The bioaccumulation of organic contaminants in aquatic ecosystems has been a key focus in environmental toxicology over the last decades. Bioaccumulation is a key concept in ecological risk assessments since it controls the internal dose of potential environmental contaminants. Information on the bioaccumulation of contaminants is used by regulatory authorities in the development of water quality standards, categorizing substances that are potential hazards and quantifying the risk of chemicals to human health. A basis for identifying priority chemicals has been the use of the octanol-water partition coefficient (KOW) as a criterion to estimate bioaccumulation potential. However, recognizing that the bioaccumulation process is not controlled by the hydrophobicity of a chemical alone, this thesis proposes a set of tools, incorporating chemical properties, environmental characteristics and physiological properties of organisms, to study the bioaccumulation of contaminants in aquatic ecosystems.  In striving to achieve this objective, a tool based on an equilibrium lipid partitioning approach was used in Paper I to evaluate monitoring data for bioaccumulation of organic contaminants. In Papers II and III, mechanistic based modelling tools were developed to describe bioaccumulation of hydrophobic compounds in aquatic food webs. In Paper IV, the bioaccumulation of organic compounds in aquatic food chains was studied using stable isotopes of nitrogen. The mechanistic fate and food web models developed in this thesis provide regulators and chemical manufacturers with a means of communicating scientific information to the general public and readily applicable mechanistic fate and food web models that are easily modified for evaluative assessments purposes.

One of the most fundamental human needs is fresh air. It has been estimated that people spend comparatively much time in indoor premises. That creates an elevated need for high-quality ventilation systems in buildings. The ventilation airflow rate is recognised as the main parameter for measuring the indoor air quality. It has been shown that the ventilation airflow rates have effects on respiratory diseases, on “sick building syndrome” symptoms, on productivity and perceived air quality. Ventilation is necessary to remove indoor-generated pollutants by diluting these to an acceptable level. The choice of ventilation airflow rate is often based on norms or standards in which the airflow rate is determined based on epidemiological research and field or laboratory measurements. However, the determination of ventilation flow rate is far more complex. Indoor air quality in the occupied zone can be dependent of many factors such as outdoor air quality, airflow rate, indoor generation of pollutants, moisture content, thermal environment and how the air is supplied into the human occupied zone. One needs to acknowledge the importance of air distribution which clearly affects the comfort of occupants. To design a ventilation system which considers all aspects of room ventilation can only be achieved by computer modelling. The objective of this thesis is to investigate air diffusion, indoor air quality and comfort issues by CFD (computational fluid dynamics) modelling. The crucial part of the CFD modelling is to adopt BCs (boundary conditions) for a successful and accurate modelling procedure. Assessing the CFD simulations by validated BCs enabled constructing the ventilation system virtually and various system layouts were tested to meet given design criteria. In parallel, full-scale measurements were conducted to validate the diffuser models and the implemented simplified particle-settling model. Both the simulations and the measurements reveal the full complexity of air diffusion coupled with solid contaminants. The air supply method is an important factor for distribution of heat, air velocity and solid contaminants. The influence of air supply diffuser location, contaminant source location and air supply method was tested both numerically and by measurements to investigate the influence of different parameters on the efficiency of room ventilation. As example of this, the well-known displacement ventilation is not fully able to evacuate large 10 μm airborne particles from a room. Ventilation should control the conditions in the human breathing zone and therefore the ventilation efficiency is an important parameter. A properly designed ventilation system could use less fresh air to maintain an acceptable level of contaminant concentration in the human breathing zone. That is why complete mixing of air is not recommended as the ventilation efficiency is low and the necessary airflow rate is relatively high compared to other ventilation strategies. Especially buoyancy-driven airflows from heat sources are an important part of ventilation and should not be hampered by supply airflow from the diffusers. All the results revealed that CFD presently is the only reliable method for optimising a ventilation system considering the air diffusion and contaminant level in all locations of any kind of room. The last part of the thesis addresses the possibility to integrate the CFD modelling into a building design process where architectural space geometry, thermal simulations and diffuser BCs could be embedded into a normal building design project. / QC 20101007

<p><p>Clean water is a critical natural resource. We do not have much available: only 2.5% of water on Earth is freshwater and of that only 31% is in liquid form. 96% of the liquid fresh water is groundwater. Unfortunately that resource is subject to contamination by hazardous materials accidentally or illicitly spilled, leaked, or deposited in or on the ground. Among the methods to remediate these disasters, pump-and-treat (P&T) is the most common. The vertical circulation well (VCW) is a P&T configuration with extraction and injection sites within the same well. It can be adapted to many remediation techniques and has been gaining popularity since the 1990s and is often a better alternative to conventional P&T. Conventional P&T and VCWs are typically run with steady flow.</p></p><p><p>The major bottleneck to steady flow remediation is that contaminants become trapped in dead-end pores. In an aquifer there are two types of pores: <it>pass-through</it> pores and <it>dead-end</it> pores. The flow in former completely sweeps through the pore space while the flow does not enter the later; however, the flow through the <it>pass-through</it> pore induces a vortex in the <it>dead-end</it> pore. Under steady flow the only mechanism for contaminants to escape the <it>dead-end</it> pores is molecular diffusion.</p></p><p><p>A similar problem is encountered in the removal of surfactants in the manufacture of semiconductor and the removal of oil residue build-up in small ducts. Manufacturers discovered that pulsed flow would accelerate the mass transfer between the cavities and grooves on these surfaces and the external flow. This was because the unsteady ramp-up in flow rate initiated a deep sweep of the cavities. The unsteady ramp-down in flow rate initiated a vortex ejection where the sequestered vortex is no longer constrained and protrudes from the cavity.</p></p><p><p>We hypothesized that just as pulsed flow improves cleaning of grooved surfaces in several manufacturing procedures, rapidly pulsed pumping (with a period on the order of a second rather than weeks or months) in pump-and-treat groundwater remediation would boost the diffusion-limited removal of contaminants trapped in dead-end pores by generating transient deep sweeps and vortex ejections in these pores. These processes have not yet been exploited in groundwater remediation to any significant degree.</p></p><p><p>We tested our hypothesis in a series of numerical and laboratory experiments. We considered unwashed and washed media. For unwashed media (Chapter 1) we used as a square pore in the numerical domain and crushed glass (for its negligible sorption capacity) in laboratory column studies. For washed media (Chapter 2) we used a smooth dead-end pore constructed with two tangential quarter circles as the pore in the numerical domain and glass spheres in the laboratory column studies. In all our laboratory experiments we used a fluorescent dye, Fluorescein, as a conservative tracer. We used the same parameters in our numerical experiments. However, in some we also considered immiscible contaminants such as NAPLs (Chapter 4).</p></p><p><p>All numerical experiments were conducted with the computational fluid dynamics software, FIDAP. In numerical experiments we studied the contaminant removal from interacting dead-end pores connected to both a straight pass-through pore and a divergent pass-through pore. The latter with the flow somewhat analogous to the radial spreading encountered around a around a well in field applications (Chapter 5).</p></p><p><p>To elucidate the dead-end pore dynamics (Chapter 3), we performed numerical experiments and used a physical model to obtain a relationship between the rapidly pulsed flow frequency and length of the pore. Our dimensional analysis pointed to the change in pressure as the key component in the initiation of transient deep sweeps and vortex ejections, two new pore-cleaning mechanisms.</p></p><p><p>We conclude that the rapidly pulsed flow improves the recovery of contaminants from unwashed, or rough, porous media. In numerical experiments with a pore system consisting of just a single square dead-end pore and a single pass-through pore, at 100 pore volumes pumped the rapidly pulsed flow improved cleanup of the dead-end pore alone by approximately 40%. This translates into a 10% improvement of the cleanup of the pore system (dead-end and pass-through pore). Since the dead-end pore is the bottleneck of the current groundwater remediation, it the first measure that is relevant.</p></p><p><p>In corresponding laboratory column experiments with crushed glass, the dead-end pore volume alone is not known. The cleanup of the whole pore space was improved by roughly 10% with the rapidly pulsed pumping, which corresponds nicely to our numerical results.</p></p><p><p>Our numerical experiments demonstrate that there exists an optimal pulsed pumping frequency that is a function of the local flow velocity and the pore geometry (size and morphology).</p></p><p><p>The contaminant recovery from washed, or rounded, media was not as pronounced in the laboratory experiments and the numerical experiments showed no improvement. While both rapidly pulsed and steady flow recovered all of the contaminant in the laboratory column tests, the difference in the time between the two pumping schemes was approximately 0.9 pore volumes pumped. This improvement is likely to be amplified with sorbing contaminants.</p></p><p><p>Many contaminants are non-aqueous phase liquids (NAPLs), which do not readily dissolve in water. We showed in numerical experiments that rapidly pulsed flow can recover NAPLs with viscosity lower than water, but is not as effective with higher viscosity materials; however, these results were based on a model that did not account for interfacial tension and wetting; therefore we will require additional numerical and laboratory experiments.</p></p><p><p>In practice, a flow through porous media is significantly more complex than the one-directional dominated flows considered in our numerical and laboratory column experiments. Around a well the flow is typically three-dimensional and largely radially dominated. We constructed two numerical domains to study the interactions between the cleanup of three square pores: one in a straight channel and one in a divergent channel to study the radial spread that would be experienced around a well. For a series of three dead-end pores, there was a 35% improvement by rapidly pulsed flow over steady flow in the straight channel and a 33% improvement in the divergent domain. The optimal frequency was different in the divergent flow even though the pores were the same size as in the previous study. Since the divergent channel reduced the flow velocity, the pulses reached the pores at a decreasing rate. Due to this divergence and the range of pore-sizes in a natural aquifer, implementation of rapidly pulsed flow should likely include a range of frequencies.</p></p><p><p>We concluded that the rapidly pulsed flow on the time scale of one-second would greatly enhance the cleanup of contaminated aquifers by P&T or VCW approaches. We measured significant improvements in the time to recovery. For our preliminary VCW experiment showed that rapidly pulsed pumping recovers 50% of the contaminant four times faster than steady pumping. P&T and VCW remediation typically use a steady flow; there are some methods that change the flow rate in P&T and other configurations, such as the VCW. These periodic changes in rate are on the scale of months to years. Some VCWs and air sparging technologies pulse oxygen, surfactants, and/or nutrients into the aquifer to oxidize, mobilize, or bioremediate the contaminants. As reviewed in chapter 6 in detail, all pulsing so far applied in remediation is on the time scale of a day or longer. Such low pulsing frequency does not produce sufficiently many deep sweeps to make a significant difference in cleaning dead-end pores.</p></p><p><p>Implementation of rapidly pulsed technology will utilize the same extraction and injection wells currently used in pump-and-treat remediation but will require replacement or significant modification of the pumps.</p></p><p><p>There are public health and financial implications of this research. In the dissertation conclusions section we reinterpret our numerical experiments with the multiple interacting dead-end pores and a divergent pass-through pore and laboratory experiments with a vertical circulation well chamber by calculating and plotting the ratio of times needed to reach a specified fraction recovered (specified cleanup level) in the steady and rapidly pulsed pumping modes, \tau_{s} / \tau_{p}. This ratio represents the speedup factor, i.e., the factor by which the time needed to reach the specified cleanup level with the conventional remediation (with steady pumping) would be reduced. From our experiments it appears that with the increasing level of targeted cleanup (contaminant fraction recovered), the speedup factor increases and may even exceed an order of magnitude. As we demonstrate in the dissertation conclusions section, this could translate into tens of billions of dollars in savings. Whether or not the laboratory speedup factors would hold in the field cannot be established without field-scale experiments.</p></p> / Dissertation

Background and objective: Major risk factors for congestive heart failure (CHF) are myocardial infarction, hypertension, diabetes, atrial fibrillation, smoking, left ventricular hypertrophy (LVH) and obesity. However, since these risk factors only explain part of the risk of CHF, we investigated whether persistent organic pollutants (POPs) might also play a role. Methods: In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, left ventricular ejection fraction, (EF), E/A-ratio and isovolumic relaxation time (IVRT), were determined by echocardiography and serum samples of 21 POPs were analyzed in serum measured by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) in 998 subjects all aged 70 years. Results: In this cross-sectional analysis, high levels of several of the polychlorinated biphenyls (PCB congeners 99, 118, 105, 138, 153, and 180) and octachlorodibenzo-p-dioxin (OCDD) were significantly related to a decreased EF. Some POPs were also related to a decreased E/A-ratio (PCBs 206 and 209). All the results were adjusted for gender, hypertension, diabetes, smoking, LVH and BMI, and subjects with myocardial infarction or atrial fibrillation were excluded from the analysis. Conclusions: Circulating levels of POPs were related to impairments in both left ventricular systolic and diastolic function independently of major congestive heart failure risk factors, suggesting a possible role of POPs in heart failure.

<p><p>I investigated the usefulness of phytoplankton for the removal of surface water contaminants. Three experiments, consisting of nine large mesocosms (92.2 m³) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with contaminated mine water. During the summer of 2003, each mesocosm was fertilized with a different amount of phosphorus throughout the 35 day experiment to stimulate phytoplankton growth, and to create a range in phosphorus load (g) to examine how contaminants may be affected by different nutrient regimes. Algal growth was rapid in fertilized mesocosms as demonstrated by chlorophyll a profiles. As phosphorus loads increased there were significant declines in the surface water concentrations of As, Co, Cu, Mn, Ni, and Zn. This decline was near significant for uranium. The surface water concentrations of Ra²²⁶, Mo, and Se showed no relationship to phosphorus load. Contaminant concentrations in sediment traps suspended at the bottom of each mesocosm generally showed the opposite trend to that observed in the surface water, with most contaminants (As, Co, Cu, Mn, Ni, Ra²²⁶, U, and Zn) exhibiting a significant positive relationship (<i>P</i> < 0.05) with phosphorus load. Sediment trap concentration of Se and Mo did not respond to nutrient treatments.</p> <p>Similar experiments were repeated during the mid- and late-summer of 2004, with 5 mesocosms being fertilized with phosphorus, and another 4 with both phosphorus and ammonium to create different nutrient gradients. Results from these experiments were much more variable than those seen in the experiment conducted in 2003, and small samples (<i>n</i> = 5 for phosphorus treatments and <i>n</i> = 4 for both phosphorus and ammonium treatments) yielded insufficient statistical power to effectively determine statistically significant trends. However, contaminant sedimentation tended to respond to phosphorus treatments in a similar manner as results from 2003; phosphorus-with-ammonium treatments had little positive effect on contaminant sedimentation rates.</p> <p>My results suggest that phytoremediation has the potential to lower many surface water contaminants through the sedimentation of phytoplankton. Based on our results from 2003, we estimate that the Saskatchewan Surface Water Quality Objectives (SSWQO) for the DJX pit would be met in approximately 45 weeks for Co, 65 weeks for Ni, 15 weeks for U, and 5 weeks for Zn if treated using phytoremediation.</p><p>Note:</p><p>Appendix A content (pages 92-95) contains copyrighted material which has been removed. It can be viewed in the original thesis upon request.</p>

During 40 years of industrial production, from the end of the 1890’s until the end of 1930’s, coal and wood distillation products were manufactured in AB Carbo’s tar factory along the River Gimån in Grötingen, in the county of Jämtland, Sweden. In accordance with the Swedish Environmental Protection Agency’s Methods for Inventories of contaminated sites, MIFO, the site in Grötingen has been identified as a potentially contaminated site. In order to determine whether toxic substances pose a threat to human health and ecological systems in the area, there was a need to investigate the presence of contaminants, their levels and potential for migration. Sensitivity and protection value regarding exposure of man and the environment at the site is high, since people live next to the site and River Gimån is a part of the Natura 2000 network. The initial phase of the MIFO method includes a preliminary survey. Information regarding AB Carbo’s activities and production has been obtained by studying map and archive material, as well as by interviews and site inspections. Potential point sources have been identified around the factory forge, storage cellar, distillation building and the wooden channel for the discharge of tar and other condensates into the River Gimån. Guided by the information gathered in MIFO phase 1, a preliminary site investigation was carried out at the site. It included sampling of soil, sediment, groundwater and surface water together with sample analysis of heavy metals and organic pollutants. The result of the analysis shows that very high levels of the contaminants PAH, aromatics and lead are found in both soil and groundwater. The sediment contamination level is high while that of surface water is very low. The distribution of contamination levels among the samples indicates a likely point source close to the distillation building due to very high contamination levels in soil and groundwater close to that point. The point source may represent a larger spillage or dumped waste products. Two of the contaminants present at the site, phenantrene and phenol, were studied by using the model CHEMFLO-2000. The analysis focussed on mobility in unsaturated soils under conditions that prevail at the site in Grötingen. The adsorption of phenantrene is significantly higher in comparison to that of phenol. Comprehensive assessment and risk classification results in risk class 2 for the site in Grötingen, which implies a need for further investigations and measurements. The risk of human exposure could be reduced by removing contaminated soil around the factory forge. Additional studies should focus on finding the location of the point source around the distillation building as well as contaminant migration from the wooden channel and the geographical spreading of heavy metal contamination. / Från slutet av 1890-talet och fram till slutet av 1930-talet tillverkades träkol och trädestillationsprodukter vid AB Carbos kolugnsanläggning i Grötingen, Jämtlands län. En undersökning enligt MIFO-modellen motsvarande fas 1 och fas 2 har genomförts på området med syfte att fastställa vilka föroreningar som förekommer på området, föroreningsnivå, spridningsförutsättningar och sammanfattningsvis bedöma föroreningssituationen på området utifrån de miljö- samt hälsorisker som området ger eller kan ge upphov till. Objektsområdet har hög känslighet och högt skyddsvärde då människor bor permanent alldeles intill objektsområdet samt att det intilliggande vattendraget Gimån ingår i Natura 2000-nätverket. Genom de orienterande studier som genomfördes i MIFO fas 1 har kart- och arkivstudier samt intervjuer resulterat i information om kolugnsanläggningens verksamhet samt tillverkade produkter. På fabriksområdet identifierades potentiella punktkällor vid fabrikens smedja, källare, reningsverk samt vid den träränna varigenom spilltjära släpptes ut till Gimån. Utifrån den information som erhölls i den orienterande fasen genomfördes en riktad provtagning enligt MIFO fas 2 i såväl mark och sediment som grund- och ytvatten. Bedömning av uppmätta föroreningshalter baseras på riktvärden och skattas från mindre allvarliga till mycket allvarliga. Analysresultaten påvisar allvarliga till mycket allvarliga halter av PAH, aromater och bly i jorden och grundvattnet. Andra föroreningar som påvisas i högre halter på området är alifater och koppar. Föroreningsnivån med avseende på PAH i sedimenten bedöms som allvarlig medan analysresultaten från ytvattenprovtagningen påvisar mycket låga föroreningsnivåer. Provtagningsresultaten påvisar ett mycket förorenat grundvattenflöde från reningsverket, där en punktkälla i form av större spill eller nedgrävda förvaringskärl kan vara lokaliserad. Eventuell spridning av föroreningar från trärännan går inte att fastställa då föroreningsspridning även kan ske från det intilliggande området där kolugnar och kondenseringshus har varit lokaliserade. Föroreningarna fenantren och fenol studerades genom modellering i CHEMFLO-2000 med avseende på deras rörlighet i omättad jord under de geohydrologiska förhållanden som råder på objektsområdet i Grötingen. Resultatet visar att fenantren adsorberas i marken i betydligt större grad än fenol. Koncentrationen fenantren i porvattnet minskar nästan lika mycket som den totala koncentrationen fenantren i marken, vilket tyder på att fenantren binds starkt genom adsorbtion i marken. Den samlade riskbedömningen av objektet resulterar i att objektet bedöms tillhöra riskklass 2, vilket innebär att objektet ger upphov till en stor risk för människa och miljön. Fortsatta undersökningar på området i Grötingen bör fokusera på att hitta den punktkälla vid reningsverket som bedöms vara orsaken till de höga föroreningsnivåer som uppmättes i grundvattenrör V1. Den geografiska utbredningen av de ytliga föroreningarna som påträffades där smedjan har stått bör också utredas vidare och eventuellt avlägsna förorenad jord eller vidta åtgärder för att minska exponeringen. Vidare undersökningar bör även klarlägga spridningen från trärännan samt orsakerna till de höga föroreningsnivåer av bly som uppmättes på området.

With the prospect of future construction on the Skutskär Pulp Mill property, Stora Enso Fine Paper has initiated an investigation of soil contaminants and a risk assessment of these contaminants. A soil and groundwater investigation has therefore been conducted on an open area of about 16 000 square meters, situated between the current wood room and digester house. To be able to integrate this study into an investigation for the whole industrial property, the study has been carried out as a phase 2 study according to the Swedish Environmental Protection Agency’s Methods of Inventories of Contaminated sites (MIFO). The site investigation has involved soil and groundwater sampling, together with the analysis of heavy metals and organic contaminants. The degree of hazard posed by the contaminants, the level of contamination, the potential for migration of the contaminants, as well as the degree to which protection of human health and the environment is required in the area, have been weighed together for an overall risk assessment of the area with regard to human health and the environment. The investigated area was built up by filling in the coastal waters. The fill material consists mainly of sand that becomes finer below the groundwater surface at the depth of about 2.3 m. Above the groundwater surface pyrite cinders was encountered. Underneath the cinders, lime sludge, bark and wood fiber were found at different depths. The deepest layer encountered consists of moraine. The results showed that most of the heavy metals in the soil originate from the pyrite cinders. The level of contamination was assessed as very high for Zn, Pb, Cu, Cd and Hg. In the groundwater, the level of contamination was assessed as high for Al and moderate for Pb and Cr. The level of organic contaminants was in general low. Heavy oils were encountered in shallow soil layers. Mercury was analysed due to risk of migration from an earlier factory that produced chlorine alkali. The metal was encountered in both the shallow and the deeper layers of soil. Only three of 56 soil samples exceeded the Swedish Environmental Protection Agency’s guideline value for less sensitive land use of 7 mg Hg/kg dry weight. The investigation indicates that the metals still are bound to the pyrite cinders and that most of the leachable parts were mobilized during the years when the ground was not covered with asphalt. Most of the contaminant migration is assumed to take place through groundwater advection. The groundwater flows in the direction of the dock and was calculated to about 3 m3 per day. The gradient in the area is about 0.5 %. The average linear groundwater velocity was computed to about 5 m per year. The transport of the pollutants might be slower due to adsorption and precipitation. Groundwater sampling indicates that the transport to the dock is up to 100 g Zn, 10 g Cr, 8 g Pb and 0.02 g Hg per year. The site was assigned to risk class 3, i.e. moderate risk regarding human health and environment and relatively low urgency concerning additional investigations. / Inför framtida ombyggnationer inom industrifastigheten vill Skutskärs Bruk, Stora Enso, kartlägga markföroreningar och utvärdera vilken spridningsrisk de utgör. En undersökning av mark- och grundvattenförhållanden har därför utförts på en ca 16 000 m2 stor yta, belägen mellan dagens renseri och kokeri. Undersökningen har utförts enligt Naturvårdsverkets Metodik för Inventering av Förorenade Områden (MIFO) för att i framtiden kunna integreras i en fas 2- undersökning för hela fastigheten. Arbetet har inneburit provtagning av mark- och grundvatten som analyserats med avseende på tungmetaller och organiska föroreningar. Föroreningarnas farlighet, föroreningsnivån, spridningsförutsättningarna samt objektets känslighet och skyddsvärde har vägts samman för att bedöma områdets risk för människors hälsa och miljö. Området utgörs av utfylld havsbotten. Massorna består främst av sand som blir siltigare under grundvattenytan på ca 2,3 m djup under markytan. Ovan grundvattenytan påträffades kisaska. Därefter hittades mesa, bark och träfiber på varierande djup. Fyllningen underlagras av morän. Resultatet visade att huvuddelen av tungmetallerna i marken härstammade från kisaskan. Föroreningsnivån bedömdes som mycket stor för Zn, Pb, Cu, Cd och Hg. I grundvattnet bedömdes föroreningsnivån som stor för Al och måttlig för Pb och Cr. Halten organiska föroreningar var generellt sett låg. Tyngre oljor påträffades i ytliga marklager. Kvicksilver har analyserats eftersom risk för spridning från en före detta kloralkalifabrik uppströms området förelåg. Ämnet påträffades både i ytnära marklager och på större djup. Endast tre av 56 markprover översteg Naturvårdsverkets gränsvärde för mindre känslig markanvändning på 7 mg/kg TS. Undersökningen tyder på att metallerna fortfarande är bundna till kisaskan och att stora delar av den lakbara delen transporterades bort under de år som ytan var oasfalterad. Huvuddelen av föroreningstransporten antas ske genom advektion. Grundvattnet flödar i riktning mot hamnbassängen och beräknas uppgå till ca 3 m3/dygn. Områdets gradient är ca 0,5 %. Vattenpartiklarnas hastighet beräknades till ca 5 m/år. Föroreningstransporten kan vara lägre på grund av adsorption och utfällning. Grundvattenprovtagningen tyder på att den årliga transporten till hamnbassängen skulle kunna uppgå till 100 g Zn, 10 g Cr, 8 g Pb och 0,02 g Hg. Objektet bedömdes tillhöra riskklass 3, det vill säga måttlig risk för människa och miljö samt relativt låg angelägenhet för vidare undersökningar.

<p><p>I investigated the usefulness of phytoplankton for the removal of surface water contaminants. Three experiments, consisting of nine large mesocosms (92.2 m³) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with contaminated mine water. During the summer of 2003, each mesocosm was fertilized with a different amount of phosphorus throughout the 35 day experiment to stimulate phytoplankton growth, and to create a range in phosphorus load (g) to examine how contaminants may be affected by different nutrient regimes. Algal growth was rapid in fertilized mesocosms as demonstrated by chlorophyll a profiles. As phosphorus loads increased there were significant declines in the surface water concentrations of As, Co, Cu, Mn, Ni, and Zn. This decline was near significant for uranium. The surface water concentrations of Ra²²⁶, Mo, and Se showed no relationship to phosphorus load. Contaminant concentrations in sediment traps suspended at the bottom of each mesocosm generally showed the opposite trend to that observed in the surface water, with most contaminants (As, Co, Cu, Mn, Ni, Ra²²⁶, U, and Zn) exhibiting a significant positive relationship (<i>P</i> < 0.05) with phosphorus load. Sediment trap concentration of Se and Mo did not respond to nutrient treatments.</p> <p>Similar experiments were repeated during the mid- and late-summer of 2004, with 5 mesocosms being fertilized with phosphorus, and another 4 with both phosphorus and ammonium to create different nutrient gradients. Results from these experiments were much more variable than those seen in the experiment conducted in 2003, and small samples (<i>n</i> = 5 for phosphorus treatments and <i>n</i> = 4 for both phosphorus and ammonium treatments) yielded insufficient statistical power to effectively determine statistically significant trends. However, contaminant sedimentation tended to respond to phosphorus treatments in a similar manner as results from 2003; phosphorus-with-ammonium treatments had little positive effect on contaminant sedimentation rates.</p> <p>My results suggest that phytoremediation has the potential to lower many surface water contaminants through the sedimentation of phytoplankton. Based on our results from 2003, we estimate that the Saskatchewan Surface Water Quality Objectives (SSWQO) for the DJX pit would be met in approximately 45 weeks for Co, 65 weeks for Ni, 15 weeks for U, and 5 weeks for Zn if treated using phytoremediation.</p><p>Note:</p><p>Appendix A content (pages 92-95) contains copyrighted material which has been removed. It can be viewed in the original thesis upon request.</p>

The cabin environment of a commercial aircraft, including cabin layout and the quality of air supply, is crucial to the airline operators. These aspects directly affect the passengers’ experience and willing to travel. This aim of this thesis is to design the cabin layout for flying wing aircraft as part of cabin environment work, followed by the air quality work, which is to understand what effect the ECS can have in terms of cabin air contamination. The project, initially, focuses on the cabin layout, including passenger cabin configuration, seat arrangement and its own size due to the top requirements, of a conventional aircraft and further into that of a flying wing aircraft. The cabin work in respect of aircraft conceptual design is discussed and conducted by comparing different design approaches. Before the evaluation of cabin air quality, an overall examination of the main ECS components involved in the contaminants access will be carried on and, therefore, attempt to discover how these components influence the property of the concerned contaminants. By case study in the B767 ECS, there are some comments and discussions regarding the relationship between the cabin air contaminations and the passing by ambient environment. The thesis ends up with a conclusion explaining whether or not the contaminated air enters the occupants’ compartments on aircraft and proposing some approaches and engineering solutions to the continue research.

Up until relatively recently, the discharging of waste in the environment was the way of eliminating them, until the auto-purifying capacity of the environment was not sufficient. The permitted levels have been vastly exceeded, causing such environmental contamination that our natural resources cannot be used for certain uses and their characteristics have been altered. The main problem stems from waste coming from industry and agriculture, despite the fact that the population also plays an important role in environmental contamination. Phenols, pesticides, fertilizers, detergents, and other chemical products are disposed of directly into the environment, without being treated, via controlled or uncontrolled discharging and without a treatment strategy.In this general context, it is very clear that the strategy to continue in the search of solutions to this problem that every day presents a sensitive growth, mainly in the developing countries, will be guided to two fundamental aspects:- The development of appropriate methods for contaminated drinking, ground, and surfaces waters, and mainly- The development of appropriate methods for wastewaters containing toxic or non-biodegradable compounds.This thesis is focused in the second of these aspects. In this sense, it has been deepened in the treatment of organic compounds in aqueous solution by means of advanced oxidation processes (AOP), in the search of their elimination or transformation into more biodegradable compounds.The experimental work has been divided into four chapters. First part (chapter 3) is focused on the kinetic study of Fenton process for what two model compounds have been chosen: phenol, as reference (model compound widely studied) and an aromatic non-biodegradable compound, nitrobenzene.The second part (chapter 4) addresses to the optimisation of some treatment processes, such as photo-Fenton, H2O2/UV and Fe3+/UV-vis using different sources of artificial light and sunlight. The experimental work of this chapter was divided into two parts. In the first one, experiments were performed at laboratory scale at the University of Barcelona. In the second one, experiments in pilot plants were carried out at the EPFL (Ecole Politechnique Federale de Lausanne, Switzerland) and at the Plataforma Solar de Almería, Spain. The experimental results showed that the photo-Fenton process was the most effective method in the mineralization of the treated solutions. It is very important to stand out that it was more effective when solar light was used as radiation source.Chapters 5 and 6 represent an application of the treatment methods used in chapter 4, in which their influence on the biodegradability of an organic chloride compound (DCDE) and of waters coming from a textile industry was studied. For this final part of the thesis, the experimental work was carried out at the University of San Diego (San Diego, USA) and at the EPFL (Lausanne, Switzerland), respectively. In the case of water solutions of DCDE, H2O2/UV process was used as pre-treatment method to obtain oxidized solutions of 25, 50, 75 and 100% DCDE degrdation. After applying different biodegradability tests, it was observed that, as the percentage of oxidation increased, it increased the biodegradability of the treated solution, thus demostrating the effectiveness of the pre-treatment. In the case of treated textile wastewaters, a strategy was put in practice to obtain a general vision when it facing the case industrial wastewaters. When applied to the textile water under study, it was found that the photo-Fenton process should be used as post-treatment step of a biological process.