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  • 1.
    Galfi, Helen
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Assessment of stormwater and snowmelt quality based on water management priorities and the consequent water quality parameters2020Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Dagvatten från regn och snösmältning är viktiga komponenter i föroreningstransport till ytvattentäkter som används för dricksvattenproduktion och badvatten. I denna studie har potentiella källor och transportvägar av mikrobiologiska föroreningar studerats i Östersund genom mätningar och utvärdering av fekala indikatorbakterier (FIB) i dagvatten som släpps ut i den närliggande Storsjön. Även andra föroreningar, så som metaller, ingick i studien för att bättre förstå källorna till och förhållanden mellan dessa parametrar och FIB.

    Transport av FIB i dagvatten som släppts ut från fyra urbana avrinningsområden gav följande resultat: (a) E. koli, med medelkoncentration av all data sammanlagt (Cmean = 430 cfu (kolonibildande enheter)/100 ml), och enterokocker (Cmean = 1380 cfu/100 ml), var de bästa fekala indikatorerna; (b) koliformer (Cmean = 3130 cfu/100 ml) och C. perfringens (Cmean = 150 cfu/100 ml) var mycket mindre effektiv som indikator; där koliformer inkluderar icke-fekala bakterier och C. perfringens uppvisade knappt någon variation mellan platser och provtagningstillfällen; (c) mellan de olika avrinningsområdena uppmättes de högsta halterna av FIB i ett centralt avrinningsområde med blandad markanvändning; (d) FIB-halter i snösmältning var endast signifikanta för enterokocker (400 = cfu/100 ml) och (e) i basflöden, vilket förekom i två av avrinningsområdena, uppmättes nästan inga FIB. Följaktligen har dagvattnet i dessa områden inte påverkats av felkopplingar eller inläckage av spillvatten.

    FIB-halter varierade i dagvatten från regn och snösmältning beroende av andra parametrar. Hur dessa parametrar relaterade till FIB identifierades genom klusteranalys. Parametrarna var: temperatur, konduktivitet, suspenderade ämnen (TSS), flödeshastighet och fosfor. Dessa har vidare använts i regressionsanalys. E. koli och enterokocker kunde statistiskt modelleras i tre avrinningsområden med determinationskoefficienter, R2, mellan 38-66%. Trots osäkerheter skulle sådan modellering vara användbar för framtida FIB-övervakning eller för att jämföra olika alternativ av åtgärder. Uppskattning av FIB genom provtagning av dagvattensediment i rännstensbrunnar lyckades inte, eftersom dessa mycket mineralhaltiga partiklar innehöll låga FIB-halter.

    Dagvatten analyserades även för oorganiska ämnen såsom mineraler (Al, Ca, Fe, K, Mg, Na) och antropogena tungmetaller (Cd, Cr, Cu, Ni, Pb, Zn). Transport av oorganiska ämnen från avrinningsområden via dagvattenledningar dominerades av mineraler som uppvisade höga halter i basflöden. Tungmetallhalter jämfördes med riktvärden som föreslagits i Sverige. Dagvatten i respektive avrinningsområde överskred de rekommenderade värdena fem gånger för Zn.

    Vid genomförda fältstudier påvisades osäkerheter i uppmätta FIB-halter och suspenderade ämnen. Automatiserad provtagning med kraftigt varierande FIB-halter påverkades av rester av vattnet i provtagningsslangarna, vilket kan minimeras genom kortare provtagningsslang utan böjar i provtagningslinjen. Vidare påvisades att mängden suspenderade ämnen i dagvatten underskattades med den konventionella TSS-metoden som innebär analys på delprov istället av helprov. Felkällor i uppskattning kan elimineras med hjälp av helprovsanalys; antingen den befintliga SSC-metoden (suspenderad sedimentkoncentration) eller i denna studie föreslagen MFP (multipel filter procedure) som innebär filtrering av hela provet genom succesivt finare filter (porstorlekar 25, 1,6 och 0,45 µm). MFP genererade resultat som var ekvivalenta med de som erhölls med SSC, vilket bekräftas genom statistiska metoder.

  • 2.
    Broekhuizen, Ico
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Leonhardt, Günther
    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.
    Event selection and two-stage approach for calibrating models of green urban drainage systems2020Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 24, s. 869-885Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The calibration of urban drainage models is typically performed based on a limited number of observed rainfall–runoff events, which may be selected from a larger dataset in different ways. In this study, 14 single- and two-stage strategies for selecting the calibration events were tested in calibration of a high- and low-resolution Storm Water Management Model (SWMM) of a predominantly green urban area. The two-stage strategies used events with runoff only from impervious areas to calibrate the associated parameters, prior to using larger events to calibrate the parameters relating to green areas. Even though all 14 strategies resulted in successful model calibration (Nash–Sutcliffe efficiency; NSE >0.5), the difference between the best and worst strategies reached 0.2 in the NSE, and the calibrated parameter values notably varied. The various calibration strategies satisfactorily predicted 7 to 13 out of 19 validation events. The two-stage strategies reproduced more validation events poorly (NSE <0) than the single-stage strategies, but they also reproduced more events well (NSE >0.5) and performed better than the single-stage strategies in terms of total runoff volume and peak flow rates, particularly when using a low spatial model resolution. The results show that various strategies for selecting calibration events may lead in some cases to different results in the validation phase and that calibrating impervious and green-area parameters in two separate steps in two-stage strategies may increase the effectiveness of model calibration and validation by reducing the computational demand in the calibration phase and improving model performance in the validation phase.

  • 3.
    Wang, Zihan
    et al.
    College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Hartmann, Tobias Edward
    Institute of Crop Science, University of Hohenheim, Germany.
    Wang, Xiuheng
    State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, PR China.
    Cui, Zhenling
    College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Hou, Yong
    College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Meng, Fanlei
    College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Yu, Xingchen
    College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Wu, Jiechen
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Zhang, Fusuo
    College of Resources and Environmental Sciences, China Agricultural University, PR China.
    Phosphorus flow analysis in the maize based food-feed-energy systems in China2020Ingår i: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 184, artikel-id 109319Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phosphorus (P) is an essential and limiting nutrient for agricultural systems, where the demand for agricultural products such as food, feed, and bio-fuel are the major drivers of the intensification of agricultural production systems. Globally, maize is one of three main cereal crops, a main feedstock for animal production and a substrate for the production of bio-ethanol. This study investigated P flows through the multiple utilization systems of maize (as represented by the subsystems of food, feed and energy production) at a crop level of 2016 as reference year and made future predictions of P flows for the year 2030 based on different scenarios for food-feed-energy systems in China. For 2016, the subsystem of animal production resulted in the highest waste of P due to inappropriate manure management, but the subsystem of value-added products (Bio-fuel production, distillers dried grains with solubles (DDGS), maize-oil) showed the lowest P use efficiency (39%). From the value-added subsystem, 17% of P from the process flow to the subsystem of animal production as DDGS, and 61% of P is wasted associated with wastewater and sludge. Future scenarios of structural adjustments in the maize consumption system predict that the supply of maize for animal feed will be threatened if the policy of the Biofuel National Promotion before 2020 is fully implemented in China, as current maize production will not meet the future demand of food, feed and energy simultaneously. The results emphasized the use of P waste resources and better sludge management from a systems perspective. This also implied the importance of exploring coordinated development and integrated strategies for sustainable P flow management in multiple utilization systems.

  • 4.
    Al-Madhlom, Qais
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Nordell, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Chabuk, Ali
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi. University of Babylon, Babylon, Hilla, Iraq.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Lindblom, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hussain, Hussain M.
    University of Kufa, Kufa, Najaf, Iraq.
    Potential use of UTES in Babylon Governorate, Iraq2020Ingår i: Groundwater for Sustainable Development, ISSN 2352-801X, Vol. 10, artikel-id 100283Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a global attention that the future energy systems will be based on renewable energy like solar and wind. The large-scale utilization of renewables in space heating and cooling requires large Thermal Energy Storage TES to overcome the varying supply and demand. The process of producing the best Underground Thermal Energy Storage UTES system pass through two steps: first, finding the best type of UTES system, second, finding the best locations to install UTES system. Both of these two steps depend extremely on the site specific parameters such that the depth to the groundwater, transmissivity, type of soil, the depth to the bedrock, and seepage velocity. The purpose of this paper is to explain some of the site specific parameters that the type of UTES-system depends on and explain the suitable type of UTES systems. This study considers Babylon province (Iraq) as study area. This province has electricity deficiency due to Heating Ventilating and Air Conditioning HVAC applications. The methodology of this study includes reviewing the literature that consider the study area, and using Arc Map/GIS to visualize some of the in-site parameters. The results indicate that the best type of UTES system for the considered region is either aquifer or pit type, due to the type of the soil and the depth to the crystalline bedrock. The hydraulic conductivity and the seepage velocity in the considered region are (0.0023–2.5) m/d and (1.3 × 10−6 – 3.45 × 10−3) m/d respectively. These conditions satisfy the standards which regard aquifer type.

  • 5.
    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 ground2020Ingår i: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 97, artikel-id 103261Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heat-traced utility corridors (utilidors) can be used in cold regions to install the drinking water and sewer pipes in a shallow trench above the frost depth, thereby limiting excavation needs and the associated economic, social, and environmental costs. Several of these infrastructures were built in the 60s and 70s in Canada, Alaska, Russia, and Norway. More recently, a new type of heat-traced utilidor was built as a pilot project in Kiruna, Sweden to increase the viability of district heating in the area by allowing co-location of all the utility pipes in a shallow trench. Despite several reported cases of undesirably warm drinking water from full-scale projects, previous research efforts on heat-traced utilidors have mainly focused on pipe freeze protection, not on the prevention of excessive temperatures of the drinking water. To ensure comfortable drinking water in terms of taste and smell, an upper temperature limit of 15 °C is usually recommended. The objective of this study was to evaluate the long-term ability of a heat-traced utilidor to maintain sewer temperatures above 0 °C and drinking water temperatures between 0 and 15 °C. Pipe temperatures were measured continuously at two cross sections of a heat-traced utilidor located in Northern Sweden over a period of 22 months. A thermal model, set up and calibrated on the measurements, was used to simulate the impact of extraordinary cold weather conditions on the pipes’ temperatures. The results showed that the utilidor could keep the pipe temperatures within the desired ranges in most cases but that special care should be taken during design to limit drinking water temperatures during the summer.

  • 6.
    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, 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 sources2020Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 709, artikel-id 136125Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Urban stormwater and snowmelt pollution contributes significantly to the deterioration of surface waters quality in many locations. Consequently, the sources of such pollution have been studied for the past 50 years, with the vehicular transportation sector and the atmospheric deposition identified early as the major pollution sources. In search for mitigation of this pollution, source controls, besides other measures, were recognised as effective pollution mitigation tools, whose successful implementation requires a good knowledge of pollution sources. Even though great research efforts have been exerted to document specific sources of urban runoff pollution, or specific groups of pollutants present in urban runoff, a comprehensive overview of all known contributing sources is still missing. This review contributes to closing this gap by compiling findings of previous research and critically synthesizing the current knowledge of various stormwater pollution sources. As the emphasis is placed on the sources, the related issues of implications for urban surface water quality and possible source controls for individual sources are touched upon just briefly, where required. The review showed that the atmospheric deposition, vehicular transportation-related activities and metallic building envelopes continue to be among the major pollution sources, which have been studied in a far greater detail than other sources. Furthermore, it was noted that because of the rapid advances in clean manufacturing and pollution control technologies, a large part of the body of data on stormwater quality available in the literature should be considered as historical data, which may no longer describe well the current conditions. Progressing historical data obsolescence, combined with continuing releases of new materials and chemicals, and, in some cases of new substances of potential concern, into the environment, suggests that the identification of important stormwater runoff/snowmelt pollution sources, and the associated pollutants, has been and will remain to be a work in progress.

  • 7.
    Garmabaki, Amir Soleimani
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Marklund, Stefan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Thaduri, Adithya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Underground pipelines and railway infrastructure: failure consequences and restrictions2020Ingår i: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 16, nr 3, s. 412-430Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Underground pipelines are an essential part of the transportation infrastructure. The structural deterioration of pipelines crossing railways and their subsequent failures can entail critical consequences for society and industry, resulting in direct and indirect costs for all the stakeholders involved. Therefore, continuous and accurate condition assessment is critical for the effective management and maintenance of pipeline networks within the transportation infrastructure. The aim of this study has been to identify failure modes and consequences related to pipelines crossing railway corridors. Expert opinions have been collected through interviews and two sets of questionnaires have been distributed to the 291 municipalities in Sweden, with 137 responses in total. The failure analysis has revealed that pipe deformation has the highest impact, followed by pipe rupture at locations where pipelines cross railway infrastructure. For underground pipelines under railway infrastructure, ageing and the external load were awarded a higher ranking than other potential causes of pipeline failure.

    Authors gratefully acknowledge the funding provided by Sweden’sinnovation agency, Vinnova, through the strategic innovation programmeInfraSweden2030. The funding was granted in a competitiveapplication process that assessed replies to an open call for proposalsconcerning “Condition Assessment and Maintenance of TransportInfrastructure (Grant No. 2016-033113)”.

    Authors gratefully acknowledge the technical support and collaboration(In-kind support) of Arrsleff R€orteknik at Sweden, Luleå RailwayResearch Center (JVTC), Stormwater&Sewers and the SwedishTransport Administration (Trafikverket). In addition, the authors arethankful to the anonymous referees for their constructive commentsand Dr Matthias Asplund and Dr Masoud Naseri for their support andsuggestions.

  • 8.
    Vidal, Brenda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    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 analysis2019Ingår i: Environmental Science: Water Research & Technology, ISSN 2053-1400, Vol. 5, s. 1599-1615Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Small on-site sanitation systems are widely present in suburban and rural areas in many countries. As these systems often underperform and have an impact on receiving waters, understanding their overall sustainability is of interest for policy and decision-makers. However, the definition and estimation of indicators defining sustainability are challenging, as it is finding the methodological approach to combine qualitative and quantitative indicators into one comprehensive assessment. In this study, twelve indicators defined by environmental, economic, social, technical and health-related criteria were used to compare nine alternatives of on-site sanitation for single households. A non-compensatory method for multi-criteria decision analysis, ELECTRE III, was used for the assessment together with weights assigned to each indicator by a reference group. Several scenarios were developed to reflect different goals and a sensitivity analysis was conducted. Overall, the graywater–blackwater separation system resulted as the most sustainable option and, in terms of polishing steps for phosphorus removal, chemical treatment was preferred over the phosphorus filter, both options being implemented together with sand filters. Assessing the robustness of the systems was a crucial step in the analysis given the high importance assigned to the aforementioned indicator by the stakeholders, thus the assessment method must be justified. The proposed multi-criteria approach contributes to aid the assessment of complex information needed in the selection of sustainable sanitation systems and in the provision of informed preferences.

  • 9.
    Søberg, Laila
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Bioretention for stormwater quality treatment: Effects of design features and ambient conditions2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
  • 10.
    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, Arkitektur och vatten.
    Nordqvist, Kerstin
    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.
    Building surface materials as sources of micropollutants in building runoff: A pilot study2019Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 680, s. 190-197Artikel i tidskrift (Refereegranskat)
    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.

  • 11.
    Broekhuizen, Ico
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Leonhardt, Günther
    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.
    Calibration event selection for green urban drainage modelling2019Manuskript (preprint) (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    Calibration of urban drainage models is typically performed based on a limited number of observed rainfall-runoff events, which may be selected from a longer time-series of measurements in different ways. In this study, 14 single- and two-stage strategies for selecting these events were tested for calibration of a SWMM model of a predominantly green urban area. The event selection was considered in relation to other sources of uncertainty such as measurement uncertainties, objective functions, and catchment discretization. Even though all 14 strategies resulted in successful model calibration, the difference between the best and worst strategies reached 0.2 in Nash–Sutcliffe Efficiency (NSE) and the calibrated parameter values notably varied. Most, but not all, calibration strategies were robust to changes in objective function, perturbations in calibration data and the use of a low spatial resolution model in the calibration phase. The various calibration strategies satisfactorily predicted 7 to 13 out of 19 validation events. The two-stage strategies performed better than the single-stage strategies when measuring performance using the Root Mean Square Error, flow volume error or peak flow error (but not using NSE); when flow data in the calibration period had been perturbed by ±40 %; and when using a lower model resolution. The two calibration strategies that performed best in the validation period were two-stage strategies. The findings in this paper show that different strategies for selecting calibration events may lead in some cases to different results for the validation period, and that calibrating impermeable and green area parameters in two separate steps may improve model performance in the validation period, while also reducing the computational demand in the calibration phase.

  • 12.
    Lindfors, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Helene
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Meyn, Thomas
    Muthanna, Tone Merete
    Lundy, Lian
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Characterisation of Dissolved Metal Fractions in Urban Runoff2019Konferensbidrag (Övrigt vetenskapligt)
  • 13.
    Nyström, Fredrik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Coagulation process characteristics and pollutant removal from urban runoff2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Many different stormwater control measures (SCMs) can be implemented in order to mitigate issues with polluted stormwater flows into receiving water bodies.  The treatment function of  SCMs is commonly based on the removal of particles by sedimentation, thereby also removing pollutants associated with particles. In recent years, more attention has been given to characterizing and understanding of different particle size fractions and their association with pollutants commonly found in stormwater. It has become increasingly clear that the smaller sized particles are very important pollutant transporters and should be considered when designing and implementing SCMs. However, the settling velocities for smaller sized particles are very low and may not be effectively removed in existing SCMs. One treatment process with a proven ability to enhance sedimentation is coagulation/flocculation, widespread in water and wastewater treatment, but with very few accounts of it being used in a stormwater context. This thesis aims to investigate the treatability of stormwater with a coagulation/flocculation process. This includes the determination of operating conditions, the dominating coagulation mechanism and the reduction efficiency of stormwater related pollutants. The objectives of the thesis were achieved in laboratory tests treating stormwater in a jar-testing procedure.

    An initial screening of primary coagulants and flocculant aids was conducted using an urban snowmelt mixture. Five of the chemicals were then selected for an extended testing regime which was setup up to determine the operating conditions where maximal turbidity reduction was attained by measuring the pH, conductivity, alkalinity and zeta-potential over the tested doses for each coagulant. Criteria used for chemical selection included high turbidity reduction, low dose requirement and low pH/alkalinity impacts.

    Charge reversal was observed at positive zeta-potential indicating that the dominating coagulation mechanism was charge neutralization. The content of turbidity/total suspended solids, total organic carbon, total metals and hydrocarbons by >90%. Dissolved copper was reduced by 40% on average, and the reduction rates for dissolved zinc were varying with up to a 300% increase, presumably due to changes in pH, leading to a higher mobility. Changes in the particle size distribution after coagulation/flocculation as compared to sedimentation indicated an effect on the size fraction corresponding to smaller particles.

    The performance of the coagulation/flocculation process was also tested on road runoff collected from a central road in Luleå with a high traffic intensity. Two coagulants were tested, iron chloride and pre-hydrolyzed aluminum chloride. Reduction rates for the total metal fraction were >90% on average for both coagulants, but for the dissolved metal fractions differences could be observed between the coagulants with the iron chloride resulting in higher reductions for dissolved chrome (57% compared to 34%) and copper (47% compared to 30%). Both products increased the dissolved fractions of nickel and zinc due to lower final pH.

  • 14.
    Pericault, Youen
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Bruaset, Stian
    Norwegian University of Science and Technology.
    Ugarelli, Rita
    Norwegian University of Science and Technology.
    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.
    Correcting for the impact of past coordination on the estimation of pipe cohorts survival functions2019Konferensbidrag (Övrigt vetenskapligt)
  • 15.
    Søberg, Laila
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Winston, Ryan
    Departments of Food, Agricultural, and Biological Engineering and Civil, Environmental, and Geodetic Engineering, Ohio State University, 590 Woody Hayes Drive, Columbus, OH, United States of America.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Blecken, Godecke-Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Dissolved metal adsorption capacities and fractionation in filter materials for use in stormwater bioretention facilities2019Ingår i: Water Research X, ISSN 2589-9147, Vol. 4, artikel-id 100032Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dissolved metal adsorption and association was determined for ten different filter materials recommended and/or implemented in bioretention facilities. Batch adsorption and batch kinetic experiments were performed at lab-scale using both single and multi-metal solutions. Metal strengths and association were determined by sequential extraction analysis. All materials adsorbed metals and 90% of adsorption occurred within 1 h. However, as metal solutions became more complex, adsorption behavior changed. Generally, filter materials classified as sand with a naturally high pH, relatively low organic matter (OM) content and large specific surface area seem to be good choices for removing dissolved metals. Additionally, a chalk additive might improve metal adsorption whereas biochar did not significantly improve metal retention and may be an unwanted (due to degradation over time) extra source of OM. Regardless of filter material, metals primarily adsorbed to the exchangeable form which indicates that metal adsorption might not be permanent, but rather substantially reversible in some cases. More research is needed to assess whether dissolved metals adsorbed in filter materials of bioretention systems pose a delayed threat instead of an immediate threat. Finally, the authors strongly recommend filter materials intended for stormwater bioretention facilities to be tested prior to implementation.

  • 16.
    Milovanovic, Ivan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Bareš, Vojtech
    Czech Technical University in Prague.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Herrmann, Inga
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Piscek, Tomas
    Czech Technical University in Prague.
    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.
    Enhancing stormwater sediment settling at detention pond inlets by a Bottom Grid Structure2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Stormwater sediments of various sizes and densities are recognised as one of the most important stormwater quality parameters that can be conventionally controlled by settling in detention ponds. The Bottom Grid Structure (BGS) is an innovative (non-proprietary) concept proposed in this study to enhance removal of stormwater sediments entering ponds and reduce sediment resuspension. This concept was studied in a hydraulic scale model with the objective of elucidating the effects of the BGS geometry on stormwater sediment trapping. Towards this end, the BGS cell size and depth, and the cell cross-wall angle were varied for a range of flow rates, and the sediment trapping efficiency was measured in the model. The main value of the observed sediment trapping efficiencies, in the range from 13 to 55%, was a comparative assessment of various BGS designs. In general, larger cells (footprint 10x10 cm, in the model) were more effective than the smaller cells (5x5 cm), the cell depth exerted small influence on sediment trapping, and the cells with inclined cross-walls proved more effective in sediment trapping than the vertical cross-walls. However, the BGS with inclined cross-walls would be harder to maintain. Future studies should address an optimal cell design and testing in an actual stormwater pond.

  • 17.
    Lindfors, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Heléne
    Lundy, Lian
    Viklander, Maria
    Evaluation of Truly Dissolved and Bioavailable Metal Concentrations in Snowmelt and Rainfall Runoff2019Ingår i: Novatech 2019 Proceedings, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Environment Quality Standards (EQS) stated by the EU Water Framework Directive complemented by national EQS support the work of risk assessments of bioavailable metals in freshwater environments. In this paper, dissolved and truly dissolved (operationally defined by ultrafiltration) Cu, Ni, Pb and Zn concentrations were used to predict and evaluate the bioavailable metal fraction (calculated using Bio-met) in snowmelt and rainfall runoff samples from two urban catchments. The results show that the bioavailable Cu and Zn concentrations exceed the EQSbioavailable and that there is a metal by metal variation regarding the fraction of truly dissolved metals that is also bioavailable. The results indicate that the truly dissolved metal fraction is not a suitable surrogate for the bioavailable fraction for these metals.

  • 18.
    Viklander, Maria
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Helene
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Müller, Alexandra
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Marsalek, Jiri
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Borris, Matthias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Kunskapssammanställning: Dagvattenkvalitet2019Rapport (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Rapporten sammanställer internationella forskningsresultat om källor till dagvattenföroreningar samt föroreningarnas koncentration, mängd och variation mellan platser och årstider. Den beskriver vad man bör tänka på vid utformning av provtagningsprogram och vid val av modellverktyg, och den diskuterar effekter på hälsa, miljö och samhälle samt vilka regelverk och riktlinjer som finns.

  • 19.
    Vijayan, Arya
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Helene
    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.
    Laboratory Melting of Late-Winter Urban Snow Samples: The Magnitude and Dynamics of Releases of Heavy Metals and PAHs2019Ingår i: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 230, nr 8, artikel-id 182Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Laboratory snow melting experiments were conducted with actual late-winter snow samples, collected just before the final snowmelt, in two similar northern Swedish cities, Luleå and Umeå, to investigate releases of the selected heavy metals (HM) (Cu, Pb, Zn, and Cd) and 16 USEPA PAHs from melting snow. Metal concentrations were determined in three fractions: total, dissolved, and truly dissolved (defined as the fraction passing through a 3-kMWCO ultrafilter). Total HM concentrations in snowmelt were rather high at both sites and reflected the accumulation of pollutants in the roadside snowbanks over a period of about 5 months: Cd = 0.43, Cu = 303, Pb = 41.9, Zn = 817 (μg/l), and TSS = 2000 (mg/l) in Luleå samples and Cd = 1.87, Cu = 905, Pb = 165, Zn = 3150 (μg/l), and TSS = 4800 (mg/l) in Umeå samples. The difference between metal and TSS concentrations at the two sites of similar characteristics was attributed to a smaller volume snowbank in Umeå. The dissolved HM concentrations represented relatively small fractions of the total concentrations (0.3–6.9% in Luleå and 0.01–3.1% in Umeå). The truly dissolved fraction represented 71–90% of the dissolved fraction in Luleå and 74–98% in Umeå. At both sites, the dissolved fractions exhibited preferential elution from the laboratory snow piles. The PAHs studied (16 US EPA PAHs) were mostly particulate bound, with only 5–12% of the total burden contributed by the meltwater, and most dissolved concentrations below the reporting limits. PAH concentrations in the Luleå samples were about one-third to one-fourth of those in Umeå. In general, the releases of PAHs from the snowbank were delayed, compared with releases of meltwater, and showed similar release patterns as TSS.

  • 20.
    Gavric, Snezana
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Larm, Thomas
    StormTac corporation, Stockholm, Sweden.
    Österlund, Helene
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Marsalek, Jiri
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Wahlsten, Anna
    StormTac corporation, Stockholm, Sweden.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Measurement and conceptual modelling of retention of metals (Cu, Pb, Zn) in soils of three grass swales2019Ingår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 574, s. 1053-1061Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Grass swales are important elements of the urban green infrastructure that convey and attenuate urban runoff and improve its quality mostly through stormwater infiltration into, and retention of conveyed pollutants by, swale soils. The retention of metals by grass swales was addressed in this study investigating the enrichment of swale soils by three common traffic-related metals: Cu, Pb and Zn. Three swales of various characteristics (L1, L2, L3) were selected for study and their soils were sampled by coring the top 30 cm and dividing the cores into 5 cm thick layers. Cumulative metal burdens were compared to those modelled by the proprietary StormTac Web model, which estimates annual loads of specific constituents for the given land uses and stormwater treatment. The comparisons of measured (MBm) and simulated (MBs) metal burdens retained by swales showed that the measured values exceed the simulated ones, as described by average ratios MBs/MBm = 0.64, 0.50 and 0.59, for swales L1, L2 and L3, respectively. The measured burdens were calculated after subtracting the native soil metal concentrations, assumed equal to those found in the deepest sampled layer, 25–30 cm below the surface. The results suggest the feasibility of assessing performance of grass swales by modelling metal (Cu, Pb, Zn) retention by swales, however for older facilities considered for rehabilitation, the simulated results should be supplemented by soil chemistry sampling.

  • 21.
    Gavric, Snezana
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Larm, Thomas
    StormTac AB, Stockholm.
    Österlund, Helene
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Marsalek, Jiri
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Wahlsten, Anna
    StormTac AB, Stockholm.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Measurement and Planning–Level Modelling of Retention of Trace Metals (Cu, Pb, Zn) in Soils of Three Urban Drainage Grass Swales2019Ingår i: New Trends in Urban Drainage Modelling: UDM 2018 / [ed] Giorgio Mannina, Cham: Springer, 2019, s. 85-90Konferensbidrag (Refereegranskat)
    Abstract [en]

    Grass swales are important elements of urban green infrastructure that convey, attenuate and improve the quality of urban runoff mostly through stormwater infiltration into and retention of conveyed pollutants by swale soils. Such processes were addressed in this study, investigating the enrichment of swale soils by ubiquitous urban trace metals, Cu, Pb and Zn. Three swales were selected for study in the City of Lulea (Northern Sweden) and their soils were sampled by coring. Sample cores covered soil depths up to 30 cm, but only the results from the top 5 cm layer characterized by 9–15 samples in each swale are discussed here. After estimating metal mass in this layer in individual swales, such burdens were compared to those modelled by the proprietary StormTac Web model, which estimates annual loads of specific constituents for given land uses and is supported by an extensive database referenced to Swedish environmental conditions. The annual loads modelled for individual swales were multiplied by the swale age to obtain long–term inputs of the trace metals. A good agreement between the measured and modelled loads in soils was obtained and characterized by the ratio Lmod/Lmeas, with an average value of 0.96 and standard deviation of 0.55. Such results suggest the feasibility of assessing the long–term performance of grass swales by modelling trace metal (Cu, Pb, Zn) inputs into swales, estimating the metal loads retained in soils by sampling and analyses, and taking the difference (Lin − Lret) as the exported load.

  • 22.
    Österlund, Heléne
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Renberg, Lovisa
    Luleå tekniska universitet, Extern.
    Nordqvist, Kerstin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Micro litter in the urban environment: sampling and analysis of undisturbed snow2019Konferensbidrag (Refereegranskat)
    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.

  • 23.
    Vijayan, Arya
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Heléne
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Magnusson, Kerstin
    Luleå tekniska universitet, Extern.
    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.
    Microplastics pathways in the urban environment: Urban roadside snowbanks2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    The knowledge base concerning microplastics (MPs) in the environment is rapidly developing with the goal of closing the existing knowledge gaps. One of such gaps, the occurrence of MPs in roadside snowbanks in urban areas, was surveyed at 16 sites in two northern Swedish cities, Luleå and Umeå, with the objective of estimating the quantities of MPs in snowbanks and evaluating the influence of site characteristics on such estimates. The MPs extracted from the melted snow samples were classified into three categories (the mean particle concentrations are shown in the brackets): 1. Tire and pavement wear particles (19,300 particles/L), 2. Road marking paint particles (430 particles/L), and 3. Plastics particles (33 particles/L), No correlations were found between the MP concentrations and site characteristics. The study provided the evidence that urban snow stores MPs, which may reach the receiving waters either with direct snow disposal or snowmelt discharge via storm sewers.

  • 24.
    Okwori, Emmanuel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Performance assessment of Swedish sewer pipe networks using pipe blockage and other associated performance indicators2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Sewer networks are expected to operate with minimal or no interruptions. The complex nature of randomly occurring failures in sewer networks arising from blockages significantly adds to the cost of operation and maintenance. Blockages are significant due to sewage backup or basements flooding, resulting from their occurrence. Continuous performance assessment of sewer pipe networks is necessary to ensure a required level of service at an acceptable cost. This study provides insight into the performance of the sewer pipe networks by assessing the proneness of the network to blockages and drawing inferences at a holistic strategic level of influential explanatory factors of blockage proneness, using data available in the VASS statistics database managed by Swedish Water and Wastewater Association. Results indicate that medium sized municipalities are prone to at least 30% more blockages per km per year compared to other municipalities. A hypothesis of explanatory factors includes, reduced flow volumes and design flow depth resulting in flow velocities below self-cleaning velocity in sewer pipe networks encouraging the sluggishness of flow and increased possibility for sediment deposition and accumulation in sewer leading to blockages. This is also exacerbated by the deposition of non-disposables (wet wipes, baby diapers, hard paper etc.), accumulation of FOGs in sewers and increased water conservation measures. Blockages also show a trend indicating occurrence may have a constant return frequency in medium – less than small sized municipalities.

  • 25.
    Gavric, Snezana
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Leonhardt, Günther
    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.
    Processes improving urban stormwater quality in grass swales and filter strips: A review of research findings2019Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 669, s. 431-447Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Increasing interest in urban drainage green infrastructure brings attention to grass swales and filter strips (GS&GFS) and their role in stormwater management. While the understanding of the hydrology and hydraulics of these stormwater control measures is adequate for current needs, there are knowledge gaps in understanding the water quality processes in GS&GFS and such a finding motivated preparation of the review paper that follows. The review revealed that most of the empirical studies of GS&GFS flow quality focused on the removal of pollutants associated with road runoff, and particularly solids, with relatively few studies addressing nutrients, traffic associated hydrocarbons, oxygen demanding substances, chloride, and faecal indicator bacteria. The reported results suffer from limitations caused by experimental conditions often representing a steady flow used to irrigate GS&GFS and generate runoff, non-submerged flows, no lateral inflows along swale side slopes, constant dosing of solids, emphasis on larger-than-typical solids, incomplete descriptions of experimental conditions, and limited attention to experimental uncertainties. Besides settling, other treatment processes, like adsorption/desorption, plant uptake, chemical precipitation and microbial degradation are often acknowledged, but without attempting to quantify their effects on flow quality. The modelling of GS&GFS flow quality would be beneficial for an improved understanding of green urban drainage infrastructure, but currently it is infeasible without a better knowledge of stormwater quality processes in GS&GFS facilities.

  • 26.
    Søberg, Laila
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Blecken, Godecke-Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Reduction of Escherichia coliEnterococcus faecalisand Pseudomonas aeruginosa in stormwater bioretention: Effect of drying, temperature and submerged zone2019Ingår i: Journal of Hydrology X, ISSN 2589-9155, Vol. 3, artikel-id 100025Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The impact of drying and temperature on the reduction of Escherichia coliEnterococcus faecalis and Pseudomonas aeruginosa in stormwater bioretention systems with and without a submerged zone was assessed using 16 pilot-scale bioretention columns under controlled laboratory conditions. The experimental design enabled analysis of possible interactions between the factors. First outflow and event-based samples were collected. Outflow concentrations were independent of inflow concentrations and hence controlled by internal processes. Overall TSS removal was high but sensitive to bacterial synthesis. Event-based samples had significantly higher bacteria concentrations than first outflow samples, suggesting that remaining/surviving bacteria in the bioretention cells have little effect on initial peak outflow concentrations. The effect of temperature varied between bacterial species and sample types. Long dry periods seemed beneficial for bacteria reduction, but outflow bacteria concentrations peaked during the second watering after long dry periods. Submerged zones significantly reduced bacteria outflow concentrations. However, sudden temperature increases caused bioretention cells with a submerged zone to produce significantly higher bacteria outflow concentrations than before the temperature increase, which was not the case for standard cells. Bioretention cells with submerged zones may thus be poor choices for reducing bacterial concentrations in stormwater runoff in areas experiencing winter conditions. Finally, our results suggest that adsorption (e.g. further enhanced by biofilm formation) is the major mechanism governing bacteria reduction in bioretention systems.

  • 27.
    Broekhuizen, Ico
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Leonhardt, Günther
    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.
    Selection of Calibration Events for Modelling Green Urban Drainage2019Ingår i: New Trends in Urban Drainage Modelling: UDM 2018 / [ed] Giorgio Mannina, Cham: Springer, 2019, s. 608-613Konferensbidrag (Refereegranskat)
    Abstract [en]

    Urban drainage models are often calibrated using a limited number of rainfall-runoff events, which may be selected in different ways from a longer observation series. This paper compares 13 different single- and two-stage strategies for selecting events used to calibrate a SWMM model of a predominantly green urban area. Most led to successful calibration, but performance varied for various validation events. Most selection strategies were insensitive to the choice of Nash-Sutcliffe Model Efficiency or Root Mean Squared Error as the objective function. Calibrating impervious and green area parameters separately in two-stage strategies can help improve prediction of low-flow events in validation.

  • 28.
    Pericault, Youen
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Shallow co-location of water, sewer and district heating pipes: Applicability in cold climate regions2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 29.
    Al-Madhlom, Qais
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi. University of Babylon, Babylon, Iraq.
    Hamza, B.
    University of Babylon, Babylon, Iraq.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Nordell, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hussain, Hussain M.
    Kufa University, Kufa, Iraq.
    Site Selection Criteria of UTES Systems in Hot Climate2019Ingår i: Proceedings of the XVII ECSMGE-2019: Geotechnical Engineering foundation of the future, Iceland: The Icelandic Geotechnical Society (IGS) , 2019, Vol. 1, s. 1-8Konferensbidrag (Refereegranskat)
    Abstract [en]

    Underground Thermal Energy Storage UTES systems are widely used around the world. The reason is that UTES is essential in utilizing Renewable Energy sources (RE). The efficiency of the energy system relies strongly on the efficiency of the storage system. Therefore, in the installation of a hyper-energy system, a lot of attention is to be paid in improving the storage system. In order to design an efficient storage system, firstly, standard criteria are to be investigated. These explain the process of making high efficiency storage system that must be specified. The criteria, mainly, depends on: best type and best location. These two variables are in high interference with each other. The bond between the two variables is represented by the geological, hydrological, meteorological, soil, hydrogeological properties/factors of the site. These factors are specified by geo-energy mapping. Despite the importance of this type of mapping, there is no specific criteria/formula that defines the choice. This paper aims to: give a brief literature review for UTES systems (types, classification, advantages/disadvantages for each type, and examples of an installed system). In addition, some factors within geo-energy mapping are highlighted and standard criteria to achieve good storage system are suggested. The suggested criterion comprises a process to transfer the quantity values to quality values according to the expert opinion. The suggested criteria are defined through the following stages: selecting the best type of UTES systems according to hydro-geological in site conditions; using the analytical hierarchy process to rank the best location to install the storage system and then using ArcMap (GIS-Software) to provide representative results as maps. Karbala Province (Iraq) is the study area used here

  • 30.
    Al-Madhlom, Qais
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi. College of Engineering/Al-Musaib, University of Babylon, Hillah, Iraq.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Nordell, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hussain, Hussain Musa
    Remote Sensing Center, University of Kufa, Kufa, Iraq.
    Site Selection of Aquifer Thermal Energy Storage Systems in Shallow Groundwater Conditions2019Ingår i: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 11, nr 7, artikel-id 1393Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Underground thermal energy storage (UTES) systems are widely used around the world, due to their relations to heating ventilating and air conditioning (HVAC) applications [1]. To achieve the required objectives of these systems, the best design of these systems should be accessed first. The process of determining the best design for any UTES system has two stages, the type selection stage and the site selection stage. In the type selection stage, the best sort of UTES system is determined. There are six kinds of UTES systems, they are: boreholes, aquifer, bit, tank, tubes in clay, and cavern [2–5]. The selection of a particular type depends on three groups of parameters. They are: Site specific, design, and operation parameters (Figure 1). Apart from site specific parameters, the other two types can be changed through the life time of the system. The site specific parameters, e.g., geological, hydrogeological, and metrological, cannot be changed during the service period of the  ystem. Therefore, the design of the best type should depend, at first consideration, on site specific parameters.

  • 31.
    Herrmann, Inga
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Larsson, Charlotta
    Wilen, Britt-
    Slambildning och mikrobiell sammansättning av biofilm i infiltrationsanläggningar2019Rapport (Övrigt vetenskapligt)
  • 32.
    Vidal, Brenda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Herrmann, Inga
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Små avloppssystem: hur hållbara är de?2019Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Små avloppssystem släpper ut avloppsvattnet lokalt, och därför är det viktigt att systemen uppfyller de krav som finns för utsläpp av organiskt material och näringsämnen och även klarar krav på smittskydd. Ofta fungerar, tyvärr, de små systemen inte som de borde, och när anläggningar ska uppgraderas eller när det ska byggas nya system bör det ske med tanke på hållbarheten. I ett nyligen avslutat projekt har vi arbetat med små avloppssystem i relation till hållbarhetskriterier och olika scenarier. Studien visar att det är viktigt att sätta upp mål och prioriteringar när man ska välja avloppslösning. Vilket som är det mest hållbara alternativet beror på vilka aspekter som prioriteras.

  • 33.
    Panasiuk, Oleksandr
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Ashley, Richard
    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 feasibility of using flap gates as constriction flow meters for estimating sanitary sewer overflows (SSO)2019Ingår i: Desalination and Water Treatment, ISSN 1944-3994, E-ISSN 1944-3986, Vol. 155, s. 113-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Increased awareness of the negative effects of sanitary sewer overflow (SSO) events on human health and aquatic life led to the development of various control measures, of which implementation is impeded by the lack of information on SSO occurrences, flows and volumes. The collection of such information requires data acquisition systems, which can be costly and are fully utilized just during limited time periods of the year. In search for inexpensive approaches to SSO monitoring, the feasibility of using existing flap gate installations, serving for prevention of back-up flows into sewers, as constriction flow meters was investigated, with promising results. An experimental pilotscale setup was designed to allow steady water flow through a flap gate built into a partition wall between two chambers. The stabilized water heads in the chambers and the flow rate through the flap gate were measured, for both dry and submerged flap gate conditions, and five flap gate sizes (200, 300, 400, 500 and 600 mm), with relatively heavy covers (6–102 kg). The measured data were used to develop flow rating curves, by non-linear regression, in the form Q = f (ΔH), where Q is the discharge through the flap gate and ΔH is the pressure differential upstream and downstream of the gate. The regression curves fitted the experimental data with high precision (R2 >0.99). The use of flow rating curves for estimation of the SSO volume was discussed. This study demonstrated that the water head measurements upstream and downstream of the flap gate can provide a reliable, accurate and inexpensive method for quantification of the SSO discharges and volumes.

  • 34.
    Wu, Jiechen
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. College of Resources and Environmental Sciences, China Agricultural University, Beijing, PR China.
    Hartmann, Tobias Edward
    Fertilisation and Soil Matter Dynamics (340i), Institute of Crop Science, University of Hohenheim, Stuttgart, Germany.
    Chen, Wei-Shan
    Environmental Technology Group, Wageningen University & Research, The Netherlands.
    Toward sustainable management of phosphorus flows in a changing rural–urban environment: recent advances, challenges, and opportunities2019Ingår i: Current Opinion in Environmental Sustainability, ISSN 1877-3435, E-ISSN 1877-3443, Vol. 40, s. 81-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    While food is mainly produced in rural areas, the main drivers of consumption are urban environments. The increasing demand for food in cities leads to an accumulation of phosphorus (P) in urban environments, which affects P flows at multiple scales. This study reviewed recent advances, challenges, and opportunities for sustainable management of P flows in decoupled rural–urban environments. We discussed recent advances in Substance Flow Analysis (SFA) that enable the characterization of P flows in rural–urban environments and illustrate how urban consumption affects rural food production systems. Most challenges of SFA are associated with the (1) spatial decoupling of food production in rural areas and food consumption in urban systems at multiple scales, (2) temporal implications of substance flows on system analysis, and (3) increasing complexity of resource flows in rural–urban environments. We identified three main opportunities for future research on sustainable management of P flows. These opportunities lie in linking urban and rural SFA through multi-scale analysis, increasing both spatial and temporal resolution of P flows within various environments and identifying how linking urban to rural environments can reduce pressure on primary production systems. Also, we highlighted that methodological development on high-resolution SFA at multiple scales is needed to close P cycles between rural and urban systems and to allow the development of future, sustainable P management systems in the anthropogenic food production chain.

  • 35.
    Broekhuizen, Ico
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Rujner, Hendrik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Roldin, Maria
    DHI Sweden.
    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.
    Towards using soil water content observations for calibration of distributed urban drainage models2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Fully distributed urban drainage models can be used to analyse and predict the behaviour of green urban drainage infrastructure such as swales, but they need to be calibrated for specific study sites. Using only drainage outflow measurements may not provide enough information to do this in an optimal way, so additional types of measurements have to be considered. This study identifies different approaches to including soil water content (SWC) observations in the calibration process and investigates how they affect parameter identifiability and the predictive uncertainty of the calibrated model. This is done using the Generalized Likelihood Uncertainty Estimation methodology applied to a model of a large urban swale. It was found that setting initial conditions based on the SWC measurements improved the fit between observed and simulated SWC, but also reduced the accuracy of the simulated amount of infiltration. Including SWC observations allowed to identify one parameter (saturated moisture content of the swale bottom) that was not identifiable from outflow measurements alone. Including SWC observations in the derivation of predictive uncertainty bounds made those bounds narrower (more precise), but where SWC had been used to set initial conditions the uncertainty bound failed to capture the observations. It is concluded that SWC observations can provide useful information for the calibration of distributed urban drainage models.

  • 36.
    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
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    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.
    Treatment of road runoff by coagulation/flocculation and sedimentation2019Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 79, nr 3, s. 518-525Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A laboratory investigation of the treatment potential of a coagulation process in the context of stormwater treatment was undertaken. The initial 25 L road runoff generated from four rain events was collected and subjected to a jar-testing regime with two commercial coagulants. The treatment effect was assessed by analysing the runoff before and after treatment for turbidity, suspended solids and metal content. The coagulation process resulted in particle and total metal reduction of more than 90% compared to 40% for only sedimentation. Up to 40% reduction of dissolved Cr, Cu and Pb was also observed compared to 0% for sedimentation. This study shows that coagulation may be a useful process for stormwater treatment systems when the treatment requirements are high.

  • 37.
    Broekhuizen, Ico
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Uncertainties in rainfall-runoff modelling of green urban drainage systems: Measurements, data selection and model structure2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Green urban drainage systems are used to avoid flooding and damages to people and property, while limiting the downstream flooding and water quality problems caused by pipe-based drainage systems. Computer models are used to analyse and predict the performance of such systems for design and operation purposes. Such models are simplifications of reality and based on uncertain measured data, so uncertainties will be involved in the modelling process and its outcomes, which can affect the design and operation of these systems. These uncertainties have been investigated extensively for traditional pipe-based urban drainage systems, but not yet for green alternatives. Therefore, the overall objective of this thesis is to contribute to improved applicability and reliability of computer models of green urban drainage systems. Specifically, the thesis aims to (1) improve understanding of the uncertainties arising from (a) model structure and (b) calibration data selection, (2) evaluate two alternative calibration methods for green urban drainage models, (3) discuss desirable structural features in urban drainage models, and (4) evaluate several sensors for hydrometeorological measurements in urban catchments.

    The effects of model structure uncertainty were investigated using long-term simulations of synthetic catchments with varying soil types and depths for three different models. First, it was found that surface runoff could be a significant part of the annual water balance in all three models, depending on the soil type and depth considered. Second, differences were found in how sensitive the different models were to changes in soil type and depth. Third, the variation between different models was often large compared to the variation between different soil types. Fourth, the magnitude of inter-annual and inter-event variation varied between the models. Overall, the findings indicate that significant differences may occur in urban drainage modelling studies, depending on which model is used, and this may affect the design or operation of such systems.

    The uncertainty from calibration data selection was investigated primarily by calibrating both a low- and high-resolution stormwater model using different sets of events. These event sets used different rainfall-runoff statistics to rank all observed events before selecting the top six for use in calibration. In addition, they varied by either calibrating all parameters simultaneously, or by calibrating parameters for impervious and pervious surfaces separately. This last approach sped up the calibration process. In the validation period the high-resolution models performed better than their low-resolution counterparts and the two-stage calibrations matched runoff volume and peak flows better than single-stage calibrations. Overall, the way in which the calibration events are selected was shown to have a major impact on the performance of the calibrated model.

    Calibration data selection was also investigated by examining different ways of including soil water content (SWC) observations in the calibration process of a model of a swale. Some model parameters could be identified from SWC, but not from outflow observations. Including SWC in the model evaluation affected the precision of swale outflow predictions. Different ways of setting initial conditions in the model (observations or an equilibrium condition) affected both of these findings.

    The precipitation sensors used in this thesis showed generally satisfactory performance in field calibration checks. Different types of precipitation sensors were associated with different requirements for maintenance and data acquisition. Sensors for sewer pipe flow rates showed good agreement with a reference instrument in the laboratory, as long as installation conditions were good. Higher pipe slopes and upstream obstacles lead to larger measurement errors, but this last effect was reduced by increasing water levels in the pipe. Sensor fouling was a source of errors and gaps in field measurements, showing that regular maintenance is required. The findings show that the evaluated flow sensors can perform satisfactorily, if measurement sites are carefully selected.

  • 38.
    Broekhuizen, Ico
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Muthanna, Tone M.
    Norwegian University of Science and Technology, Trondheim, Norway.
    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.
    Urban drainage models for green areas: Structural differences and their effects on simulated runoff2019Ingår i: Journal of Hydrology X, ISSN 2589-9155, Vol. 5, artikel-id 100044Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mathematical stormwater models are often used as tools for planning and analysing urban drainage systems. However, the inherent uncertainties of the models must be properly understood in order to make optimal use of them. One source of uncertainty that has received relatively little attention, particularly for increasingly popular green areas as part of urban drainage systems, is the mathematical model structure. This paper analyses the differences between three different widely-used models (SWMM, MOUSE and Mike SHE) when simulating rainfall runoff from green areas over a 26-year period. Eleven different soil types and six different soil depths were used to investigate the 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 significantly between the three models. MOUSE generated the highest runoff volumes, while it was rather insensitive to changes in soil type and depth. Mike SHE was mainly sensitive to changes in soil type. 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 studies on the design or analysis 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.

  • 39.
    Müller, Alexandra
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Urban Surfaces as Sources of Stormwater Pollution: An Evaluation of Substances Released from Building Envelopes2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 40.
    Panasiuk, Oleksandr
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Langeveld, Jeroen
    Department of Water Management, TU Delft. Partners4UrbanWater, The Netherlands.
    de Haan, Cornelis
    Partners4UrbanWater, The Netherlands.
    Liefting, Erik
    Partners4UrbanWater, The Netherlands.
    Schilperoort, Remy
    Partners4UrbanWater, The Netherlands.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Using Distributed Temperature Sensing (DTS) for Locating and Characterising Infiltration and Inflow into Foul Sewers before, during and after Snowmelt Period2019Ingår i: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 11, nr 8, artikel-id 1529Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Infiltration and inflow (I/I) into sewers cause negative effects on the sewer system,wastewater treatment plant and environment. Identifying the causes and locating the inflows isnecessary in order to address the I/I problem. This paper focuses on using distributed temperaturesensing (DTS) for identifying, locating and characterising I/I into a sewer system during the endof winter–beginning of summer transition period under dry and wet weather conditions. Duringsnowmelt, several locations with I/I were identified, while these locations did not show I/I duringstorm events after the snowmelt. In addition, during a very heavy storm after the snowmelt period,I/I was found at other locations. Therefore, DTS was demonstrated to be effective in identifying thetype of I/I and in locating I/I. Finally, I/I monitoring campaigns in cold climates should take intoaccount the variety of pathways of I/I during snowmelt and during rainfall.

  • 41.
    McCarthy, David T.
    et al.
    Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University.
    Zhang, Kefeng
    Monash Infrastructure Research Institute, Department of Civil Engineering, Monash University.
    Westerlund, Camilla
    Water Coordinator, Water Authority-bottenvikens Water District Lulea.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Bertrand-Krajewski, Jean-Luc
    Univ Lyon, INSA Lyon.
    Fletcher, Tim D.
    School of Ecosystem and Forest Sciences, Faculty of Science, The University of Melbourne.
    Deletic, Ana
    Monash Infrastructure Research Institute, Department of Civil Engineering, Monash University.
    Assessment of sampling strategies for estimation of site mean concentrations of stormwater pollutants2018Ingår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 129, s. 297-304Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The estimation of stormwater pollutant concentrations is a primary requirement of integrated urban water management. In order to determine effective sampling strategies for estimating pollutant concentrations, data from extensive field measurements at seven different catchments was used. At all sites, 1-min resolution continuous flow measurements, as well as flow-weighted samples, were taken and analysed for total suspend solids (TSS), total nitrogen (TN) and Escherichia coli (E. coli). For each of these parameters, the data was used to calculate the Event Mean Concentrations (EMCs) for each event. The measured Site Mean Concentrations (SMCs) were taken as the volume-weighted average of these EMCs for each parameter, at each site. 17 different sampling strategies, including random and fixed strategies were tested to estimate SMCs, which were compared with the measured SMCs. The ratios of estimated/measured SMCs were further analysed to determine the most effective sampling strategies. Results indicate that the random sampling strategies were the most promising method in reproducing SMCs for TSS and TN, while some fixed sampling strategies were better for estimating the SMC of E. coli. The differences in taking one, two or three random samples were small (up to 20% for TSS, and 10% for TN and E. coli), indicating that there is little benefit in investing in collection of more than one sample per event if attempting to estimate the SMC through monitoring of multiple events. It was estimated that an average of 27 events across the studied catchments are needed for characterising SMCs of TSS with a 90% confidence interval (CI) width of 1.0, followed by E.coli (average 12 events) and TN (average 11 events). The coefficient of variation of pollutant concentrations was linearly and significantly correlated to the 90% confidence interval ratio of the estimated/measured SMCs (R2 = 0.49; P < 0.01) as well as the number of events required to achieve certain accuracy, and hence could be a promising surrogate for determining the sampling frequency needed to accurately estimate SMCs of pollutants

  • 42.
    Blecken, Godecke-Tobias
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Karlsson, Kristin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Closure to “Environmental Risk Assessment of Sediments Deposited in Stormwater Treatment Facilities: Trace Metal Fractionation and Its Implication for Sediment Management”2018Ingår i: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 144, nr 4Artikel i tidskrift (Refereegranskat)
  • 43.
    Pericault, Youen
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Kärrman, Erik
    RISE Research Institutes of Sweden, 11894 Stockholm, Sweden.
    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.
    Data supporting the life cycle impact assessment and cost evaluation of technical alternatives for providing water and heating services to a suburban development in Gällivare Sweden2018Ingår i: Data in Brief, E-ISSN 2352-3409, Vol. 21, s. 1204-1208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The article presents input data that were used in Pericault et al. (2018) for life cycle impact assessment and total cost assessment of five technical alternatives for heat and water services provision in a suburban development in Sweden. The data consists of a list of environmental impacts (cumulative exergy demand of energy carriers – CExDe, global warming potential – GWP, abiotic depletion potential of elements – ADPE), costs, amortisation periods, lifetimes and output flows of the system processes composing the alternatives. The data was derived from values collected in lifecycle databases, environmental product declarations, scientific publications and personal communications with companies.

  • 44.
    Nordell, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. Lillpite älvdals ekonomiska förening.
    Bergman, Gunnar
    Lillpite älvdals ekonomiska förening.
    Wiklund, Matz
    Lillpite älvdals ekonomiska förening.
    Development of the Lillpite River Valley after Dam Removal2018Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The Lillpite River Valley stretches 45 km NV, from Piteå at the Gulf of Bothnia. The 619 km2 large catchment area comprises a dozen lakes. The average flow rate of the river is 6.24 m3/s. Lillpite Kraft AB, which owns the two power plants in the Lillpite River, has now applied for a demolition permit after 30 years of unprofitable operation. This demolition will take place in 2020, after which there are no obstacles to the fish's migration in the river. The Lillpite River was famous for its large salmon but also for its trout, grayling and lamprey. River crayfish and freshwater pearl mussel exist in the river, both upstream and downstream of the two dams, and in the brooks. There are even eel and pikeperch in the river, which also hosts beaver and otter. The Lillpite River Economic Association manages the compensation (~30M€ over 50 years) for the wind power intrusion in the area. This organisation is committed to make the river the fishing water it once was, as a driving force for the development of the river valley. At this seminar, we seek your help and advice based on knowledge and experience. How to determine the river status before and after dam removal? River erosion? Timeline after dam removal? Evaluation of ecology and biodiversity? How to improve conditions for fish, crustaceans and pearl mussel? How to meet sceptical locals? What should/could we do before the dam removal?

  • 45.
    Tondera, Katharina
    et al.
    Institute of Environmental Engineering, RWTH Aachen University, Aachen.
    Blecken, Godecke-Tobias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Tournebize, Julien
    Hydrosystems and Bioprocessus Research Unit, Irstea—National Research Institute of Science and Technology for Environment and Agriculture, Antony.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Österlund, Helene
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Andersson-Wikström, Alexandra
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Tanner, Chris C.
    National Institute of Water and Atmospheric Research, Hamilton.
    Emerging Contaminants: Occurrence, Treatment Efficiency and Accumulation Under Varying Flows2018Ingår i: Ecotechnologies for the Treatment of Variable Stormwater and Wastewater Flows / [ed] Katharina Tondera, Godecke-Tobias Blecken, Florent Chazarenc, Chris C. Tanner, Cham: Springer, 2018, s. 93-109Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Emerging contaminants became a major topic in water treatment when laboratory detection methods for concentrations at a nanogram-scale improved approximately two decades ago. Research on using ecotechnologies to remove emerging contaminants in variable stormwater and wastewater flows has been conducted for more than a decade, but so far, not all removal mechanisms are well understood and only few setups have been investigated. This chapter summarises the current knowledge, focussing on pesticides and emerging contaminants listed on the watch list of the European Union. However, large-scale investigations are still rare and further research will have to be conducted in this field to enable practitioners to provide recommendations for design and maintenance of treatment facilities in the field of ecotechnologies.

  • 46.
    Galfi, Helen
    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.
    Estimation of Faecal Indicator Bacteria in Stormwater by Multiple Regression Modelling and Microbial Partitioning to Solids2018Ingår i: New Trends in Urban Drainage Modelling: UDM 2018 / [ed] Giorgio Mannina, Cham: Springer, 2019, s. 830-835, 2018, s. 830-835Konferensbidrag (Refereegranskat)
    Abstract [en]

    Concerns about the contamination of sources of drinking water by stormwater motivated a sanitary survey of several urban catchments in the City of Östersund (Northern Sweden). A data subset from these surveys, comprising of faecal indicator bacteria (FIB) concentrations (E. coli and enterococci), measured for six storm events in three catchments, was used for investigating the feasibility of developing a FIB estimation procedure for the studied catchments by two approaches: (a) Multiple regression models, and (b) microbial partitioning to solids. In regressions, five explanatory variables (associated constituents) were derived from the literature and measured data: stormwater temperature and flow rate, and measurements of total suspended solids (TSS), total phosphorus (TP) and electric conductivity (EC). The obtained regression models were satisfactory for enterococci (regression of modelled FIBs on measured FIB was described by R2 = 0.7), but less acceptable for E. coli (R2 = 0.2). Microbial partitioning to stormwater solids from gully pots was found infeasible; the sediment sampled contained very low FIB counts. Hence, the former method is recommended for further refinement and applications.

  • 47.
    Pericault, Youen
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Kärrman, Erik
    RISE Built Environment, Research Institutes of Sweden, Stockholm.
    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.
    Expansion of Sewer, Water and District Heating Networks in Cold Climate Regions: an Integrated Sustainability Assessment2018Ingår i: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 10, nr 10, artikel-id 3743Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study presents an integrated sustainability assessment of technical alternatives for water and heating services provision in suburban areas affected by a cold climate. Each alternative combines a drinking water supply, sewerage (gravity or low-pressure), pipe freeze protection (deep burial or shallow burial with heat tracing) and heating solution (district heating or geothermal heat pumps). An innovative freeze protection option was considered, in which low-temperature district heating (LTDH) is used to heat trace shallow sewer and water pipes. First, the performance of each alternative regarding seven sustainability criteria was evaluated on a projected residential area in Sweden using a systems analysis approach. A multi-criteria method was then applied to propose a sustainability ranking of the alternatives based on a set of weights obtained from local stakeholders. The alternative with a deep buried gravity sewer and geothermal heat pumps was found to have the highest sustainability score in the case study. In the sensitivity analysis, the integrated trench solution with a gravity sewer, innovative heat tracing and LTDH was found to potentially top the sustainability ranking if geothermal energy was used as the district heating source, or if the weight of the cost criterion increased from 24% to 64%. The study highlights the need for integrated decision-making between different utility providers as an integrated solution can represent sustainability gains.

  • 48.
    Rujner, Hendrik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Green Urban Drainage Infrastructure: Hydrology and Modelling of Grass Swales2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Urban dagvattenhantering har utvecklats parallellt med en ökad förståelse för dagvattnets allmänna miljöpåver­kan. Utöver ytvattenkvalitén i recipientvatten påverkas även den hydrologiska regimen genom reducerad infilt­rationsförmåga i mark orsakad av allt tätare ytskikt samt reducerad evapotranspiration orsakad av minskad vegetationsutbredning. Detta ger både förhöjda toppflöden och avrinningsvolymer, vilket kan resultera i över­svämning och slutligen en försämrad ytvattenkvalité i recipienterna. Dagens urbana dagvattensystem förändras mot en högre grad av grön infrastruktur som en central systemkomponent. Decentraliserad omhändertagning av dagvatten såsom svackdiken utjämnar och för bort dagvattensflöden, samtidigt som de fungerar tillförlitligt och deras underhållsåtgärder är välkända. Uppbyggda med små svackor och låglutande slänter samlar svackdiken in och infiltrerar dagvatten från parkeringsytor och vägar. Dessa svackdikens hydrologiska funktion bestäms av en rad faktorer, utöver teknisk dimensionering och avrinningsområdets storlek och hydrologi, även av hydraulik och jordartsrelaterad hydrologi som förändras beroende på respektive nederbördstillfälles intensitet och varak­tighet. Eftersom svackdikens utflöde passerar nedströms liggande dagvattentekniker/anordningar, antingen konventionella ledningssystem eller andra teknologier, krävs full förståelse och kunskap om de faktorer som styr svackdikens hydraulik och hydrologi.

    Mot denna bakgrund fokuserar avhandlingen på frågorna (i) vilka skillnader finns med avseende på hydraulisk och hydrologisk prestanda för de studerade svackdiken, (ii) i vilken mån påverkar markartsförhållanden, inklu­sive ingående markfuktighet, svackdikens vattenbalans vid varierande hydraulisk belastning; samt (iii) hur och i vilken mån kan ovanstående simuleras högupplöst och förutsägbart, via den rutnätsbaserade distribuerade mo­dellen Mike SHE. Därför har fullskaliga studier bedrivits i två 30 m långa svackdiken i Luleå kommuns södra stadsområde, där hydrauliska och hydrologiska data insamlats baserat på standardiserade nederbördsförlopp, återskapande blockregn med 2 månaders och 3 års återkomsttid. Data för avrinning och markfukthalter använ­des för att beräkna svackdikenas vattenbalans, nederbördförloppens hydrografer samt erhålla kalibrering- och valideringsdata för modellsimuleringar. Resultaten från experimenten visade att den volymetriska flödesre­duktionen minskade relativt sett med ökande markfukthalt, indikerande en övergång för svackdikets domine­rande funktionalitet: vid låga initiala SWC var avrinningen tydligt dämpad (upp till 74%), medan för höga SWC innebar att transportfunktionen dominerade (med dämpningsgrad ner mot 17%). Avrinnande momentana topp­flöden reducerades proportionellt mot volymreduktionen. Laggtiden för svackdikets utflödeshydrograf varierade mellan 5 och 15 minuter och reducerades med ökande markfukthalt. Fuktförhållandena i svackdiket påverkade avrinningsförloppet, flödesdämpning och efterföljande utsläpp, och enbart svackdikets översta markskikt berör­des under de kortvariga bevattningscyklerna. I de tre testade svackdikena varierade jordart, initial markfukthalt, mättad hydraulisk konduktivitet och topografi signifikant. Mätningar med dubbelrings infiltrometrar gav föl­jande resultat, 1.78, 4.04 samt 9.41 cm/h (n=9), vilket avvek från medelvärdesbaserat estimat från spatialt inte­grerade infiltrationshastigheter. Med avseende på spatial variabilitet påverkade endast svackdikenas topografi, i form av ojämnheter i och nära dikesbotten, avrinningsförloppen och bortledning under den inledande fasen av regnhändelsen. Sammantaget med uppskattningar av den lagrat vatten i marklagrets toppskikt, bedöms 4-32% av svackdikets ytavrinning från ett simulerade nederbördtillfälle med 2 månaders återkomststid kunna lagras tillfälligt. Mike SHE befanns kapabel att med god noggrannhet kunna reproducera naturbundna dräneringsför­lopp och flöden i svackdiken, förutsatt tillbörlig kalibrering. God överensstämmelse (NSE>0.8) framkom inte bara mellan uppmätta och simulerade utgående hydrografer, utan också beträffande ändring av markfukthalt i ytligt marklager med snabb höjning av fukthalt upp emot full vattenmättnad. Däremot framkom endast mindre (eller total frånvaro av) överensstämmelse vad gäller markdjup av 0.2 m. Modellens output uppvisade låg käns­lighet för ursprunglig markfukthalt, speciellt gällande lågt flöde vilket resulterade i större residualer för simule­rade toppflöden och avrinningsvolymer. För fältförsöken framkom att den initiala markfukthaltens spatiala variabilitet inte påverkade utflödet från svackdiket – i motsats till noggrannheten i dikets topografiska repre­sentation. Denna uppsats belyser samband och följdverkningar beträffande påverkan från undersökta parametrar på en modell för flödes- och vattenföring i ett svackdike och framledes framtida design av svackdiken.

  • 49.
    Rujner, Hendrik
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Leonhardt, Günther
    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.
    High-resolution modelling of the grass swale response to runoff inflows with Mike SHE2018Ingår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 562, s. 411-422Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The feasibility of simulating the hydrological response of a grass swale to runoff inflows was examined using the hydrological model Mike SHE and the available input data from 12 irrigation events mimicking runoff from block rainfalls. The test swale channel had a trapezoidal cross-section, bottom slope of 1.5%, length of 30 m, and was built in loamy fine sand. The irrigation events consisted in releasing two equal constant inflows to the swale: a concentrated longitudinal flow at the upstream end and a distributed lateral inflow along the swale side slope adjacent to the contributing drainage area. The total inflows approximated runoff from two events with return periods of 2 months and 3 years, respectively, for durations of 30 min. Irrigation experiments were done for two states of the initial soil moisture, dry or wet antecedent moisture conditions (AMC). Mike SHE has been extensively used on catchments of various sizes, but rarely for small stormwater management facilities and their detailed topography investigated in this study. The latter application required high spatial and temporal resolutions, with computational cells of 0.2 × 0.2 m and time steps as short as 0.6 s to avoid computational instabilities. For dominant hydrological processes, the following computational options in Mike SHE were chosen: Soil infiltration – the van Genuchten equation, unsaturated zone flow – the one-dimensional Richards equation, and overland flow – the diffusive wave approximation of the St. Venant equations. For study purposes, the model was calibrated for single events representing one of four combinations of low and high inflows, and dry and wet AMC, and then applied to the remaining 11 events. This was complemented by calibration for two events, representing high inflow on wet AMC and low inflow in dry AMC. The goodness of fit was statistically assessed for observed and simulated peak flows, hydrograph volumes, Nash-Sutcliffe model efficiencies (NSE), and soil water content (SWC) in swale soil layers. The best fit (NSE > 0.8) was obtained for high inflows and wet AMC (i.e., when the primary swale function is flow conveyance); the least fit was noted for low inflows and dry AMC, when the primary swale function is flow attenuation. Furthermore, this observation indicates the overall importance of correct modelling of the soil infiltration. The effects of spatial variation of SWC on the swale discharge hydrograph could not be confirmed from simulation results, but high topographical accuracy was beneficial for reproducing well the locations of the observed water ponding. No significant increases in simulated SWC at 0.3 m or greater depths were noted, which agreed with field observations. Overall, the results indicated that Mike SHE was effective in process-oriented small-scale modelling of grass swale flow hydrographs.

  • 50.
    Mattsson, Jonathan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten. S-Group Solutions, Malmö.
    Hedström, Annelie
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Westerlund, Lars
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Dahl, Jan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ashley, Richard
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Viklander, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Impacts on rural wastewater systems in subarctic regions due to changes in inputs from households2018Ingår i: Journal of cold regions engineering, ISSN 0887-381X, E-ISSN 1943-5495, Vol. 32, nr 1, artikel-id 04017019Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of water-saving appliances and heat exchangers is becoming increasingly popular to decrease water consumption and recover energy from preheated water. However, such in-household changes can bring particular implications for subarctic rural areas, in terms of solids deposition in sewers and drops in performance of wastewater treatment plants (WWTPs), because these are already experiencing diminishing wastewater flows due to depopulation and seasonal dips in wastewater temperature resulting from infiltration into sewers. Hence, this study has considered two communities in Sweden, postulating three different cases with various scales of retrofitting and usage. The results indicate that the decrease in in-pipe velocities when all households are retrofitted with water-saving appliances could be counteracted by sewer relining, but not by the inclusion of a conventional estimate of infiltration. However, for the case in which retrofitting was combined with decreased usage of the appliances, the decrease in self-cleansing capacity could not be counteracted. The retrofitting of heat exchangers under shower trays in all households did not have a significant effect on treatment processes at the WWTP.

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