Matching Items (1,106)
Filtering by
- Creators: Hindemith, Paul, 1895-1963
Description
The National Research Council 2011 report lists quantifying the extent of de facto (or unplanned) potable reuse in the U.S. as the top research need associated with assessing the potential for expanding the nations water supply through reuse of municipal wastewater. Efforts to identify the significance and potential health impacts of de facto water reuse are impeded by out dated information regarding the contribution of municipal wastewater effluent to potable water supplies. This project aims to answer this research need. The overall goal of the this project is to quantify the extent of de facto reuse by developing a model that estimates the amount of wastewater effluent that is present within drinking water treatment plants; and to use the model in conjunction with a survey to help assess public perceptions. The four-step approach to accomplish this goal includes: (1) creating a GIS-based model coupled with Python programming; (2) validating the model with field studies by analyzing sucralose as a wastewater tracer; (3) estimating the percentage of wastewater in raw drinking water sources under varying streamflow conditions; (4) and assessing through a social survey the perceptions of the general public relating to acceptance and occurrence of de facto reuse. The resulting De Facto Reuse in our Nations Consumable Supply (DRINCS) Model, estimates that treated municipal wastewater is present at nearly 50% of drinking water treatment plant intake sites serving greater than 10,000 people (N=2,056). Contrary to the high frequency of occurrence, the magnitude of occurrence is relatively low with 50% of impacted intakes yielding less than 1% de facto reuse under average streamflow conditions. Model estimates increase under low flow conditions (modeled by Q95), in several cases treated wastewater makes up 100% of the water supply. De facto reuse occurs at levels that surpass what is publically perceived in the three cities of Atlanta, GA, Philadelphia, PA, and Phoenix, AZ. Respondents with knowledge of de facto reuse occurrence are 10 times more likely to have a high acceptance (greater than 75%) of treated wastewater at their home tap.
ContributorsRice, Jacelyn (Author) / Westerhoff, Paul (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Vivoni, Enrique (Committee member) / Wutich, Amber (Committee member) / Arizona State University (Publisher)
Created2014
Description
Bacteria of the Legionella genus are a water-borne pathogen of increasing concern due to being responsible for more annual drinking water related disease outbreaks in the United States than all other microbes combined. Unfortunately, the development of public health policies concerning Legionella has impeded by several key factors, including a paucity of data on their interactions and growth requirements in water distribution networks, a poor understanding of potential transmission sources for legionellosis, and limitations in current methodology for the characterization of these pathogens. To address these issues, a variety of research approaches were taken. By measuring Legionella survival in tap water, association in pipe material biofilms, population dynamics in a model distribution system, and occurrence in drinking water distribution system biofilms, key aspects of Legionella ecology in drinking water systems were revealed. Through a series of experiments qualitatively and quantitatively examining the growth of Legionella via nutrients obtained from several water sources, environmental nutritional requirements and capability for growth in the absence of host organisms were demonstrated. An examination of automobile windshield washer fluid as a possible source of legionellosis transmission revealed Legionella survival in certain windshield washer fluids, growth within washer fluid reservoirs, high levels and frequency of contamination in washer fluid reservoirs, and the presence of viable cells in washer fluid spray, suggesting the potential for exposure to Legionella from this novel source. After performing a systematic and quantitative analysis of methodology optimization for the analysis of Legionella cells via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, several strains of this microbe isolated from separated and varied environmental water sampling sites were distinctly typed, demonstrating a potential application of this technology for the characterization of Legionella. The results from this study provide novel insight and methodology relevant to the development of programs for the monitoring and treatment of Legionella in drinking water systems.
ContributorsSchwake, David Otto (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2014
Description
Since its first report in 1976, many outbreaks of Legionella have been reported in the world. These outbreaks are a public health concern because of legionellosis, which cause Pontiac fever and Legionnaires disease. Legionnaires disease is a type of pneumonia responsible for the majority of the illness in the reported outbreaks. This study consists of an extensive literature review and experimental work on the aerosolization of Legionella and a bacterial surrogate under laboratory conditions. The literature review summarizes Legionella characteristics, legionellosis, potential sources of Legionella, disease outbreaks, collection and detection methodologies, environmental conditions for growth and survival of Legionella, Gaussian plume dispersion modeling, and recommendations for reducing potential Legionella outbreaks. The aerosolization and airborne dispersion of Legionella and E. coli was conducted separately inside of a closed environment. First, the bacterial cells were sprayed inside of an airtight box and then samples were collected using a microbial air sampler to measure the number of bacterial cells aerosolized and transported in air. Furthermore, a Gaussian plume dispersion model was used to estimate the dispersion under the experimental conditions and parameters. The concentration of Legionella was estimated for a person inhaling the air at three different distances away from the spray. The concentration of Legionella at distances of 0.1 km, 1 km, and 10 km away from the source was predicted to be 1.7x10-1, 2.2x10-3, and 2.6x10-5 CFU/m3, respectively.
ContributorsTaghdiri, Sepideh (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Estes, Robert (Committee member) / Arizona State University (Publisher)
Created2014
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
Research in microbial biofuels has dramatically increased over the last decade. The bulk of this research has focused on increasing the production yields of cyanobacteria and algal cells and improving extraction processes. However, there has been little to no research on the potential impact of viruses on the yields of these phototrophic microbes for biofuel production. Viruses have the potential to significantly reduce microbial populations and limit their growth rates. It is therefore important to understand how viruses affect phototrophic microbes and the prevalence of these viruses in the environment. For this study, phototrophic microbes were grown in glass bioreactors, under continuous light and aeration. Detection and quantification of viruses of both environmental and laboratory microbial strains were measured through the use of a plaque assay. Plates were incubated at 25º C under continuous direct florescent light. Several environmental samples were taken from Tempe Town Lake (Tempe, AZ) and all the samples tested positive for viruses. Virus free phototrophic microbes were obtained from plaque assay plates by using a sterile loop to scoop up a virus free portion of the microbial lawn and transferred into a new bioreactor. Isolated cells were confirmed virus free through subsequent plaque assays. Viruses were detected from the bench scale bioreactors of Cyanobacteria Synechocystis PCC 6803 and the environmental samples. Viruses were consistently present through subsequent passage in fresh cultures; demonstrating viral contamination can be a chronic problem. In addition TEM was performed to examine presence or viral attachment to cyanobacterial cells and to characterize viral particles morphology. Electron micrographs obtained confirmed viral attachment and that the viruses detected were all of a similar size and shape. Particle sizes were measured to be approximately 50-60 nm. Cell reduction was observed as a decrease in optical density, with a transition from a dark green to a yellow green color for the cultures. Phototrophic microbial viruses were demonstrated to persist in the natural environment and to cause a reduction in algal populations in the bioreactors. Therefore it is likely that viruses could have a significant impact on microbial biofuel production by limiting the yields of production ponds.
ContributorsKraft, Kyle (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
Analysis of photocatalysis for precursor removal and formation inhibition of disinfection byproducts
Description
Disinfection byproducts are the result of reactions between natural organic matter (NOM) and a disinfectant. The formation and speciation of DBP formation is largely dependent on the disinfectant used and the natural organic matter (NOM) concentration and composition. This study examined the use of photocatalysis with titanium dioxide for the oxidation and removal of DBP precursors (NOM) and the inhibition of DBP formation. Water sources were collected from various points in the treatment process, treated with photocatalysis, and chlorinated to analyze the implications on total trihalomethane (TTHM) and the five haloacetic acids (HAA5) formations. The three sub-objectives for this study included: the comparison of enhanced and standard coagulation to photocatalysis for the removal of DBP precursors; the analysis of photocatalysis and characterization of organic matter using size exclusion chromatography and fluorescence spectroscopy and excitation-emission matrices; and the analysis of photocatalysis before GAC filtration. There were consistencies in the trends for each objective including reduced DBP precursors, measured as dissolved organic carbon DOC concentration and UV absorbance at 254 nm. Both of these parameters decreased with increased photocatalytic treatment and could be due in part to the adsorption to as well as the oxidation of NOM on the TiO2 surface. This resulted in lower THM and HAA concentrations at Medium and High photocatalytic treatment levels. However, at No UV exposure and Low photocatalytic treatment levels where oxidation reactions were inherently incomplete, there was an increase in THM and HAA formation potential, in most cases being significantly greater than those found in the raw water or Control samples. The size exclusion chromatography (SEC) results suggest that photocatalysis preferentially degrades the higher molecular mass fraction of NOM releasing lower molecular mass (LMM) compounds that have not been completely oxidized. The molecular weight distributions could explain the THM and HAA formation potentials that decreased at the No UV exposure samples but increased at Low photocatalytic treatment levels. The use of photocatalysis before GAC adsorption appears to increase bed life of the contactors; however, higher photocatalytic treatment levels have been shown to completely mineralize NOM and would therefore not require additional GAC adsorption after photocatalysis.
ContributorsDaugherty, Erin (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Mayer, Brooke (Committee member) / Arizona State University (Publisher)
Created2011
Description
Nanotechnology is a scientific field that has recently expanded due to its applications in pharmaceutical and personal care products, industry and agriculture. As result of this unprecedented growth, nanoparticles (NPs) have become a significant environmental contaminant, with potential to impact various forms of life in environment. Metal nanoparticles (mNPs) exhibit unique properties such as increased chemical reactivity due to high specific surface area to volume ratios. Bacteria play a major role in many natural and engineered biogeochemical reactions in wastewater treatment plants and other environmental compartments. I have evaluated the laboratory isolates of E. coli, Bacillus, Alcaligenes, Pseudomonas; wastewater isolates of E. coli and Bacillus; and pathogenic isolate of E. coli for their response to 50 & 100 nm sized Cu nanoparticles (CuNPs). Bactericidal tests, scanning electron microscopy (SEM) analyses, and probable toxicity pathways assays were performed. The results indicate that under continuous mixing conditions, CuNPs are effective in inactivation of the selected bacterial isolates. In general, exposure to CuNPs resulted in 4 to >6 log reduction in bacterial population within 2 hours. Based on the GR, LDH and MTT assays, bacterial cells showed different toxicity elicitation pathways after exposure to CuNPs. Therefore, it can be concluded that the laboratory isolates are good candidates for predicting the behavior of environmental isolates exposed to CuNPs. Also, high inactivation values recorded in this study suggest that the presence of CuNPs in different environmental compartments may have an impact on pollutants attenuation and wastewater biological treatment processes. These results point towards the need for an in depth investigation of the impact of NPs on the biological processes; and long-term effect of high load of NPs on the stability of aquatic and terrestrial ecologies.
ContributorsAlboloushi, Ali (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Olson, Larry (Committee member) / Arizona State University (Publisher)
Created2012
Description
Water quality in surface water is frequently degraded by fecal contamination from human and animal sources, imposing negative implications for recreational water use and public safety. For this reason it is critical to identify the source of fecal contamination in bodies of water in order to take proper corrective actions for controlling fecal pollution. Bacteroides genetic markers have been widely used to differentiate human from other sources of fecal bacteria in water. The results of this study indicate that many assays currently used to detect human-specific Bacteroides produce false positive results in the presence of freshwater fish. To further characterize Bacteroides from fish and human, the fecal samples were cultured, speciated, and identified. As a result, forty six new Bacteroides 16S rRNA gene sequences have been deposited to the NCBI database. These sequences, along with selected animal fecal sample Bacteroides, were aligned against human B. volgatus, B. fragilis, and B. dorei to identify multi-segmented variable regions within the 16S rRNA gene sequence. The collected sequences were truncated and used to construct a cladogram, showing a clear separation between human B. dorei and Bacteroides from other sources. A proposed strategy for source tracking was field tested by collecting water samples from central AZ source water and three different recreational ponds. PCR using HF134 and HF183 primer sets were performed and sequences for positive reactions were then aligned against human Bacteroides to identify the source of contamination. For the samples testing positive using the HF183 primer set (8/13), fecal contamination was determined to be from human sources. To confirm the results, PCR products were sequenced and aligned against the four variable regions and incorporated within the truncated cladogram. As expected, the sequences from water samples with human fecal contamination grouped within the human clade. As an outcome of this study, a tool box strategy for Bacteroides source identification relying on PCR amplification, variable region analysis, human-specific Bacteroides PCR assays, and subsequent truncated cladogram grouping analysis has been developed. The proposed strategy offers a new method for microbial source tracking and provides step-wise methodology essential for identifying sources of fecal pollution.
ContributorsKabiri-Badr, Leila (Author) / Abbaszadegan, Morteza (Thesis advisor) / Bingham, Scott (Committee member) / Rock, Channah (Committee member) / Fox, Peter (Committee member) / Mclain, Jean (Committee member) / Arizona State University (Publisher)
Created2012
Description
Bacteroides have been suggested as alternative indicators of fecal pollution since they are highly abundant in feces and are thought to have limited potential to grow in environment. However, recent literature suggests that Bacteroides can potentially survive within water distribution systems. The first objective of this study was therefore to investigate the validity of Bacteroides as a fecal indicator for drinking water through laboratory experiments and field studies. Experiments were performed using a laboratory scale PVC model water distribution system that was spiked with 109 Bacteroides. Samples were collected over the following four and analyzed by culture and molecular-based techniques. Second, field studies were performed by collecting water meters from two large chlorinated water distribution systems in central Arizona. Upon removal for repair by city personnel, meters were collected and biofilms samples were gathered within two hours. The biofilms were then analyzed using culture and molecular-based assays. The results from these studies support the hypothesis that Bacteroides DNA may be found in water distribution systems despite the difficulty of cultivating these bacterial cells. These experiments present the importance of considering biofilm interactions with fecal indicator bacteria when performing molecular assays on environmental samples, as biofilms may provide protection from high oxygen concentrations and grazing protozoa in bulk water that limit the persistence Bacteroides in the environment. Although the significance of biofilm interactions with surface or recreational waters may be small, they are likely important when considering drinking water delivered through distribution systems. The second objective of this study was to investigate alternative detection methodologies for the fecal indicator Bacteroides. In particular, this study focused on using a simplified protocol of Nucleic Acid Sequence Based Amplification (NASBA) and Thermophilic Helicase-Dependent Amplification (tHDA) to amplify the highly conserved 16s rRNA gene in the genomic DNA of fecal indicator Bacteroides. The results of this study show that the simplified NASBA procedure was not able to amplify the target, while continuous problems with tHDA exposed the methods lack of reliability. These results suggest higher reliability in the isothermal amplification methods needs to be achieved before application to environmental samples.
ContributorsDunkin, Nate (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2012