The capture of methane from waste disposal facilities can have a significant impact on the reduction of anthropogenic methane emissions. In the United States, more than six hundred facilities are capturing approximately 26.3 MMTCO2e methane annually (U.S. EPA, 2015). The importance of the capture is two-fold: reduction of greenhouse gases and the exploitation of a beneficial energy source. Yet methane capture efficiencies have been moderate due to many logistical issues. Few methods currently exist to rehabilitate marginally producing extraction wells at landfills. This study was designed to test whether post-perforation technology, invented in 2009, is effective in increasing the efficiency of gas capture from marginally producing wells. This study examined the effectiveness of post-perforation technology to improve the environmental and energy benefits associated with additional methane capture. Post perforation technology was designed and developed to rehabilitate marginal extraction wells. The technology creates new openings to allow more methane to enter an extraction well. Prior to this technology low yield or marginal extraction wells were abandoned and new extraction wells were drilled and installed. The study consisted of gathering data from nine existing municipal solid waste facilities that had extraction wells previously post-perforated. After review, five of the nine facilities were selected for the study. For adequate sample size, facilities with nine or more post-perforated extraction wells were included in this study. The number of post perforated wells from the five facilities ranged from 9 to 19. All facilities were from Texas or Florida. Post-perforation at these facilities was conducted between September 2009 and October 2014. The number of methane extraction wells from the five facilities ranged from 49 to 138. Measurements for % methane (CH4), initial flow (standard cubic feet per minute scfm) and adjusted flow (scfm) were obtained at each extraction well at least on a monthly basis. One year’s worth of data was obtained at each facility, six months prior and six month after post-perforation for each extraction well. All extraction at each of the five facilities wells were categorized into one of three groups for analyses based on the following criteria. If the initial flow was ≤2 (scfm) or the % methane was ˂50% the extraction well was a candidate for post-perforation. If this type of extraction well was subsequently post-perforated, it was categorized into group 1, but if not selected for post-perforation it was categorized into group 2, serving as a control group within that landfill. However, if the initial flow was >3 (scfm) the extraction wells was categorized into group 3. The total sample size for group 1 was 67, group 2 contained 165, and group 3 contained 261 extraction wells. The results of the analyses demonstrated a statistical effect after post-perforation on the initial flow (scfm) and on adjusted flow (scfm) in Group 1, the treatment group. The mean initial flow after post-perforation increased from 16.9 to 28.5 scfm (t = 3.05; p = 0.016; n=67), and the adjusted flow increased from 16.8 to 30.1 scfm (t = 3.66; p = 0.002; n=67). Group 2 and Group 3 mean values also increased after the time of perforation of Group 1 wells, but with not as large an increase in either variable. The added methane capture from landfills yielded substantial environmental and energy benefits. Four facilities yielded mean flow increases of methane at 125, 157, 120 and 558 scfm, for a total 960 scfm methane. The increase from those four facilities represents a total equivalent emission reduction of 0.1329 MMTCO2E/year, equivalent to 5,336 tons of CH4/year or 13,171 tons of CO2/ year. The energy benefit from 960 scfm could heat 3,315 homes for a year. This study demonstrates that post-perforation does increase the capture of methane in extraction wells at municipal solid waste facilities. Furthermore, this study demonstrated the advantages to be gained from any methodology or innovation that decreases fugitive emissions from landfills. Further research is required to increase the efficiency of methane capture. Industry change is slow due to the inconsistencies between federal, state and local regulatory requirements, but this study helps point the way.

The application of the widely used mass balance model in determining portable air purifier (PAP) effectiveness in particulate matter (PM) removal was not validated in occupied residential settings. The corresponding size-resolved information and measurements for the model parameters and PAP effectiveness were also limited to better characterize human exposure to indoor PM. Additionally, effects of ambient factors, such as meteorology, and their long-term impacts on occupant indoor exposure to outdoor PM was unclear. We achieved well-mixed environment and steady state of PM concentrations that met the mass balance model assumptions. Size-resolved particle deposition rate was determined using non-linear mixed effects model, whereas linear mixed effects model was used to estimate the slope between the measured and modeled effectiveness for validation purpose. To evaluate the impact of ambient factors on PM exposure, we assembled data from two cohorts in the greater Boston area, assessing the monthly and long-term effect of temperature and other meteorology on Sr. Long-term meteorology was projected using 15 weather models for the past and future 20 years to estimate Sr for the corresponding periods with mixed effects models. Both particle deposition rate and portable air purifier effectiveness were highly particle size-dependent. Filtration was found to be the dominant removal mechanism for submicrometer particles, whereas deposition could play a more important role in ultrafine particle removal. There was reasonable agreement between measured and modeled effectiveness with size-resolved slopes ranging from 1.11±0.06 to 1.25±0.07 (mean±SE), except for particles <35 nm. Sr was found to be a robust measure of indoor exposure to outdoor PM, and temperature was its significant predictor. Seasonal effect of temperature was much more dominant when compared to long-term effect on Sr, which differed in the whole population and the subpopulation of naturally ventilated homes. However, long-term temperature effect was small, with maximum of <10% for summer Sr compared to the past. Findings from the studies improved characterization of indoor PM exposure. The study design and methods can be used in the future to better understand exposure scenarios and their correlation to health effects in other homes or populations.

The purpose of my study was to collect data on managed cat (Felis catus) colonies located in two Miami-Dade County, Florida, parks, in order to test the following assertions put forward by proponents of the colonies: 1) Managed cat colonies will decline in size over time and 2) The territorial behavior of cats living in established cat colonies will prevent additional cats from joining. I collected observational and photographic capture-recapture data in order to track colony population dynamics. Behavioral data were also collected in order to understand the role that cat behavior plays in influencing colony population dynamics. My results do not support the assertion that colonies will decline over time. Instead, my findings demonstrate that the establishment of colonies on public lands encourages dumping of cats and creates an attractive nuisance. Furthermore, my behavioral analysis suggests that territorial behavior does not play a role in excluding new cats.

Aquatic ecosystems exhibit different vulnerabilities to anthropogenic disturbances. I examined this problem in the Upper Napo River Basin (UNRB), Ecuador. I ranked from 1 to 5 aquatic ecosystem uniqueness, health and threats. I stratified the basin into five Ecological Drainage Units (EDU), 48 Aquatic Ecological Systems (AES), and 203 macrohabitats. I found main threats (habitat conversion/degradation, land development, mining, oil industries, and water diversion) cover 54% of the UNRB, but have different scores and extents in each EDU. I assessed the health of 111 AESs, under three land use treatments, by analyzing the streamside zone, physical forms, water quality, aquatic life, and hydrology. Overall, health of AESs varied from 5 to 2.58, with 5 being the highest level of health. Threats and health of AESs were inversely related (F=34.119, P

This thesis tried to determine the socioeconomic contributions of a renewable-hybrid energy system in San Juanico, Mexico. It also tried to analyze if the hybrid system was designed based on sustainable development principles. A survey of 91 electrified homes was conducted in San Juanico to gather information on consumer satisfaction and data analyzed using simple means and group mean comparisons, with suitable tests as needed. A binomial probit model for two dependent variables was applied to survey data. An energy price-comparison exercise was conducted as well. Findings showed the hybrid system had suffered from weak institutional frameworks, low community participation and a lack of long-term system and financial planning. Although the system made improvements in quality of life, it had not been reliable and lacked organizational ability to supply rural electricity in a sustainable fashion.

Two protected areas: Royal Bardia National Park (RBNP) and Royal Suklaphanta Wildlife Reserve (RSWR) in the Western Terai, Nepal, are under threats due to present political turmoil, uncontrolled immigration, inefficient land reform policies and unsustainable resource use. I did a stratified random questionnaire survey of 234 households to determine how resource use patterns and problems influence conservation attitudes. Chi-square, Student's t, Mann-Whitney and Kruskal-Wallis tests, and multiple regression were used. There was spatio-temporal variability in resource use patterns and dependency. People were collecting eight and seven types of resources in RBNP and RSWR, respectively. However, people in RBNP were more dependent on resources than RSWR. In both areas, the problem of firewood is serious. The mean attitude score of RBNP (8.4 ± 1.44) was significantly higher than the score of RSWR (7.7 ± 1.66; t = 3.24, p = 0.0007). Conservation attitude was determined by variables such as participation in trainings, wildlife damage, and satisfaction towards user groups.

A comprehensive forensic investigation of sensitive ecosystems in the Everglades Area is presented. Assessing the background levels of contamination in these ecosystems represents a vital resource to build up forensic evidence required to enforce future environmental crimes within the studied areas. This investigation presents the development and validation of a fractionation and isolation method for two families of herbicides commonly applied in the vicinity of the study area, including phenoxy acids like 2,4-D, MCPA, and silvex; as well as the most common triazine-based herbicides like atrazine, prometyne, simazine and related metabolites like DIA and DEA. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used to isolate the analytes from abiotic matrices containing large amounts of organic material. Atmospheric-pressure ionization (API) with electrospray ionization in negative mode (ESP-), and Chemical Ionization in the positive mode (APCI+) were used to perform the characterization of the herbicides of interest.

In this study, the relationships between the time since last fire and the contributions of two palm species (Silverpalm, Coccothrinax argentata and Key Thatch Palm, Thrinax morrisii) to the burnable fuel load in the lower Florida Keys were examined. The population size distributions, effects of fire and plant size on mortality, annual growth rate, minimum reproductive size, and leaf moisture content of the palms were also determined. Regression models were developed to estimate the live and attached dead burnable biomass for both palm species. Equations with crown area and number of leaves as independent variables best predicted the amount of burnable biomass. Fuel accumulation was then modeled to determine the time until different biomass components begin to stabilize after fire. Live palm biomass continued to increase for approximately 2-5 years after fire, while dead attached biomass continued to increase for up to 15-20 years. In the burned sites a greater percent of mortality was observed in the larger palms.

The purpose of this research was to determine what challenges small-scale organic farmers face in choosing their particular production, marketing, and organizational strategies in Miami-Dade County. Rapid soil assessments were used on six organic farms to determine the effects of soil nutrient management in terms of pH, soil organic matter (SOM), and phosphorus (P). Potential costs of inputs were documented for each farm to determine the largest challenges facing the profitability of organic farms. A production, marketing, and organizational analysis determined how farmers shape their inter-farm competitive and cooperative relations. Preliminary findings from soil, input, labor, marketing, and organizational factors indicate that soil health varies dramatically from farm to farm, inputs and labor constitute significant costs, and marketing, production, and organizational strategies show no signs of immediate growth.

The Maya of the Yucatan region have a long history of keeping the native stingless bees (subfamily Meliponinae). However, market forces in the last two decades have driven the Maya to favor the use of invasive Africanized honey bees (Apis mellifera scutellata) for producing large quantities of high quality honey which has an international market. Furthermore, the native bees traditionally used by the Maya are now disappearing, along with the practice of keeping them. An interdisciplinary approach was taken in order to determine the social factors behind the decrease in stingless beekeeping and the ecological driving forces behind their disappearance from the wild. Social research methods included participant observation with stingless beekeepers, Apis beekeepers, and marketing intermediaries. Ecological research methods included point observations of commonly known melliferous and polliniferous plants along transects in three communities with different degrees of human induced ecosystem disturbance. The stingless bee species most important to the Maya, Melipona beecheii, has become extremely rare, and this has caused a breakdown of stingless beekeeping tradition, compounded with the pressure of the market economy, which fuels Apis beekeeping and has lessened the influence of traditional practices. The community with the heaviest amount of human induced ecosystem disturbance also had the lowest degree of bee diversity, while the area with the most intact ecosystem had the highest diversity of stingless bees, though Apis mellifera was still the dominant species. Aggressive competitive behavior involving physical attacks by Apis mellifera against stingless bees was observed on several occasions, and this is a new observation previously unreported by science. Human induced disturbance of the ecosystem and competition with the Africanized honey bee are affecting the diversity and abundance of various bee species.