Digitized by Kansas Correctional Industries

Nitric oxide (NO) is one of the most important air pollutants in atmosphere mainly emitted from combustion exhaust gas. In this research, a biotrickling filter was designed and operated to remove this pollutant from an air stream using bacteria extracted from the sewage sludge of a municipal sewage-treatment plant. The bacteria were cultured and enriched by either petri dish’s cultivation or liquid cultivation. The adsorption capacity of the ceramic material, which was used as the packing material, was determined to be 34 g-NO/L under 37℃. However, the saturated adsorption capacity of the packing material with the recycling solution is 236 mg-NO/L under the operation temperature 37℃.The result suggested that the microporous structure of the ceramic material not the humidity is the main contributor to the ceramic material adsorption capacity. Both the ceramic material adsorption capacity and the removal capacity of the liquid were limited and saturated in 540 min and 2 min operation, respectively. To obtain the best operation conditions for the biotrickling filter, orthogonal experiments (L9 (34)) were designed. The experimental data were analyzed by the signal to noise (S/N) ratio and ANOVA. The optimal conditions of the biotrickling filter occurred at a temperature of 40℃, a pH of 8.00.05 and a chemical oxygen demand (COD) of 165 mg/L in the recycled water with no oxygen in the system. Inlet oxygen concentration was found to be the most significant factor of the biotrickling filter that has a significant negative effect on the NO removal efficiency. The DNA sequencing of four clones of bacteria showed 93-98% similarity to Pseudomonas mendocina strain. This strain has been analysed by full gene sequencing and proved to be a brand-new strain named as Pseudomonas mendocina DLHK. This strain can transfer nitrate to organic nitrogen. This result indicated the assimilation nitrogen process in this system and suggested that the main nitrogen removal capacity in this system was through biological function. Through the isotope experimental analysis, two intermediate products (15NO and 15N2O) have been found during the biological process of the system by using quantitative gas analysis (QGA). These results indicated the denitrification function in this biotrickling filter. A model was developed to explain the biological process in the biotrickling filter. The averaged error of the measured and modeled data is -0.047. The standard deviation of the error is 0.039. The model prediction is in good agreement with the experimental data, particularly at small packing height. Most NO removal capacity was achieved at the first 5 cm packing material. The effects of the axial interstitial velocity and the biofilm coverage to the NO elimination were studied by the model that provided a basic for the design of a biotrickling filter. The biotrickling filter could be used for exhaust gases treatment. The assimilation function in the biological system could be another way to utilize the nitrogen component in the waste gas from harmful to benign nature. The isotope labeling technology is a new method to detect gas components for complex gas samples. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

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published_or_final_version / abstract / Mechanical Engineering / Master / Master of Philosophy

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by Yuk-Lin Chan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 78-83). / Abstracts in English and Chinese. / Abstract (English version) --- p.i / Abstract (Chinese version) --- p.ii / Acknowledgments --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.vii / Chapter 1. --- Introduction / Chapter 1.1 --- Indoor Air Pollution --- p.1 / Chapter 1.2 --- Typical Treatment of Air Pollutant --- p.6 / Chapter 1.3 --- Photocatalytic Degradation over Titanium Dioxide --- p.7 / Chapter 1.4 --- Advantages of Titanium Dioxide as a Photocatalyst --- p.12 / Chapter 1.5 --- Applications of Photocatalytic Degradation in Pollution Control --- p.14 / Chapter 1.5.1 --- Aqueous Phase Decontamination --- p.15 / Chapter 1.5.2 --- Gas Phase Decontamination --- p.15 / Chapter 1.6 --- Development of the Photocatalytic Degradation Technique --- p.16 / Chapter 1.6.1 --- Pure Ti02 --- p.17 / Chapter 1.6.2 --- Design of the Reactors --- p.18 / Chapter 1.6.3 --- Metal Ion Dopants --- p.21 / Chapter 1.6.4 --- Mixture with Supports --- p.21 / Chapter 1.7 --- Adsorbent-Supported Titanium Dioxide --- p.22 / Chapter 1.7.1 --- Use of Adsorbents other than Zeolites --- p.22 / Chapter 1.7.2 --- Use of Zeolites --- p.25 / Chapter 1.8 --- Molecular Sieves --- p.29 / Chapter 2. --- Experimental / Chapter 2.1 --- Block diagram of the Reaction Setup --- p.31 / Chapter 2.2 --- Fixed Volume Batch Reactor --- p.32 / Chapter 2.3 --- Reagents --- p.34 / Chapter 2.3.1 --- Degussa P25 Ti02 powder --- p.34 / Chapter 2.3.2 --- Aldrich Molecular Sieves (Organophilic) --- p.35 / Chapter 2.3.3 --- Other Adsorbents Used for Comparison --- p.35 / Chapter 2.4 --- Instrumental Analysis --- p.36 / Chapter 2.4.1 --- Photoacoustic Multi-gas Monitor --- p.36 / Chapter 2.4.2 --- X-Ray Diffraction Analysis --- p.42 / Chapter 2.4.3 --- Scanning Electron Microscopy --- p.42 / Chapter 2.4.4 --- UV-vis Diffuse Reflectance Spectroscopy --- p.42 / Chapter 2.4.5 --- Iso-electron Point Measurements --- p.43 / Chapter 2.5 --- Photocatalytic Degradation of Simple Alkanes by P25 Titanium Dioxide --- p.45 / Chapter 2.6 --- Photocatalytic Degradation of Gaseous Acetone over Organophilic Molecular Sieves-Supported Titanium Dioxide --- p.49 / Chapter 3. --- Results and Discussion / Chapter 3.1 --- Photocatalytic Degradation of Simple Alkanes by P25 Titanium Dioxide --- p.52 / Chapter 3.1.1 --- Rate of Photocatalytic Degradation of Simple Alkanes --- p.52 / Chapter 3.1.2 --- Summary of Rate of Photocatalytic Degradation of Simple Alkanes --- p.57 / Chapter 3.2 --- Photocatalytic Degradation of Gaseous Acetone over Organophilic Molecular Sieves-Supported Titanium Dioxide --- p.58 / Chapter 3.2.1 --- The Adsorption Ability of Various Adsorbents --- p.58 / Chapter 3.2.2 --- XRD Pattern Measurement --- p.60 / Chapter 3.2.3 --- Scanning Electron Microscopy --- p.64 / Chapter 3.2.4 --- UV-vis Diffuse Reflectance Spectroscopy --- p.65 / Chapter 3.2.5 --- Iso-electron Point Measurements --- p.67 / Chapter 3.2.6 --- Photocatalytic Activity of Various Catalysts --- p.69 / Chapter 4. --- Conclusion --- p.76 / Bibliography --- p.78 / Appendix / "A Demonstration of Photocatalytic Degradation by Gaseous Organic Pollutant, Dichloromethane " --- p.83

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