Indoor air concentrations of volatile organic compounds (VOCs), including many with documented adverse health effects, vary widely but are generally higher than found outdoors. Volatile organic compounds can enter indoor environments via internal (e.g. paints, paint strippers, fuels, cleaning supplies, pesticides, building materials, adhesives) and external sources (e.g. vapor intrusion (VI) from contaminated soil and/or groundwater and ambient air from automobiles and industrial facilities). Since many consumer products contain volatile organic compounds (VOCs) that are also the focus of soil and groundwater cleanup projects, emissions of these VOCs can lead to false source identifications during VI investigations. Laboratory-measured emissions of VOCs from several consumer products were used with a standard box model to predict indoor air concentrations. The predicted concentrations were compared to measured values generated by introducing the same consumer products into an actual residence. The screening level agreement between measured and estimated air concentrations suggests that a standard box model can be used with laboratory measured emission rates to show if an emission source can cause a potential health risk or lead to false assumption during VI investigations. The use of plant leaves as a simple, cost-effective and sustainable approach to sampling indoor air concentrations of VOCs was also investigated in three studies: 1) a headspace approach; 2) a flow-through glass and stainless steel plant growth chamber, and 3) a house-scale study where plant leaf and air concentrations of VOC were simultaneously measured. Similar relationships between the leaf and air concentrations observed in the three studies suggest that plant leaf concentrations can be used as a surrogate for indoor air concentrations of VOCs.

Since its creation in the late 19th century, mass spectrometry has evolved into one of the most versatile analytical methods in science. To chart this evolution this thesis includes a historical overview of mass spectrometry and a description of the role of mass spectrometry in oceanography. The development and deployment of underwater mass spectrometers (UMS) at the University of South Florida's Center for Ocean Technology has made possible the collection of real-time data with greatly increased spatial and temporal density. The UMS was deployed via both remotely guided surface vehicles (GSV) and ship's cables to monitor a suite of dissolved gases and volatile organic compounds in saltwater and freshwater environments. Spectrometer data in Lake Maggiore, Florida were acquired at a rate of 0.7-3.6 seconds/sample for 2-3 hours. The resulting multi-analyte spectrometer data were recorded in real time with the Global Positioning System (GPS) observations of an associated surface vehicle and transmitted to a remote laptop computer via a wireless Ethernet link. These data were merged to create high-resolution maps of chemical distributions. Of particular interest were the co-varying oxygen and carbon dioxide mass spectrometer signals, diagnostic of photosynthesis-respiration processes, that were collected over a 10,800 square-meter area of the lake. The UMS was also deployed on a shipborne hydrowire in Saanich Inlet, a 200-meter deep fjord in the western Canadian province of British Columbia. The concentrations of a broad suite of dissolved gases were monitored on both downcast and upcast over a total depth range of 200 meters. Spectrometer data were acquired at a rate of 4.2 seconds/sample for the duration of the deployment. Mass spectrometer signals diagnostic of reduced species (CH4, H2S,) in the anoxic waters of the inlet below a depth of 100 meters were consistent with previous descriptions of the fjord's chemistry. The UMS was deployed on a remotely guided surface vehicle on the Hillsborough River in central Hillsborough County. Spectrometer data were acquired at a rate of 0.7 seconds/sample, and geographic location was recorded by an onboard GPS during a 2,640 meter transect of the river. Prior to the deployment, the mass spectrometer was calibrated using certified gas standards. The calibration experiments correlated mass spectrometer ion intensity data with dissolved gas concentrations, whereupon the mass spectrometer data collected during the deployment were reported in units of micromole/kilogram (µmol/kg). The mass spectrometer recorded changes in gas concentrations associated with changing physical conditions and biological activity along the 2,640 meters of the river that was transited by the GSV.

This project was the very beginning of research into the chemistry of eastern Australian banksia flowers. Using dynamic headspace sampling (DHS) analysis, differences in volatile components, consistent with detection of differences in odour, were detected among three different species and one commercial cultivar. Infraspecific variation was also observed between two known subspecies of Banksia ericifolia and between differently coloured forms of Banksia spinulosa var. collina. The cultivar, Banksia 'Giant Candles', was shown to have some of the chemical components of each of its supposed ancestors. The absence of known wound-response chemicals indicated that this DHS method was successful in leaving the inflorescences undamaged throughout the sampling procedure. The Likens-Nickerson modification of classical hydrodistillation methods was useful. The static headspace method (SHS) was easily automated and was shown to be chemically robust and sufficiently sensitive to detect volatile compounds from only a few flowers. The milder DHS method, which minimised mechanical and heat damage to the plant tissue, produced a different set of results. From the results of this project, a suite of volatile compounds has been proposed that may be useful in future behavioural studies to help determine whether animals are attracted to components of banksia odours. These candidates include some compounds that have been reported in animal secretions, wound-response chemicals that may be produced by the plant to aid its communication with other organisms, and a compound (suggested to be sulfanylmethyl acetate) not previously reported from natural sources. The mildest of the three analytical methods used, dynamic headspace sampling, was shown to be suitable for the potential chemotaxonomic evaluation of some members of the Banksia genus. / Doctor of Philosophy (PhD)

<p>Hammarby Sjöstad is a new district of southern Stockholm built with focus on reduced environmental impact by recirculation of materials and sustainability. The environmental goals aim to cut the water consumption by half and a separate storm water treatment. Thus, the wastewater will be more concentrated and will originate from the households only. The Sjöstad project includes the idea of a local treatment plant for the household wastewater. To evaluate this possibility, Sjöstadsverket, an experimental treatment plant was constructed. New wastewater treatment processes are tested and evaluated and compared to conventional methods including both aerobic and anaerobic treatment processes.</p><p>One of the aerobic treatment processes includes enhanced biological phosphorus removal (EBPR or Bio-P) as the method for the removal of phosphorus. In biological phosphorus removal the wastewater is alternately being exposed to anaerobic and aerobic conditions, which favours a certain bacteria, which can accumulate more phosphorus than is required for their growth. For this phosphorus accumulation the bacteria need volatile fatty acids (VFA) to cover their energy demand, but normally there is a shortage in VFA in the incoming wastewater.</p><p>The main purpose of this master thesis work has been to create the best possible conditions in order to produce VFA by hydrolysis and fermentation of primary sludge. In this way the organic material in the incoming wastewater can be used in biological phosphorus removal.</p><p>The sludge temperature, total solids (TS) and retention time are regarded as important parameters for a successful biological phosphorus removal and a laboratory study was set up to investigate these conditions for the wastewater at the Hammarby Sjöstad experimental plant. These laboratory-scale hydrolysis experiments showed that high temperature and high TS favours VFA-production. The results have also shown that four to five days retention time is suitable at a process temperature higher than 23°C, but also that the retention time likely should be extended at lower temperatures.</p><p>In a full-scale process experiment, primary sludge was pumped from a primary clarifier to a hydrolysis tank and then back to the primary clarifier. The hydrolysis gave rise to increased VFA-production when TS was increased. A temperature difference between the primary sludge and the hydrolysis sludge of 3°C was observed. The reason behind the difference has not been determined, but is considered important, since the temperature affects the VFA-production. Further on, analyses with gas chromatograph (GC) have shown that acetate has been the most frequently occurring VFA, although significant levels of other VFA, such as propionate, has also been detected.</p><p>Phosphorus release tests in laboratory-scale, where phosphorus was released during an anaerobic phase and taken up during an aerobic phase, proved that biological phosphorus removal occurred at the full-scale experimental train.</p><p>The full-scale hydrolysis experiment has shown that the VFA contribution by the hydrolysis tank to the biological phosphorus removal was low. The main reason is that the sludge-flow through the hydrolysis tank has been insignificant compared to the incoming wastewater flow. The problem is most likely connected to the incoming wastewater characteristics, since the low share of suspended solids (SS) entailed that not enough organic material in the primary clarifier settled.</p> / I figur 57 på sidan 76 stämmer inte trendlinjernas ekvationer i den tryckta versionen. Dessa är nu korrigerade i den elektroniska versionen, så att rätt ekvationer finns i den aktuella figuren.

<p>Emissions from Particles and Volatile Organic Compounds (VOC) in Falun.-How is the emission divided between particles and VOC?</p><p>This study investigates the air quality in Falun, a small city in central Sweden, with a focus on particles and volatile organic compounds (VOC). Falun is located in a valley which makes it sensitive to inversions, when the vertical mixing of air over the city is prevented. When this happens emissions over the city can stay for days and the pollution levels can be high. The report is based upon a literature review, calculation of emissions from traffic and a survey of industrial emissions. Emission of VOCs can be dangerous to people and contributes to the production of ground- level ozone. Particles can be a carrier for other dangerous compounds. The result shows that high pollution levels caused by inversions can happen. The temperature, wind and temperature differences show that inversions during the winter months are possible up to half of the time. Emissions from cars and industries are a problem. The municipality forced to control air pollution and in Swedish law there is a threshold value for both particles and the volatile organic compounds benzene. Spreading of pollution in air in Falun is centered around the emission sourses. Because it´s hard to prevent inversions, the municipality must focus on reducing emission of pollutants. This can be done through road planning and diverting traffic to other routes around the city.</p>

Petrol attendants are exposed to petrol volatile organic compounds (VOCs) which may have genotoxic and carcinogenic effects. The single cell gel electrophoresis assay (comet assay) is a method highly sensitive to DNA damage induced by environmental and occupational exposure to carcinogenic and mutagenic agents. The aim of this study was to evaluate the level of exposure of petrol attendants to petrol VOCs and also to determine their effect on DNA damage and repair in lymphocytes of African petrol attendants. The exposed group consisted of 20 subjects, randomly selected from three petrol stations. A control group of 20 unexposed subjects was also chosen and matched for age and smoking habits with the exposed group. Sorbent tubes were used to assess personal exposure of petrol attendants. The comet assay was used to investigate the basal DNA damage and repair capacity in isolated lymphocytes of petrol attendants and control subjects. Blood samples were taken from the petrol attendants at the end of their 8 hour working shift and also from the control subjects. The petrol attendants were found to be exposed to levels of petrol VOCs lower than the occupational exposure limit (OEL) for constituent chemicals. A significant relationship was found between the volume of petrol sold during the shift and the average concentrations of benzene, toluene and the total VOCs measured. However, relative humidity had a negative correlation with the average concentrations of benzene, toluene, xylene and the total VOCs. Significantly higher basal DNA damage was observed with the exposed group compared to the control group. The period of exposure influenced the level of DNA damage and the calculated repair capacity. Smoking and age had a significant influence on the level of DNA damage. DNA repair capacity was delayed in smokers of both exposed and non-exposed group. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2008.

Whey protein isolate (WPI) contains at least 90% protein and should ideally possess a bland flavor without typical dairy flavors including sweet aromatic and cooked/milky notes. However, its flavor may be highly variable due to factors including original whey source, processing and storage conditions. Novel technologies removing nonpolar compounds responsible for off-flavors and off-flavor formations are desirable. The major objective of this research was to evaluate impacts of supercritical carbon dioxide (scCO2) extraction, a known green process, on volatile profiles of WPI. A prior sub-objective was to establish an analytical technique for characterization of volatiles. Specifically, adsorption conditions in a well-established head-space solid-phase microextraction (SPME) method were used for quick and reliable assays of volatiles in WPI, using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber. The adsorption of volatiles on the SPME fiber was studied at 21, 40 or 50 °C, each with durations of 5, 15 and 20 min, and analyzed by GC/MS. Based on the number of GC/MS peaks and the corresponding peak areas, adsorption conditions of 50 °C for 20 min were selected for subsequent studies. In the second sub-objective, GC/MS profiles of WPI were characterized after scCO2 extraction using a continuous stream of CO2 at 50 g/min, controlled at various combinations of temperature (30-65°C), pressure (7.0-30.0 MPa), and duration (10-90 min). Extractions with a higher temperature and a higher pressure for a longer time were generally more effective in removing volatiles, and most peaks on the chromatogram of the unprocessed WPI sample disappeared or were reduced very significantly after all studied extraction conditions, even at subcritical conditions of 7.0 MPa and 30 °C for 1 hour. Our findings demonstrated that supercritical or subcritical CO2 may provide a green approach to reduce volatiles in whey protein preparations for novel food applications.

Récemment, de nombreuses recherches ont été dévolues à la mise au point de réacteurs biphasiques, perçus comme une nouvelle technologie pour le traitement des polluants organiques dans les effluents gazeux. Ces réacteurs impliquent lutilisation dune seconde phase non aqueuse pour améliorer la solubilité et le transfert de masse des composés hydrophobes. Dans ce travail, nous avons développé un réacteur biphasique agité utilisant lhuile de silicone comme seconde phase. Initialement, Rhodococcus erythropolis T 902.1 a été sélectionné sur base de sa capacité à dégrader lisopropylbenzène (IPB), un composé choisi comme modèle représentatif de la famille du benzène. Deuxièmement, le transfert de masse de loxygène et de lIPB a été étudié en relation avec les conditions hydrodynamiques du réacteur et le type dhuile de silicone. Lutilisation dune proportion de 10 % dhuile de faible viscosité (10cSt) naffecte pas significativement le transfert de masse de loxygène. Cependant la grande solubilité de lIPB dans lhuile de silicone conduit à une forte augmentation du potentiel de transfert, spécialement pour les proportions en huile les plus élevées. Néanmoins, il ne semble pas utile de dépasser une proportion de 10 % car le KLaIPB et le KLaO2 diminuent drastiquement pour des proportions supérieures. Lexistence dune concentration optimale en élément biotique apparaît également. En effet, les concentrations optimales en biomasse (B) et extrait surfactant (ES) peuvent être évaluées à, respectivement 0,5 g/L et 0,7 g/L, elles assurent une valeur maximale du coefficient global de transfert de masse de loxygène (KLaO2). Plus spécifiquement, lES augmente laire interfaciale « a » en diminuant le diamètre des bulles tandis que la biomasse la diminue dès quune concentration de 1 g/L est atteinte. Au contraire, lES agit négativement sur le KL tandis que la biomasse laméliore globalement. En terme de performance, il est clairement montré que la taux de biodégradation de lIPB est davantage corrélé au débit gazeux de leffluent quà la concentration en polluant. Le réacteur biphasique a été suivi sur une période de 38 jours afin de caractériser son comportement à moyen terme pour différentes conditions opératoires. Lors dune phase dalimentation transitoire (10h/j), la capacité moyenne délimination est denviron 240 g/m3 pour une charge massique de 390 g/m3. Finalement, une approche originale a été développée en utilisant un bioréacteur de type scale-down pour reproduire les conditions hydrodynamiques rencontrées dans les réacteurs industriels. Il est clairement démontré que le polluant (IPB) affecte négativement lextrapolation en augmentant la vitesse de séparation de phase. Cependant cet impact négatif est largement compensé par la présence déléments biotiques qui stabilise fortement le système biphasique, rendant totalement envisageable lextrapolation à grande échelle. En conclusion, lutilisation dun réacteur biphasique eau-huile de silicone pour lélimination de concentrations élevées (~ 6g/m3) en polluants hydrophobes est adéquate. Le réacteur proposé présente de réelles opportunités pour le traitement biologique deffluents pollués par des composés hydrophobes. Son utilisation pourrait être envisagée lorsque loxydation thermique savère trop onéreuse ou lorsque les biofiltres classiques atteignent leurs limites ( >1 g/Nm3 et une charge volumique de 90m3/m3.h.)./Recently, a lot of research has been devoted to the study of two-phase partitioning bioreactors (TPPB) as new technology for xenobiotic degradation in gaseous effluents. These reactors involve the use of a second non-aqueous phase to improve the solubility and transfer of hydrophobic compounds. In this work, we have developed a stirred two-phase partitioning bioreactor using silicone oil as second phase. Initially, Rhodococcus erythropolis T 902.1 was selected on the basis of its capacity to metabolize isopropyl-benzene (IPB), used as representative of the benzene-containing compounds. Secondly, the mass transfer of both IPB and oxygen has been considered with relation to their influence on the hydrodynamics of the reactor and the type of silicone oil used. The addition of 10% low viscosity silicone oil (10 cSt) in the reactor does not significantly affect the oxygen transfer rate. The very high solubility of IPB in the silicone oil leads to an enhancement of the driving force term, especially when high proportion of silicone oil are used. However, it is not necessary to use a volume fraction higher than 10% since KLaIPB and KLaO2 decrease sharply at above such proportion. In addition, an optimal concentration appeared to exist for both biotic components, respectively 0,5 g/L and 0,7 g/L for biomass (B) and surfactant extract (SE) when the global mass transfer coefficient (KLa) of oxygen was measured in the TPPB. More specifically, SE improved the interfacial area a by decreasing the bubble diameter, while B reduced it at concentrations up to 1 g/L. In contrast, the SE concentration acted negatively on KL, while it was favoured by the B concentration. In term of performances, it was clearly shown that the biodegradation rate is more directly related to the inlet flow of IPB than to the concentration of IPB in the inlet gas. The TPPB was monitored for 38 days to characterise its behaviour under several operational conditions. During an intermittent loading phase (10 h/day), the average elimination capacity remained above 240 g/m3.h for an average IPB inlet load of 390 g/m3. h. Finaly, an original approach was developed using a scale-down bioreactor allowing to reproduce the hydrodynamics encountered under full scale TPPB. It was clearly shown that the IPB affects negatively the scaling-up of the process by increasing the speed of phase partitioning. However, this negative impact was strongly compensated by the presence of biotic compounds stabilizing the two phase system and rendering the scaling-up process feasible. In conclusion, the use of a water-silicone oil TPPB to remove a high inlet load of IPB was successful. The proposed reactor retains a high potential for the biological treatment of gas effluents polluted by hydrophobic aromatic compounds. The suggested process might be applied in the range of concentration and flow where thermal oxidation is too expensive (between 1 and 7 g/Nm3) or when the biofilters are usually limited, i.e. to treat a polluted effluent concentrated with > 1 g/Nm3 at a flow of 90m3/m3.h.

In this thesis the sink-effect in indoor materials wasstudied using mathematical modelling and experimental studies.The sink-effect is a concept which is commonly used tocharacterise the ability of different indoor materials to sorbcontaminants present in the indoor air. The sorption process ismore or less reversible, i.e. molecules sorbed in materials athigh contaminant concentrations may again be desorbed at lowerconcentrations. Knowledge of the sorption capacity of materialsand the rate at which sorption and desorption takes place is offundamental importance for mathematical simulation of indoorair quality. The aim of this work is to contribute withknowledge about how the sink-effect can be described inmathematical terms and how the interaction parametersdescribing the sorption capacity and sorption/desorptionkinetics can be determined. The work has been of amethodological nature. The procedure has been to set upphysically sound mathematical models of varying complexity andto develop small-scale chamber experiments. Two differentdynamic chamber methods have been used. One is based on amodified standard FLEC-chamber while the other uses a chamberwith two compartments, one on each side of the material. The"twin-compartment" method was designed due to the observationthat the contaminant readily permeated straight through theselected materials, which resulted in uncontrolled radiallosses in the FLEC-chamber. In order to be useful forcomparison between experiments and calculations and parameterfitting, the boundary conditions in the chambers must beprecisely known and controlled. This matter has shown to be themost crucial and difficult problem in the research. A varietyof mathematical models for the sink-effect have been proposed.In some models advanced fluid simulations were used in order totest the influence ofill-defined flow boundary conditions. Theaim of the modelling is to find a formulation with a minimum ofinteraction parameters, which is generally useful, i.e. both insmall-scale laboratory environments and in full-scale like anoffice room. Estimated model parameters are shown to be able toyield a reasonably good fit to experimental data for thesorption process but a less satisfactory fit for the desorptionprocess. <b>Keywords:</b>sink-effect, sorption, adsorption, diffusion,indoor air quality, volatile organic compounds, VOC,contaminants, building materials

Emissions from Particles and Volatile Organic Compounds (VOC) in Falun.-How is the emission divided between particles and VOC? This study investigates the air quality in Falun, a small city in central Sweden, with a focus on particles and volatile organic compounds (VOC). Falun is located in a valley which makes it sensitive to inversions, when the vertical mixing of air over the city is prevented. When this happens emissions over the city can stay for days and the pollution levels can be high. The report is based upon a literature review, calculation of emissions from traffic and a survey of industrial emissions. Emission of VOCs can be dangerous to people and contributes to the production of ground- level ozone. Particles can be a carrier for other dangerous compounds. The result shows that high pollution levels caused by inversions can happen. The temperature, wind and temperature differences show that inversions during the winter months are possible up to half of the time. Emissions from cars and industries are a problem. The municipality forced to control air pollution and in Swedish law there is a threshold value for both particles and the volatile organic compounds benzene. Spreading of pollution in air in Falun is centered around the emission sourses. Because it´s hard to prevent inversions, the municipality must focus on reducing emission of pollutants. This can be done through road planning and diverting traffic to other routes around the city.