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Air -- water partitioning of volatile organic compounds and greehouse gases in the presence of saltsFalabella, James Benjamin. January 2007 (has links)
Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2008. / Teja, Amyn S., Committee Chair ; Frederick, James, Committee Member ; Wine, Paul H., Committee Member ; Eckert, Charles A., Committee Member ; Nenes, Athanasios, Committee Member.
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Advantages of using the ANSI/ASHRAE 110-1995 tracer gas test method vs. the ANSI/AIHA Z9.5-1992 face velocity test method for the chemical laboratory hood certificationFahim, Mahdi. January 2006 (has links)
Thesis (M.S.)--University of Toledo, 2006. / "In partial fulfillment of the requirements for the degree of Master of Science in Occupational Health." Major advisor: Sheryl Milz. Includes abstract. Document formatted into pages: iv, 66 p. Title from title page of PDF document. Title at ETD Web site: Advantages of using the ANSI/ASHRAE 110-1995 tracer gas test method versus the ANSI/AIHA Z9.5-1992 face velocity test method for chemical laboratory hood certification. Bibliography: pages 58-61.
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Phosphinimines as potential technetium environmental sensorsArrigo, Leah M., January 2007 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 4, 2007) Vita. Includes bibliographical references.
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Occupational exposure to ultrafine particles and polycyclic aromatic hydrocarbons from candle emissionsSilver, David J. January 2005 (has links)
Dissertation (Ph.D.)--University of South Florida, 2005. / Includes vita. Title from PDF of title page. Document formatted into pages; contains 99 pages. Includes bibliographical references.
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Evaluation of the use of algae for bioremediation of toxic metal pollutantsIbuot, Aniefon January 2015 (has links)
Metal pollution has been a great challenge in most industrialized countries as a result of waste generated from industrial activities being introduced into the environment. Unicellular green algae have been considered a potential biological tool for bioremediation of metal pollutants due to its metal sequestration properties. However, methods for further improving unicellular green algae metal sequestration by manipulating metal uptake and tolerance in unicellular green algae have not been studied in detail. In this study, a family metal transport protein named MTP1 - MTP4 from C. reinhardtii were screened by yeast heterologous expression for metal transport activity. MTP1 was able to strongly rescue the Zn and Co sensitivity of the zrc1cot1 strain, MTP3 could weakly mediate Zn and Co growth, but MTP2 and MTP4 appeared to have no Zn or Co tolerance activity. MTP2, MTP3 and MTP4 but not MTP1 could strongly rescue the Mn sensitivity of the pmr1 strain. When MTP4 was over-expressed in C. reinhardtii the strain showed a significant increase in Cd tolerance compared to the wild type, but no significant difference in Mn tolerance and uptake. AtHMA4 a Zn2+ and Cd2+ transporter from the plant Arabidopsis thaliana, which is a member of the Heavy Metal ATPase family, was also expressed in C. reinhardtii. HMA4 full length and C-terminal tail expression strains were screened for Zn and Cd tolerance and uptake. Both sets of strains showed a significant increase in Cd and Zn tolerance and uptake compared to the wild type. Metal tolerance and uptake was compared between the genetically engineered C. reinhardtii strains and unicellular green algal strains that are naturally adapted to metal tolerance which were P. hussi, P. kessleri, and C. luteoviridis. Results showed significant increase in Zn and Cd tolerance and uptake in the natural strains compared to the engineered strains. Therefore in addition to genetically engineered strains, naturally adapted strains could also be used as tools for effective metal bioremediation and pollutant treatment.
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Spatial and seasonal distribution of selected persistent organic pollutants and phenolic derivatives along the course of the Buffalo River in the Eastern Cape Province of South AfricaYahaya, Abdulrazaq January 2017 (has links)
Persistent organic pollutants (POPs) fall under a group of synthetic chemicals known for their persistence in environmental matrices such as soil and water, and are used in industrial, domestic and agricultural applications. Because of their volatility and lipophilicity, POPs can be transported far away from their point sources and bio-accumulate in food and in fatty tissues of humans and animals. In view of their toxicity and carcinogenicity some organic pollutants such as polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs) and phenolic derivatives (chlorophenol and nitrophenol) have been classified by United State Environmental Protection Agency (USEPA) and World Health Organization (WHO) as priority pollutants. The present work evaluated the distribution patterns of 19 polychlorinated biphenyls congeners, 17 organochlorine pesticides and selected phenolic derivatives (USEPA 11-priority pollutants) in the Buffalo River, in the Eastern Cape Province, South Africa between December 2015 and May 2016. The Liquid-liquid extraction technique was used for PCBs, OCPs and phenolic derivatives in the river water samples. Silica gel and florisil clean up were carried out for PCBs and OCPs samples respectively and analyzed with gas chromatography electron capture detector (GC/ECD). Phenolic compounds were derivatized and analyzed by gas chromatography mass spectrometer (GC/MS). Limits of detection (LOD), limit of quantitation (LOQ) and relative standard deviation (RSD) for the PCBs were 10 to 330 ng/L, 20 to 1,060 ng/L and 1.18 to 14.1 percent respectively. The LOD, LOQ and RSD for the OCPs were from 20 - 60 ng/L, 110 - 530 ng/L and 0.02 - 0.06 percent, while the corresponding values for the phenolic derivatives were 10 to 70 ng/L, 33 to 222 ng/L and 1.99 - 10.86 percent. In summer, the concentrations of PCBs, OCPs and phenolic derivatives ranged from <LOD to 482 ng/L, <LOD to 4,403 ng/L and <LOD to 1,546 ng/L respectively, while in autumn they were from <LOD to 2,383 ng/L, <LOD to 858 ng/L and <LOD to 713 ng/L in that order. Also, in summer, the level of occurrence of total PCB congeners detected at the various sampling sites were Buffalo River Estuary (BRE) 11 percent, Mdantsane (MSN) 16 percent, Zwelitsha (ZW) 26 percent, King William’s Town (KWT) 47 percent, Izele (IZ) 32 percent, and Maden (MD) 21 percent. The level of occurrence of total OCPs at BRE was 65 percent, at MSN 65 percent, at ZW 82 percent, at KWT 47 percent, at IZ 29 percent, and at MD 18 percent. The level of occurrence of total phenolic derivatives at BRE was 63 percent, at MSN 63 percent, at ZW 54 percent, at KWT 63 percent, at IZ 63 percent, and at MD 54 percent. In autumn, the level of occurrence of total PCBs at BRE was 68 percent, at MSN 16 percent, at ZW 42 percent, at KWT 26 percent, at IZ 47 percent, and at MD 0 percent. The level of occurrence of total OCPs at BRE was 65 percent, at MSN 53 percent, at ZW 41 percent, at KWT 35 percent, at IZ 53 percent, and at MD 18 percent. The level of occurrence of total phenolic derivatives at BRE was 63 percent, at MSN 63 percent, at ZW 54 percent, at KWT 18 percent, at IZ 18 percent, and at MD 45 percent. In summer, the levels of PCBs in all sampling sites were below WHO recommended maximum permissible levels (500 ng/L) for humans but in autumn the levels were above the recommended values in all the sites except MD. The cancer risk assessment values were above permissible 10-6 while hazard quotients were above the USEPA maximum limits of unity. OCPs levels were above the USEPA limits (100 ng/L) in all sampling locations in both seasons. The cancer risk assessment values were below permissible 10-6 but hazard quotients were above the USEPA maximum limits. Phenolic derivatives were also above the USEPA maximum permissible limit (500 ng/L) in most of the sampling locations in summer whereas during autumn the values were notably below the permissible limit at ZW, KWT, IZ and MD. The cancer risk assessment values and hazard quotients were above USEPA maximum limits of 10-6 and unity respectively. Conclusively, the results of this study reveal that the pollutants were present in the river at concentrations higher than the tolerable limit for human and wildlife and thereby may constitute a serious risk to public health. Therefore, it is recommended that proper regulation of the use of the compounds and their safe disposal be ensured to protect aquatic resources and the well-being of humans.
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Polychlorinated biphenyl exposure reduces reproductive performance of male bluegills (Lepomis macrochirus)Hillis, Jeffrey Jackson 01 December 2013 (has links)
Endocrine disrupting chemicals in wild animals, including fish, can disrupt reproduction by causing intersexuality. Organic pollutants, specifically polychlorinated biphenyls (PCBs), have been shown to be estrogenic or anti-androgenic likely contributing to intersexuality in males. Organic pollutants persist in the environment despite being restricted for use in the United States. Bluegills, Lepomis macrochirus, play a crucial role in lake food webs as forage and sport fish and may be affected by PCBs. In the current study, male bluegills collected in 2010 from selected Illinois lakes were analyzed to quantify PCB body residues and the incidence of intersexuality (n=200). Experiments were then conducted in 2011 and 2012 to assess the reproductive output of mature males with varying PCB body residues paired with mature females containing no detectable PCB body residues held in uncontaminated 0.05-hectare research ponds (Southern Illinois University Touch of Nature Pond Facility). Lake-specific male bluegill whole-body tissue PCB body residues ranged from below reporting limit to 2 mg/kg dry weight (non-lipid normalized basis) and varied significantly among lakes (F7,32= 9.59, p<0.0001). No male intersex bluegills were found. In both reproductive experiments, abundance of young declined as male PCB body residues increased (F 4,18 = 13.28; P=0.002). Adult survival was unrelated to reproductive output. Taken together, these results suggest PCBs, which are ubiquitous in aquatic and terrestrial habitats, have the ability to alter male reproductive performance, and possibly population dynamics and community structure through reduced recruitment, in the absence of overt intersexuality.
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Inlet monitoring of a potable water supply using a sensor arrayHogben, Peter James January 2003 (has links)
Monitoring for pollutants in potable water is an area of interest and concern for water supply companies. Supply of sub-standard water can draw complaints from public and industrial customers. Water and water tainted with pollutants were used to assess the application of a non-specific chemical sensor array (eNose) to monitor for changes in the headspace generated from a flow-cell by means of statistically designed experiments. 2-chlorophenol and diesel were used to further assess trends in headspace generation during trials where different combinations of sampling parameters were applied. Field trials were conducted in accordance with the most suitable methodology determined during initial studies under laboratory conditions. The headspace is generated by bubbling nitrogen through the flow-cell containing a water sample. The liquid sample is flushed and regenerated after each sensor acquisition cycle. The resultant headspace sample is transferred to the sensor array module where the resistance of the conducting polymer sensors is monitored as they are exposed to each respective headspace sample. The change in each sensor resistance after 60 seconds of exposure is used to represent the headspace character. Subsequent acquisitions are added to a data set and then presented graphically. Sudden changes in the sensor resistance plots represent changes in water quality. The results showed that the developed apparatus and sampling methodology can determine the presence or absence of pollution in a water matrix. Laboratory analysis showed that detection levels for 2-chlorophenol and diesel were both <5 ppm in the mixed stream. Future developments should focus on increasing the sensitivity of the system by concentrating the pollutants in either the liquid or gas phase or by modifying the sampling protocol to enable sensor recognition at lower concentration levels. The sensor array could act as a screening technique to support quantitative and characterising analytical equipment at the abstraction point. Establishing a pollution alarm limit, within the bounds of acceptable system variation, would enable conventional analytical techniques to remain on standby until activated by a statistically significant change in water quality. Once established continued testing would enable alarm levels to be incorporated into a contaminant database for additional pollutant compounds and combinations of known taste and odour causing compounds.
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Phototransformation of pollutants using lutetium and zinc phthalocyanines anchored on electrospun polymer fibersZugle, Ruphino January 2013 (has links)
Novel lanthanide phthalocyanines containing dysprosium, erbium and lutetium as central metals were synthesized using phthalonitrile:metal salt ratio of 4:1 or lower phthalonitrile content as well as using unmetallated phthalocyanine. They were characterized using various spectroscopic and elemental analyses. Dysprosium bis-phthalocyanine was obtained while monomers were obtained for erbium and lutetium phthalocyanines. Theopen-shelldysprosiumbis-phthalocyanine and the monomeric complex of the open-shell erbium were neither fluorescent nor showed the ability to generate singlet oxygen. The triplet states of all the lutetium phthalocyanines were found to be populated with high triplet quantum yields and corresponding high singlet oxygen quantum yields. The fluorescence quantum yields of the lutetium phthalocyanines were however found to be very low. The lutetium phthalocyanines together with unsubstituted zinc phthalocyanine and its derivatives were successfully incorporated into electrospun polymer fibers either by covalent linkage or sorption forces. Spectral characteristics of the functionalized electrospun polymer fibers indicated that the phthalocyanines were bound and their integrity maintained within the fiber matrices. Most importantly the fluorescence and photoactivity of the phthalocyanines were equally maintained within the electrospun fibers. The functionalized electrospun polymer fibers especially those containing the zinc phthalocyanines could qualitatively detect nitrogen dioxide, a known environmental air pollutant. Also all the functionalized electrospun polystyrene and polysulfone fibers containing lutetium and zinc phthalocyanines could be applied for the photoconversion of 4-chlorophenol, 4-nitrophenol and methyl orange. Those of polystyrene could be re-used. Polyacrylic acid and polyurethane functionalized electrospun fibers were found not to be suitable for photocatalytic applications in aqueous medium. 4-Chlorophenol was found to be more susceptible to photodegradation while methyl orange very difficult to degrade.
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Environmental Releases of Neonicotinoid and Fipronil Insecticides via U.S. Wastewater InfrastructureJanuary 2017 (has links)
abstract: This dissertation is focused on environmental releases from U.S. wastewater infrastructure of recently introduced, mass-produced insecticides, namely neonicotinoids as well as fipronil and its major degradates (sulfone, sulfide, amide, and desulfinyl derivatives), jointly known as fiproles. Both groups of compounds recently have caught the attention of regulatory agencies worldwide due to their toxic effects on pollinators and on aquatic invertebrates at very low, part-per-trillion levels (Chapter 1). Mass balance studies conducted for 13 U.S. wastewater treatment plants (WWTPs) showed ubiquitous occurrence (3-666 ng/L) and persistence of neonicotinoids (Chapter 2). For the years 2001 through 2016, a longitudinal nationwide study was conducted on the occurrence of fiproles, via analysis of sludge as well as raw and treated wastewater samples. Sludge analysis revealed ubiquitous fiprole occurrence since 2001 (0.2-385 µg/kg dry weight) and a significant increase (2.4±0.3-fold; p<0.005) to elevated levels found both in 2006/7 and 2015/6. This study established a marked persistence of fiproles during both wastewater and sludge treatment, while also identifying non-agricultural uses as a major source of fiprole loading to wastewater (Chapter 3). Eight WWTPs were monitored in Northern California to assess pesticide inputs into San Francisco Bay from wastewater discharge. Per-capita-contaminant-loading calculations identified flea and tick control agents for use on pets as a previously underappreciated source term dominating the mass loading of insecticides to WWTPs in sewage and to the Bay in treated wastewater (Chapter 4). A nationwide assessment of fipronil emissions revealed that pet products, while representing only 22±7% of total fipronil usage (2011-2015), accounted for 86±5% of the mass loading to U.S. surface waters (Chapter 5). In summary, the root cause for considerable annual discharges into U.S. surface waters of the neonicotinoid imidacloprid (3,700-5,500 kg/y) and of fipronil related compounds (1,600-2,400 kg/y) is domestic rather than agricultural insecticide use. Reclaimed effluent from U.S. WWTPs contained insecticide levels that exceed toxicity benchmarks for sensitive aquatic invertebrates in 83% of cases for imidacloprid and in 67% of cases for fipronil. Recommendations are provided on how to limit toxic inputs in the future. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2017
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