn, Pb) loads contained in snow were transported with snowmelt, the rest remained in situ with the particulate residue. The TSS loads transported with snowmelt were 3, 3.4, and 4.8% of the initial TSS mass in the small, intermediate and large lysimeters, respectively. Particulate heavy metal loads transported with snowmelt, during the whole melting process, were measured in the intermediate lysimeter for copper and zinc, and for lead in the large lysimeter. The measured mass loads in snowmelt leaving the intermediate lysimeter were 7.5 and 7.2% for copper and zinc, respectively, and 1.7% for lead leaving the large lysimeter. The remainder of the loads stayed in situ with the particulate residue. The loads transported with snowmelt were independent of the initial TSS and metal concentrations in bulk snow. These findings have implications for siting and operating snow disposal facilities; most of the initial TSS and particulate heavy metal loads can be retained on site, rather than released with snowmelt into the receiving environments.

    Download full text (pdf)
    FULLTEXT01
  • 29.
    Öborn, Lisa
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Heléne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Svedin, Jonathan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Litter in Urban Areas May Contribute to Microplastics Pollution: Laboratory Study of the Photodegradation of Four Commonly Discarded Plastics2022In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 148, no 11, article id 06022004Article in journal (Refereed)
    Abstract [en]

    Plastic litter in the urban environment has been identified as a source of microplastics and stormwater a pathway for its transportation to freshwater and marine environments. However, few studies exist on the potential for litter to contribute to microplastics in a land-based system. This laboratory-based study involves simulation of the weathering of four polymers [low-density polyethylene (PE-LD), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET)] in a land-based environment using accelerated photodegradation with three exposure times. Microplastics generated were quantified with Fourier transform infrared spectroscopy and identified using a spectra reference library. The results showed differences in release patterns and number of particles produced. For LD-PE, no clear pattern of UV-degradation was demonstrated, because the number of particles released from exposed and unexposed (control) samples was in the same order of magnitude. PS and PET showed similar patterns, where the number of particles released increased with exposure duration. The numbers of particles detected were, on average, 1, 8, and 31  particles/cm2 for PS and 3, 3, and 16  particles/cm2 for PET for exposures of seven, 28, and 56 days, respectively. PP produced the largest number of particles after 28 days exposure (ca. 58  particles/cm2) which then decreased after 56 days (ca. 21  particles/cm2). It was hypothesized that the number of particles increased with exposure time and that the generated particles then further fragmented into pieces of undetectable particle size (<10  μm). 

    Download full text (pdf)
    fulltext
  • 30.
    Öhman, Johan
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Sjödahl, Mikael
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Polarization-Resolved Digital Holographic Measurements of MicroplasticsManuscript (preprint) (Other academic)
    Abstract [en]

    Dual-view digital holography is used to image samples of microplastics. The detection is polarization-resolved and produces, in total, four different intensities, one in each polarization direction on each camera. Ratio angles between all four components are calculated, and differences between the samples are investigated. This paper uses four different samples, particles from rubber tires, plastic bottles, coffee cups, and a reference sample. It is found that the data varies a lot for all samples. But when calculating the correlation coefficients differences between the samples are observed.

  • 31.
    Österlund, Heléne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Renberg, Lovisa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Micro litter in the urban environment: sampling andanalysis of undisturbed snow2019In: 10e Conférence internationale L'eau dans la ville: Programme et résumés [Urban water: Programme and abstracts], GRAIE , 2019, p. 185-185Conference paper (Refereed)
    Abstract [en]

    Micro litter was analysed in undisturbed urban snow samples from six sites in the Town of Luleå, Northern Sweden and one control/reference site in the rural areas outside the city. All samples were taken through the whole snow depth, 72-106 cm deep and 107/8 days old, using a snow core sampler. The snow samples were melted, filtered consecutively on 300 and 50 µm filters, and finally analysis of micro litter particles on the filters were counted and categorised under a microscope. The categories were natural and synthetic fibres, plastic fragments, black rubber and other anthropogenic black particles. The results showed that fibres were in the same order of magnitude in the snow as in untreated wastewater and atmospheric fallout. Rubber particles were only detected in snow from the sites near trafficked roads indicating that this size range of rubber does not transport very far. Combustion particles were detected in the highest concentration in all samples. These are proposed to originate from traffic (central sites) and wood burning (residential sites). Plastic fragments were the least detected category in this study corresponding to only a few items per litre of melted snow.

1 - 31 of 31
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf