Wetlands water quality is influenced by the anthopogenic activities in the catchments’ areas. Wastewaters from the urban storm, agricultural runoff and sewage treatment often end up in wetlands before flowing to rivers, lakes and the sea. A lot of pollutants are readily transported in these wastewaters, thus subjecting the wetland ecosystem into a continuous resilience. Importantly, heavy metals like Cu, Zn, and Pb etc. are constituents of such pollutants in the wastewaters. The study has as a specific objective to investigate the effects of heavy metal Cu, Zn and Pb on denitrification, an important ecosystem process and service. In a wetland situation, denitrification is a permanent nitrogen removal process accounting for about 90% of the total nitrogen removal. The research was carried out in the laboratory and sediment samples were taken from a constructed wetland in Linkoping. We employed acetylene inhibition technique in obtaining N2O as a product resulting from nitrate reduction. The treatments (Cu, Zn and Pb) levels were 100 mg/kg, 250 mg/kg, 500 mg/kg and 1000 mg/kg of sediment, in three replicates and a control. Samplings of the assay were taken within 24hours. Gas chromatography was used to analyse and quantify N2O in the various samples. A linear regression analysis was carried out with Windows Excel and SPSS to compare the various treatments with the control at 95% confidence level. The results show that there were no inhibitions of denitrification at 100 mg/kg sediment treatment level for any of the element. Inhibition of denitrification was observed at treatment levels 500 mg/kg and 1000 mg/kg of sediment. The rate of nitrate reduction was compared from the slope of the regression curve. The rate for Cu at 500 mg and 1000 mg /kg of sediment was moderately related to that of the control, Zn shows a similar trend but a higher rate in some samples, while Pb shows more inhibition.

I denne oppgaven har det blitt utført en kartlegging og evaluering av miljøstatus i overflatevann rundt Statoils oljesandområde i Alberta, Canada. Det har blitt prøvetatt vann for oppløst og syreoppløst konsentrasjon av grunnstoff for analyse på ICP-MS. Det har blitt målt for viktige parametere som pH, SUVA254 og oppløst organisk karbon. Hensikten med denne undersøkelsen er å følge opp miljøundersøkelsen utført av masterstudent i 2010 som ble gjort for å etablere bakgrunnsinformasjon fra området før produksjonen ble igangsatt, for å se om produksjonen har ført til høyere konsentrasjoner av grunnstoff i området. Resultatene viser at det ikke er store endringer fra undersøkelsen i 2010 og at vannkvaliteten i Christina River generelt sett er god. De fleste konsentrasjonene av grunnstoff er under grenseverdiene som er oppgitt. Det har også blitt utført forsøk på en ny type passiv prøvetaker kalt Metrox. Denne er en fortsettelse av en oppgave fra 2009/2010 der det ble gjort innledende forsøk, med forskjellige typer elektroder. Hensikten i denne oppgave var å videre teste den ut på lab. Det ble store forsinkelser fra bedriften som laget Metrox og forsøkene ble derfor ikke startet før i februar. Testene viste at Metrox var for ustabil til å testes i felt på grunn av at det ble brukt toelektrodesystem.

Environmental impacts of aquaculture can be widespread and serious, and one of the problems connected to this activity is the release of waste in the form of macronutrients. One important aspect is the potential of a shift in the available nitrogen form from nitrate to ammonium. This has the potential of causing harmful algal blooms, and changing the composition of pelagic microbial communities. Because trace metals are linked to enzymatic transformations of nitrogen it can be expected that a shift in the available nitrogen form to also change the cycling of trace metals in the water column and the microbial uptake. This work presented in this thesis has been part of the large collaborative WAFOW project, and was carried out at the Huinay Scientific Field Station in the Comau Fjord (Northern Patagonian region of Chile). The experiment was designed to follow changes in different variables as a gradient of ammonium was added to different bodies of water (mesocosms). Two types of water were studied (surface and ~10 m depth), and five treatments with increasing ammonium flux were carried out for each water type. In this thesis the variations in the distribution of four different trace metals (Cd, Mo, Ni and Cu) with an increasing ammonium flux has been studied. Samples were analyzed for chelex labile and DGT labile forms of the metals, as well for metal concentration in different size fractions of particles. The enrichment by ammonium caused a bloom in biomass, and caused changes in the distribution of all four metals studied. Most of the metals showed decreasing chelex labile and DGT labile concentration with rising ammonium concentration. For cadmium there was a marked increased uptake per g carbon up to a certain point of ammonium enrichment, and a marked decreased uptake per g carbon when very high amounts of ammonium were added. This suggests that the very high ammonium enrichment scenario somehow has had an inhibiting effect on phytoplankton cadmium uptake. For molybdenum there was a decreasing uptake per g carbon with increasing ammonium flux. This is probably caused by a decreased need for molybdenum in enzymatic transformations of nitrogen when ammonium is supplied in place of nitrate.

I denne oppgaven har det blitt utført kartlegging av innhold av elementer og oppløst organisk karbon (DOC) i elvevann og skum i Bayelva og Londonelva, to arktiske elver med utløp i Kongsfjorden på Svalbard. Andre viktige parametere som pH, redokspotensiale, ledningsevne og temperatur har også blitt målt. Filtrerte (0,45 µm) og ufiltrerte vannprøver har blitt prøvetatt manuelt, samt med DGT (diffusjonsgradienter i tynne filmer), og analysert med HR-ICP-MS. Det ble funnet generelt lave konsentrasjoner av oppløste sporelementer i elvevannet i både Bayelva og Londonelva, og konsentrasjonene var under grenseverdier fra norske myndigheter for metaller i ferskvann. Det er forskjeller på elementkonsentrasjoner innad i elvene, og innholdet er høyere for de aller fleste elementer i Bayelva sammenliknet med Londonelva. Forskjellene i konsentrasjoner i de to elvene kan forklares av ulik geologi og hydrologi i de to nedbørsfeltene. DGT-ene ser ut til å ha blitt kontaminert. Innhold av oppløst organisk materiale er lavt, men detekterbart i begge elver. SUVA254 indikerer at det organiske materialet har hovedsaklig aromatisk karakter. Estimat for årlig tilførsel av oppløste metaller til Kongsfjorden har blitt regnet ut. Skumprøver inneholdt betydelige konsentrasjoner av DOC og elementer, og en oppkonsentrering av metaller i forhold til elvevannet er tydelig i både Bayelva og Londonelva. Høyest oppkonsentrering ble funnet for Pb, Zn og Cu. Signifikante positive korrelasjoner ble funnet mellom Fe og Mn og Fe og Al i vannprøver fra Bayelva, samt mellom Fe og Pb i to av prøvepunktene. I Londonelva ble det funnet signifikant positiv korrelasjon mellom Fe og Pb, i tillegg til en negativ relasjon mellom Al og As. Korrelasjoner mellom metaller er en indikasjon på at disse metallene har felles kilde og/eller transportmekanismer. Tydelige signifikante positive korrelasjoner ble funnet for Mn, Cu og Pb mot DOC i vannprøver fra Londonelva, og for Mn, As, U og hardhet mot DOC i skumprøver fra Bayelva. Det ble funnet dagsvariasjoner i elementkonsentrasjoner og ulike måleparametere i de to elvene, men variasjonene er mindre tydelig i Londonelva. Prøveantallet var lavt, og endring i vannføring ser ut til å forklare vari

Volatile organochlorine compounds emitted from natural sources can participate in environmentally relevant processes affecting life on Earth, such as stratospheric ozone destruction and warming of the troposphere. The aim of this study was to investigate if forest bogs contribute to the environmental input of naturally produced volatile organochlorine compounds. The concentrations of four different volatile organochlorine compounds were determined in ambient air, rainwater, surface water, and sub-surface water. For chloroform, up to 10-times higher concentrations were detected in the surface water compared to the sub-surface water taken at 40 cm depth. As the concentrations of chloroform in rainwater where almost in the same range as the concentrations in the sub-surface water, a formation of chloroform is suggested in the surface water. The results of this study indicate forest bogs as a possible new natural source for the input of volatile organochlorine into the environment.

This project employs the biological compounds hemin, melanin, and retinoic acid as photoactive dyes in dye-sensitized solar cells (DSSCs). These dyes are environmentally and economically superior to the standard ruthenium-based dyes currently used in DSSCs because they are nontoxic and widely available. Characterization by linear sweep voltammetry yielded averaged maximum overall conversion efficiency values of 0.059% for retinoic acid, 0.023% for melanin, and 0.015% for hemin. Absorption spectra of hemin and retinoic acid suggest that they would complement each other well when used in tandem in one cell because hemin has a secondary maximum absorption peak at 613nm and retinoic acid has maximum absorption at 352nm. Cells made with hemin or melanin performed better with the use of lower temperatures to seal the cells, and hemin cells performed exceptionally well with exclusion of the sealing procedure. These biologically-derived cells have the potential to advance the development of inexpensive and safer solar energy sources, which promise to serve as clean energy sources in the near future.

Contamination of drinking water with metals is a major problem facing many areas of United States and the World. There is a need for an inexpensive remediation technology for the removal of metals in drinking water that can be applied to small rural water systems. This research will focus on the development of a process for removal of select metals from drinking water by limestone-based material. Metals in drinking water considered for this research include lead and selenium. Limestone-based material has demonstrated the potential to reduce select metals (lead, cadmium and arsenic) in drinking water, with the additional benefit of low-cost disposal of a stable waste product in ordinary landfills. Earlier research by the principal investigators using limestone-based material for drinking water treatment has clearly shown that this material can achieve metals removal of greater than 90 percent. This project will investigate techniques to improve removal efficiency of limestone-based material through adsorption and precipitation. This research will assist in the development of a granular adsorbent product that will remove metals and that can be manufactured and sold for use at the drinking water source, at point-of-use, or at point-of entry.

This work investigates mercury flux in soil amended by gypsum from flue gas desulphurization (FGD) units of coal-fired power plants. There are two phases of this research, including field and greenhouse studies. Previous studies indicate that FGD gypsum could increase corn yield, but may lead to more mercury uptake by corn. Recent studies have been carried out in greenhouses to investigate mercury transport in FGD gypsum treated soil. Major aspects include uptake of mercury by plants and emission of mercury into the atmosphere based on application rates of FGD gypsum. Additional aspects include rainfall, temperature, soil, and plants types. Higher FGD gypsum application rates generally led to higher mercury concentration in the soil, as well as, increased mercury emission into the atmosphere, and increased mercury levels in plants, especially roots and leaves. Soil properties and plant species also played important roles in mercury transport. In addition, it was also found that increased water and higher temperatures may contribute to mercury emission in the atmosphere. Some plants, such as tall fescue, were able to prevent mercury from atmospheric emission and infiltration within the soil. Mercury concentration in the stem of plants was found to be increased and then plateaued upon increasing FGD gypsum application. However, mercury in roots and leaves was generally increased upon increasing FGD gypsum application rates. Some mercury was likely absorbed by leaves of plants from mercury in the surrounding atmosphere.

This study was part of the WAFOW project “Can waste emission from fish farms change the structure of marine food webs?” whose objective was to perform mesocosms experiment to simulate the ammonium enriched environment, caused by salmon aquaculture. In order to assess how changes in the stoichiometry of major elements (nitrogen) in the sea affect the distribution of bioactive trace metals, and its effects on the base of the pelagic food web, the distribution and variation in time of the trace metal iron in the water and within the plankton community was studied along a 22 day experiment. It involved 2 types of water (surface and marine systems) each one, with 1 control and 4 NH4+ concentrations. Additional samples collected in a river transect and in depth provided the general Fe distribution in the environment. The iron concentration in the water was determine for three fractions as: Chelex labile (Total: TFeCh and dissolved: DFeCH), DGT labile (FeDGT) and direct (Total: TFe and dissolved: DFe), whereas the particulate concentration iron in the plankton community was determined both per fraction (PFeSF) and total content (PFe>0.2). Total average per treatments showed higher concentrations for both TfeCh and DFeCh in the marine systems compare to the surface. TFeCh showed general increasing trend in time and with increase NH4+ concentration, with a sharp decrease towards the end of the experiment in both systems. DFeCh pattern was inverse to TFeCh, with general decrease over time but lower in magnitude. FeDGT showed an average lower concentration compare to DFeCh with no define trend over time. Final FeDGT concentrations were significantly lower in treatments with artificial NH4+ addition. PFe>0.2 showed an increasing trend in time and with increased NH4+ in both systems. However when normalized to Chlorophyll-a (Chl-a) or particulate organic carbon (POC) the trend inverted, showing that at higher NH4+ influx the iron per Chl-a or POC decreases. PFeSF major changes occurred in the marine system where a estimation of the ratio between the 20-140 µm and the 2-20 µm fractions, indicative of the dominant phytoplankton size class, was significantly higher in 2 of the 3 treatments with artificial NH4+ addition. This point that the microphytoplankton increased significantly with higher NH4+. The variation over time of the concentration of Fe in the water as in the plankton community, indicate that the concentration of NH4+ can have positive or negative relation depending on the iron form. Whether via increasing the PFeCh, or by reducing the uptake by phytoplankton, a modified C:N:P can affect the cycling of iron, which in turn can have negative or positive feedbacks over the major biogeochemical cycles.

En utvärdering av befintlig data från referensfasen av kontrollprogrammet för Grimstorp Lillesjön har utförts. De studerade parametrarna i rapporten är ytvatten- och grundvattenhalter (grundvattenrör och brunnar) av arsenik och tre utvalda PAH (acenaften, fluoren och naftalen) ämnen samt fysikaliska-kemiska stödparametrar. För att bidra med information till kontrollprogrammet har i denna rapport statistiska parametrar beräknats i form av kontrollmål för årsmedelvärde och stickprov för de studerade parametrarna. Det har även i förväg angetts den förändring från kontrollmålet som kan påvisas enligt planerad provtagning. Arsenikhalterna har 1-5 ggr mindre relativa standard avvikelsen (CV) än för de tre valda PAH ämnena, där CV i många fall är över ett. Det största bidraget till variationen i data kommer från säsongsvariationer, där temperaturen har den största inverkan till variationen. För ytvatten- samt brunnsdata för de undersökta parametrarna kan halvårsvisa säsongsmässiga indelningar ses och genom att dela in data enligt säsongsvariationen kan variationskoefficienten minskas. Från jämförelse med andra genomförda impregneringprojekt vid före detta impregneringsanläggningar kan konstateras att i entreprenadfasen sker ett läckage av arsenik. I uppföljningsfasen påverkas visa grundvattenrör nedströms det före detta impregneringsområdet med högre halter av arsenik och PAH. Dessa haltökningar kan påvisas tre år efter utförd sanering. Sammantaget är bättre att köra kontrollprogrammet för Grimstorp Lillesjön mindre intensivt men under en längre tidsperiod och då ta prover under samma säsong, vilket ger jämförbara resultat. Detta medför att totalt sett kan färre prov tas jämfört med planerad provtagning eller en mindre förändring av halter kan detekteras i entreprenad och uppföljningsfasen.