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- Genre: Doctoral Dissertation
Description
This thesis research focuses on phylogenetic and functional studies of microbial communities in deep-sea water, an untapped reservoir of high metabolic and genetic diversity of microorganisms. The presence of photosynthetic cyanobacteria and diatoms is an interesting and unexpected discovery during a 16S ribosomal rRNA-based community structure analyses for microbial communities in the deep-sea water of the Pacific Ocean. Both RT-PCR and qRT-PCR approaches were employed to detect expression of the genes involved in photosynthesis of photoautotrophic organisms. Positive results were obtained and further proved the functional activity of these detected photosynthetic microbes in the deep-sea. Metagenomic and metatranscriptomic data was obtained, integrated, and analyzed from deep-sea microbial communities, including both prokaryotes and eukaryotes, from four different deep-sea sites ranging from the mesopelagic to the pelagic ocean. The RNA/DNA ratio was employed as an index to show the strength of metabolic activity of deep-sea microbes. These taxonomic and functional analyses of deep-sea microbial communities revealed a `defensive' life style of microbial communities living in the deep-sea water. Pseudoalteromonas sp.WG07 was subjected to transcriptomic analysis by application of RNA-Seq technology through the transcriptomic annotation using the genomes of closely related surface-water strain Pseudoalteromonas haloplanktis TAC125 and sediment strain Pseudoalteromonas sp. SM9913. The transcriptome survey and related functional analysis of WG07 revealed unique features different from TAC125 and SM9913 and provided clues as to how it adapted to its environmental niche. Also, a comparative transcriptomic analysis of WG07 revealed transcriptome changes between its exponential and stationary growing phases.
ContributorsWu, Jieying (Author) / Meldrum, Deirdre R. (Thesis advisor) / Zhang, Weiwen (Committee member) / Abbaszadegan, Morteza (Committee member) / Neuer, Susanne (Committee member) / Arizona State University (Publisher)
Created2013
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
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
The objective of this research was to predict the persistence of potential future contaminants in indirect potable reuse systems. In order to accurately estimate the fates of future contaminants in indirect potable reuse systems, results describing persistence from EPI Suite were modified to include sorption and oxidation. The target future contaminants studied were the approximately 2000 pharmaceuticals currently undergoing testing by United States Food and Drug Administration (US FDA). Specific organic substances such as analgesics, antibiotics, and pesticides were used to verify the predicted half-lives by comparing with reported values in the literature. During sub-surface transport, an important component of indirect potable reuse systems, the effects of sorption and oxidation are important mechanisms. These mechanisms are not considered by the quantitative structure activity relationship (QSAR) model predictions for half-lives from EPI Suite. Modifying the predictions from EPI Suite to include the effects of sorption and oxidation greatly improved the accuracy of predictions in the sub-surface environment. During validation, the error was reduced by over 50% when the predictions were modified to include sorption and oxidation. Molecular weight (MW) is an important criteria for estimating the persistence of chemicals in the sub-surface environment. EPI Suite predicts that high MW compounds are persistent since the QSAR model assumes steric hindrances will prevent transformations. Therefore, results from EPI Suite can be very misleading for high MW compounds. Persistence was affected by the total number of halogen atoms in chemicals more than the sum of N-heterocyclic aromatics in chemicals. Most contaminants (over 90%) were non-persistent in the sub-surface environment suggesting that the target future drugs do not pose a significant risk to potable reuse systems. Another important finding is that the percentage of compounds produced from the biotechnology industry is increasing rapidly and should dominate the future production of pharmaceuticals. In turn, pharmaceuticals should become less persistent in the future. An evaluation of indirect potable reuse systems that use reverse osmosis (RO) for potential rejection of the target contaminants was performed by statistical analysis. Most target compounds (over 95%) can be removed by RO based on size rejection and other removal mechanisms.
ContributorsLim, Seung (Author) / Fox, Peter (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Halden, Rolf (Committee member) / Arizona State University (Publisher)
Created2011
Description
The deterioration of drinking-water quality within distribution systems is a serious cause for concern. Extensive water-quality deterioration often results in violations against regulatory standards and has been linked to water-borne disease outbreaks. The causes for the deterioration of drinking water quality inside distribution systems are not yet fully understood. Mathematical models are often used to analyze how different biological, chemical, and physical phenomena interact and cause water quality deterioration inside distribution systems. In this dissertation research I developed a mathematical model, the Expanded Comprehensive Disinfection and Water Quality (CDWQ-E) model, to track water quality changes in chloraminated water. I then applied CDWQ-E to forecast water quality deterioration trends and the ability of Naegleria fowleri (N.fowleri), a protozoan pathogen, to thrive within drinking-water distribution systems. When used to assess the efficacy of substrate limitation versus disinfection in controlling bacterial growth, CDWQ-E demonstrated that bacterial growth is more effectively controlled by lowering substrate loading into distribution systems than by adding residual disinfectants. High substrate concentrations supported extensive bacterial growth even in the presence of high levels of chloramine. Model results also showed that chloramine decay and oxidation of organic matter increase the pool of available ammonia, and thus have potential to advance nitrification within distribution systems. Without exception, trends predicted by CDWQ-E matched trends observed from experimental studies. When CDWQ-E was used to evaluate the ability N. fowleri to survive in finished drinking water, the model predicted that N. fowleri can survive for extended periods of time in distribution systems. Model results also showed that N. fowleri growth depends on the availability of high bacterial densities in the 105 CFU/mL range. Since HPC levels this high are rarely reported in bulk water, it is clear that in distribution systems biofilms are the prime reservoirs N. fowleri because of their high bacterial densities. Controlled laboratory experiments also showed that drinking water can be a source of N. fowleri, and the main reservoir appeared to be biofilms dominated by bacteria. When introduced to pipe-loops N. fowleri successfully attached to biofilms and survived for 5 months.
ContributorsBiyela, Precious Thabisile (Author) / Rittmann, Bruce E. (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Butler, Caitlyn (Committee member) / Arizona State University (Publisher)
Created2010
Description
Bacterial biofilms exist on surfaces within pressurized water systems, posing threats to water quality and causing fouling or microbial induced corrosion. Germicidal UV irradiation has shown promise in deactivating planktonic pathogens in water but challenges in delivering light to surfaces where biofilms exist have limited advancement in understanding biofilm response to UV-C light. This dissertation aims to overcome the limitation of delivering UV-C light through use of side-emitting optical fibers (SEOFs), advance capabilities to produce SEOFs and understand if a minimum UV-C irradiance can prevent biofilm formation. Two scalable manufacturing approaches were developed for producing kilometer lengths of thin (≤500-µm) and physically flexible SEOFs. One strategy involved dip-coating amine-functionalized SiO2 nanoparticles (NPs) on bare optical fiber, followed by a coating of UV-C transparent polymer (CyTop). I showed that NPs closer to the surface achieved with higher ionic strength solutions increased side-scattering of UV-C light. This phenomenon was primarily attributed to the interaction between NPs and evanescent wave energy. The second strategy omitted NPs but utilized a post-treatment to the UV-C transparent polymer that increased surface roughness on the outer fiber surface. This modification maintained the physical flexibility of the fiber while promoting side-emission of UV-C light. The side emission was due to the enhancement of refracted light energy. Both methods were successfully scaled up for potential commercial production.
Experimental platforms were created to study biofilm responses to UV light on metal or flexible plastic pipe (1/4” ID) surfaces. Delivering UV-C light via SEOFs with irradiances >8 µW/cm2 inhibited biofilm accumulation. Neither UV-A nor UV-B light inhibited biofilm growth. At very low UV-C irradiance (<3 µW/cm2), biofilms were not inhibited. Functional genomic analysis revealed that biofilms irradiated by insufficient UV-C irradiance upregulated various essential genes related to DNA repair, energy metabolism, quorum sensing, mobility, and EPS synthesis. When net UV-C biofilm inactivation rates exceeded the biofilm growth rate, biofilms were inhibited. Insights gained from this dissertation work shed light on the prospective applications of UV-C technology in addressing biofilm challenges within water infrastructure across multiple sectors, from potable water to healthcare applications.
ContributorsZhao, Zhe (Author) / Westerhoff, Paul (Thesis advisor) / Rittmann, Bruce (Committee member) / Abbaszadegan, Morteza (Committee member) / Álvarez, Pedro (Committee member) / Arizona State University (Publisher)
Created2023
Description
Water quality assessment is essential for maintaining healthy ecosystems and protecting human health. Data interrogation and exploratory data analysis techniques are used to analyze the spatial and temporal variability of water quality parameters, identifying correlations, and to better understand the factors that impacts microbial and chemical quality of water. The seasonal dynamics of microbiome in surface waters were investigated to identify the factors driving these dynamics. Initial investigation analyzed two decades of regional water quality data from 20 various locations in Central Arizona, USA. Leveraging advanced data science techniques, the study uncovered correlations between crucial parameters, including dissolved organic carbon (DOC), ultraviolet absorbance (UVA), and specific ultraviolet absorbance (SUVA). These findings provide foundational insights into the dynamic of overall water quality. A comprehensive 12-month surface water sample collection and study was conducted to investigate potential bias in bacterial detection using EPA approved Membrane Filtration (MF) technique. The results underscore that while MF excels in recovering bacteria of public health significance, it exhibits biases, particularly against small and spore-forming bacteria and Archaea, such as Bacilli, Mollicutes, Methylacidiphilae, and Parvarchaea. This emphasizes the importance of complementing standard microbiology approaches to mitigate technological biases and enhance the accuracy of microbial water quality testing, especially for emerging pathogens. Furthermore, a complementary study of microbial dynamics within a model drinking water distribution systems (DWDSs) using treated water from the same source water as the above study. The influence of pipe material and water temperature on the microbiome and trace element composition was investigated. The research unveiled a preferential link between pipe material and trace elements, with water temperature significantly impacting the microbiome to a higher degree than the chemical composition of water. Notably, Legionellaceae and Mycobacteriaceae were found to be prevalent in warmer waters, highlighting the substantial influence of water temperature on the microbiome, surpassing that of pipe material. These studies provide comprehensive insights into the spatial and temporal variability of water quality parameters. Analyzing microbial data in depth is crucial in detecting bacterial species within a monitoring program for adjusting operational conditions to reduce the presence of microbial pathogens and enhance the quality of drinking water.
ContributorsAloraini, Saleh (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Perreault, Francois (Committee member) / Alum, Absar (Committee member) / Arizona State University (Publisher)
Created2023
Description
This dissertation focused on studying risks associated with emerging drinking water contaminants and tradeoffs related to water management interventions. The built environment impacts health, as humans on average spend ~90% of their time indoors. Federal regulations generally focus on drinking water at the water treatment plant and within the distribution system as opposed to when it enters buildings after crossing the property line. If drinking water is not properly managed in buildings, it can be a source or amplifier of microbial and chemical contaminants. Unlike regulations for chemical contaminants that are risk-based, for pathogens, regulations are either based on recommended treatment technologies or designated as zero, which is not achievable in practice. Practice-based judgments are typically made at the building level to maintain water quality. This research focuses on two drinking water opportunistic pathogens of public health concern, Legionella pneumophila and Mycobacterium avium complex (MAC). Multiple aspects of drinking water quality in two green buildings were monitored in tandem with water management interventions. Additionally, a quantitative microbial risk assessment framework was used to predict risk-based critical concentrations of MAC for drinking water-related exposures in the indoor environment corresponding to a 1 in 10,000 annual infection target risk benchmark. The overall goal of this work was to inform the development of water management plans and guidelines for buildings that will improve water quality in the built environment and promote better public health. It was determined that a whole building water softening system with ion exchange softening resin and expansion tanks were unexplored reservoirs for the colonization of L. pneumophila. Furthermore, it was observed that typical water management interventions such as flushing and thermal disinfection did not always mitigate water quality issues. Thus, there was a need to implement several atypical interventions such as equipment replacement to improve the building water quality. This work has contributed comprehensive field studies and models that have highlighted the need for additional niches, facility management challenges, and risk tradeoffs for focus in water safety plans. The work also informs additional risk-based water quality policy approaches for reducing drinking water risks.
ContributorsJoshi, Sayalee (Author) / Hamilton, Kerry A (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Conroy-Ben, Otakuye (Committee member) / Halden, Rolf (Committee member) / Arizona State University (Publisher)
Created2023
Description
In the recent years, there have been massive technological advancements which have led to increased radical industrialization resulting in a significant impact on the environment. Effluents and by-products of the production processes from industries such as pharmaceutical and personal care products (PPCPs) have increased the concerns of “emerging contaminants” (ECs) in surface waters and drinking water systems. This study focuses on the treatment of emerging chemical contaminants including nitrosodimethylamine (NDMA) and 1,4-dioxane. In addition, the inactivation of microbial contaminants of concern in water including E. coli, Legionella, Mycobacterium and fungal spores were studied using the same treatment technologies. The ECs chosen are not susceptible to conventional treatment process and there still remains a need for alternate processes for their removing/remediating to ensure safe drinking water. The treatment technologies utilized were Advanced Oxidation Processes (AOP) involving UV 220 /254 nm employing an excimer lamp and a low-pressure mercury lamp with ReFLeXTM technology and peracetic acid (PAA). The main objective of this study was to develop a new alternate technology for the enhanced remediation of chemical and microorganisms of concerns in water. The specific research objectives included: 1) To study the efficacy of the UV system to treat the selected contaminants. 2) To study the effect of PAA on the remediation of the contaminants. 3) To explore a new AOP technology under dynamic flow conditions with varying UV and PAA doses. 4) To determine optimized UV and PAA dosages to obtain enhanced remediation of the selected contaminant under dynamic flow conditions to better mimic the real-world applications.
ContributorsNatekar, Sunny Anand (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Alum, Absar (Committee member) / Diefenthal, George (Committee member) / Arizona State University (Publisher)
Created2021
Description
Monitoring human exposure to chemicals posing public health threats is critically important for risk management and for informing regulatory actions. Chemical threats result from both environmental pollutants and elected substance use (e.g., consumption of drugs, alcohol and tobacco). Measuring chemical occurrence and concentrations in environmental matrices can help to pinpoint human exposure routes. For instance, indoor dust, a sink of indoor environmental contaminants, can serve to assess indoor air contamination and associated human exposures. Urban wastewater arriving at treatment plants contains urine and stool from the general population, the analysis of which can provide information on chemical threats in the community and ongoing harmful exposures. Analysis of sewage sludge can serve to reveal the identity and quantity of persistent organic pollutants in cities and inform estimates of toxic body burdens in local populations.
The objective of this dissertation was to investigate the occurrence and quantity of select, potentially harmful, anthropogenic chemicals in various environmental matrices and to explore the diagnostic value of analytical assays for informing public health decision-making. This dissertation (i) is the first to report spatio-temporal variations and estrogenic burdens of five parabens in sewage sludge from at the U.S. nationwide scale; (ii) represents the first China-wide survey to assess the occurrence and toxic emissions of parabens, triclosan, triclocarban, as well as triclocarban metabolites and transformation products contained in Chinese sewage sludge; (iii) documents the first use of a dispersive solid phase extraction method for indoor dust to measure dust-borne parabens, triclosan and triclocarban and estimating associated human exposures from dust ingestion; and (iv) is the first U.S. study to assess population-level alcohol and nicotine consumption in three U.S. communities using wastewater-based epidemiology (WBE). Obtained data on baseline levels of selected emerging contaminants in sewage sludge and indoor dust can serve to inform the future monitoring needs, risk assessment, and policy making. This work showcases the utility of WBE and urban metabolism metrology via dust and sewage sludge analysis to assess human behavior (e.g., drinking and smoking) and exposure risks more rapidly, efficiently and anonymously than traditional approaches can.
The objective of this dissertation was to investigate the occurrence and quantity of select, potentially harmful, anthropogenic chemicals in various environmental matrices and to explore the diagnostic value of analytical assays for informing public health decision-making. This dissertation (i) is the first to report spatio-temporal variations and estrogenic burdens of five parabens in sewage sludge from at the U.S. nationwide scale; (ii) represents the first China-wide survey to assess the occurrence and toxic emissions of parabens, triclosan, triclocarban, as well as triclocarban metabolites and transformation products contained in Chinese sewage sludge; (iii) documents the first use of a dispersive solid phase extraction method for indoor dust to measure dust-borne parabens, triclosan and triclocarban and estimating associated human exposures from dust ingestion; and (iv) is the first U.S. study to assess population-level alcohol and nicotine consumption in three U.S. communities using wastewater-based epidemiology (WBE). Obtained data on baseline levels of selected emerging contaminants in sewage sludge and indoor dust can serve to inform the future monitoring needs, risk assessment, and policy making. This work showcases the utility of WBE and urban metabolism metrology via dust and sewage sludge analysis to assess human behavior (e.g., drinking and smoking) and exposure risks more rapidly, efficiently and anonymously than traditional approaches can.
ContributorsChen, Jing (Author) / Halden, Rolf U. (Thesis advisor) / Borges, Chad R (Committee member) / Abbaszadegan, Morteza (Committee member) / Arizona State University (Publisher)
Created2018