Dissolved organic matter (DOM) is found in all freshwaters globally, by dissolving in rainwaterduring its path through soil and on to oceans via. rivers and streams. To provide potable water fit for human consumption, selected streams and rivers are used by either direct abstraction, or by diversion into reservoirs prior to treatment. For ca.100 years, chlorine and its compounds have been used by water treatment companies to disinfect water. However, research has shown that reactions between chlorine and DOM can produce compounds (disinfection by-products, or DBPs) which may be hazardous to human health. This thesis explores the relationship between catchment character, organic matter concentration, and the potential formation of DBPs. In particular, trihalomethanes (THMs) were measured as these are currently the only regulated DBPs in the UK. To achieve this, water samples were collected quarterly over one year from two contrasting catchments, to study seasonal variations in DOM concentration and character. A third catchment was also sampled, with similar catchment characters to the first two catchments, to determine whether geographical location and land use types affected the data. Each catchment was studied to see if catchment characteristics (e.g. class of vegetation, soil type or bedrock) could be mapped using a Geographical Information Systems (GIS) approach), to observe any effects on DOM and/or the DBPs found in treated water, with the aim of producing a risk assessment map to aid the choice of future abstraction locations for drinking water. Hence, samples were chlorinated and chloraminatedin the laboratory before being analysed for DBP formation and residual chlorine concentrations were measured. Catchment specific GIS derived data were statistically analysed with water chemistry data, and detected relationships were explored statistically. Major findings include medium to strong positive correlations between the standardised THM4 (STHM4 - the concentration of THM4 formed from 1 mg L-1 dissolved organic carbon (DOC)) concentration and geology, where an increase of the area of inland rock in a catchment increases STHM4 concentration. Medium strength positive correlations were found between STHM4 and vegetation classes, where, as the area of acid grassland, and heather increase, so does the concentration of STHM4. Negative relationships were discovered showing the obverse, where, as loamy and clayey floodplain soils with naturally high groundwater increased in area, STHM4 concentration dropped (at the Hampshire Avon ii and Conwy catchments combined). The occurrence of coniferous woodland in a catchment was found to correlate with the CHCl3 formation potential of waters (Pearsons, f=0.530, p= < 0.05, n=20), supporting findings in published literature. Laboratory based chlorination and chloramination of sample waters, followed by gas chromatography provided DBP data, specifically THM4. These data show that more chloroform was formed after chlorination than chloramination, and that chloramination formed 3 times more CHBr3 (another THM4 compound) than chlorination, under laboratory formation potential conditions. Results showed that the chlorination of water prior to DOM removal could result in a THM4 concentrations 5 times greater than the current UK regulatory limit, per mg L-1 dissolved organic carbon (DOC), whereas chloramination forms ca.5 times less than the current UK regulation per 1 mg L-1 DOC. However, chlorination of water prior to DOM removal is never done in practice, so this data provides information on the composition of the organic matter and whether DOM from a specific catchment contains specific components that are responsible for an increase in a specific DBP. Data also show that increasing organic nitrogen or organic carbon does not necessarily increase nitrogenous or carbonaceousDBPs (N-DBPs or C-DBPs). However, importantly, data shows that an increase in the area of land use classed as 'urban', results in an increase in DON (likely due to human influences) in the water draining from them, posing potential issues for eutrophication in downstream water bodies and the formation of N-DBPs at water treatment works. Whilst N-DBP detection was explored from several different angles, the development of a definitive method was not possible due to very low N-DBP concentrations, time and financial constraints. However, various methods were adapted to aid in the detection of them, showing promising initial results, providing the background for future projects into the discovery of a suite of N-DBPs such as haloacetonitriles and halonitromethanes. Finally, the data in this thesis have been inputted into maps for each major catchment to present data with a high visual impact, but also to illustrate land use types that have been found to correlate with increases in DBPs and specific nutrients in the water draining from them. However, the high variation in DOM concentration and character from site to site make extrapolation of these risk assessment data, to other catchments, unsafe. Nevertheless, collection of data from a catchment (similar to the work presented here) where a new water abstraction location is desired can prove advantageous in providing information to utility companies of what difficulties they may encounter when treating the water. Though this can be done by grab sampling at each site of interest, this can prove costly and timely and involves both field and laboratory based work aspects, wheras the method presented here requires less cost and time, once the method is initialised, to derive data of similar value. Despite the fact that disinfection performance would always trump DBP minimalisation, this is likely to be a vital tool in ensuring the provision of safe and healthy water fit for the consumption of an ever increasing human population.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Suc Chiu Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 57-60). / Abstracts in English and Chinese. / TITLE PAGE --- p.i / THESIS COMMUTE --- p.ii / ABSTRACT (English) --- p.iii / ABSTRACT (Chinese) --- p.iv / ACKNOWLEDGMENTS --- p.v / TABLE OF CONTENTS --- p.vi / LIST OF FIGURES --- p.viii / LIST OF TABLES --- p.ix / Chapter CHAPTER ONE --- General introduction and methodology / Chapter 1.1 --- General introduction --- p.1 / Chapter 1.2 --- Approximation in ab initio calculation --- p.4 / Chapter 1.2.1 --- Born-Oppenheimer approximation --- p.5 / Chapter 1.2.2 --- Density function theory (DFT) --- p.6 / Chapter 1.2.3 --- Periodic supercell approach for solid reaction --- p.8 / Chapter 1.2.4 --- Pseudopotential approximation --- p.11 / Chapter CHAPTER TWO --- "Adsorption of N02 molecules on zigzag (6,0) and (8,0) single-walled carbon nanotubes (SWNTs)" / Chapter 2.1 --- Introduction --- p.15 / Chapter 2.2 --- Computational details --- p.17 / Chapter 2.3 --- Resultsand discussion --- p.19 / Chapter 2.3.1 --- "Adsorption of a single N02 on (6,0) SWNT" --- p.19 / Chapter 2.3.2 --- "Adsorption of a second N02 on (6,0) SWNT" --- p.22 / Chapter 2.3.3 --- "Comparison of NO2 adsorptions on (8,0) SWNT with different cutoff energies" --- p.25 / Chapter 2.3.4 --- "Adsorption of more N02 on a (8,0) SWNT" --- p.28 / Chapter 2.4 --- Summary --- p.34 / Chapter CHAPTER THREE --- Diameter dependence for the adsorption of N02 molecules on zigzag single-walled carbon nanotubes (SWNTs) (n=6~12) / Chapter 3.1 --- Introduction --- p.35 / Chapter 3.2 --- Computational method --- p.37 / Chapter 3.3 --- Results and discussion --- p.38 / Chapter 3.3.1 --- Adsorption of a single N02 on SWNT --- p.38 / Chapter 3.3.2 --- Adsorption of a second on N02 SWNT --- p.40 / Chapter 3.3.3 --- Electronic structures of SWNTs after NO2 adsorption --- p.42 / Chapter 3.4 --- Summary --- p.55 / References --- p.57

by To Ching Yuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Table of contents --- p.ix / Chapter Chapter 1. --- Introduction / Chapter 1.1. --- Introduction --- p.1-1 / Chapter 1.2. --- One-dimensional (1-D) nanomaterials --- p.1-1 / Chapter 1.3. --- Growth mechanisms --- p.1-2 / Chapter 1.3.1. --- The Vapor-liquid-solid mechanism --- p.1-2 / Chapter 1.3.2. --- The Vapor-Solid (VS) mechanism --- p.1-3 / Chapter 1.4. --- A1203 --- p.1-4 / Chapter 1.5. --- Recent works on 1-D alumina nanomaterials --- p.1-5 / Chapter 1.6. --- AlON --- p.1-6 / Chapter 1.7. --- Objectives and approaches --- p.1-8 / Chapter 1.8. --- Thesis layout --- p.1-9 / References --- p.1-10 / Tables --- p.1-14 / Chapter Chapter 2. --- Methodology and instrumentation / Chapter 2.1. --- Introduction --- p.2-1 / Chapter 2.2. --- Experimental setup --- p.2-1 / Chapter 2.3. --- Experimental conditions --- p.2-2 / Chapter 2.3.1. --- Fabrication of A12O3 nanobelts --- p.2-2 / Chapter 2.3.1.1. --- Heating environments --- p.2-3 / Chapter 2.3.1.2. --- Heating temperature --- p.2-3 / Chapter 2.3.1.3. --- Heating duration --- p.2-3 / Chapter 2.3.1.4. --- Substrates --- p.2-4 / Chapter 2.3.2. --- Nitridation of alumina --- p.2-4 / Chapter 2.3.2.1. --- Control experiments without residual A1 --- p.2-5 / Chapter 2.4. --- Methods of characterization --- p.2-6 / Chapter 2.4.1. --- Morphology --- p.2-6 / Chapter 2.4.2. --- Phase and micro structures --- p.2-7 / References --- p.2-8 / Figures --- p.2-9 / Chapter Chapter 3. --- Fabrication of alumina nanobelts / Chapter 3.1. --- Introduction --- p.3-1 / Chapter 3.2. --- General morphologies --- p.3-1 / Chapter 3.3. --- Microstructural analysis --- p.3-2 / Chapter 3.4. --- Effects of heating environments --- p.3-3 / Chapter 3.5. --- Effects of heating temperatures --- p.3-3 / Chapter 3.6. --- Effects of heating duration --- p.3-5 / Chapter 3.7. --- Effects of substrate orientation --- p.3-6 / Chapter 3.8. --- Proposed growth model --- p.3-7 / Chapter 3.8.1. --- Thermodynamic considerations --- p.3-7 / Chapter 3.8.2. --- Molecules impinging model --- p.3-9 / Chapter 3.8.3. --- 2-D nucleation model and surface diffusion --- p.3-11 / References --- p.3-14 / Figures --- p.3-16 / Chapter Chapter 4. --- Nitridation of alumina / Chapter 4.1. --- Introduction --- p.4-1 / Chapter 4.2. --- Effects of heating temperature in Nitrogen --- p.4-1 / Chapter 4.3. --- Nitridation with ammonia --- p.4-3 / Chapter 4.4. --- Removal of residual A1 powder --- p.4-4 / Chapter 4.5. --- Chemical reactions and the growth model --- p.4-6 / Chapter 4.5.1. --- Preferential nitridation --- p.4-6 / Chapter 4.5.2. --- Formation of γ-AlON nano-particles --- p.4-8 / References --- p.4-10 / Figures --- p.4-11 / Chapter Chapter 5. --- Conclusions and future works / Chapter 5.1. --- Conclusions --- p.5-1 / Chapter 5.2. --- Future works --- p.5-2

Reciprocating biofilters known as ReCip is a viable technology to manage nutrients, mainly nitrogen, problems at livestock operations such as swine farms and dairies. Past studies have demonstrated that ReCip is more adept at total nitrogen (TN) removal than traditional subsurface flow wetland systems. The traditional substrate used to attach biomass was rock aggregate; this media may be hard to obtain for some agricultural projects, so alternate substrates are tested and compared with the rock aggregate. The purpose of the study was twofold: first, different biofilm media were tested and compared in terms of treatment performance and, second, the long-term performance of a ReCip in continuous operation for 3 years was characterized. Four, 2.67 square meter ReCip systems with different treatment media – rock aggregate, recycled concrete aggregate (RCA), vertical-flow plastic media, and walnut shells – were operated at a 2-day THRT over the course of a 16 week study. The TN removal efficiencies for rock aggregate, RCA, plastic media, and walnut shell media were 43%, 53%, 25%, and 69% respectively. Surface based mass TN removal rates for the same media were 103, 128, 172, and 276 kg/ha-d respectively. A 134.2 square meter ReCip with rock aggregate media was running concurrently with the smaller ReCip systems. This ReCip was constructed ant operated since January 2010. TN removal efficiency and mass removal rate were 44% and 105 kg/ha-day. These values were close to results from the smaller rock media system.

Nutrient inputs from productive marine environments have been shown to directly and indirectly subsidise primary producers and consumers in terrestrial ecosystems (e.g. Polis and Hurd 1995; 1996; Anderson and Polis 1998; 1999). But does this theory hold true on islands surrounded by oligotrophic waters, which account for a significant proportion of the marine environment? The aim of the present study was to examine the applicability of the spatial subsidisation hypotheses proposed by Polis and his co-authors to an oligotrophic system in south-western region of Western Australia. These aims were achieved by comparing soil and plant nutrients, and the nitrogen stable isotope signatures of soil, plants, detritus and invertebrates in areas with (islands) and without (mainland sites) inputs from seabirds. In addition, the responses of plant nutrients and vegetation assemblages to guano additions were examined in a controlled field experiment.

This thesis describes investigations into the metal-mediated formation of nitrogen-carbon bonds from hydrazines and alkynes. Rh, Ir, Ru and Os metal complexes containing bidentate P,N- and N,N-donor ligands were all studied during the course of this work. A series of stereoisomers of metal complexes of general formula MCl2(PyP)2 (where M = Ru and Os, PyP = 1-(2-(diphenylphosphino)ethyl)pyrazole) (2.01-2.05) were synthesised. The isomerisation process of complexes 2.01-2.05 in solution was investigated. The ruthenium complex RuCl2(CO)(1-P-PyP)(2-P,N-PyP) (2.14), which contains one pendant PyP ligand bound through the P-donor ligand was synthesised, confirming the potential hemilability of the mixed P,N-donor ligand PyP. Chloride abstraction from the ruthenium complex trans,cis,cis-RuCl2(PyP)2 (2.01) was achieved using either a sodium or silver salt to yield the dimeric complexes of general formula [Ru(μ-Cl)(PyP)2]2[X]2 (where M = Ru, X = OSO2CF3 (2.06), BF4 (2.07), BPh4 (2.08), and BArF 2.09). [Os(μ-Cl)(PyP)2]2[BPh4]2 (2.10) was synthesised from sodium tetraphenylborate and trans,cis,cis-OsCl2(PyP)2 (2.04). The reactivity of dimeric complexes 2.06 and 2.08 towards substituted hydrazines was investigated. The methylhydrazine complex [Ru(PyP)2(NH2NHMe)][Cl][BPh4] (3.12) was synthesised. The methylhydrazine adduct of 3.12 binds to the metal centre in an end-on fashion via the NH2 group in solution, and in a bidentate fashion in the solid-state. This is the first reported example of a ruthenium complex containing a bidentate hydrazine ligand. The ruthenium-vinylidene complexes [RuCl(Me2PyP)2(=C=C(H)Ph)]BPh4 (4.15) and [RuCl(Me2PyP)2(=C=C(H)n-Bu)]BPh4 (4.16) (Me2PyP = 1-(2-(diphenylphosphino)ethyl)-3,5-dimethylpyrazole) were synthesised from trans,cis,cis-RuCl2(Me2PyP)2 (4.10) and the appropriate terminal alkyne. The reaction of alkynes with ruthenium complexes containing the PyP ligand was also investigated. Nitrogen-carbon bond formation was achieved through reaction of mono-substituted hydrazines with 4.06 and 4.07 to yield complexes of general formula [RuCl(1-P-Me2PyP)(2-P,N-Me2PyP)(2-N,C-(NH2N(R2)C(CH2R1)]BPh4 (where R1 = R2 = Ph (4.19), R1= Ph, R2 = Me (4.20), R1 = n-Bu, R2 = Ph, (4.21) or R1 = n-Bu, R2 = Me (4.22)). The mechanism of the formation of the stable metallocyclic complexes 4.19-4.22 was elucidated through studies of the reactivity of 4.15 towards a series of amines and hydrazines and relies on the labile nature of the N-donor of the P,N-donor ligand Me2PyP. A method for the synthesis of triflate complexes of rhodium Rh(PyP)(CO)(OSO2CF3) (5.13) and Rh(PyPhP)(CO)(OSO2CF3) (PyPhP = 1-(2-(diphenylphosphino)phenyl)pyrazole) (5.14) from rhodium chloride complexes was developed. The solid-state structure of rhodium triflate complex 5.14, which contained the more sterically rigid ligand PyPhP, exhibited a much greater distortion from the ideal square planar geometry than the rhodium analogue 5.13 which contains the PyP ligand. The triflate group of 5.13 and 5.14 was displaced by substituted hydrazines to yield new hydrazine complexes of rhodium. A series of Rh and Ir complexes with bidentate P,N- and N,N-donor ligands were found to catalyse the intermolecular hydroamination of alkynes with hydrazines. [Ir(bpm)(CO)2]BArF (6.08) was found to be the most efficient catalyst of those studies for this transformation, and was amongst the most efficient catalysts reported to date for this transformation. The influence of counter-ion was highly significant in the catalysed intermolecular hydroamination reaction. The substrate scope of the intermolecular hydroamination of alkynes with hydrazines was investigated using [Ir(bpm)(CO)2]BArF (6.08) as the catalyst.

This thesis consists of three manuscripts describing ecophysiological research on the cyanolichen Lobaria oregana. The first manuscript includes a re-evaluation of the assumptions underlying past estimates of N fixation by this species and provides an estimate of annual N fixation at the Wind River Canopy Crane (WRCC). Based upon litterfall data, canopy biomass data, N content of lichen tissue, and published growth rates, L. oregana fixes 0.4-1.6 kg N₂ ha⁻¹ yr⁻¹. The second manuscript presents a series of physiological response curves and a model of N fixation by L. oregana. Temperature is the most important parameter controlling nitrogenase activity in hydrated thalli. The model is used to predict annual N fixation at the WRCC and at the H.J. Andrews (HJA) Experimental Forest. Lobaria oregana fixes 1.4-1.8 kg N₂ ha⁻¹ yr⁻¹ at the WRCC, and low winter temperatures often inhibit nitrogenase activity. Temperatures at the HJA are slightly warmer during the winter, and L. oregana fixes 2.6-16.5 kg N₂ ha⁻¹ yr⁻¹ depending on its stand-level biomass. The third manuscript investigates the effects of thallus water content, light, and temperature on CO₂ exchange in L. oregana. This species shows a typical photosynthetic response upon rehydration, and like other lichens it becomes light-saturated at low PAR levels. Positive net photosynthesis in L. oregana occurs only between 1-12°C. High respiration rates prevent carbon gain at warmer temperatures. The temperature constraints on carbon gain and nitrogen fixation may explain some of the landscape distribution patterns of L. oregana. / Graduation date: 2002

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983. / Includes bibliographical references (p. 268-279).

Intensive biomass production in emerging bioenergy systems could increase nonpoint-source sediment and nutrient losses and impair surface and groundwater quality. Recycling biochar, a charcoal byproduct from pyrolysis of biomass, provides potential sources of mineral nutrients and organic carbon for sustaining biomass productivity and preserving soil and water. Yet, research is needed to verify that recycling of pyrolysis biochars will enhance crop growth and soil and environmental quality similar to black carbon or biochar derived from burning of biomass in tropical or Terra Preta soils. The experimental design of this study consisted of 3 replications and four biochar rates (0, 4, 16, and 64 Mg ha-1) incorporated in both a sandy loam and clay soil with and without fertilizer sources of N, P, and K. The sandy loam and clay soils were studied in separate experiments within a set of 24 box lysimeters seeded with switchgrass. Simulated rain was applied at 50 percent and 100 percent establishment of switchgrass for each soil type. Runoff and leachate were collected and analyzed for total and dissolved N, P, K and organic C. After the second rain event, each soil type and the accumulated switchgrass was sampled and analyzed. In the Boonville soil, biochar applied at 64 Mg ha-1 decreased switchgrass emergence from 42 percent to 14 percent when compared to soil alone. In the Burleson soil, 64 Mg ha-1 biochar had no effect (P > 0.05) on biomass production or leaf area index (LAI). Fertilizer N, P, and K had no effect (P > 0.05) on switchgrass emergence for either soil, but did increase (P < 0.001) N, P, and K uptake, biomass production, and LAI. Increasing rates of biochar increased (P < 0.001) runoff concentrations of DRP during each rain event for both the Boonville and Burleson soils. Four rates of biochar receiving supplemental N, P, and K fertilizer also resulted in greater runoff concentrations of DRP. Emergence tests under increased heat showed electrical conductivities of soil-water solutions to be as high as 600 microS cm-1, even after biochar was washed with acetone and water to remove residual oils and tars and soluble salts. Increasing biochar rates decreased soil bulk density and increased pH and SOC in the 0- to 5-cm depth of soil. As a result of high nutrient recovery during pyrolysis (58 percent of total N, 86 percent of total P and 101 percent of total K), high rates of biochar applied at 64 Mg ha-1 increased mass losses of TN, TP, and TK from both soils. Yet, the mass balance of nutrients showed a surplus of N, P, and K at 64 Mg ha-1 biochar, which suggests some nutrient inputs are not plant available and remain in soil. Careful management of biochar, especially at high rates with these high nutrient contents, is critical when trying to improve soil fertility while protecting water quality.