In this thesis empirical relationships and modeling tools are used to describe the relationship between human activities and meso- and large scale riverine N fluxes from land to sea. On a large scale Paper I showed that by only having knowledge about human population size and runoff one can estimate the riverine export of DIN (r2= 0.76). In Paper II we included two other important anthropogenic N inputs, i.e. atmospheric deposition and primary emission (PE) from animals. In most of the catchments the PE from animals were larger than the PE from humans. Hence, development of livestock is important and increased animal protein consumption by humans might increase the riverine N export. Scenario analysis (Paper II) show that climate change is expected to both decrease and increase the riverine N export depending on which part of the catchment is modeled. In the southern and eastern parts of the Baltic Sea catchment there is large potential for N reductions from point sources (Papers III & V). The diffuse sources are more difficult to decrease and a reduction of mineral fertilizer does not always lead to reduced N loadings because the agricultural systems can buffer even a slight surplus (Paper III). There is inertia in the catchments which can be seen in for example in the northern part of the catchment. Here atmospheric N deposition is almost as high as in the southern part but the nitrogen flux from these rivers is not elevated. These northern river catchments have N exports of the same magnitude as the natural background (Paper IV), indicating that the atmospheric N deposition is retained in the system and probably taken up by N limited boreal forests. However, important reductions can be achieved in the agricultural sector by detailed management of the planted land and animal manure. The highest sensitivity is in catchments with high animal density and high specific discharge, primarily draining to Kattegat and Danish Straits (Paper II & IV). / At the time of doctoral dissertation the following publications were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript

During pulp and papermaking process a huge amount of water is used. The wastewater contains a large amount of pollutants and has to be treated before it reaches the recipient. In March 2004 a new bleaching plant was started up at SCA Graphic Sundsvall AB, Ortviken’s paper mill using peroxide. The production of bleached thermo mechanical pulp and thus the load to the wastewater plant increased. During bleaching substances dissolve from the pulp and the amount of COD in the wastewater increase. To keep the efficiency of chemical and biological oxygen demand (COD, BOD) removal, the aerated lagoon is supplied by liquid oxygen. In November the same year a new pre-step including a pre-aeration, carrier and selector step was added to the existing wastewater plant. The COD-loading to the lagoon decreased and the supply of liquid oxygen was reduced. This master thesis has been carried out at SCA Graphic Research AB, Sundsvall. The aim was to chemically characterize the wastewater with focus on the composition of carbohydrates, lignin and extractives and its influence on the biodegradability. Measurements have been carried out on total samples, suspended solids, colloidal and dissolved substances using GF/A and ultra filtration. Measurements were performed on process water from the bleaching plant and on water during the wastewater treatment process. The results show that the chemical composition of dissolved substances has a larger impact on the biodegradability than the total amount of COD. A large amount of lignin will make the wastewater harder to degrade. Suspended solids have lower biodegradability compared to the dissolved fraction. Analyzes of suspended material from the bleaching plant show a relative composition of around 41 % lignin. Analyzes done before on the dissolved fraction show a composition of 29 %. It seems that a larger amount of lignin is represented in suspended solids compared to the dissolved fraction. This can explain the low biodegradability, combined with the theory that the suspended solids are less accessible for the microorganisms. To reduce the outgoing COD the incoming flow of dissolved lignin and suspended solids to the active sludge plant has to decrease. COD in the outgoing wastewater to the recipient consists of around 90 % lignin. Extractives as saturated fatty acids, palmitic and stearic acid plus lignans (which is interpreted as a byproduct from lignin degradation) do not degrade remarkable during wastewater treatment. Flocculation of COD is one way to reduce the discharge to the recipient. Addition of 2,6 g/l PAX-18 (a high charged aluminum complex) to the wastewater from the bleaching plant gives a reduction of 40 % COD and 50 % lignin in laboratory scale and it is recommended to study further. Time related studies of BOD show that the microorganisms need five days to degrade organic material and the hydraulic retention time in the aerated lagoon has to be guaranteed. / Vid massa- och pappersframställning åtgår stora mängder vatten. Det processberörda avloppsvattnet innehåller mycket föroreningar varför det måste renas innan det släpps ut till recipienten. I mars 2004 startades ett nytt väteperoxidblekeri vid SCA Graphic Sundsvall AB, Ortvikens pappersbruk varvid produktionen av blekt termomekanisk massa ökade och den biologiska reningen belastades hårdare. Blekning löser ut vedämnen från massan och bidrar således till ökad mängd syreförbrukande ämnen i avloppet. För att upprätthålla reduktionen av syreförbrukande ämnen (COD, BOD) tillförs ren syrgas till den luftade dammen. I november samma år utökades den externa reningsanläggningen med ett biologiskt försteg, en s.k. multibioanläggning bestående av ett frisimmarsteg, ett bärarsteg samt ett selektorsteg. COD-belastningen in till den luftade dammen minskade och tillförseln av ren syrgas kunde reduceras. Examensarbetet har utförts vid SCA Graphic Research AB, Sundsvall med syftet att kemiskt karaktärisera avloppsvattnets sammansättning av kolhydrater, lignin och extraktivämnen och dess inverkan på vattnets grad av biologisk nedbrytbarhet. Analyser har gjorts på totalprov, suspenderande ämnen samt kolloidalt och löst material via fraktionering med hjälp av GF/A- och ultrafiltrering. Analyser gjordes dels på processvatten från blekerierna och dels på avloppsvatten under reningsprocessen. Resultaten visar att den kemiska sammansättningen hos löst material har större inverkan på avloppsvattnets grad av nedbrytbarhet än den absoluta halten av syreförbrukande ämnen. En hög andel lignin ger ett mer svårnedbrytbart vatten. Suspenderat material är vidare mer svårnedbrytbart än de lösta fraktionerna. Analys av suspenderande substans hos blekpressat visar att andelen lignin är omkring 41 % medan arkiverade analysresultat på den lösta fasen visar ett innehåll på omkring 29 %. Det tyder alltså på en betydligt högre andel lignin i den partikulära fasen jämfört med den lösta, vilket i kombination med att materialet inte är lika lättillgängligt för mikroorganismerna kan förklara den låga bionedbrytbarheten. Om COD-utsläppet ska minskas bör inkommande flöde av löst lignin och suspenderande substans till den biologiska reningen reduceras. COD-halten i utgående avloppsvatten till recipienten utgörs av omkring 90 % lignin. De extraktivämnen som inte bryts ned är mättade fettsyror, exempelvis palmitin- och stearinsyra samt lignan, vilket antas bildas som restprodukt vid degradering av lignin. Flockning av syreförbrukande ämnen är ett sätt att gå till väga för att minska utsläppet av dessa till recipienten. Genom tillsats av 2,6 g/l PAX-18 (ett högladdat aluminiumkomplex) till blekeriavloppet kunde 40 % COD och 50 % lignin reduceras. Flockningsförsöket är gjort i laboratorieskala vid rumstemperatur och ytterligare utvärdering rekommenderas. Tidsstudier av BOD visar att mikroorganismerna behöver fem dagars uppehållstid för att hinna bryta ned organiskt material i avloppsvattnet, varför omloppstiden i den luftade lagunen inte bör understiga denna tidsrymd.

In this study potential health risks for employees in connection with handling of bottom ash and bottom ash water at a Municipal Waste Incineration (MWI) plant have been investigated. Air surrounding the bottom ash and the bottom ash water has been examined. MWI is one of the primary ways to manage solid household waste, and bottom ash is the main solid residue produced by the incineration process. Bottom ash constitutes about 15-20% of the original waste. The bottom ash is extinguished in a water bath (bottom ash water). The study was carried out in a MWI plant in Karlstad, Sweden. The plant is equipped with a grate furnace with a capacity of 7 tonnes per hour. Annually about 50 000 tonnes are incinerated at the plant. Levels of airborne particles, metals present in the airborne particles, volatile organic compounds (VOC), and phosphine were measured in the air. Analysis of the bottom ash water including: pH, total phosphorus, ammonium, chemical oxygen demand (COD), suspended solids, and bacteria were also carried out. Further, a questionnaire was distributed to investigate how the workers at the MWI plant re°ected on health when working. The results showed that the levels of airborne particles, metals and VOC did not pose any major health risks. The bacterial analysis demonstrated very low concentrations of bacteria in the water and thus that the bacteria posed no risk for the workers. The phosphine measurements did not result in levels exceeding the Swedish threshold limit value. However, the method used in this study was not well-tested in these sorts of environments and the results implied that higher levels of phosphine might be present. The conclusion from the questionnaire was that there is a concern about health risks in connection with certain tasks at the plant. / På Hedenverket, Karlstads Energi AB, förbränner man årligen cirka 50 000 ton hushålls- och verksamhetsavfall. En av restprodukterna av förbränningen kallas slagg (bottenaska) och utgör ca 15-20% av det inmatade avfallet. Slaggen släcks i ett vattenbad under själva pannan (slaggsläckningsbad) och matas sedan ut, via ett skakbord för reduktion av vatten, till containrar innan det slutligen körs på deponi. Syftet med det här projekt var att utreda om det föreligger några hälsorisker vid arbete kring slaggen och slaggsläckningsvattnet. För att skapa en bild av möjliga hälsorisker gjordes en inledande studie av tidigare utredningar, mätningar gjorda på avfallsförbränningsanläggningar runt om i Svergie och vad kemiska och biologiska hälsorisker innebär. Även lagstiftning på området har berörts. Med tidigare utredningar och mätningar samt diskussioner som grund utfördes mätningar av damm, metallhalter i damm, VOC och fosfin i luften samt en analys av slaggvattnet och bakterier i slaggvattnet. För att skapa en uppfattning av hur personalen, som arbetar med driften, upplever sin arbetssituation ur hälsorisksynpunkt genomfördes även en enkätundersökning. Resultaten av undersökningarna på Karlstads Energi AB visade att varken damm, metaller eller VOC utgör någon hälsorisk. Bakterieprovtagningen av slaggsläckningsvattnet visade på mycket låga halter av bakterier och bakterier kan därför inte sägas utgöra någon hälsorisk. Undersökningar av slaggvatten på andra anläggningar i Sverige visar däremot på höga metallhalter i slaggvattnet och det vore således inte särskilt hälsosamt att få i sig större mängder av detta. Resultaten av fosfinmätningen visar inte heller på några alarmerande nivåer, men metoden som användes är inte väl beprövad i den här typen av miljö. Resultaten kan tyda på att högre halter av fosfin förekommer, men hur höga de är inte möjligt att svara på. Fosfin är ett ämne som i små mängder kan ge upphov till bland annat illamående. I enkätundersökningen påtalades att obehag och illamående uppstºar vid längre arbeten över skakbordet och det är möjligt att fosfin kan vara en orsak till detta. Enkätundersökningen visade även att det finns en oro för hälsan vid vissa typer av arbeten på anläggningen och oro för att hälsan ska påverkas negativt på längre sikt.

Green chemistry principles have been applied to the enhancement of two industrial chemistry problems. An industrially used reaction to form alcohols from aldehydes and ketones, the Meerwein-Ponndorf-Verley reduction, was improved by introducing a new catalyst Al(OtBu)₃. Due to the lower state of aggregation of this catalyst versus the conventional Al(OiPr)₃ catalyst, reduction rates were found to be faster in both pure iPrOH and mixed solvent systems for three model compounds: benzaldehyde, acetophenone, and a complex, chiral ketone, (S)-CMK. This allowed for the successful implementation of two important milestones; lowering the amount of catalyst needed necessary to complete the reactions (an economic benefit and lower waste) and the conversion from traditional batch reactions to continuous flow (a processing benefit) whereby reactions can be scaled-out rather than scaled-up. Another industrially important field of research that was focused on was CO₂ capture. High energy demands from current CO₂ capture methods such as aqueous amine solvents, specifically from coal-fired power plant flue gas, led to the development of non-aqueous reversible ionic liquids based on silylated amines. Structural modifications of the substitution around the silicon atom, the length of the alkyl chain bonding the silicon and amine, branching along the alkyl backbone, and investigating secondary and primary amines within this class of silylated amines were completed. These amines were reacted with CO₂ and the CO₂ capacity, the ionic liquid viscosity, reversal temperature and reaction enthalpy were all considered as a function of structure. In all cases the capacity was found to be not only greater than that of monethanolamine, an industrial standard, but higher than theoretical predictions through the formation of carbamic acid. Viscosity, reversal temperature, and reaction enthalpy were all found to be tunable through structure. These modifications gave significant insight into the necessary direction for optimization of these solvents as energy-efficient replacements of current CO₂ capture technology.

The extensive agricultural usage of organohalogenated pesticides has raised many concerns about their potential hazards especially in the soil environment. Environmental metabolomics is an emerging field that investigates the changes in the metabolic profile of native organisms in their environment due to the presence of an environmental stressor. Research presented here explores the potential of Nuclear Magnetic Resonance (NMR)-based metabolomics to examine the sub-lethal exposure of the earthworm, Eisenia fetida to sub-lethal concentrations of organohalogenated pesticides. Various one-dimensional (1-D) and two dimensional (2-D) NMR techniques were compared in a contact filter paper test earthworm metabolomic study using endosulfan, a prevalent pesticide in the environment. The results determined that both the 1H Presaturation Utilizing Gradients and Echos (PURGE) and the 1H-13C Heteronuclear Single Quantum Coherence (HSQC) NMR techniques were most effective in discriminating and identifying significant metabolites in earthworms due to contaminant exposure. These two NMR techniques were further explored in another metabolomic study using various sub-lethal concentrations of endosulfan and an organofluorine pesticide, trifluralin to E. fetida. Principal component analysis (PCA) tests showed increasing separation between the exposed and unexposed earthworms as the concentrations for both contaminants increased. A neurotoxic mode of action (MOA) for endosulfan and a non-polar narcotic MOA for trifluralin were delineated as many significant metabolites, arising from exposure, were identified. The earthworm tissue extract is commonly used as the biological medium for metabolomic studies. However, many overlapping resonances are apparent in an earthworm tissue extract NMR spectrum due to the abundance of metabolites present. To mitigate this spectral overlap, the earthworm’s coelomic fluid (CF) was tested as a complementary biological medium to the tissue extract in an endosulfan exposure metabolomic study to identify additional metabolites of stress. Compared to tests on the tissue extract, a plethora of different metabolites were identified in the earthworm CF using 1-D PURGE and 2-D HSQC NMR techniques. In addition to the neurotoxic MOA identified previously, an apoptotic MOA was also postulated due to endosulfan exposure. This thesis also explored the application of 1-D and 2-D NMR techniques in a soil metabolomic study to understand the exposure of E. fetida to sub-lethal concentrations of endosulfan and its main degradation product, endosulfan sulfate. The earthworm’s CF and tissue extract were both analyzed to maximize the significant metabolites identified due to contaminant exposure. The PCA results identified similar toxicity for both organochlorine contaminants as the same separation, between exposed to the unexposed earthworms, were detected at various concentrations. Both neurotoxic and apopotic MOAs were observed as identical fluctuations of significant metabolites were found. This research demonstrates the potential of NMR-based metabolomics as a powerful environmental monitoring tool to understand sub-lethal organohalogenated pesticide exposure in soil using earthworms as living probes.

The alternative fuel biodiesel is produced from the transesterification of vegetable oils or animal fat to fatty acid methyl esters. Pomona has a reactor on campus that can be used to run this reaction and produce biodiesel. The use of biodiesel has been found to lower air pollutant and greenhouse gas emissions, but can be potentially harmful to the engines if it contains impurities. This paper proposes a method using high-performance liquid chromatography to test the quality of biodiesel. This method utilizes instrumentation and materials that are available in Pomona College's Chemistry Department, requires very little sample preparation, and is relatively safe, as long as general lab safety practices are followed. This method can also be used to optimize the procedure used to make the biodiesel. An optimized production procedure and a test method to assess the final product will ensure high quality fuel that can be used with confidence in diesel engines. This will likely add strength to proposals to increase the use of the on-campus reactor and produce biodiesel for campus grounds equipment from waste vegetable oil.

A 25% niobium substituted sitinakite was exchanged with strontium as time resolved X-ray diffraction data was collected. The structural modeling of this data by Rietveld method1 has lead to the determination of the atomic positions of the ions and unit cell parameters as strontium occupancy increases. The starting material of the exchange experiment is the protonated phase, H2Nb0.67Ti1.33SiO7·1.9 H2O, with space group P42/mcm2,3. Once strontium (Sr2+) enters the unit cell, extra-framework H2O molecules shift to provide the necessary hydration coordination. These new positions of H2O result in a lowering of symmetry to the P-42m space group, and it is thought that the new hydrogen bonding network serves to enhance strontium ion diffusion into the channels of sitinakite. Exchange of strontium into the microporous material reaches a maximum fractional occupancy of 21% when a 10.0 mM strontium ion solution is forced over the powdered material. Sequestration of strontium into this material has contributed valuable information to the study of microporous materials and ion exchange chemistries.

Macrocyclic ligand-complexed transition metal-oxo intermediates are the active oxidizing species in a variety of important biological and catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in Nature, namely the cytochrome P450 enzymes. Ruthenium porphyrin complexes have been the center of the research and have successfully been utilized, as catalysts, in major oxidation reactions such as the hydroxylation of alkanes. This study focuses on kinetic and photocatalytic studies of oxidation reactions with wellcharacterized high-valent ruthenium-oxo porphyrin complexes. The trans-dioxoruthenium(VI) porphyrins have been among the best characterized metal-oxo intermediates and their involvement as the active oxidant in the hydrocarbon oxidation have been extensively studied. Following the literature known methods, a series of trans-dioxoruthenium(VI) porphyrin complexes (3a-b) were synthesized and spectroscopically characterized by UV-vis, IR and lH-NMR. In addition to the well-known chemical methods, we developed a novel photochemical approach for generation of trans-dioxoruthenium(VI) porphyrins with visible light. The fast kinetic study of two-electron oxidations of para-substituted phenyl methyl sulfides by these dioxoruthenium(VI) species was conducted by using stopped-flow spectroscopy. Results showed that the decay of trans--dioxoruthenium(VI) porphyrins in the presence of reactive sulfides follows a biexponential process. The reactivity order in the series of dioxoruthenium complexes follows TPFPP> TPP> TMP, consistent with expectations based on the electrophilic nature of high-valent metal-oxo species. Moreover, the sulfoxidation reactions are 3 to 4 orders of magnitude faster than the well-known epoxidation reactions. In addition, several ruthenium porphyrins were used as the catalysts in the competitive oxidation reactions to identify the kinetically competent oxidants during catalytic turnover conditions. The photocatalytic studies of aerobic oxidation reactions of hydrocarbons catalyzed by a bis-porphyrin-ruthenium(lV) fl-OXO dimer using atmospheric oxygen as oxygen source in the absence of co-reductants were investigated as well. The ruthenium(lV) fl-OXO bisporphyrin (6a) was found to catalyze aerobic oxidation of a variety of organic substrates efficiently. By comparison, 6a was found to be more efficient photocatalyst than the well-known 3a under identical conditions. A KIE at 298K was found to be larger than those observed in autoxidation processes, suggesting a nonradical mechanism that involved the intermediacy of ruthenium(V)-oxo species as postulated.

Homogenous acid catalysts are prevalent throughout the chemical industry but all have the drawback of requiring post reaction neutralization and subsequent downstream removal of the product salt. The use of a base to neutralize the acid and the processing of the salt are ancillary to the process and the disposal of the salt is an environmental concern. The work presented here shows the use of alkylcarbonic acids, which form in situ with CO₂ pressure and neutralize on loss of CO₂ pressure rather than requiring a base. Thus CO₂ can be used to "switch" the acid on and off. The properties of alkylcarbonic acids are explored to gain understanding of the mechanisms by which they act. The acids are also used to catalyze the synthesis of α-pinene, methyl yellow, and benzyl iodide. These reactions are examples of common acid catalyzed reactions where this technology could be implemented. The second half of the work explores two other "switches". The first is using temperature to break an emulsion with a novel thermally cleavable surfactant. This technology has potential applications in a wide range of fields where surfactants are used including polymerization, oil recovery, and biosynthesis. The second is using CO₂ to liquefy a solid ionic compound to allow its use as a solvent. This would greatly increase the number of ionic species available for use in ionic liquid-CO₂ biphasic systems.

N-Nitrosamines are an emerging group of disinfection byproducts characterized by high carcinogenic risks at ng/L levels and by their frequent detection in water and wastewater treatment systems in the U.S. and other parts of the world. The overall goal of this research is to achieve a better understanding of the roles of common nitrosamine precursors in leading to N-nitrosamine formation in water and wastewater treatment systems. The specific objectives of this research are: (a) To probe the mechanisms of nitrosamine formation from commonly employed water treatment polymers, particularly polyDADMACs, during ozonation, (b) To evaluate the role of dithiocarbamate compounds as nitrosamine precursors in reaction with common water disinfection oxidants, and (c) To investigate the potential enhancement effect of activated carbons (AC) to promote transformation of amines to nitrosamines and identify the involved reaction mechanism. Results of this research show that, upon ozonation, polyDADMACs may yield N-nitrosodimethylamine (NDMA) at levels up to two orders of magnitude higher than current advisory guidelines for NDMA. Radical pathways may be responsible for the degradation of the quaternary ammonium ring groups in polyDADMACs to release of dimethylamine (DMA). Detection of significant amounts of nitrite after ozonation of polyDADMACs and DMA suggests the potential role of nitrosation pathway in NDMA formation. Study results also reveal dithiocarbamates as potent nitrosamine precursors with significant nitrosamine yields upon ozonation and monochloramination. Identification and quantification of reaction products suggest nitrosation and chlorinated-UDMH oxidation as primary reaction mechanisms in nitrosamine formation from ozonation and monochloramination of dithiocarbamates compounds, respectively. This research also demonstrates that many commercial AC materials may catalyze transformation of secondary amines to yield trace levels of N-nitrosamines under ambient aerobic conditions. This is a novel discovery with far-reaching implications because of the widespread usage of AC materials in numerous analytical and environmental applications. The study results show that the properties of AC materials and reaction conditions play a crucial role in the catalyzed nitrosamine formation and should be carefully selected to minimize analytical errors and undesirable nitrosamine formation in water samples. Overall, the mechanistic information obtained in this research will be useful for the water industry and research communities to develop more effective strategies to control undesirable nitrosamine formation in water and wastewater treatment systems and thus better protect the public health.