by Hei Yuk Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 81-87). / Abstract also in Chinese. / ABSTRACT --- p.i / DECLARATION --- p.ii / ACKNOWLEDGEMENT --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF TABLES --- p.vi / LIST OF FIGURES --- p.vii / Chapter CHAPTER ONE : --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1. --- Volatile Organic Compounds --- p.1 / Chapter 1.1.2. --- Photocatalytic Oxidation --- p.2 / Chapter 1.1.3. --- Adsorption --- p.4 / Chapter 1.2. --- Scope of Work --- p.8 / Chapter CHAPTER TWO : --- PHOTOCATALYSIS --- p.10 / Chapter 2.1 --- Fundamental --- p.10 / Chapter 2.2. --- Experimental --- p.14 / Chapter 2.2.1. --- Materials --- p.14 / Chapter 2.2.2. --- Instruments --- p.14 / Chapter 2.2.3. --- Experimental Conditions --- p.19 / Chapter 2.2.4. --- Procedure --- p.20 / Chapter 2.3. --- Results and Discussion --- p.28 / Chapter 2.3.1. --- Photocatalytic Degradation of DCE --- p.28 / Chapter 2.3.2. --- Photocatalytic Degradation of TCE --- p.31 / Chapter 2.3.3. --- Photocatalytic Degradation of DCE and TCE Binary System --- p.34 / Chapter 2.3.4. --- Photocatalytic Degradation of Ethyl Acetate --- p.39 / Chapter 2.3.5. --- Photocatalytic Degradation of Methyl Isopropyl Ketone --- p.41 / Chapter 2.3.6. --- Photocatalytic Degradation of Ethyl Acetate and Methyl Isopropyl Ketone Binary System --- p.43 / Chapter CHAPTER THREE : --- ADSORPTION --- p.47 / Chapter 3.1. --- Fundamental --- p.47 / Chapter 3.1.1. --- Mordenite --- p.51 / Chapter 3.1.2. --- Activated Carbon --- p.55 / Chapter 3.2. --- Experimental --- p.58 / Chapter 3.2.1. --- Materials --- p.58 / Chapter 3.2.2. --- Instrument --- p.59 / Chapter 3.2.3. --- Procedure --- p.60 / Chapter 3.3. --- Results and Discussion --- p.65 / Chapter 3.4. --- "Adsorption Isotherm of 1,3,5-trimethylbenzene on Mordenite in Aqueous Phase" --- p.70 / Chapter 3.5. --- "Thermal Regeneration of 1,3,5-trimethylbenzene on Mordenite in Aqueous Phase" --- p.72 / Chapter CHAPTER FOUR : --- CONCLUSION --- p.79 / REFERENCES --- p.81

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Sources of polar/water-soluble organic compounds conjunctly with apolar biomarkers were characterized in natural organic matter. This multi-biomarker approach was accomplished by a simple analytical method consisting of extraction with dichloromethane:methanol (2:1, v/v), silylation and analysis by gaschromatography- mass spectrometry (GC-MS). Polar and apolar biomarkers, derived mainly from higher plants and microorganisms, were used as tracers of processes occurring in the environmental compartments and registered in aerosol, soil and sediment samples. Sugars (monosaccharides, disaccharides, anhydrosugars and sugar alcohols) were utilized to trace seasonal variation inputs of biogenic organic carbon to aerosols over a pristine forest and the passage of a smoke plume from the long-range transport wildfire emissions. Sugars and fatty acid methyl esters were target compounds used to better understand the plant-microorganism dynamics in a ryegrass soil over a one-year period. Distributions and abundances of straight chain homologous series (n-alkanes, n-alkanols, n-alkanoic acids), cyclic components (e.g., diterpenoids, triterpenoids, steroids) and polar biomakers (e.g., sugars) were determined for sediment and smoke samples. In the first study, the transport and alterations of major terrestrial biomarkers were assessed for small rivers draining the northwestern US. In the latter, biomarkers and their thermal alteration derivatives were identified in smoke emissions from known temperate and semi-arid green vegetation to be applied as tracers of wildfires. This work demonstrated that a multi-biomarker tracer analysis is a useful tool for describing and understanding the biogeochemistry occurring in various environmental compartments. / Graduation date: 2006

Ambient high-volume (hi-vol) air samples were collected between March 15th and May 30th 2002, at Cheeka Peak Observatory (CPO), located on the tip of the Olympic Peninsula, Washington State. This sampling campaign was in conjunction with the 2002 Inter-Continental Transport and Chemical Transformation (ITCT 2K2) Campaign and the Photochemical Ozone Budget of the Eastern North Pacific Atmosphere (PHOEBA2) experiment, both of which studied the effect of Trans-Pacific transport on the U.S. West Coast. The anthropogenic semi-volatile organic compounds (SOCs) measured during this time period included polycyclic aromatic hydrocarbons (PAHs) and various U.S. current-use and historical-use pesticides. The total PAH concentration ranged from 0.480-4.49 ng/m³, which is comparable to other remote sites throughout the globe. Ten pesticides (hexachlorobenzene, dacthal, chlorothalonil, heptachlor, trans-nonachlor, cis-nonachlor, endosulfan I, triallate, trifluralin, and mirex) were also measured and their concentrations (0.104-57.0 pg/m³) were comparable to other remote sites and less than agricultural areas. Gas-phase/particle-phase partitioning of SOCs was explored, with a significant correlation with temperature found for endosulfan I and retene. A possible relationship at CPO of low total suspended particulate (TSP) concentration with the concentration of non-exchangeable SOCs in the particle phase was found. Principal Component Analysis, as well as a t-test, showed there were elevated concentrations and a unique pattern of anthropogenic SOCs measured during possible Trans-Pacific events on March 15th-16th March 27th-28th and April 22nd-23rd, 2002. These Trans-Pacific events were identified using the GEOS-CHEM model and 10-day back air trajectories. The potential sources of these compounds at CPO were determined using diagnostic ratios of their concentrations, back trajectories calculated using HYSPLIT4, local meteorological conditions, and U.S. pesticide use data. / Graduation date: 2004

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The objective of this thesis was to construct general models to predict pollutant fluxes in limnoplankton by incorporating characteristics of the organism and the structures of the chemical. A two-compartmental pharmacokinetic model was used to quantify the pollutant uptake, depuration and intercompartmental exchanges. The model pollutants were phosphorus and 22 organic chemicals. / The rate constants of phosphorus uptake, excretion and intercompartmental changes by algae and cladocerans decreased with cell volume or body size raised to a power close to $-$0.25, except the intercompartmental exchanges for cladocerans which showed more negative slopes. In contrast, uptake, excretion and internal exchange rates per individual increased with cell size or body weight to a power similar to 0.75 with a similar exception for the cladoceran intercompartmental exchanges, which had slopes $<$0.75. / Bioconcentration factors, rate constants and flux rates of uptake and intercompartmental exchange from metabolic pool to structural pool of 22 $ sp{14}$C-labelled organic toxicants by Chlorella pyrenoidosa and Daphnia magna were positively correlated with the octanol/water partition coefficient, molecular weight, parachor, connectivity index, boiling point and melting point, and negatively with aqueous solubility. However, those of elimination and internal transfer from structural pool to metabolic pool showed opposite changes. Comparisons of pharmacokinetic parameters between Daphnia and Chlorella demonstrated that, although all kinetic parameters displayed similar patterns, the relative magnitudes of each corresponding parameters were significantly different between two species.

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The current work determined whether there is a constant tissue residue associated with narcotic compounds. In this investigation, the cladoceran, Daphnia magna was exposed to lethal levels (48h LC50) of ten, $ sp{14}$C-labelled, narcotic organic chemicals in a closed system. Exposure times, ambient concentrations, and body sizes were varied to evaluate their effects. The $ sp{14}$C-method developed in current work can detect chemicals in single D. magna in concentrations ranging from 0.02 to 6310 mmol/kg. Moreover, the technique detected phobic and lipophilic chemicals equally well. The technique's sensitivity (nmol/kg) allowed for detection of differences in the internal concentrations of pollutants among the unaffected, immobilized, and dead D. magna. Immobilized D. magna contained between 0.14 mmol/kg and 200 mmol/kg of narcotics. On the average, however, the internal residues were 3.1 mmol/kg (95%CL = 3.1 $ pm$ 2.0). This agreed with literature values. The effects of time of exposure, ambient concentration, and body size on the tissue residues of narcotics varied with the chemical compound.

Two compartment (sediment and water) flow-through model ecosystems were constructed to investigate the compartmentalization of different organic chemicals. Lindane, naphthalene, and mirex were pumped into the systems and resultant compartmental chemical concentrations determined. Steady state concentrations were compared to those predicted by two environmental fate models - EXAMS (Exposure Analysis Modeling System) and SLSA (Simplified Lake and Stream Analysis) which were developed by EPA-Athens, Georgia and HydroQual, Inc., respectively.