This study investigated the changes in leachate composition and clogging evolution in leachate transmission pipes and the use of methanogenesis as a leachate treatment alternative for Bioreactor landfills, by using pilot-scale and laboratory studies. The pilot-scale study consisted of a research station built at Brady Road Landfill, housing sixteen HDPE pipes of three different diameters, conveying leachate intermittently at eight different Reynolds numbers, under reasonably controlled conditions. The pipes were tested for leachate degradation, clogging evolution and hydraulic impairment over time. The laboratory studies carried out tested (1) the effect of turbulence intensity and temperature on leachate degradation and clogging effects and (2) biological pretreatment of leachate prior to injection into a bioreactor cell. The pilot study results showed that under the conditions tested, pipes developed a significant amount of organic and inorganic clog material in less than a year of operation. Since limited quantities of fresh leachate (approx. 3 m3) were used during each leachate degradation analyses, the anticipated effects of clogging in a full scale injection system are expected to be more pronounced, which can negatively impact the long-term hydraulic performance, operation, and service life of a Bioreactor Landfill. The first laboratory study showed that increasing the turbulent energy dissipation rate caused greater amounts of CO2 evolution from the leachate, and temperature increase had an impact on dissolved Ca2+ under atmospheric conditions, affecting clog development. The second and third laboratory studies showed that performing leachate methanogenesis reduces organic (COD, VFA) and inorganic (Ca2+, ISS) clog constituents within the leachate However, the rate of methanogenesis was influenced by the ratio of acetate and propionate. It is suggested that if leachate undergoes methanogenesis in a separate leachate digester prior to re-injection into a bioreactor waste cell, it may protect the pipes and other engineered landfill systems against clogging and its detrimental effects, while allowing for CH4 recovery. However, blending of leachates from different wells or cells prior to the methanogenic digester may be needed to balance the variable concentrations and ratios of acetate and propionate over time from different landfill wells and cells.

This study investigated the changes in leachate composition and clogging evolution in leachate transmission pipes and the use of methanogenesis as a leachate treatment alternative for Bioreactor landfills, by using pilot-scale and laboratory studies. The pilot-scale study consisted of a research station built at Brady Road Landfill, housing sixteen HDPE pipes of three different diameters, conveying leachate intermittently at eight different Reynolds numbers, under reasonably controlled conditions. The pipes were tested for leachate degradation, clogging evolution and hydraulic impairment over time. The laboratory studies carried out tested (1) the effect of turbulence intensity and temperature on leachate degradation and clogging effects and (2) biological pretreatment of leachate prior to injection into a bioreactor cell. The pilot study results showed that under the conditions tested, pipes developed a significant amount of organic and inorganic clog material in less than a year of operation. Since limited quantities of fresh leachate (approx. 3 m3) were used during each leachate degradation analyses, the anticipated effects of clogging in a full scale injection system are expected to be more pronounced, which can negatively impact the long-term hydraulic performance, operation, and service life of a Bioreactor Landfill. The first laboratory study showed that increasing the turbulent energy dissipation rate caused greater amounts of CO2 evolution from the leachate, and temperature increase had an impact on dissolved Ca2+ under atmospheric conditions, affecting clog development. The second and third laboratory studies showed that performing leachate methanogenesis reduces organic (COD, VFA) and inorganic (Ca2+, ISS) clog constituents within the leachate However, the rate of methanogenesis was influenced by the ratio of acetate and propionate. It is suggested that if leachate undergoes methanogenesis in a separate leachate digester prior to re-injection into a bioreactor waste cell, it may protect the pipes and other engineered landfill systems against clogging and its detrimental effects, while allowing for CH4 recovery. However, blending of leachates from different wells or cells prior to the methanogenic digester may be needed to balance the variable concentrations and ratios of acetate and propionate over time from different landfill wells and cells.

The stoichiometric relationship between carbon dioxide (CO2) generated and glucose consumed during fermentation can be utilized to predict glucose consumption as well as yeast growth by measuring the CO2 concentration. Dissolved CO2 was chosen as opposed to off-gas CO2 due to the high solubility of CO2 in the fermentation broth as well as its ability to reflect on yeast growth more accurately than off-gas CO2. Typical very-high-gravity (VHG) ethanol fermentation is plagued by incomplete glucose utilization and longer durations. Aiming to improve substrate utilization and enhance VHG fermentation performance, characteristics of dissolved CO2 concentration in fermentation broths using Saccharomyces cerevisiae were studied under batch conditions. Based on this study a novel control methodology based on dissolved CO2 was developed and its effectiveness on enhancing VHG fermentation was evaluated by measuring the fermentation duration, glucose conversion efficiency and ethanol productivity. Four different initial concentrations 150, 200.05±0.21, 250.32±0.12, and 300.24±0.28 g glucose/L were used for batch ethanol fermentation without control. Zero substrate was indicated for 150 and 200.05±0.21 g glucose/L by a characteristic abrupt drop in dissolved CO2 concentration. On the other hand sluggish fermentation and incomplete substrate utilization were witnessed for 250.32±0.12, and 300.24±0.28 g glucose/L. A material balance equation was developed to compensate for the inability of the dissolved CO2 profiles to accurately predict the different growth phases of yeast. Dissolved CO2 was controlled at three distinct levels of 500, 750 and 1000 mg/L using aeration rates of 820 and 1300 mL/min for initial concentrations of 259.72±7.96 and 303.92±10.66 g glucose/L. Enhancement of VHG fermentation was achieved in the form of complete glucose utilization and higher ethanol productivities and shorter fermentation duration in comparison to batches without control. Complete glucose utilization was facilitated under ~250 and ~300 g glucose/L in 27.02±0.91 and 36.8±3.56 h respectively. Irrespective of the control set points and aeration rates, ethanol productivities of 3.98±0.28 g/L-h and 3.44±0.32 g/L-h were obtained for 259.72±7.96 and 303.92±10.66 g glucose/L respectively. The glucose conversion efficiencies for both 259.85±9.02 and 299.36±6.66 g glucose/L when dissolved CO2 was controlled were on par with that of batches without control.

Since its creation in the late 19th century, mass spectrometry has evolved into one of the most versatile analytical methods in science. To chart this evolution this thesis includes a historical overview of mass spectrometry and a description of the role of mass spectrometry in oceanography. The development and deployment of underwater mass spectrometers (UMS) at the University of South Florida's Center for Ocean Technology has made possible the collection of real-time data with greatly increased spatial and temporal density. The UMS was deployed via both remotely guided surface vehicles (GSV) and ship's cables to monitor a suite of dissolved gases and volatile organic compounds in saltwater and freshwater environments. Spectrometer data in Lake Maggiore, Florida were acquired at a rate of 0.7-3.6 seconds/sample for 2-3 hours. The resulting multi-analyte spectrometer data were recorded in real time with the Global Positioning System (GPS) observations of an associated surface vehicle and transmitted to a remote laptop computer via a wireless Ethernet link. These data were merged to create high-resolution maps of chemical distributions. Of particular interest were the co-varying oxygen and carbon dioxide mass spectrometer signals, diagnostic of photosynthesis-respiration processes, that were collected over a 10,800 square-meter area of the lake. The UMS was also deployed on a shipborne hydrowire in Saanich Inlet, a 200-meter deep fjord in the western Canadian province of British Columbia. The concentrations of a broad suite of dissolved gases were monitored on both downcast and upcast over a total depth range of 200 meters. Spectrometer data were acquired at a rate of 4.2 seconds/sample for the duration of the deployment. Mass spectrometer signals diagnostic of reduced species (CH4, H2S,) in the anoxic waters of the inlet below a depth of 100 meters were consistent with previous descriptions of the fjord's chemistry. The UMS was deployed on a remotely guided surface vehicle on the Hillsborough River in central Hillsborough County. Spectrometer data were acquired at a rate of 0.7 seconds/sample, and geographic location was recorded by an onboard GPS during a 2,640 meter transect of the river. Prior to the deployment, the mass spectrometer was calibrated using certified gas standards. The calibration experiments correlated mass spectrometer ion intensity data with dissolved gas concentrations, whereupon the mass spectrometer data collected during the deployment were reported in units of micromole/kilogram (µmol/kg). The mass spectrometer recorded changes in gas concentrations associated with changing physical conditions and biological activity along the 2,640 meters of the river that was transited by the GSV.

Dissolved carbon dioxide driven repeated batch fermentation has been performed under four glucose concentrations: ~150, ~200, ~250 and ~300 g glucose l-1, with three dissolved carbon dioxide (DCO2) control conditions: without DCO2 control, with DCO2 control at 750 and 1000 mg l-1 levels. No residual glucose was observed under all performed fermentation conditions, and the repeated batch fermentation system could be operated by a computer as self-cycling system. The collected fermentation results presented that, under the same feeding concentration, ethanol concentration in the presence of DCO2 control was significantly lower than that in the absence of DCO2 control; and a higher biomass concentration in the presence of control was observed in this comparison as well. A higher biomass concentration resulted in a shorter fermentation time, which contributed to a higher ethanol production rate. The highest final ethanol concentration was observed as 113.5 g l-1 at 1000 mg DCO2 l-1 control level under ~300 g glucose l-1 condition, where the lowest ethanol production rate of 1.18 g l-1 h-1 was observed. The highest ethanol production rate was 4.57 g l-1 h-1 and its corresponding ethanol concentration was 66.7 g ethanol l-1 at 1000 mg l-1 DCO¬2 control level under ~200 g glucose l-1 condition. For all fermentation conditions, the viabilities of yeast at the end of fermentation were maintained at near 90% where their corresponding final ethanol concentrations were lower than 100 g l-1. As soon as the final ethanol concentration at the end of each cycle was greater than 110 g l-1, its corresponding viability decreased to ~70%. The ethanol conversion efficiency was maintained at ~90% and ~65% in the absence and presence of DCO2 control, respectively. Based on the changing of biomass concentration profiles in the stabilized cycles, two cell growth phases could be identified in the absence of DCO2 control, and only one cell growth phase was noticeable in the presence of DCO2 control cases. Meanwhile, a sudden decline of DCO2 readings at the end of fermentation was constantly observed in both of in the absence and in the presence of DCO2 control cases, which resulted in developing two control algorithms to determine self-cycling time. Comparison of carbon balance analysis between in the absence and in the presence of DCO2 control suggested that the availability of DCO2 control might alter the metabolic flow during fermentation; and the figure of ethanol concentration against fermentation time illustrated that the changing of DCO2 control level did not affect fermentation results, significantly. Moreover, comparisons of ethanol production rate between different processes and different initial glucose concentrations concluded that the ethanol production rate in the presence of DCO2 control was generally higher than that in the absence of DCO2 control under the same glucose concentration; and the ethanol production rate was decreased with the increasing of glucose concentration under the same DCO2 control condition. The experiment results were scaled up to 106 L as a sample analysis in production scale, which suggested that the fermentation with ~200 g glucose l-1 feeding concentration in the absence of DCO2 controlled would provide best profits in the all fermentation conditions.

Background and Aims: Volatile loss of carbon dioxide, ethanol, esters and other compounds occurs during wine fermentation. When collected nondestructively, valuable ethanol and aroma compounds can be preserved for various uses while mitigating production restrictions and regulations regarding volatile organic compound (VOC) loss from wine production. Knowledge of the volume of volatiles lost during wine fermentation contributes to a better understanding of the magnitude of possibilities for resource recovery/aroma recovery, the implications of volatile loss on wine composition as well as a more clear understanding of the possible effect of alcoholic fermentation on air quality. The aim of this study was to contribute to a better understanding of how the loss of volatiles from wine fermentation varies with temperature. Methods and Results: Temperature controlled microscale fermenters were developed and infrared detection technology was adapted to study the effect of temperature on volatile loss. Results are presented for the rates and volumes of volatile loss from the fermentation of California Syrah at constant temperatures (17, 23, 27, 33˚C) in 1.9L containers. Observed volatile losses are compared to theoretical losses based on kinetic and stoichiometric principals. Each ferment started with 1200g of fruit and was adjusted to 23.5˚B. Following Brix adjustment, final volumes ranged from 1129.16mL to 1160.10mL. Conclusion: The loss of VOC from fermentation increases exponentially with temperature. Total VOC and CO2 loss appears to be slightly less than theory predicts. Significance of the Study: A significant loss of compounds occurs during wine fermentation. Commercial and environmental benefits may be achieved if efforts are made to recover and make use of these otherwise wasted compounds. Funding provided by the Agricultural Research Initiative, California State University.