Since odor-complaint events have been increased year by year in Taiwan, odor control has become an important issue in the air pollution control field. Thus, this paper attempted to investigate if ¡§ozone scrubbing-activation carbon adsorption¡¨ is feasible for efficiently reducing the odor intensity of vented gas from recycled polypropylene (PP) fusion operations. A pilot scrubber (0.17 m L ¡Ñ0.17 m W ¡Ñ1.2m H, packed with Intalox saddles to a total volume of around 0.018 m3) was used for the feasibility test. Odorous gases vented from the fusing operation kept at 200 ¢J in a temperature-controlled oven were used as the target waste gases. Results indicated that with operation conditions of VOCs (as methane) 10-40 ppm, an ozone concentration of 4.0 ppm in the influent gas, a liquid/gas (L/G) ratio of 0.030 L/m3 in the scrubber, and an empty bed retention time of around 9.7 s in the packed section, around 60% of the VOCs in the influent gas was removed. Most alkenes in the gas were converted into sweet-smell ketones in the ozonated gas. Vented gas from the scrubber was further treated by a granulated activated carbon (GAC) adsorption column with an EBRT of less than 1 s for the gas. An overall VOC removal of around 70% was observed for the full ozonation-GAC process. Only trace amounts of original fume-like and sweet-ketone smells were detected in the treated gases. A test indicated that the overall odor (expressed as the dilution to threshold D/T value) removal was around 70% and the D/T were 733, 309, and 232, respectively, for the influent, ozonation-scrubbing effluent, and GAC effluent. It was estimated that the cost is around NT$ 9.57 for treating 1,000 m3 of the teat gas by the system. Efforts should be made by decreasing the cost by other alternative technologies.

This dissertation consists of two parts on the treatment of hydrogen sulfide and odorants in gases emitted from rubber processing industry. In the first part, we study performance of removal hydrogen sulfide with bioscrubber. An activated sludge aeration tank (W ¡Ñ L ¡Ñ H = 0.40 ¡Ñ 0.40 ¡Ñ 3.00 m) with a 2 mm-orifice air sparger was used to treat gaseous hydrogen sulfide (H2S). The investigation tested the operational stability as well as how the removal ability of H2S was affected by influent H2S concentration (C0 = 50-900 ppm), aeration intensity (Q/V = 0.083-0.50 m3 m-3 min-1), liquid depth (H = 0.5-3.0 m), and mixed-liquor suspended solids concentration (MLSS = 970-2,800 mg L-1). Experimental results indicate that H2S removal efficiencies of 96% and over 98% were obtained with H = 0.5 m and H > 1.0 m in the cited operation conditions, respectively. Experimental results also indicate no sludge bulking problem occurred with total sulfide loadings of 0.047-0.148 kg S kg-1 MLSS d-1. The second part aimed at the removal of odorous compounds in gases emitted from rubber processing industries. Simulated odorous gas for test was prepared by mixing fresh air and an odorous gas drawn from an oven in which a sample of rubber powder was kept either at 160¢XC (for a thermal plastic rubber) or 200¢XC (for a thermal setting rubber). The prepared odorous gas was then premixed with a definite amount of ozone-enriched air and introduced into a contact system. The contact system consists of two sieve-plate columns connected in series and each column has four 1-L chambers. Depending on with or without introducing circulating scrubbing water into the columns, the oxidation reaction could be either wet or dry one. Results indicate the wet oxidation got better performances than the dry one. The former got 97 and over 90% removal of VOCs (volatile organic compounds) and odorous intensity removal, respectively, with the operation conditions of initial ozone concentration 4.0 ppm, THC (total hydrocarbon) concentrations 6.5¡V10.3 ppm (methane equivalent), oxidation temperature 37.3¢XC, gas empty bed retention time (EBRT) 12 s, and liquid/gas rate ratio 0.01 m3/m3. With conditions similar to those cited above, odor concentration (dilutions to the threshold, D/T) in the test gas could be reduced from 1,738¡V3,090 to 31¡V98 with EBRTs of 11.4¡V14.5 s. Activated carbon is effective for both physical and chemical removals of residual VOCs, odorous compounds, and ozone in the effluent gas from the ozonation system. Economical analysis indicates that around US$ 0.16 is required for treating 1,000 m3 of the tested foul gas by the proposed ozonation process.

Recently, restaurant employees exposing to cooking oil fume with potential lung cancer was highly concerned, indicating cooking oil fume emitted from restaurants might cause tremendous hazard to human health. This study combined photocatalytic oxidation and ozone oxidation technology to decompose VOCs from the exhaust of cooking oil fume from restaurants. Firstly, this study selected three different types of restaurants to implement air pollutant measurements in the indoor dinning room and stack emission. Indoor TVOCs continuous monitoring data showed that the highest TVOCs concentration was generally observed in the dining peak time. In this study, photocatalyst coated fiberglass filter was prepared by impregnation procedure and its characteristics was analyzed by SEM and XRD. Experimental results showed that the particle size of photocatalyst ranged from 25 to 50 nm and had high percentage of Anatase, suggesting that it had high photocatalytic reactivity. This study designed a continuous-flow reaction system combined nano-sized TiO2 photocatalysis with ozone oxidation technology to decompose VOCs from cooking oil fume. After passing through a fiberglass filter to remove oil droplets, the cooking oil fume then coated with nano-sized titanium oxide (UV/TiO2) fiberglass filter purification system, and then injected ozone into the system to decompose residual VOCs. This study further investigated the influences of operating parameters, including TVOCs initial concentration, O3 injection concentration, and reaction temperature on the decomposition efficiency of TVOCs by using the UV/TiO2/O3 technology. When the photocatalytic reaction temperature was 35~50¢J, the TVOC decomposition efficiency slightly increased with reaction temperature, however, when the reaction temperature went up to 55¢J, the TVOC decomposition efficiency increased only slightly, but did not increased linearly. Combination of photocatalysis and ozone oxidation system performance test results showed that ozone could decompose approximately 34% VOCs, and followed by the photocatalytical reaction of residual pollutants, achieving an overall decomposition efficiency of about 75%; while photocatalytic reaction can remove 64% of TVOCs and followed by O3 for the decomposition of residual pollutants, achieving an overall decomposition efficiency up to 94%. It showed that the combined UV/TiO2+O3 system could effectively remove VOCs in the cooking oil fume from the exhaust of restaurants. By using GC/MS to qualitatively analyze the speciation of TVOCs from cooking oil fume before and after UV/TiO2/O3, the results showed that the composition of VOCs had a decreasing trend. The peak area and dilution factor were applied to estimate the decomposition efficiency of different VOCs species. The decomposition efficiencies of pentane, 2-acrolein, acrolein, heptane, pentanal, hexanal, 2-hexenal, heptanal, heptenal and ethylhexenal were 56.21%, 72.88%, 51.33%, 32.23%, 59.04%, 69.22%, 73.53%, 41.37%, 92.57%, and 96.02%. Finally, a Langmuir-Hinshelwood kinetic model was applied to simulate the photocatalytic decomposition efficiency with the initial concentration of cooking oil fume. Model simulation results showed that the reaction rate increased with the initial TVOCs concentration. However, when TVOCs concentration increased gradually, the reaction rate became constant since the activated sites on the photocatalyst¡¦s surface was limited and cannot allow more VOC molecules diffuse to the activated sites for further photocatalytic reaction.

This study was aimed at the removal of odorous compounds in gases emitted from rubber processing industries. Odorous gas for test was prepared by mixing fresh air and an odorous gas drawn from an oven in which a sample of rubber powder was kept at 160 and 200 oC, respectively. For ozonation tests, the prepared odorous gas was then premixed with a definite amount of ozone-enriched air before entering into a contact system. The contact system consists of two sieve-plate columns connected in series and each column has four 1-L chambers. Depending on with or without introducing a circulating scrubbing water into the columns, the oxidation reaction could be either wet or dry one. For UV/ozonation (UV/O3) tests, batch reactions were performed in a 3.63-L chamber fitted with an UV lamp inserted in a quartz column. A definite volume of the odorous gas generated from the oven was injected into the chamber containing a definite concentration of ozone. Results from the dry-ozonation tests indicate that that 82 and 70% of VOCs and odorous intensity in the influent gas could be removed, respectively, with the operation conditions of an initial ozone concentration of 4.0 ppm, VOC (methane equivalent) concentrations of 6.5-9.0 ppm, an oxidation temperature of 38.5 oC, and a gas empty-bed-retention time (EBRT) of 8.6 s. Both the VOC and odorous intensity removal efficiencies were roughly proportional to the EBRT in the range of 1.4-11.4 s. Wet-ozonation got 97 and over 90% of VOC and odorous intensity removal, respectively, with the operation conditions of initial ozone concentration 4.0 ppm, VOC (methane equivalent) concentrations 6.5-10.3 ppm, oxidation temperature 37.3 oC, gas EBRT 12 s, and liquid/gas rate ratio 0.01 m3/m3. With conditions similar to those cited above, odor concentration (dilutions to the threshold) in the test gas could be removed from 3,090 to 130 with an EBRT of 14.5 s. Tests also indicate that activated carbon is effective for both physical and chemical removals of the residual VOCs, odorous compounds, and ozone in the effluent gas from the ozonation system. Economical analysis indicates that around NT$ 5.4 is required for treating 1,000 m3 of the tested foul gas by the proposed wet-ozonation and activated carbon adsorption process. Odor concentration (dilutions to the threshold) in a test could be reduced from around 4,000 to 70. Results of UV/O3 tests indicate that the introduction of the 185 nm UV irradiation at the intensity of 5W/3.63L did not help in the additional VOC and odor removals with an initial ozone concentration 4.0 ppm, VOC (methane equivalent) concentrations of 12.2-15.0 ppm, oxidation temperature of 31.5 oC, and reaction time 18.2 s. UV irradiation is not necessary for the ozonation odor removal of the test gas samples.

Aerosols are either emitted directly into the atmosphere or are generated in the atmosphere; the latter process forms secondary organic aerosol (SOA). One of the important sources for SOA is the oxidation of volatile organic compounds (VOCs) by OH radicals, NOx, and O3. Aerosol can be visualized as suspended solid or liquid particle which is in equilibrium with surrounding gases. The products of SOA formation is a mixture of semi volatile organic compounds and a fraction of the products are condensable under atmospheric conditions. The condensable portion of aerosol is called particulate matter (PM) and these suspended particles can range in diameter from a few nanometers to microns. PM can impact climate through direct and indirect radiative forcing and can degrade air quality by reducing visibility and causing detrimental health effects. SOA can also form indoors, which also contributes to the health risk of PM. The severe impact of PM on human health and climate drives the scientific community to investigate the volatile organic compounds (VOCs) and their potential to form SOA, as well as the factors that alter the efficiency of SOA generation and the type of products. In a similar pursuit, the focus of this dissertation is the investigation of the SOA precursors that are emitted from trees and how they vary as a function of insect infestation. Also, the role of mixtures of VOCs as SOA precursors are investigated; commercial and lab made VOC mixtures are studied for SOA generation, product analysis, and absorption characteristics of aged SOA. Chapter 1 introduces PM, VOCs present in atmosphere, SOA generation, and speciation of products generated from the ozonolysis of VOCs. The impact of PM on human health and climate are summarized. A literature survey on the VOCs that are precursors to SOA and present in the outdoor and indoor environment is presented along with factors that may lead to variability in amount of VOCs. SOA generation from direct plant emissions and consumer products is surveyed. These studies show that VOC oxidation generate SOA which is important in the atmosphere due to climate and health effects and indoors due to health effects. A summary of SOA phase partitioning theories, the reaction mechanism for the formation of products from ozonolysis of the dominant biogenic SOA precursors (monoterpenes), and the factors that affect SOA generation is presented. Chapter 2 summarizes the results obtained from a field study assessing the impact of bark beetle infestation on SOA precursor emissions from forests in the Western United States. Samples of VOCs were collected by our collaborators from healthy and bark beetle infested trees using scent traps. We solvent extracted and analyzed by gas chromatography/mass spectrometry (GC/MS) nearly four hundred scent traps. An increase in the total and the individual VOCs emitted by infested trees was measured. A statistical analysis shows significant differences between the emissions from infested and healthy trees. A perspective is provided on potential impact of bark beetle infestation on regional SOA. The majority of the laboratory experiments for SOA generation have focused on individual VOCs as the single SOA precursor. However, as demonstrated in Chapter 2 for example, in a real environment multiple VOCs co-exist. Multiple SOA precursors undergo concurrent oxidation reactions, and it is not known if the products from concurrent oxidation of multiple precursors are the same as the sum of the products from individual SOA precursors. Mass closure analysis of field samples show that a significant fraction of the chemical identity of organic PM is unknown, but the chemistry impacts the toxicity of PM. Hence, it is important to understand SOA formation from realistic SOA mixtures. Chapter 3 describes the results of the SOA generation by ozonolysis of limonene and VOC mixtures containing limonene. We use an additive approach for building a surrogate VOC mixture close in composition to a commercially-available mixture. The yield of PM as a function of VOC precursor mixture was measured with respect to VOC composition using smog chamber SOA generation and scanning mobility particle sizing. PM in the chamber was collected onto filters and extracted, and the individual products of SOA were identified and quantified by GC/MS. The condensed-phase SOA products generated during these experiments for different VOC mixtures are compared. In Chapter 4, condensed-phase products sampled from SOA generated by the ozonolysis of α pinene and VOC mixtures containing α pinene, including two fir needle essential oils, are studied by extracting filter samples and analyzing the extracts by GC/MS. The products generated from VOC mixtures are characteristic of the most dominant VOC present in the mixture i.e. either limonene or α pinene. Some mixtures show the generation of new products which are not observed for corresponding individual VOC ozonolysis and hence can be used as marker for the corresponding VOC mixture. The distribution of α-pinene SOA products changes as the composition of the SOA precursor mixture changes. In Chapter 5, the UV visible absorption characteristics of ammonium ion aged SOA are discussed. Ammonium ion aging of aerosol leads impacts the radiative properties of aerosol and has the potential to impact aerosol's role in climate change. Filter samples containing SOA generated from two mixtures with different dominant monoterpenes (α-pinene-based Siberian fir needle oil and a limonene-based air freshener) were extracted. The absorption coefficients of the extracts were measured as a function of ammonium ion aging time using UV-visible absorption spectrometry. The conclusions from all above chapters are summarized in Chapter 6.

This work investigates fabrication methods of nickel oxide thin films and their use in organic electronics. Two fabrication techniques were studied: UV-ozone oxidation of pure nickel films and reactive RF magnetron sputtering. The former was used to produce Ni/Ni2O3 bi-layer anodes to use as a substitute for the de facto standard ITO anode. OLEDs fabricated using Ni/Ni2O3 bi-layer anodes exhibited comparable device performance to standard ITO devices. UV-ozone oxidation was also used to fabricate Ni2O3 buffer layers for OPVs. Solar cells fabricated using Ni2O3 coated ITO exhibited an enhanced power conversion efficiency of up to 90%. RF magnetron sputtering was used to produce NiOx buffer layers with tunable conductivity and optical transparency for OPVs. Solar cells fabricated using NiOx coated ITO exhibited an enhanced power conversion efficiency of up to 60%. Nickel oxide films have been characterized with various techniques: sheet resistance measurements, optical transmission, XPS, UPS, AFM, and TEM.

This work investigates fabrication methods of nickel oxide thin films and their use in organic electronics. Two fabrication techniques were studied: UV-ozone oxidation of pure nickel films and reactive RF magnetron sputtering. The former was used to produce Ni/Ni2O3 bi-layer anodes to use as a substitute for the de facto standard ITO anode. OLEDs fabricated using Ni/Ni2O3 bi-layer anodes exhibited comparable device performance to standard ITO devices. UV-ozone oxidation was also used to fabricate Ni2O3 buffer layers for OPVs. Solar cells fabricated using Ni2O3 coated ITO exhibited an enhanced power conversion efficiency of up to 90%. RF magnetron sputtering was used to produce NiOx buffer layers with tunable conductivity and optical transparency for OPVs. Solar cells fabricated using NiOx coated ITO exhibited an enhanced power conversion efficiency of up to 60%. Nickel oxide films have been characterized with various techniques: sheet resistance measurements, optical transmission, XPS, UPS, AFM, and TEM.

Detta examensarbete initierades och handledes av Mellifiq, ett företag som arbetar med rening av luft och vatten, där en applikation är rening av köksfrånluft med ozon. Ozon förhindrar att fettpartiklar i frånluften ansamlas på väggarna i kanalen och värmeväxlaren, vilket leder till högre brandsäkerhet och mer effektiv användning av värmeväxlaren. Syftet med detta examensarbete var att öka förståelsen av reaktionen mellan ozon och ytan av fettpartiklarna. Tunna fettsyrafilmer ovanpå ett fast underlag användes som modellsystem för att representera ytan av en fettpartikel. Tre fettsyror undersöktes, en mättad fettsyra, fettsyra A, en enkelomättad fettsyra, fettsyra B, och en fleromättad fettsyra, fettsyra C. TIR Raman-spektroskopi användes för att analysera effekten på fettsyrafilmen vid exponering av torr luft, fuktig luft med en relativ fuktighet på 80 % och fuktig luft med en konstant ozonkoncentration. Effekten av ozon undersöktes även med kontaktvinkelmätningar på fettsyrafilmerna. Resultaten från TIR Raman visade att torr luft och fuktig luft (RH 80 %) inte hade någon effekt på fettsyrafilmen, oberoende av vilken typ av fettsyra som användes. När det gäller effekterna av exponering för ozon kunde inga effekter observeras på filmen av fettsyra A i vare sig TIR Raman eller kontaktvinkelmätningar. Därför kunde ingen reaktion mellan fettsyra A och ozon bekräftas vid den ozonkoncentration som användes och de exponeringstiderna som undersöktes. Däremot oxiderades de omättade fettsyrafilmerna av fettsyra B och C när de exponerades för ozon, vilket bekräftades av den snabba minskningen av C-C-dubbelbindningarna i TIR Raman-spektra. Oxidationen av dubbelbindningar i fettsyra B verkade visa en mer komplex kinetik, med en tvåstegsprocess kopplad till en förändring av antalet molekyler vid ytan. Filmerna bestående av fettsyra C visade sig förlora materia när de exponerades för ozon, vilket tyder på att korta flyktiga ämnen bildades under oxidationsprocessen. Denna effekt observerades inte för fettsyra B, där även om den spektrala formen i CH-sträckningsområdet ändrades, vilket bevisade närvaron av nya arter, förblev den totala mängden material i filmen ungefär konstant. Dessutom gav både fettsyra B och C upphov till nya karbonyl-C=O-sträckningstoppar i spektra efter ozonisering, vilket visar att aldehyder, estrar eller båda bildas under processen. Slutligen bekräftade kontaktvinkelmätningarna med en minskning av statiska vinklar att ytan på filmerna av fettsyra B och C förändrades efter ozonisering. / This master thesis project was initiated and managed by Mellifiq, a company that works with purification of air and water, where one application is purification of kitchen exhaust air with ozone. Ozone prevents fat particles in the exhaust air from accumulating on the walls in the duct and the heat exchanger, reducing fire safety concerns and making the use of the heat exchanger more effective. The aim of this master thesis project was to further understand the reaction between ozone and the surface of the fat particles. Thin fatty acid films on top of a solid support were used as model systems to represent the surface of a fat particle. Three fatty acids were investigated, a saturated fatty acid, fatty acid A, a monounsaturated fatty acid, fatty acid B, and a polyunsaturated fatty acid, fatty acid C. TIR Raman spectroscopy was used to analyze the effect on the fatty acid film as it was exposed to dry air, humid air with a relative humidity of 80 %, and humid air with a fixed ozone concentration. The effect of ozone was also investigated with contact angle measurements on the fatty acid films. The results from TIR Raman showed that dry air and humid air (RH 80 %) had no effect on the fatty acid film, independent of the type of fatty acid used. Regarding the effects of exposure to ozone, no effects could be observed on the fatty acid A field in either the TIR Raman or contact angle measurements. Therefore, no reaction between fatty acid A and ozone could be confirmed at the fixed ozone concentration used and exposure times investigated. In contrast, the unsaturated fatty acid films of fatty acid B and fatty acid C were oxidized when exposed to ozone, as confirmed by the rapid decrease of the C-C double bonds in the TIR Raman spectra. However, the oxidation of double bonds in oleic acid appeared to show more complex kinetics, with a two-step process linked to a change in the number density of molecules at the surface. Interestingly, the films consisting of fatty acid C were shown to lose matter when exposed to ozone, indicating that short volatile species were formed during the oxidation process. This effect was not observed for fatty acid B, where though the spectral shape in the C-H stretching region changed, proving the presence of new species, the overall amount of material in the film remained approximately constant. Moreover, both fatty acid B and C gave rise to new carbonyl C=O stretching peaks in the spectra after ozonation, showing that aldehydes, esters, or both are formed during the process. Finally, the contact angle measurements confirmed with a decrease in static angles that the surface of the fatty acid B and C films changed after ozonation.