Fresh beef packaged in high-oxygen modified atmosphere packaging (MAP) has longer red color stability than beef in oxygen-permeable polyvinyl chloride (PVC) film. However, fresh beef in high oxygen becomes rancid by 10 days storage at 2°C. Thus the objective of this study was to evaluate the effectiveness of various antioxidants (milk mineral, MM; sodium tripolyphosphate, STP; vitamin E, E) on color and thiobarbituric acid (TBA) values of ground chuck stored in 80% oxygen MAP for 14 days at 1° C. A preliminary experiment was also done to determine the effect of raw meat history (surface area during storage and storage temperature) on stability of ground beef in 80% oxygen MAP. For the preliminary experiment, select beef clods ( 48 hrs postmortem) were cut 11 into trim or coarsely ground and stored frozen or at 2°C in vacuum packaging (VP) for 30 days. Raw meat was then finely ground and wrapped in PVC film or in 80% oxygen. For experiment 2, fresh beef clods were coarsely ground and antioxidants (0.75 or 1.5% MM; 0.25 or 0.5% STP; 50 or J 00 ppm vitamin E) were added, followed by fine grounding and packaging in 80% oxygen MAP. Thiobarbituric acid assay was performed as a measure of rancidity. Hunter color L*, a*, b* values were measured on raw samples through the packaging film. Trim history greatly affected stability of beef in 80% oxygen MAP. VP refrigerated trim yielded ground beef with low oxidative and color stability compared to frozen trim. In comparison of antioxidants, 0.75% MM gave highest redness values (13-15) and lowest TBA values (< 0.5) after storage of ground beef in 80% oxygen MAP for J 4 days. STP-treated beef also had low TBA values(< 0.5) at 14 days storage but samples were less red (a* of J 0-J 2) than MM- treated samples. Samples with E were slightly better than controls, with redness values of 7.9 and J0.8, respectively. Thus, iron-chelating agents (MM and STP) were very effective for preventing rancidity and improving color stability in ground beef packaged in a high oxygen atmosphere.

The photocatalytic oxidation of trichloroethylene (TCE), ethylene. ethane and toluene on TiO2, Pt/TiO2 and Ag/TiO2 were investigated in a dedicated reactor set-up operated at room temperature and ambient pressure condition. The gas phase experiments were carried out for both single and binary mixtures of these chemicals to identify the role of Pt and Ag metallisation in the photocatalytic oxidation of different contaminants. In a single contaminant system, the presence of Pt enhanced the oxidation of ethylene, ethane and toluene but detrimental to the oxidation of TCE. In the oxidation of ethylene, Pt enhanced the oxidation by acting as catalyst and as electron sink. However, in ethane oxidation, the enhancement was solely associated to the ability of Pt to act as electron sink. The detrimental effect observed in TCE oxidation was attributed to Pt and Cl interaction, which formed a persistent inorganic chlorine species decreasing the overall Pt/TiO2 photocatalyst performance. Interestingly, Ag did not show any significant effect to the oxidation of any single system degradation. In binary system degradation, where TCE and another organic compound either ethylene, ethane or toluene were degraded simultaneously, Pt always caused a detrimental effect due to its strong interaction with Cl. However, the presence of Ag and Cl gives a more synergetic effect. Ag was found to provide sites to temporarily trap chlorine radicals as AgCl. Under illumination, electrons transferred from Cl to Ag forming chlorine radicals that could react with the surface contaminant enhancing its breakdown and mineralization.

Nitrogen is known to be a limiting factor in polluted environments, however many studies overlook the potential role for nitrogen to significantly influence the removal rate and efficiency with which microorganisms can degrade aromatic hydrocarbons. In this study, inoculated and uninoculated aerated soil microcosms containing different s-triazines were examined for their ability to efficiently and rapidly treat contaminated soils containing naphthalene, nitrobenzene, and toluene (NNT), via a microbial consortium consisting of Pseudomonas, Rhodococcus, and Aeromonas. After an experimental period of 14 days, greater than 90% degradation of NNT supplemented with different s-triazines, at concentrations of 1000-3000 ppm was observed. A difference in the degradation of NNT was seen in inoculated box reactors supplemented with cyanuric acid, melamine, and atrazine in comparison to uninoculated box reactors. Combined usage of 16s rDNA and 16s rRNA analysis was then applied to study the bacterial communities, and determine the abundance and survival of inoculated strains within box reactors contaminated with NNT. The bacterial diversity within clone libraries obtained illustrated a dominance of proteobacteria and gram positive bacteria. Analysis from clone libraries also showed that inoculated strains did survive within each condition, but were not the most predominant members present in the communities. This research shows that significant removal of NNT can be achieved in two weeks with the supplementation of one of the s-triazines. However, differences in degradation and the microbial populations present within contaminated communities will be seen depending on which nitrogen sources are used and whether or not environments are bioaugmented or not.

Benzene and toluene are representative volatile organic compounds (VOCs) released during production, storage, and transportation associated with the oil and gas industry. Benzene and toluene are chemicals of concern because they are released in greater and possibly more biologically significant concentrations than other compounds. <p>Most studies of air pollution in high oil and gas activity areas have neglected to consider risks to top-level predators. Birds can be used as highly sensitive monitors of air quality. Since the avian respiratory tract is physiologically different from a rodent respiratory tract, effects of gases cannot be safely extrapolated from rodent studies. I hypothesized that benzene, being haematotoxic and immunotoxic, along with the neurological and possible endocrine disrupting effects of toluene would be more toxic in birds than in mammals. <p>After two summers of experimental exposure of wild and captive American kestrels to high (10ppm and 80ppm) or environmentally relevant (0.1ppm and 0.8ppm) levels of benzene and toluene, respectively, altered immune, haematopoeitic, behavioural, and endocrine responses characteristic in mammals, were evident in the kestrels.<p>There was a decreased cell mediated immune response as measured by delayed type hypersensitivity tests in all exposed birds (p = 0.028, 0.004). An increase in humoral immunity as compared to control individuals (p = 0.041, 0.031) was also apparent in both dose groups. Plasma retinol levels were decreased in 2005 and 2006 high dose individuals (p = 0.008, 0.048). <p>The majority of haematopoeitic effects involved the erythroid lineage in the bone marrow and the polychromatophilic erythrocytes systemically. There were no significantly adverse responses in the bone marrow with regards to the granuloid lineage but systemically there was a prominent eosinophilia (p = 0.045) and basophilia (p = 0.006) in low exposure groups. The loss of communication between polychromatophilic erythrocytes in the post-mitotic pool within the bone marrow and the peripheral blood was present in low and high exposure individuals compared to control birds (p = 0.013, 0.402, 0.974). The number of polychromatophils in the circulation of low dose group individuals was decreased compared to control birds (p = 0.029). This may be a function of toluenes inability to inhibit biotransformation enzymes at low concentrations leading to blood cell targeting by benzenes increased phenolic metabolite production. This theory is corroborated by the possible decreased benzene metabolism and increased toluene distribution manifesting as increased aggressive responses such as wing beating and vocalization time in the high dose group (p = 0.025, 0.086). <p>The work here has shown American kestrels are sensitive to the air contaminants, benzene and toluene. The present study illustrates the need for reference concentrations for airborne pollutants that are calculated based on data measuring sensitive endpoints specific for avian models. Future studies should evaluate immune, haematopoeitic, and behavioural endpoints, as well as develop more sensitive isoform specific enzyme activity assays to further determine the susceptibility of birds to inhaled toxicants.

Benzene and toluene are representative volatile organic compounds (VOCs) released during production, storage, and transportation associated with the oil and gas industry. Benzene and toluene are chemicals of concern because they are released in greater and possibly more biologically significant concentrations than other compounds. <p>Most studies of air pollution in high oil and gas activity areas have neglected to consider risks to top-level predators. Birds can be used as highly sensitive monitors of air quality. Since the avian respiratory tract is physiologically different from a rodent respiratory tract, effects of gases cannot be safely extrapolated from rodent studies. I hypothesized that benzene, being haematotoxic and immunotoxic, along with the neurological and possible endocrine disrupting effects of toluene would be more toxic in birds than in mammals. <p>After two summers of experimental exposure of wild and captive American kestrels to high (10ppm and 80ppm) or environmentally relevant (0.1ppm and 0.8ppm) levels of benzene and toluene, respectively, altered immune, haematopoeitic, behavioural, and endocrine responses characteristic in mammals, were evident in the kestrels.<p>There was a decreased cell mediated immune response as measured by delayed type hypersensitivity tests in all exposed birds (p = 0.028, 0.004). An increase in humoral immunity as compared to control individuals (p = 0.041, 0.031) was also apparent in both dose groups. Plasma retinol levels were decreased in 2005 and 2006 high dose individuals (p = 0.008, 0.048). <p>The majority of haematopoeitic effects involved the erythroid lineage in the bone marrow and the polychromatophilic erythrocytes systemically. There were no significantly adverse responses in the bone marrow with regards to the granuloid lineage but systemically there was a prominent eosinophilia (p = 0.045) and basophilia (p = 0.006) in low exposure groups. The loss of communication between polychromatophilic erythrocytes in the post-mitotic pool within the bone marrow and the peripheral blood was present in low and high exposure individuals compared to control birds (p = 0.013, 0.402, 0.974). The number of polychromatophils in the circulation of low dose group individuals was decreased compared to control birds (p = 0.029). This may be a function of toluenes inability to inhibit biotransformation enzymes at low concentrations leading to blood cell targeting by benzenes increased phenolic metabolite production. This theory is corroborated by the possible decreased benzene metabolism and increased toluene distribution manifesting as increased aggressive responses such as wing beating and vocalization time in the high dose group (p = 0.025, 0.086). <p>The work here has shown American kestrels are sensitive to the air contaminants, benzene and toluene. The present study illustrates the need for reference concentrations for airborne pollutants that are calculated based on data measuring sensitive endpoints specific for avian models. Future studies should evaluate immune, haematopoeitic, and behavioural endpoints, as well as develop more sensitive isoform specific enzyme activity assays to further determine the susceptibility of birds to inhaled toxicants.

Performance studies on the treatment of VOCs in air streams by a pilot-scale regenerative catalytic oxidizer (RCO) and a full-scale regenerative thermal oxidizer (RTO) were conducted. The pilot-scale RCO was constructed with two 20-cm x 200-cm (inside diameter x packing height) regenerative beds packed with gravel (average particle size = 1.25 cm) used as the thermal regenerative solid material. Experimental results indicate that destruction efficiencies of 97 and 90%, respectively, were obtained for methyl ethyl ketone and toluene at a superficial gas velocity of 0.372 m/s (evaluated at 25¢J) and a maximum bed temperature of 400¢J. It was estimated that an electrical thermal energy of approximately 84 kWh was required for treating 1,000 m3 of the waste air stream by the RCO. The full-scale RTO was constructed with two regenerative beds of 100-cm square x 200-cm height packed with the gravel used in the RCO. A paint solvent containing methyl ethyl ketone, ethyl benzene, xylenes, and ethyl acetate was used for the target VOCs. Experimental results indicate that, at a superficial gas velocity of 0.372 m/s (evaluated at 25¢J), VOC destruction efficiencies of 84, 92, 95 and 98% were obtained for the beds at temperature ranges of 200-300, 300-500, 400-700, and 500-700¢J. These conditions corresponded to empty gas retention times of 1.07, 0.85, 0.41, and 0.39s, respectively, for the cited temperature ranges. Finally, it was estimated that electrical watts of approximately 0.10, 0.45, 1.78, 2.43 kWh were required for treating 1,000 m3 of the waste air stream, respectively, at bed temperature ranges of 200-300, 300-500, 400-700, and 500-700¢J.

Aromatic hydrocarbons constitute an important fraction (~20%) of total volatile organic compounds (VOCs) in the urban atmosphere. A better understanding of the aromatic oxidation and its association in urban and regional ozone and organic aerosol formation is essential to assess the urban air pollution. This dissertation consists of two parts: (1) theoretical investigation of the toluene oxidation initiated by OH radical using quantum chemical and kinetic calculations to understand the mechanism of O3 and SOA precursors and (2) experimental investigation of atmospheric new particle formation from aromatic acids. Density functional theory (DFT) and ab initio multiconfigurational calculations have been performed to investigate the OH-toluene reaction. The branching ratios of OH addition to ortho, para, meta, and ipso positions are predicted to be 0.52, 0.34, 0.11, and 0.03, respectively, significantly different from a recent theoretical study of the same reaction system. Aromatic peroxy radicals arising from initial OH and subsequent O2 additions to the toluene ring are shown to cyclize to form bicyclic radicals rather than undergoing reaction with NO under atmospheric conditions.Isomerization of bicyclic radicals to more stable epoxide radicals possesses significantly higher barriers and hence has slower rates than O2 addition to form bicyclic peroxy radicals. At each OH attachment site, only one isomeric pathway via the bicyclic peroxy radical is accessible to lead to ring cleavage. Decomposition of the bicyclic alkoxy radicals leads primarily to formation of glyoxal and methyl glyoxal along with other dicarbonyl compounds. Atmospheric aerosols often contain a considerable fraction of organic matter, but the role of organic compounds in new nanometer-sized particle formation is highly uncertain. Laboratory experiments show that nucleation of sulfuric acid is considerably enhanced in the presence of aromatic acids. Theoretical calculations identify the formation of an unusually stable aromatic acid-sulfuric acid complex, which likely leads to a reduced nucleation barrier. The results imply that the interaction between organic and sulfuric acids promotes efficient formation of organic and sulfate aerosols in the polluted atmosphere because of emissions from burning of fossil fuels, which strongly impact human health and global climate.

Volatile organic compounds (VOCs) can detrimentally affect human health directly and indirectly. However, the main environmental concern of VOCs involves the formation of smog. In the presence of nitrogen oxides, VOCs are the precursors to the formation of ground level ozone. Isopropyl alcohol (IPA) and toluene are extensively used in industry as solvents. They are all highly toxic to animals and humans. Accordingly, IPA and toluene are strongly associated with problems of VOCs. Catalytic incinerations and a regenerative catalytic oxidizer (RCO) were adopted to decompose VOCs herein. Various catalysts were prepared and developed in this study. The screening test of catalytic activity and the influences of the operational parameters on VOCs removal efficiencies were widely discussed through catalytic incinerations of VOCs. The more effective and cheaper catalysts through above discussions of catalytic incineration were selected. And they were utilized in an RCO to investigate their performance in VOCs oxidation and RCO operations. Experimental results demonstrate that 10 wt%CuCo/(G) catalyst performed well in an RCO because it has the excellent performance in incineration efficiency and economic efficiency. The achievements of this study are summarized as follows: (1) Treatment of isopropyl alcohol (IPA) using ceramic honeycomb(CH) catalyst The eighteen ceramic honeycomb catalysts we prepared by various methods (co-precipitation, wet impregnation and incipient impregnation), various metal weight loadings (5 ~ 20 wt %), and various metals (Cu and CuCe) were used in the experiment. The results indicate that 20 wt%CuCe/(CH) catalyst prepared by wet impregnation had the best performance in CO2 yield because TC50 and TC95 were 245¢J and 370¢J, respectively, under the following operating conditions; a space velocity of 12000 hr-1, an inlet IPA concentration of 1600 ppm, an oxygen concentration of 21%, and a relative humidity of 25%. Given the operational parameters of IPA oxidation experiments, the CO2 yields increased with higher temperature and oxygen concentration, but decreased with inlet IPA concentration, space velocity and the relative humidity increased. Moreover, the stability test results show that the 20 wt%CuCe/(CH) catalyst had excellent stability. (2) Treatment of toluene using molecular sieve(MS) catalyst Molecular sieve catalysts with various metals (Cu, Co, Mn, CuMn, CuCo, MnCo) and various loadings (5~10 wt %) were produced by wet impregnation to treat toluene. The results indicate that 10 wt%CuCo/(MS) had the best performance in toluene conversion because T50 and T95 were 295¢J and 425¢J, respectively, at an influent concentration of toluene of 900 ppm, an oxygen concentration of 21%, a space velocity of 12000 hr-1, and a relative humidity of 26%. The conversions of toluene increased with the reaction temperature and the influent concentration of oxygen, but decreased as the initial concentration of toluene and the space velocity increased. Moreover, we did not find any decay between the fresh and used catalysts using SEM and EDS. (3) Treatment of isopropyl alcohol (IPA) using Cu/(CH) and CuCo/(CH) catalysts We used the 20 wt% CuCo/(CH) and 20 wt% Cu/(CH) catalysts in a pilot RCO to test IPA oxidation performance under various conditions. The best catalyst was selected, and the economic efficiency of RCO and the phenomenon of RCO operations were more widely discussed. The results demonstrate that 20 wt% CuCo/(CH) catalyst performed well in an RCO because it was effective in treating IPA, with a CO2 yield of up to 95%. It also had the largest tolerance of variations in inlet IPA concentration and gas velocity. The 20 wt% CuCo/(CH) catalyst in an RCO also performed well in terms of TRE, pressure drop and selectivity to CO2. The thermal recovery efficiency (TRE) decreased as gas velocity increased. The temperature difference (Td) and pressure drop increased with gas velocity and heating zone temperature. The TRE range was from 87.8 to 91.2 % and the Td ranged from 22.1~35.1¢Junder various conditions. Finally, the stability test results indicate that the 20 wt% CuCo/(CH) catalyst was very stable at various CO2 yields and temperatures. (4) Treatment of toluene using CuCo/(CH) catalysts with various carriers In this work, three catalysts (10 wt%CuCo/(G)¡B10 wt%CuCo/(MS) and 20 wt% Cu/(CH)) were prepared by wet impregnation, and used in an RCO to test their performance in incineration efficiency and economic efficiency under various operational conditions. Then the best catalyst was selected and the phenomenons of RCO operations were further investigated. Experimental results demonstrate that 10 wt%CuCo/(G) catalyst performed well in an RCO because it is effective in treating toluene with a toluene conversion of up to 95% at the heating zone temperature (Tset) = 400¢J under various conditions. The 10 wt% CuCo/(G) catalyst had the greatest tolerance against the effects of inlet toluene concentration and gas velocity, and exhibited the best performance in terms of TRE , Td and pressure drop. The TRE range was from 90.2 to 92.9 % and Td ranged from 18.2 to 30.9¢J under various conditions at Tset = 300~400¢J. Moreover, when 10 wt% CuCo/(G) catalyst was used in an RCO, the results demonstrate that (1) high selectivity to CO2 ; (2) decrease in TRE and increase in Td as increasing the shifting time; (3) an insignificant effect of shifting time on pressure drop and (4) excellent stability of 10 wt% CuCo/(G) catalyst in a long period test.

The purpose of this study was to examine the hairdresser’s knowledge about the chemicals they handle in their business and how they were handling the chemicals and the risks that follows. 9 Salons were visited to gather information. The same questions were asked at the salons. A sample of hair color products was photographed to gather information about ingredients and labeling. The conclusions of the study were that hairdressers have good knowledge about the risks related to human health but they need to improve their knowledge when it comes to environmental risks. The deficiencies that were found were that they lack knowledge about the laws concerning the use and distribution of cosmetics products and that not all saloons are handling the hazardous waste and residues from treatments correctly. The risks that could follow are that not enough is done to protect human health and the environmental. To prevent that damage to human health and the environmental occurs they should use more sources that focus on health and environmental to gather information about the risks with the chemicals they are handling, they should also limit the treatments on children and always inform about the risks when they are using products that can cause an allergic reaction. Keywords: Risks hairdressing, cosmetics products, p-phenylenediamine, Toluene-2,5-diamine, ammonia.

Separation of aromatic/aliphatic hydrocarbon mixtures by pervaporation has been of increasing interest in recent decades. Dozens of polymer materials have been reported for separations of benzene/cyclohexane and toluene/iso-ocatne mixtures. However, fundamental understanding of material structure and transport relations is not adequate to generalize guidelines for materials screening. The goals of this study are to tailor the structure of the polyimide materials, correlate the structure and transport relations, and establish guidelines for future materials. The 3, 5-Diaminobenzoic acid (DABA) containing polyimides were synthesized by both chemical and thermal solution imidization. The synthesized polyimides were formed into dense films by solution casting. The physical properties of the polyimides synthesized with monomers: 2, 2-bis (3, 4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), 4, 6-trimethyl-1, 3-phenylendiamine (DAM) and DABA, were characterized by DSC, WAXD, GPC and density. The chemical structures were assessed by FTIR and NMR. The pervaporation and sorption of the synthesized polyimide membranes were tested in toluene/iso-octane mixtures at 100°C. The structure- transport property relations were established for the 6FDA-DAM/DABA membranes. The 6FDA-DAM/DABA polyimides were crosslinked by ethylene glycol. The pervaporation and sorption of the crosslinked membranes were tested in toluene/iso-octane mixtures at 100°C. Thermal imidization was found to give a higher imidization degree than chemical imidization. As a result, the polyimides made by chemical imidization contain a higher percentage of carboxylic acid groups than those made by thermal imidization. Chemical imidization gives higher film density, glass transition temperature and lower flux and higher selectivity for the toluene/iso-octane pervaporation than the thermally imidized membranes because of the higher carboxylic acid concentration. The chemically imidized membranes are slightly brittle after the crosslinking. Only the thermal imidization membranes have good flexibility and its pervaporation selectivity improves significantly after the crosslinking. Solubility selectivity and diffusivity selectivity of the 6FDA-DAM/DABA membranes were correlated with solubility parameters and fractional free volume, respectively. The structure-mass transport relations show that for the 6FDA-DAM/DABA membranes, both solubility selectivity and diffusivity selectivity contribute to the pervaporation selectivity. For the chemically imidized membranes, increased DABA concentration has a positive effect on solubility selectivity and diffusivity selectivity. For the thermally imidized membranes, increased DABA concentration has a significant effect on diffusivity selectivity only. / text