Matching Items (8)
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- All Subjects: Environmental Management
- All Subjects: Legionella
- Genre: Masters Thesis
- Creators: Fox, Peter
Description
The consumption of feedstocks from agriculture and forestry by current biofuel production has raised concerns about food security and land availability. In the meantime, intensive human activities have created a large amount of marginal lands that require management. This study investigated the viability of aligning land management with biofuel production on marginal lands. Biofuel crop production on two types of marginal lands, namely urban vacant lots and abandoned mine lands (AMLs), were assessed. The investigation of biofuel production on urban marginal land was carried out in Pittsburgh between 2008 and 2011, using the sunflower gardens developed by a Pittsburgh non-profit as an example. Results showed that the crops from urban marginal lands were safe for biofuel. The crop yield was 20% of that on agricultural land while the low input agriculture was used in crop cultivation. The energy balance analysis demonstrated that the sunflower gardens could produce a net energy return even at the current low yield. Biofuel production on AML was assessed from experiments conducted in a greenhouse for sunflower, soybean, corn, canola and camelina. The research successfully created an industrial symbiosis by using bauxite as soil amendment to enable plant growth on very acidic mine refuse. Phytoremediation and soil amendments were found to be able to effectively reduce contamination in the AML and its runoff. Results from this research supported that biofuel production on marginal lands could be a unique and feasible option for cultivating biofuel feedstocks.
ContributorsZhao, Xi (Author) / Landis, Amy (Thesis advisor) / Fox, Peter (Committee member) / Chester, Mikhail (Committee member) / Arizona State University (Publisher)
Created2013
Description
Ecolabels are the main driving force of consumer knowledge in the realm of sustainable product purchasing. While ecolabels strive to improve consumer's purchasing decisions, they have overwhelmed the market, leaving consumers confused and distrustful of what each label means. This study attempts to validate and understand environmental concerns commonly found in ecolabel criteria and the implications they have within the life cycle of a product. A life cycle assessment (LCA) case study of cosmetic products is used in comparison with current ecolabel program criteria to assess whether or not ecolabels are effectively driving environmental improvements in high impact areas throughout the life cycle of a product. Focus is placed on determining the general issues addressed by ecolabelling criteria and how these issues relate to hotspots derived through a practiced scientific methodology. Through this analysis, it was determined that a majority the top performing supply chain environmental impacts are covered, in some fashion, within ecolabelling criteria, but some, such as agricultural land occupation, are covered to a lesser extent or not at all. Additional criteria are suggested to fill the gaps found in ecolabelling programs and better address the environmental impacts most pertinent to the supply chain. Ecolabels have also been found to have a broader coverage then what can currently be addressed using LCA. The results of this analysis have led to a set of recommendations for furthering the integration between ecolabels and life cycle tools.
ContributorsBernardo, Melissa (Author) / Dooley, Kevin (Thesis advisor) / Chester, Mikhail (Thesis advisor) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2012
Description
In rural and urban areas of Nigeria, dependence on groundwater is increasing since the population is growing and high quality, treated municipal water is scarce. Municipal drinking water is often compromised because of old and leaking distribution pipes. About 58% of the water consumed in Lagos State, Nigeria, comes from residential wells. However, a majority of residential wells are shallow wells that are constructed relatively close to septic tanks or pit latrines and are therefore subject to contamination. In certain parts of Africa, there is high potential of severe epidemic if water quality is not improved. With increasing reliance on groundwater, a need exists to monitor the quality of groundwater. This thesis develops a plan for a monitoring program for residential wells in Lagos State, Nigeria. The program focuses on ways by which owners can maintain reasonably good water quality, and on the role of government in implementing water quality requirements. In addition, this thesis describes a survey conducted in various areas of Lagos State to assess community awareness of the importance of groundwater quality and its impact on individuals and the community at large. The survey shows that 30% to 40% of the households have located their wells and septic tanks in the same general area. Various templates have been created to help the staff of a future monitoring program team to effectively gather information during site characterization. A "Questions and Answers" leaflet has been developed to educate citizens about the need for monitoring residential wells.
ContributorsTalabi, Omogbemiga Adepitan (Author) / Edwards, David (Thesis advisor) / Hild, Nicholas (Committee member) / Olson, Larry (Committee member) / Arizona State University (Publisher)
Created2010
Description
Quagga Mussels (Dreissena bugensis) are an invasive species of mollusk that have established themselves within the Colorado River system of Arizona since 2007. However, despite close proximity and frequent travel by recreational boaters between reservoirs, they have not yet infested the Salt River or Verde River systems. Laboratory experimentation was done to test the survival rate of adult D. bugensis specimens in waters collected from Bartlett Lake (Verde River), Saguaro Lake (Salt River), and Salt River Project (SRP) canals (Salt River/Verde River/Colorado River blend) as well as Central Arizona Project (CAP) canals with the addition of turbidity to simulate high runoff storm events. Under each condition, adult survival for a time period of 21 days exceeded 98%, ruling out water chemistry or turbidity as a factor. Spawning was investigated using mussels collected from Lake Pleasant in August 2015. In 4 trials of serotonin dosage between 0.5 – 1.0 mMol, spawning was not successful. Calanoid copepod predation was also investigated by field sampling at Lake Pleasant, Saguaro Lake, and Bartlett Lake during September 2015. Calanoid copepods were identified in Lake Pleasant at a density of 104.22 individuals per cubic meter at a depth of 2 meters and 9.75 individuals per cubic meter at the surface. Calanoid copepods were not found in Bartlett Lake or Saguaro Lake, ruling out copepod predation as a factor. Finally, dissolved oxygen and temperature trends were analyzed in each reservoir. While temperature profiles are similar throughout the year, seasonal drops in dissolved oxygen below survivable concentrations for D. bugensis has been observed in both Saguaro Lake and Bartlett Lake but not Lake Pleasant, representing the most plausible explanation for no observed infestation.
ContributorsSokolowski, Matthew (Author) / Fox, Peter (Thesis advisor) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Arizona State University (Publisher)
Created2015
Description
Granular activated carbon (GAC) filters are final polishing step in the drinking water treatment systems for removal of dissolved organic carbon fractions. Generally filters are colonized by bacterial communities and their activity reduces biodegradable solutes allowing partial regeneration of GAC's adsorptive capacity. When the bacteria pass into the filtrate due to increased growth, microbiological quality of drinking water is compromised and regrowth in the distribution system occurs. Bacteria attached to carbon particles as biofilms or in conjugation with other bacteria were observed to be highly resistant to post filtration microbial mitigation techniques. Some of these bacteria were identified as pathogenic.
This study focuses on one such pathogen Legionella pneumophila which is resistant to environmental stressors and treatment conditions. It is also responsible for Legionnaires' disease outbreak through drinking water thus attracting attention of regulatory agencies. The work assessed the attachment and colonization of Legionella and heterotrophic bacteria in lab scale GAC media column filters. Quantification of Legionella and HPC in the influent, effluent, column's biofilms and on the GAC particles was performed over time using fluorescent microscopy and culture based techniques.
The results indicated gradual increase in the colonization of the GAC particles with HPC bacteria. Initially high number of Legionella cells were detected in the column effluent and were not detected on GAC suggesting low attachment of the cells to the particles potentially due to lack of any previous biofilms. With the initial colonization of the filter media by other bacteria the number of Legionella cells on the GAC particles and biofilms also increased. Presence of Legionella was confirmed in all the samples collected from the columns spiked with Legionella. Significant increase in the Legionella was observed in column's inner surface biofilm (0.25 logs up to 0.52 logs) and on GAC particles (0.42 logs up to 0.63 logs) after 2 months. Legionella and HPC attached to column's biofilm were higher than that on GAC particles indicating the strong association with biofilms. The bacterial concentration slowly increased in the effluent. This may be due to column's wall effect decreasing filter efficiency, possible exhaustion of GAC capacity over time and potential bacterial growth.
This study focuses on one such pathogen Legionella pneumophila which is resistant to environmental stressors and treatment conditions. It is also responsible for Legionnaires' disease outbreak through drinking water thus attracting attention of regulatory agencies. The work assessed the attachment and colonization of Legionella and heterotrophic bacteria in lab scale GAC media column filters. Quantification of Legionella and HPC in the influent, effluent, column's biofilms and on the GAC particles was performed over time using fluorescent microscopy and culture based techniques.
The results indicated gradual increase in the colonization of the GAC particles with HPC bacteria. Initially high number of Legionella cells were detected in the column effluent and were not detected on GAC suggesting low attachment of the cells to the particles potentially due to lack of any previous biofilms. With the initial colonization of the filter media by other bacteria the number of Legionella cells on the GAC particles and biofilms also increased. Presence of Legionella was confirmed in all the samples collected from the columns spiked with Legionella. Significant increase in the Legionella was observed in column's inner surface biofilm (0.25 logs up to 0.52 logs) and on GAC particles (0.42 logs up to 0.63 logs) after 2 months. Legionella and HPC attached to column's biofilm were higher than that on GAC particles indicating the strong association with biofilms. The bacterial concentration slowly increased in the effluent. This may be due to column's wall effect decreasing filter efficiency, possible exhaustion of GAC capacity over time and potential bacterial growth.
ContributorsSharma, Harsha (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study was devised to elucidate key information concerning the potential risk posed by Legionella in reclaimed water. A series of biological experiments and a recharge basin soil column study were conducted to examine the survival, growth, and transport of L. pneumophila through engineered reclaimed water systems. A pilot-scale, column study was set up to measure Legionella transport in the columns under Arizona recharge basin conditions. Two columns, A and B, were packed to a depth of 122 cm with a loamy sand media collected from a recharge basin in Mesa, Arizona. The grain size distribution of Column A differed from that of Column B by the removal of fines passing the #200 sieve. The different soil profiles represented by column A and B allowed for further investigation of soil attributes which influence the microbial transport mechanism. Both clear PVC columns stand at a height of 1.83 m with an inner diameter of 6.35 cm. Sampling ports were drilled into the column at the soil depths 15, 30, 60, 92, 122 cm. Both columns were acclimated with tertiary treated waste water and set to a flow rate of approximately 1.5 m/d. The columns were used to assess the transport of a bacterial indicator, E. coli, in addition to assessing the study's primary pathogen of concern, Legionella. Approximately, 〖10〗^7 to 〖10〗^9 E. coli cells or 〖10〗^6 to 〖10〗^7Legionella cells were spiked into the columns' head waters for each experiment. Periodically, samples were collected from each column's sampling ports, until a minimum of three pore volume passed through the columns.
The pilot-scale, column study produced novel results which demonstrated the mechanism for Legionella to be transported through recharge basin soil. E. coli was transported, through 122 cm of the media in under 6 hours, whereas, Legionella was transported, through the same distance, in under 30 hours. Legionella has been shown to survive in low nutrient conditions for over a year. Given the novel results of this proof of concept study, a claim can be made for the transport of Legionella into groundwater aquifers through engineering recharge basin conditions, in Central Arizona.
The pilot-scale, column study produced novel results which demonstrated the mechanism for Legionella to be transported through recharge basin soil. E. coli was transported, through 122 cm of the media in under 6 hours, whereas, Legionella was transported, through the same distance, in under 30 hours. Legionella has been shown to survive in low nutrient conditions for over a year. Given the novel results of this proof of concept study, a claim can be made for the transport of Legionella into groundwater aquifers through engineering recharge basin conditions, in Central Arizona.
ContributorsMcBurnett, Lauren Rae (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2014
Description
Legionella pneumophila is a waterborne pathogen that causes Legionnaires' disease, an infection which can lead to potentially fatal pneumonia. In a culture-based technique, Legionella is detected using buffered charcoal-yeast extract (BCYE) agar supplemented with L-cysteine, Iron salt and antibiotics. These supplements provide essential and complex nutrient requirements and help in the suppression of non-target bacteria in Legionella analysis. Legionella occurs naturally in freshwater environments and for their detection; a sample is plated on solid agar media and then incubated for several days. There are many challenges in the detection of Legionella in environmental waters and the built environments. A common challenge is that a variety of environmental bacteria can be presumptively identified as Legionella using the culture-based method. In addition, proper identification of Legionella requires long incubation period (3-9 days) while antibiotics used in BCYE agar have relatively short half-life time. In order to overcome some of the challenges, Legionella has been genetically modified to express reporter genes such Green Fluorescent Protein (GFP) that can facilitate its detection in process validation studies under controlled laboratory conditions. However, such studies had limited success due to the instability of genetically modified Legionella strains. The development of a genetically modified Legionella with a much rapid growth rate (1-2 days) in simulated environmental systems (tightly-controlled water distribution system) is achieved. The mutant Legionella is engineered by transforming with a specific plasmid encoding CymR, LacZ and TetR genes. The newly engineered Legionella can grow on conventional BCYE agar media without L-Cysteine, Iron salt and only require one antibiotic (Tetracycline) to suppress the growth of other microorganisms in media. To the best of our knowledge, this is the first report of L. pneumophila strain capable of growing without L-Cysteine. We believe that this discovery would not only facilitate the study of the fate and transport of this pathogen in environmental systems, but also further our understanding of the genetics and metabolic pathways of Legionella.
ContributorsAloraini, Saleh Ali A (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Alum, Absar (Committee member) / Arizona State University (Publisher)
Created2018
Description
Trails perform an essential function in protected lands by routing visitors along planned, sustainable surfaces. However, when visitors deviate from official trails in sufficient numbers, it can lead to the creation of social trails. These visitor-created pathways are not sustainably designed and can severely degrade both the stability and appearance of protected areas. A multitude of recreation motivations among visitors and a lack of resources among land management agencies have made the mitigation and closure of social trails a perennial concern. A sustainable, economical strategy that does not require the continual diversion of staff is needed to address social trails. In this study, two techniques that stand out in the research literature for their efficacy and practicality were tested on a social trail closure in South Mountain Park, a high-use, urban-proximate mountain park in Phoenix, AZ. A research design with additive treatments utilizing the site management technique known as trail mitigation, sometimes referred to as brushing in the literature, followed by theory-grounded signage incorporating injunctive-proscriptive wording, an attribution message, and a reasoning message targeting visitor behavioral beliefs, norms, and control was applied and assessed using unobtrusive observation. Both treatments reduced observed off-trail hiking from 75.4% to 0%, though traces of footsteps and attempts to re-open the trail revealed the existence of unobserved “entrenched” users. With entrenched users attempting to reopen the trail, trail mitigation represented an effective but vulnerable approach while the signage represented a long-lasting “hardened” approach that provides an educational message, management’s stance on the closure, and which might put social pressure on the entrenched user(s).
ContributorsRiske, Taylor (Author) / Budruk, Megha (Thesis advisor) / Andereck, Kathy (Committee member) / Avitia, Alonso (Committee member) / Arizona State University (Publisher)
Created2018