The use of Positive Matrix Factorization (PMF) in pollution source apportionment (PSA) is examined and illustrated. A study of its settings is conducted in order to optimize them in the context of PSA. The use of a priori information in PMF is examined, in the form of target factor profiles and pulling profile elements to zero. A Bayesian model using lognormal prior distributions for source profiles and source contributions is fit and examined.

We describe a method to estimate pollution profiles and contribution levels for distinct prominent pollution sources in a region based on daily pollutant concentration measurements from multiple measurement stations over a period of time. In an extension of existing work, we will estimate common source profiles but distinct contribution levels based on measurements from each station. In addition, we will explore the possibility of extending existing work to allow adjustments for synoptic regimes—large scale weather patterns which may effect the amount of pollution measured from individual sources as well as for particular pollutants. For both extensions we propose Bayesian methods to estimate pollution source profiles and contributions.

High technology industries have stringent on clean room environment. Traditional ballroom type clean room can¡¦t meet the requirement in many cases. The uni-directional laminar ballroom type cleanroom is can¡¦t fulfill such requirement. The adoption of Mini-Environment technology is becoming the mainstream of the environment control technology for high technology industries process. It is the goal of this project to simulate and design the air flow pattern, in using the current injection machine as a model, to achieve the cleanliness of class 1,000 ¡V 10,000. There are four major steps in achieving this goal, Namely: 1¡BThe dynamic 3D CFD simulation of the flow pattern of the clean bench. 2¡BThe evaluation of the pollution source and its impact on the overall cleanliness 3¡BThe basic design of the class 1,000 cleanroom for this machine 4¡BThe modification necessary to achieve this goal through design iterations. The results of this research are useful in the understanding of the flow characteristics in a mini-environment. The buffer zone of laminar flow was found to be effective to avoid cross contamination with the outside environment during door opening. The height of the processing opening of the mini-environment is found to be an important factor on the flow turbulent intensity and particle concentration. Concentration due to an operator can also be reduced by this buffer zone. The numerical techniques developed can also be used as numerical models in future studied.

Understanding the effect of human-induced pollution on the environment is an important precursor to promoting public health and environmental stability. One aspect of understanding pollution is understanding pollution sources. Various methods have been used and developed to understand pollution sources and the amount of pollution those sources emit. Multivariate receptor modeling seeks to estimate pollution source profiles and pollution emissions from concentrations of pollutants such as particulate matter (PM) in the air. Previous approaches to multivariate receptor modeling make the following two key assumptions: (1) PM measurements are independent and (2) source profiles are constant through time. Notwithstanding these assumptions, the existence of temporal correlation among PM measurements and time-varying source profiles is commonly accepted. In this thesis an approach to multivariate receptor modeling is developed in which the temporal structure of PM measurements is accounted for by modeling source profiles as a time-dependent Dirichlet process. The Dirichlet process (DP) pollution model developed herein is evaluated using several simulated data sets. In the presence of time-varying source profiles, the DP model more accurately estimates source profiles and source contributions than other multivariate receptor model approaches. Additionally, when source profiles are constant through time, the DP model outperforms other pollution receptor models by more accurately estimating source profiles and source contributions.

This study aims to determine the concentration of 16 Polycyclic Aromatic Hydrocarbons (PAHs) in urban soils from West Yorkshire in order to determine what the factors are controlling their distribution and abundances. Although PAHs have been reported before from soils and sediments, the majority of these studies have come from China, sometimes with contrasting results, which emphasises the need to obtain equivalent data from other areas. Therefore this work provides the first measurements of their type from the area studied. Soil samples were collected from one hundred sites across an area from Bradford to Leeds on two occasions, one in autumn and one in the following summer. The soil samples were analyzed by X-ray diffraction and all found to have similar mineralogical composition, which was mainly silica and calcite. Trials using iodine as a marker for PAHs showed there were notable interactions between the minerals and PAHs, with calcium carbonate absorbing PAHs much more than silica. There is a negative correlation between the soil organic content (determined by loss on ignition) and PAHs, which confirms the PAH-mineral interaction. Gas chromatography with mass spectrometry (GC-MS) using targeted selected ion monitoring was used to determine and quantify PAHs in the one hundred soil samples with the aid of PAH external standards. The results showed highest concentrations of total PAHs in the same sample from Leeds from the autumn (1,525 ng/g) and in the summer (1,768 ng/g). In Bradford there was only moderate pollution of PAHs, the maximum being 122 ng/g. However the majority of data from Bradford showed lower levels of pollution in both summer and autumn. On the basis of prior published information, the ratio of these compounds has been used to help in identifying sources. In the samples collected from Bradford in both seasons and Leeds in autumn the PAH pollution originated from pyrogenic, biomass and petroleum combustion, however in the summer the source appeared more to be from a petrogenic source. These ratios in the samples which were collected from the area between Bradford and Leeds implied pyrogenic, biomass source of pollution in the autumn, but in the summer another source of organic compounds was indicated namely petroleum combustion. When the locations were resampled nine months later, after taking into account within-site variability, there was a strong indication that the PAH concentrations were higher. This might have been due to a seasonal effect, but when a further (third) subsample was taken at a later date it showed a further increase in PAH level which suggests the effect is accumulative rather than seasonal. The results were analysed using Principal Component Analysis (PCA) to determine whether the type of road had an effect on the concentration of the 16 PAHs compounds, but it was concluded that there was no such effect. However, the distance from the soil sample to the nearest road did have an effect on the concentration of the 16 PAH compounds, especially in soil samples having the shortest distance to the road. Traffic volume was also tested and found to influence the PAH concentrations. It is notable that, comparing the groupings from autumn with those from summer by cluster analyses, they largely had the same compounds grouping together in both cases; only two compounds differed at all in where they occurred in the clusters, with consistent patterns of grouping found for the other compounds. These analyses indicate that PAH compounds behave in a consistent way amongst groups of PAH compounds. The grouping of PAHs appears linked to their sources rather than number of rings or molecular weight. / Libyan Government and Embassy

機動車輛已成為空氣污染的首要污染來源之一，其所排放大量的一氧化碳、二氧化碳對地方乃至於全球環境皆造成不利的影響。為了因應環境污染與溫室效應，各國除了採取行政管制措施外，亦引進經濟誘因工具來落實污染者付費的原則。本研究的目的即是探討，台灣地區目前所實施的政策工具對於減少來自移動污染源的污染排放量的有效性。 本文利用台灣地區二十三個縣市 1998 年至 2006 年共九年的追蹤資料，以兩種模型進行實證：第一個模型採用的是一階差分後的普通最小平方法迴歸模型，可避免假性迴歸的問題發生；第二個模型為似不相關迴歸模型，藉由誤差項間的關聯性來結合北部、中部、東部、南部四個地區的迴歸式，觀察政策工具在不同區域間對污染減量的效果。 實證結果顯示，管制與稅費這兩種政策工具確實會對移動污染源產生的空氣污染有相當的抑制效果；但是相較之下，管制措施的影響力相對於稅費的徵收來得明顯。因此，已知管制工具具有環境保護的政策有效性外，若欲使得稅費政策對空氣污染減量也有更明顯的成效，便應實施綠色租稅改革，以期能夠對生活環境產生良好的改善。 / Due to its high share in total air pollutant emissions, mobile pollution source is an issue of particular consideration. Vehicles produce large volumes of emissions such as CO, CO2, and so on. These gases can be detrimental to local, regional and global environment. With the increasing concern over rising pollution levels and greenhouse effect, the purpose of this study is to evaluate the effectiveness of different environmental policy instruments which are used to reduce mobile source air pollution. 　　For this paper, a case study of Taiwan is demonstrated for the estimation. Using the first-differenced panel data collected from 1998 to 2006, we use two models, namely “Ordinary least square model” and “Seemingly unrelated regression model” to investigate whether the command and control policy or the economic-incentive tax strategy is better for emission abatement. The first-differenced ordinary least square model can be used to avoid spurious regression, and the seemingly unrelated regression system integrates four sub-equations by assuming their disturbances are correlated, explaining some phenomenon in different areas. 　　The result shows that both control and tax strategies are worthwhile to be adopted. However, regulation policy results in cutting down much more CO and CO2 than using the excise taxes and fuel fees as an environmental instrument. Therefore, we conclude that it is required to implement the green tax system reform in order to create beneficial changes in our life.

Environmental pollution has become a global concern as consequence of industrializa-tion and urbanization. The ongoing subsurface contamination by dense non-aqueous phase liquids (DNAPLs) bears tremendous hazardous potential for humans and ecosys-tems including aquifer systems. Intended or accidental spill events have led to a vast number of registered sites affected by DNAPL type chemicals. Despite the existence of novel techniques for their exploration, characterization and remediation, economical constraints often limit efforts for risk prevention or reduction, so that information and data to characterize highly complex DNAPL contamination scenarios are often insuffi-cient and compensated by natural attenuation of groundwater-dissolved contaminant plumes. Especially, knowledge on the DNAPL source zone geometry (SZG) and source zone formation are critically required yet very scarce. Against the previously stated background, this cumulative doctoral dissertation critically examined the processes of DNAPL source zone formation at laboratory scale. A comprehensive literature review identified current limitations and open research questions in the latter research field, revealing evidence for the relevance of SZG for plume response at different scales. Giv-en only a limited number of published studies related to DNAPL source zone formation, two simplified experimental setups mimicking source zone formation in an initially fully water-saturated aquifer were developed and intensively tested. The performance of aqueous and non-wetting phase dyes was evaluated for DNAPL release into three non-consolidated porous media using reflective optical imaging in combination with a cus-tom-made image processing and analysis (IPA) framework. The latter suite allowed for the generation of physically plausible DNAPL saturation distributions with determinable level of uncertainty. Then, a limited number of DNAPL release experiments were per-formed under controlled ambient as well as with boundary and initial conditions to generate robust observation data, while further adopting the IPA framework. The latter data was introduced into a numerical multiphase flow model. While most system pa-rameters could be directly determined, the parameters defining the capillary pressure-saturation and relative permeability-saturation retention curves were inversely deline-ated through a classical Monte Carlo analysis. Overall, the successfully calibrated nu-merical setup mimicking the transient DNAPL source zone formation allowed to quanti-fy uncertainties related to the experiment, IPA framework and model setup configura-tion. In addition, a number of new research questions pointing towards future im-provements of laboratory-scale methodologies to understand DNAPL contamination were derived. Especially in light of numerous existing contaminated sites with unclear history and even more vague future, given by potential impacts through climate change and anthropogenic activity, an increasing need for sophisticated strategies to better un-derstand DNAPL contamination and to reduce hazard potential is expected.:Statement I List of publications II Abstract VI Acknowledgements and funding information IX List of figures XIII List of tables XIV Abbreviations and symbols used in the main text XV 1 Introduction and background 1-1 1.1 Motivation of this thesis 1-1 1.2 Incorporation of this thesis in research projects 1-4 1.3 Definition of objectives and workflow strategy of this thesis 1-5 1.4 Formal structure of this thesis 1-11 2 Existing knowledge on DNAPL contamination 2-1 3 Fundamentals of DNAPL migration in porous media 3-1 3.1 Basic concepts for multiphase flow in porous media 3-1 3.2 Capillary pressure-saturation correlation 3-3 3.3 Relative permeability-saturation correlation 3-5 3.4 Balance equations for laminar fluid phase flow in porous media 3-7 4 Core research complex A : Development of a framework for the semi-automatized generation of DNAPL saturation distribution observation data 4-1 5 Core research complex B : Experimental and model-based simulation of DNAPL source zone formation 5-1 6 Summary and conclusions 6-1 6.1 Summary of perceptions for each main section of this thesis 6-1 6.2 New research questions with regard to DNAPL source zone formation at the laboratory scale 6-5 6.3 General recommendations for future works related to DNAPL contamination 6-8 References Ref-1 Appendix I : ENGELMANN ET AL. (2019a) App I-1 Published journal article App I-1 Appendix II : ENGELMANN ET AL. (2019b) App II-1 Published journal article App II-1 Electronic Supplementary Material 1 : Unprocessed raw TIFF format images used for IPA frame-work evaluation App II-26 Electronic Supplementary Material 2 : Sensitivities for color model change and binary conversion algorithms App II-36 Electronic Supplementary Material 3 :Relevance of spatially non-uniform illumination correction and background exclusion App II-76 Appendix III : ENGELMANN ET AL. (2021) App III-1 Published journal article App III-1 Electronic Supplementary Material 1 : Unprocessed raw TIFF format images for IPA framework ap-plication App III-30 Electronic Supplementary Material 2 : Processed images with all intermediate steps of IPA frame-work application App III-58 Electronic Supplementary Material 3 : IPA fitness App III-86 Electronic Supplementary Material 4 : Partial objective functions App III-87 Electronic Supplementary Material 5 : Model verification App III-93