No description available.

No description available.

The movement and fate of heavy metal inputs (Cd, Zn, Mn, Cu, Al, Fe, Pb, Ni and Cr) from highway runoff were investigated in a three-year study on 1.3 hectare retention facility near the Maitland Interchange on Interstate 4, north of Orlando, Florida. Physical characteristics of the retention pond and surrounding watershed were defined and field instrumentation was installed. Stormwater samples were collected over a one-year period, representing a wide range of intensities and antecedent dry periods. Stormwater characteristics were compared with average retention pond water quality to determine removal efficiencies for heavy metals within the pond. A total of 138 core samples were collected in the pond over a three-year period to investigate the horizontal and vertical migrations of heavy metals within the pond. Sediment core samples were also carried through a series of sequential extraction procedures to examine the type of chemical associations and stability of each metal in the sediments. An apparatus was built which allowed sediments to be incubated under various conditions of redox potential and pH to investigate the effects of changes in sediment conditions on the stability of metal-sediment associations. Five groundwater monitoring wells were also installed to monitor metal movement and accumulations under stormwater management systems. Heavy metal inputs from highway runoff were found to be predominantly particulate in nature, with dissolved fractions for most metals of only 25 percent. Upon entering the retention pond, most metal species settled into the sediments within 60-90 m of the inlet. Removal efficiencies for metals after entering the pond averaged 70-90 percent for particulate species and about 50 percent for dissolved species. Sediment concentrations of heavy metals were highest near the surface, with rapidly decreasing concentrations with increasing depth. Metal-sediment associations appear to be very strong for most metals, with the vast majority of metal inputs into the pond over the eight-year life still remaining in the top 10 cm. Concentrations of all heavy metals measured were higher in groundwaters beneath the pond that in the pond water; but for most metals, the increases only extended to depths of 1-3 m beneath the pond. In general, metal concentrations beneath swale areas were significantly higher than concentrations beneath the retention pond. Due to slow groundwater movement in the area, the effects of increased metal concentrations are very localized. Evidence was presented to suggest that mobilization of metals into groundwaters could substantially increase with time if maintenance procedures are not conducted.

ABSTRACT Continuous flow column studies were conducted to characterize suspended sol ids and heavy metal reduct ions through sedimentation with varying overflow rates. The heavy metals tested were cadmium, zinc, copper, iron, lead, nickel and chromium. Stormwater derived samples spiked with street sweepings categorized into particle size ranges less than 500 microns in diameter were utilized in the research. Overflow rates investigated ranged from 28 to 3600 gallons per day per square foot. Theoretical predictions of suspended solids reductions with the application of Stoke's Law exceeded observed reductions for the continuous flow system. Performance curves for all reductions over the observed range of overflow rates are described by a parabolic relationship with the general equation as follows: Reduced fraction= a+ b(Overflow Rate - c) 2 where a, b and c are constants specific to each parameter. Similarities in performance curves for all metals indicate a dependence on suspended solids for reductions. Cadmium and chromium reductions were a function of overflow rate, but did not show a statistically significant dependence on initial total suspended solids concentration. Lead, copper, zinc and iron reductions were a function of initial total suspended solids concentration as well as overflow rate. Iron and nickel exhibited dependence on initial concentration of the specific metal for reductions, as well as dependence on overflow rate and initial total suspended solids concentration. The steady-state models selected from the results of this research for total suspended sol ids and each of the heavy metals are limited to the mixture, specific experimental conditions, and range of overflow rates observed in this research. Observed reductions of total suspended solids and heavy metals are considered to be 1 imited to physical sedimentation processes, in that processes that may effect reductions of these elements in a natural system are not factors in the results of this research.

A Statistical formulation for estimating the average time of detention within a pond for a captured runoff volume is presented. It is assumed that mixing takes place during an event and that settling occurs over the period required to empty the captured volume or the time between successive events, whichever is smaller. This analytical detention time is used in conjunction with a pollutant settling efficiency-detention time curve to estimate the settling efficiency. This curve is generated from Storm Water Management Model (SWMM) simulations and shown to be independent of runoff statistics, pond configuration, and arbitrary but constant influent concentration under complete mixing. The analytical detention time estimate, in combination with the settling efficiency curve and an expression for the capture efficiency of the pond provides a valuable desktop method for the planning level design of detention basins for pollutant removal. The method performs quite well when compared to the results obtained from long-term SWMM simulation runs. / Master of Science

Örebro flygplats är en central knutpunkt för luftfarten inom regionen. I och med att flygplatsen har Sveriges fjärde största fraktflygplansanläggning, ställs höga krav på flygsäkerheten. Därför används det varje vinter stora mängder avisningsvätska för att hålla flygplanen fria från is och snö. Senaste säsongen användes över 74 000 kg avisningsvätska som är främst bestående av propylenglykol. Men hur effektivt är reningssystemet på flygplatsen för att minimera den förbrukade vätskans miljöpåverkan? Denna studie undersöker flygplatsens rening av förbrukad avisningsvätska i deras dagvattensystem. Främsta fokus är att undersöka markbädden som är den huvudsakliga reningsmetoden för förbrukad avisningsvätska, men även dagvattendammen som ska rena övrigt dagvatten utan avisningsvätska. Tidigare har det uppdagats att höga värden av kemisk syreförbrukning (COD mg/l) förekommer i både markbädden och dagvattendammen. Det har konstaterats att propylenglykol är lätt nedbrytbart och kräver mycket syre för att brytas ned. Denna höga syreförbrukning leder till höga COD-värden samt kan leda till syrebrist i vattnet.Studien består av provtagningar och analyser av dagvatten från olika delar av dagvattensystemet, inklusive markbädden och dagvattendammen. Samtliga prover har analyserats för COD-värden, mer ingående analyser har gjorts för metaller och pH-värden i markbädden. Analyserna visar att markbäddens förmåga att rena avisningsvätska är otillfredsställande och att det fortfarande finns höga COD-värden i utloppet av bädden. Det konstateras också att dagvattendammen tar emot avisningsvätska via oavsiktliga spridningsvägar, vilket påverkar vattenkvaliteten negativt. Förbättringsåtgärder krävs för att hantera avisningsvätska mer effektivt för att minimera dess negativa miljöpåverkan. Det rekommenderas att markbädden syresätts och att mikroorganismer tillförs. Vidare är det också viktigt med en effektiv uppehållstid för det tillkommande vattnet, för att uppnå ett kontinuerligt flöde. Dagvattendammen är i behov av en längre uppehållstid för vattnet innan det når utloppet för att minimera höga COD-värden i utgående vatten mot recipient. Dessa åtgärder bidrar till att säkerhetsställa en bättre vattenkvalité för det utgående dagvattnet till recipient. / Örebro Airport is a central hub for aviation in the region. With the airport being Sweden's fourth-largest cargo aircraft facility, high demands are placed on flight safety. Therefore, large amounts of deicing fluid are used every winter to keep the aircraft free from ice and snow. Last season, over 74,000 kg of deicing fluid, primarily consisting of propylene glycol, was used. But how effective is the airport's treatment system in minimizing the environmental impact of the used fluid?This study investigates the airport's treatment of spent deicing fluid in their stormwater system. The main focus is on examining the constructed wetland, which is the primary treatment method for used deicing fluid, but also the stormwater pond, which is supposed to treat other stormwater without deicing fluid. Previously, high values of chemical oxygen demand (COD mg/l) have been found in both the constructed wetland and the stormwater pond.It has been established that propylene glycol is readily biodegradable and requires a lot of oxygen to break down. This high oxygen demand leads to high COD values and can cause oxygen depletion in the water.The study consists of sampling and analyzing stormwater from different parts of the stormwater system, including the constructed wetland and the stormwater pond. All samples have been analyzed for COD values, with more detailed analyses conducted for metals and pH levels in the constructed wetland. The analyses show that the constructed wetland's ability to treat deicing fluid is unsatisfactory and that high COD values still exist in the outflow of the wetland. It is also noted that the stormwater pond receives deicing fluid through unintended pathways, which negatively affects water quality.Improvement measures are required to handle deicing fluid more effectively to minimize its negative environmental impact. It is recommended that the constructed wetland be aerated and that microorganisms be introduced. Furthermore, an effective retention time for the incoming water is crucial to achieve a continuous flow. The stormwater pond needs a longer retention time for the water before it reaches the outflow to minimize high COD values in the outgoing water to the recipient. These measures will help ensure better water quality for the outgoing stormwater to the recipient.

I evaluated the effectiveness of plant roots to increase infiltration rates within stormwater bioretention facilities (SBFs), roadside planter compartments that filter stormwater. SBFs attenuate harmful effects of stormwater by reducing peak flow and retaining pollutants, with increased infiltration that improves both these functions. Researchers have shown that roots can increase infiltration within greenhouse, lab, field, and test SBF settings. However, no researchers have yet measured either the extent to which different root characteristics can increase infiltration or the variation in root characteristics and their effect on infiltration rates among plant assemblages within currently functioning SBFs. To determine if root-enhanced infiltration was occurring within SBFs, I hypothesized 1) there is a relationship between root characteristics and infiltration during late spring, and 2) seasonal root growth increases infiltration rates. Within Portland, OR, I measured infiltration rate from January 2014 to February 2015 and root characteristics from January-February (J-F) and May-June (M-J) 2014 in ten SBFs with "Elk Blue" rush (Juncus patens) and 1 or 2 trees of less than 8.4 cm stem diameter. During M-J, four root characteristics showed a positive relationship with infiltration rate, and two root characteristics showed a strong positive relationship with infiltration rate within the topsoil. Also, a relationship was shown between the increase (J-F to M-J 2014) in three root characteristics and the increase in infiltration rate. To determine if root morphology and infiltration rates differed among SBFs with two different dominant vegetation taxa (small and large root biomass), I hypothesized 3) Juncus patens and tree dominant assemblage (greater root biomass) exhibits greater infiltration compared to the Carex dominant assemblage, 4) the increase in infiltration rate and root characteristics from J-F to M-J is greater in the Juncus compared to the Carex assemblage, and 5) root surface area density (RSAD) within Juncus SBFs shows a positive relationship with infiltration rate in late spring. I measured infiltration rate from January 2014 to February 2015 and root characteristics from January-February (J-F) and May-June (M-J) 2014 among five large-root (Juncus and tree) and five small-root biomass (Carex sp) SBFs. Juncus SBFs showed greater values for three root characteristics during J-F and five root characteristics during M-J 2014 compared to Carex SBFs. Also, Juncus SBFs showed an increase from J-F to M-J 2014 for five root characteristics while Carex SBFs showed no root increase. Juncus SBFs showed a relationship with four root characteristics and Carex SBFs a showed relationship with one root characteristic and infiltration rate. This work strongly suggests plant roots increase infiltration, and thus the primary functions of SBFs. Different root characteristics appear to increase infiltration rate at different depths. Data also show larger-root biomass plants increase infiltration rate to a greater degree than smaller-root biomass plants. I recommend considering several site and facility characteristics when determining the potential for root-enhanced infiltration. When selecting plant species to enhance infiltration, I recommend using several criteria, determining root characteristic values at certain depths, considering installation approaches, and accounting for regional climate changes.

Material av plast är praktiska och användbara, vilket medför att de återfinns i många produkter som används i vardagen. På grund av dess egenskaper har framställning av produkter och användning av plast ökat sedan massproduktionen av plast började. Mikroplast definieras som plastobjekt med en storlek mindre än 5 millimeter. Eftersom att material av plast förekommer i många produkter så har det lett till en spridning av mikroplast som påträffas på flertalet platser i naturen runtom i världen. Svenska Miljöinstitutet, IVL, har granskat kartlagda uppkomstkällor till och spridningen av mikroplaster i Sverige. De två största landbaserade källorna till mikroplast är slitage av vägbanor och däck respektive mikroplast från konstgräsplaner. Utifrån kartläggningen sker spridning vidare till omgivningen och därför är det angeläget att undersöka belastningen som kan förekomma i dagvattnet från dessa källor. I den här studien har mängden mikroplast undersökts med en minsta storleksfraktion på 100 mikrometer i dagvatten från trafikvägen Bolandsgatan och konstgräsplanen Stenhagens IP i Uppsala. Provtagning utfördes på dagvatten i dagvattenbrunnar genom att ta stickprov och med en provtagare som möjliggjorde flödesproportionell provtagning. Insamlade prover filtrerades där mikroplast sedan analyserades visuellt i stereomikroskop. Analysen av mikroplast kombinerades även med ett smälttest. I undersökningen av den trafikerade vägen Bolandsgatan var 98 % av alla partiklar svarta. De svarta partiklarna kategoriserades som mikroplast som har uppkommit i samband med slitage av vägtrafik. Vid undersökning av konstgräsplanen Stenhagens IP påträffades ett gräsfragment som kategoriserades som mikroplast från konstgräsplanen.  Mikroplastmängden i dagvatten från den trafikerade vägen Bolandsgatan erhölls till 33 kg/år. Emissionsfaktorn för blandad trafik beräknades till 2,2∙10-5 kg/fordonskm. Emissionsfaktor för mikroplast från däck, som beräknats utifrån mätningar i dagvatten från vägtrafik, har inte presenterats i tidigare studier. Från vägtrafiken i Uppsala kommun och Sverige erhölls mängden till 27 000 kg/år respektive 1,5∙106 kg/år. Från konstgräsplanen Stenhagens IP var mängden mikroplast 6,3∙10-2 kg/år. Från konstgräsplaner i Uppsala kommun och Sverige erhölls mängden till 0,56 kg/år respektive 48 kg/år. Vid beräkning av mikroplastmängder finns det en osäkerhet i bestämningen av volymen, ökar partikelradien med en faktor 2 så ökar volymen 8 gånger. Enligt den här studien är mikroplastmängder från vägtrafik i Sverige ungefär 5 gånger mindre än Naturvårdsverkets uppskattning, mängder från konstgräsplaner i Sverige är ungefär 30-50 gånger mindre än Naturvårdsverkets resultat. / Materials made from plastic are practical and durable, therefore plastic is found in many every day products. Because of the properties of plastics, the manufacturing of products and usage of the material has increased consequently leading to the creations of microplastics in varying sizes. The definition of microplastics is plastic materials with a size smaller than 5 millimeters. Because of a huge prevalence in products the consequence is microplastics being found on many places in nature around the world. The Swedish Environmental Research Institute, IVL, has been assigned by the Swedish Environmental Protection Agency to review identified origins and the pathways of microplastics in Sweden. According to the study the largest source of microplastics from outdoor activities on land is from road wear and the abrasion of tyres followed by artificial turfs. Since microplastics are presumed to be spread to the environment, it is of concern to investigate potential microplastic load in storm water from these sources. The investigation of microplastic amounts has been studied in sizes ≥100 micrometres in storm water from the traffic road Bolandsgatan and the artificial turf Stenhagens IP in Uppsala. Samples were collected, using random sampling and with an automatic sampler enabling flow proportional sampling. Filtration of collected water samples were carried out followed by analysing microplastic visually in a stereo microscope. The analyses of microplastics were also combined with a melting test. In the study of the traffic road Bolandsgatan 98 % of all particles were black colored. The black colored particles were identified as microplastic originated from road wear. When studying the artificial turf Stenhagens IP a grass fragment was identified as microplastic originated from the artifical turf. Microplastic amounts from the traffic road Bolandsgatan are 33 kg/year. The emission factor for mixed fleet is 2.2∙10-5 kg/vehicle km. An emission factor for microplastic from road traffic has not been presented in other studies before. The amount of microplastics from road traffic in Uppsala was estimated to 27 000 kg/year and in Sweden to 1.5∙106 kg/year. From the artificial turf Stenhagens IP the amount was 6.3∙10-2 kg/year. By upscaling the amounts of microplastics from artificial turfs in Uppsala and Sweden the amounts were estimated to 0.56 and 48 kg/year, respectively. According to this study, the spread of microplastic from road traffic in Sweden is 5 times less than the estimated value and the amount from artificial turfs is 30-50 times less compared to the investigation by the Swedish Environmental Protection Agency.

<p>Förorenat dagvatten från Stena Gotthards metallåtervinningsanläggning i Eskilstuna har filtrerats genom kolonner innehållande två olika adsorbenter, torv och furubarksflis. Torv är en organisk jordart som främst används som bränsle och furubarksflis är en biprodukt från skogsindustrin. Båda filtermaterialen är relativt billiga och finns i stora kvantiteter i Sverige. Filtermaterialen har visat sig ha varierande kapacitet att adsorbera metaller i vatten på grund av själva materialet samt vattnets sammansättning. Resultatet från den här studien visar att av de två undersökta filtermaterialen så har furubarksflis störst kapacitet att reducera bly, koppar och zink från det specifika dag vattnet.</p> / <p>Polluted storm water from a metal recycling industry has been filtrated through columns that contained two different adsorbents, peat and pine bark. Peat is an organic soil, mainly used for energy production, and pine bark, a by-product from the forest industry. In Sweden, there are a lot of resources of peat as well as pine bark. Used as filter materials, they are relatively cheep and, like other kinds of filtermaterial used as adsorbents, they have varied capacity to adsorb metals in water. The capacity for the filter materials to adsorb metals depends on the physical structure and chemical contents of the peat and pine bark as well as the water metal composition. Results from this study show that pine bark had the highest adsorption capacity to reduce copper, lead and zinc from the specific storm water.</p>

<p>Sveriges avloppsledningsnät förnyas och utvidgas kontinuerligt. Idag finns ett flertal datorprogram för hydraulisk modellering av flöden och uppdämningsnivåer i spill- och dagvattennät. Modellerna kan även användas som planeringsverktyg för att bedöma effekter av planerade åtgärder samt för uppföljning av utförda åtgärder. Vid uppbyggnaden av en modell krävs beräkningsresultat från en hydrologisk avrinningsmodell som indata. Det största arbetet vid modelluppbyggandet ligger just i beskrivningen av hydrologin. För att kunna simulera avrinningsförlopp i samband med nederbörd på ett verklighetsliknande sätt är kännedom om storleken på och fördelningen av anslutna hårdgjorda ytor till ledningsnätet med snabb nederbördsavrinning väsentligt. </p><p> </p><p>Till kalibreringen och valideringen av avloppsmodellen krävs mätdata. Flödesmätningar är dyra att genomföra vilket har skapat ett intresse att hitta metoder som säkert beräknar de anslutna hårdgjorda ytorna redan från de uppgifter som finns på kartor och i databaser. Svenska riktlinjer för beräkning av hårdgjorda ytor tillhandahålls av branschorganisationen Svenskt Vatten som företräder VA-verken och VA-bolagen i Sverige. Beräkningar med dessa riktlinjer ger dock inte alltid den korrekta storleken på de hårdgjorda ytorna. Syftet med examensarbetet har varit att undersöka olika metoder att beräkna anslutna hårdgjorda ytor till spillvattennätet samt att undersöka huruvida det finns ett samband mellan de avrinningsområden där beräkningarna av de hårdgjorda ytorna inte stämmer. Nio befintliga modeller framtagna i modelleringsverktyget MIKE URBAN användes vid undersökningen. Sex av dessa modeller användes till kalibrering och tre modeller användes till validering.</p><p> </p><p>Undersökningen visade inget samband mellan ytavrinning (reduktionsfaktor) och lutning. Fördelningen av mätpunkter mellan olika jordartskategorier var väldigt ojämn vilket gjorde det svårt att studera huruvida det finns ett samband mellan avrinning och jordart. Resultatet från undersökningen visar att avrinningskoefficienter bör delas upp efter typ av ledningsnät i avrinningsområdet. Metoden med olika avrinningskoefficienter för olika typer av ytor visar på bra resultat för tätbebyggda områden. Metoden med sammanvägda avrinningskoefficienter för olika bebyggelsetyper visar relativt bra resultat med tanke på att det är en överslagsberäkningsmetod.</p><p> </p><p>För tätbebyggda områden bedöms metoden med avrinningskoefficienter för olika typer av ytor fungera bra. Vid mindre tätbebyggda områden ökar osäkerheten. Metoden med sammanvägda avrinningskoefficienter för olika bebyggelsetyper bedöms fungera väl för överslagsberäkningar då den är mindre tidskrävande än den andra metoden. Ingen av de undersökta metoderna bedöms kunna ersätta flödesmätningar. </p> / <p>Sweden’s sewage systems are continuously being maintained and expanded. Several computer programs are today available for hydraulic modeling in sewage and storm water systems. The models can also be used as a planning tool to evaluate effects of planned interventions and to follow up performed interventions. Input data from a runoff model is required at the model build-up. Most of the work in model build-up lies at the description of the hydrology. In order to simulate runoff processes in connection with precipitation, understanding of the size and distribution of impervious surfaces with fast response runoff are essential.</p><p> </p><p>Measurements are required for the calibration and validity check of the model. Unfortunately, flow measurements are expensive to perform. This has created an interest to find methods that safely calculate the connected impervious surfaces already from the information that can be found in maps and in databases. The Swedish guidelines for calculation of impervious surfaces are provided by the Swedish Water and Wastewater Association. Calculations with these guidelines do not always give the true size of the impervious surfaces. The aim of this master thesis was to examine various methods to calculate impervious surfaces connected to the sewage system and whether there is a correlation between drainage areas where the calculations do not agree. Nine existing models developed in the computer program MIKE URBAN were used in this study. Six of these models were used in the calibration and three models were used in the validity check of the methods.</p><p> </p><p>The study did not show any correlation between runoff (reduction factor) and slope. The distribution of datum points between different soil types varied so much that it made it difficult to study whether there was correlation between runoff and soil type. The result from the study showed that the runoff coefficients should be divided after type of sewage system in the drainage area. The method with runoff coefficients for different types of surfaces showed fairly good results for highly urbanized areas. The method with weighted runoff coefficients for different types of habitations showed relatively good results considering that it is a method for rough calculations.</p><p> </p><p>The method with runoff coefficients for different types of surfaces is considered well-functioning for highly urbanized areas. In less urbanized areas, this method showed shorter results. The method with weighted runoff coefficients for different types of habitations is considered well for rough calculations when it is less time consuming than the other method. None of the examined methods are considered able to replace flow measurements.</p>