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- Drinking water (5)
- Climate change (4)
- Water quality (3)
- Disinfection by-products (2)
- EPS (2)
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- Ferrate (2)
- Oxidation (2)
- Wastewater (2)
- Adsorptive contactors (1)
- Aeration-free wastewater treatment (1)
- Agent-based model (1)
- Algae (1)
- Algal Growth Yield (1)
- Annular Flume (1)
- Artefacts (1)
- Batch hydrodynamic cultivation (1)
- Biofilms (1)
- Biological Nutrient Removal (1)
- Bromate (1)
- Buried Sanitation Infrastructure (1)
- Chlorination (1)
- Civil infrastructure (1)
- Coagulation (1)
- Competition (1)
- Complex curing reaction (1)
- Computational Fluid Dynamics (1)
- Contaminant (1)
- Conventional Activated Sludge (1)
- Coupled natural and human systems (1)
- Cross-linking (1)
Articles 1 - 23 of 23
Full-Text Articles in Engineering
Predicting Water Quality Vulnerability Under Climate Change With Machine Learning, Khanh Thi Nhu Nguyen
Predicting Water Quality Vulnerability Under Climate Change With Machine Learning, Khanh Thi Nhu Nguyen
Doctoral Dissertations
Water quality deterioration is a global and pervasive issue due to pollution caused by industrialization, urbanization, agriculturalization, and human population growth in the modern era. This issue is even more challenging in the context of climate change due to warming temperatures and the intensification of precipitation. Therefore, assessing the potential impacts of climate change on water quality is a concern. Assessment is necessary so that planners can prepare for and reduce the negative impacts on water quality. At present, climate change impact assessment frameworks are relatively adolescent. Most studies rely on climate projections from General Circulation Models for simulations of …
Enhancing Management Of Built And Natural Water And Sanitation Systems With Data Science, Nelson Da Luz
Enhancing Management Of Built And Natural Water And Sanitation Systems With Data Science, Nelson Da Luz
Doctoral Dissertations
In the age of the data revolution, the civil engineer can enhance the management of infrastructure systems using new techniques focused on data. This dissertation present three studies in which data science approaches are used to enhance management of water and sanitation systems in both the built and natural environments. Chapters 1 and 2 focus on improving methods for data collection relating to water quality monitoring. In Chapter 1, the efficacy of different water quality sampling program designs is evaluated as the programs relate to meeting monitoring goals. Considerations include how timing, location, and distribution system operations can affect monitoring …
The Role Of Extracellular Polymeric Substances In The Accumulation And Transport Of Polystyrene Nanoparticles In Biofilms, Joann Marie Rodríguez Suarez
The Role Of Extracellular Polymeric Substances In The Accumulation And Transport Of Polystyrene Nanoparticles In Biofilms, Joann Marie Rodríguez Suarez
Doctoral Dissertations
With the increasing number of nanotechnology applications, it is reasonable to expect nanoparticles to be ubiquitous in biofilms found in natural and engineered aquatic systems. We studied the impact of the degree of cross-linking on the deposition and diffusion of polystyrene nanoparticles (NPs) in alginate model biofilm matrices in the presence and absence of calcium cross-linkers using image correlation methods and single particle tracking. We found that cross-linking increases the viscoelasticity and hydration of the polymeric matrix and leads to structural changes that can restrict and alter the diffusive behavior of NPs, but the magnitude of the effects on diffusion …
Analysis And Fate Of 2,6-Dichloro-1,4-Benzoquinone In Real And Model Drinking Waters, Aarthi Mohan
Analysis And Fate Of 2,6-Dichloro-1,4-Benzoquinone In Real And Model Drinking Waters, Aarthi Mohan
Doctoral Dissertations
For many years chlorination has served as a barrier to protect human health from waterborne disease outbreaks. Chlorine is viewed as a near-universal oxidant and disinfectant, that provides a stable residual preventing microbial re-growth all the way through the consumer’s tap. Upon reaction with natural organic matter (NOM) however, it forms disinfection by-products (DBPs) many of which are potent human carcinogens and therefore have been of research interest since the 1970’s (Froese et al., 1999; Krasner et al., 2006, 1989; Richardson, 2003; Rook, 1976, 1974; Singer, 1994). The trihalomethanes (THMs) and haloacetic acids (HAAs) are the most prevalent (Krasner et …
Size Progression Of Oxygenic Photogranules (Opgs) And Its Effect On Opg Wastewater Treatment, Ahmed S.A. Abouhend
Size Progression Of Oxygenic Photogranules (Opgs) And Its Effect On Opg Wastewater Treatment, Ahmed S.A. Abouhend
Doctoral Dissertations
In recent years, the oxygenic photogranule (OPG) process has gained increasing interest because of its potential to treat wastewater without supplemental aeration. Oxygenic photogranules (OPGs) are dense spherical aggregates comprised of phototrophic and nonphototrophic microorganisms. In OPG wastewater treatment reactors, photogranules grow in number as well as in size. The primary goal of this dissertation was to investigate how OPGs grow in size and how the growth affects their structure and functions. We found that OPGs undergo structural changes as they grow bigger in size. As OPGs grow larger, filamentous cyanobacteria become enriched while other phototrophic microbes diminish significantly. OPGs …
Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari
Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari
Doctoral Dissertations
Oxygenic photogranules (OPGs) are dense spherical microbial aggregates that are used for self-aerating wastewater treatment. Filamentous cyanobacteria are key granulating species, providing structural backbone and integrity in OPGs. Currently, the mechanisms for selecting filamentous cyanobacteria and their ability to form spherical OPGs are not well understood. Literature shows that iron (Fe) availability plays a significant role in the cyanobacterial growth and colony formation. Moreover, Fe availability is known to be dependent upon light, which is an essential growth substrate for the phototrophs. This research has investigated the role of Fe in the photogranulation phenomenon and the impact of light intensity …
Scaling Up The Oxygenic Photogranule (Opg) Wastewater Treatment Process, Joseph G. Gitau
Scaling Up The Oxygenic Photogranule (Opg) Wastewater Treatment Process, Joseph G. Gitau
Doctoral Dissertations
Photogranular biomass has yet to be utilized at large scale for wastewater treatment despite their potential to lower energy demand due to self-aerating capacity in addition to better process control compared to conventional technologies. An evaluation of critical driving factors affecting scaling up has yet to be undertaken. The current generation of oxygenic photogranules under hydrostatic conditions (a deviation from orthodox conditions creating other granules) limit seeding of larger reactors in time and scale. In addition, evaluating the photosynthetic productivity of granules which exist as closely commingled consortia with tightly coupled production and consumption processes, has yet to be undertaken. …
Evaluating Policy And Climate Impacts On Water Resources Systems Using Coupled Human-Natural Models, Hassaan Furqan Khan
Evaluating Policy And Climate Impacts On Water Resources Systems Using Coupled Human-Natural Models, Hassaan Furqan Khan
Doctoral Dissertations
Extensive human intervention in the terrestrial hydrosphere means that virtually every river basin globally reflects the interaction between human and natural hydrologic processes. Thus, sustainable watershed management needs to not only account for the diverse ways humans benefit from the environment but also incorporate the impact of human actions on the natural system. Informed policy making to address our water challenges requires a comprehensive understanding of these feedbacks and how they might be affected by future changes in climate. This work develops coupled human-natural models for improved surface water and groundwater management in water-scarce regions under future changes in climate. …
Evaluation Of The Erodibility Of Soft Clays And The Influence Of Biopolymers, Pamela Judge
Evaluation Of The Erodibility Of Soft Clays And The Influence Of Biopolymers, Pamela Judge
Doctoral Dissertations
Erosion of silts and clays is less well understood than erosion of sands. Further, current and anticipated climate change impacts along coastlines compel consideration of new approaches to coastal protection measures; seawalls and breakwaters designs now include natural and nature-based measures. The first research topic consists of the Adaptive Gradients Framework which was a theoretically-informed facilitation tool. The framework was intended to aid a collaborative and interdisciplinary decision-making process to encourage inclusion of natural and nature-based measures in coastal protection planning and design. This research is the culmination of a series of workshops and fieldtrips executed by the Sustainable Adaptive …
Origins And Seasonal Variation Of Disinfection Byproduct Precursors, Ran Zhao
Origins And Seasonal Variation Of Disinfection Byproduct Precursors, Ran Zhao
Doctoral Dissertations
Disinfection byproducts (DBPs) are formed from the disinfectant (e.g., chlorine) reacting with components of natural organic matter (NOM) in water drawn from surface water supplies, and are considered as the cause of potential serious human health problems. DBP precursors originate in large reservoirs from at least three types of sources: (1) watershed or allochthonous, (2) algal or autochthonous, and (3) bottom sediments or benthic. The properties of the NOM and the DBP precursor content of that NOM are unique to each source. The first objective of this dissertation was to use temporal and spatial water quality data from a drinking …
Role Of Manganese Oxide In The Formation Of Disinfection Byproducts In Drinking Water Treatment, Arianne A. Bazilio
Role Of Manganese Oxide In The Formation Of Disinfection Byproducts In Drinking Water Treatment, Arianne A. Bazilio
Doctoral Dissertations
This work examined the role of manganese oxide (MnOx) in the formation of disinfection byproducts (DBPs) in drinking water treatment. DBPs are of increasing concern as more is being learned about their carcinogenicity and genotoxicity. Studies were performed to determine the impact of MnOx and free chlorine (Cl2), used for dissolved manganese (Mn(II) removal, on the formation of these undesirable byproducts. Batch experiment results showed that the presence of MnOx did not significantly increase the haloacetic acid or trihalomethane concentrations. Rates of DBP formation were also similar in the absence and presence of Mn(II) …
Microbial Competition In Bioelectrochemical Systems, Varun Srinivasan
Microbial Competition In Bioelectrochemical Systems, Varun Srinivasan
Doctoral Dissertations
Bioelectrochemical systems(BESs)/ microbial fuel fells (MFCs) are a well-studied potential technology for bioremediation and decentralized wastewater treatment. However, progress has been somewhat stalled at the bench-scale. In well controlled experiments electron recovery is high. In natural environments, wastewaters are complex and anode-respiring bacteria can be outcompeted in the presence of competing microorganisms, leading to a loss in electron-recovery and power production. Furthermore, the cathode of the MFC plays a vital role in providing flexibility for treatment options but is an understudied part of MFCs. Modelling Intracellular Competition in a Denitrifying Biocathode: One potential MFC configuration uses an organic-oxidizing anode biofilm …
Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel
Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel
Doctoral Dissertations
A uniform dispersion of reactants is necessary to achieve a complete reaction involving multi-components, especially for the crosslinking of rigid high-performance materials. In these reactions, miscibility is crucial for curing efficiency. This miscibility is typically enhanced by adding a third component, a plasticizer. For the reaction of the highly crystalline crosslinking agent hexamethylenetetramine (HMTA) with a strongly hydrogen-bonded phenol formaldehyde resin, furfural has been traditionally used as the plasticizer. However, the reason for its effectiveness is not clear. In this doctoral thesis work, miscibility and crosslinking efficiency of plasticizers in phenolic curing reactions are studied by thermal analysis and spectroscopic …
Decision Analytical Methods For Robust Water Infrastructure Planning Under Deep Uncertainty, Mehmet Umit Taner
Decision Analytical Methods For Robust Water Infrastructure Planning Under Deep Uncertainty, Mehmet Umit Taner
Doctoral Dissertations
Deep uncertainties resulting from climate change, demographic pressures, and rapidly evolving socioeconomic conditions are challenging the way that water planners design and operate large-scale infrastructure systems. Conventionally, water infrastructures have been developed using stationary methods, assuming that the underlying uncertainties can be derived from historical data or experience. However, these methods are less useful under deeply uncertain climate and socioeconomic conditions, in which the future can be substantially different from the past and cannot be expressed by well-defined probability distributions. The recognition of deep uncertainties in long-term water resources planning has led to the development of “decision-analytical” frameworks that do …
Microbial Dynamics And Design Considerations For Decentralized Microbial Fuel Cell Applications, Cynthia Castro
Microbial Dynamics And Design Considerations For Decentralized Microbial Fuel Cell Applications, Cynthia Castro
Doctoral Dissertations
The purpose of this dissertation was to assess the practicality of using microbial fuel cells (MFCs) as alternative sanitation systems for wastewater treatment and energy recovery, focusing on identifying key design considerations for treating high strength wastewater and managing alternative metabolic pathways. We evaluated the energetic outputs of a lab-based pilot MFC designed to treat complex organics present in both synthetic feces and municipal wastewater. The pilot MFC produced two energetic products, methane and electricity, when treating two types of complex wastewaters. The energetic products associated with anode respiration and methanogenesis were simultaneously observed and yielded a combined energy ouput …
Total Organic Iodine Quantification And Occurrence In Drinking Water, And Toxicity Assessment Of Iodinated Disinfection By-Products, Rassil El Sayess
Total Organic Iodine Quantification And Occurrence In Drinking Water, And Toxicity Assessment Of Iodinated Disinfection By-Products, Rassil El Sayess
Doctoral Dissertations
The focus of this work has been placed is on iodinated DBPs (I-DBPs), measured using total organic iodine (TOI), a surrogate measure of iodinated organics. This is due to the growing toxicity literature that places I-DBPs among the most toxic of all DBPs. To measure TOI in water, a new method was developed. This method combines adsorption, combustion, and trapping of combustion products, with an offline inductively coupled plasma/mass spectrometer (ICP-MS) for iodide detection. Three factors were varied across two levels each in order to optimize the method. The chosen method used a sample pH of less than 1 prior …
The Fate Of Haloacetonitriles In Drinking Waters, Yun Yu
The Fate Of Haloacetonitriles In Drinking Waters, Yun Yu
Doctoral Dissertations
The fate of HANs in drinking waters from their precursors in natural waters to their degradation products in consumers’ tap were systematically investigated in this study. Combined amino acids were proved reactive with chlorine to form DCAN under typical drinking water conditions. However, the rate of DCAN formation from bound aspartyl residues was much slower compared to free aspartic acid. The key to DCAN formation from combined amino acids was a chlorine-induced peptide degradation process, which slowly degraded the peptide backbone to continuously produce reactive amine functional groups at the N-terminal end. Particularly, when an N-terminal aspartyl residue …
Integrated Urban Metabolism Analysis Tool (Iumat), Nariman Mostafavi
Integrated Urban Metabolism Analysis Tool (Iumat), Nariman Mostafavi
Doctoral Dissertations
A number of tools are available today for simulating different aspects of urban activity, but these efforts are fragmented and do not effectively reflect the interrelationships between very diverse groups of urban sectors and resource flows. There is a critical need for robust and reliable urban metabolism analysis tools that integrate socio-economic elements of urbanization and physicality of the built environment into evaluating sustainability in cities. This dissertation outlines the development of an Integrated Urban Metabolism Analysis Tool (IUMAT) that dynamically measures the environmental impacts of land cover, transportation, and consumption of energy, water and materials employing a holistic framework. …
Predictive Modeling Of Riverine Constituent Concentrations And Loads Using Historic And Imposed Hydrologic Conditions, Mark Hagemann
Predictive Modeling Of Riverine Constituent Concentrations And Loads Using Historic And Imposed Hydrologic Conditions, Mark Hagemann
Doctoral Dissertations
This research was principally concerned with the task of quantifying dissolved and suspended constituents carried in river water when direct measurements are not available. This is a question of scientific and societal relevance, and one with a long history of study and a great deal of remaining difficulty. The traditional approach to estimating these quantities, linear regression models (LMs), suffers from poor flexibility and high subsequent bias in many applications. This research applied semiparametric generalized additive models (GAMs), a more flexible class of regression models, evaluated their performance in various locations and conditions, and applied them in a proactive modeling …
The Stability Of Ferrate(Vi) In Water And Its Impacts On Disinfection Byproduct Precursors, Yanjun Jiang
The Stability Of Ferrate(Vi) In Water And Its Impacts On Disinfection Byproduct Precursors, Yanjun Jiang
Doctoral Dissertations
Ferrate has been proposed as an alternative pre-oxidant in drinking water treatment for many years. Despite extensive studies that examined ferrate oxidation of specific contaminants, little research has been done on the impacts of ferrate in raw waters that include natural organic matter (NOM) and bromide, and that are also treated with coagulants and chlorine. The future of ferrate as a potable water treatment chemical depends on its ability to achieve adequate disinfection while minimizing the formation of disinfection byproducts (DBPs) under these realistic scenarios. In this work, laboratory-scale treatment studies were conducted to (1) clarify the stability of ferrate …
Proactive Assessment Of Climate Change And Contaminant Spill Impacts On Source Water Quality, Lillian C. Jeznach
Proactive Assessment Of Climate Change And Contaminant Spill Impacts On Source Water Quality, Lillian C. Jeznach
Doctoral Dissertations
Managing the water quality of surface drinking water sources has become an increasingly difficult task for water suppliers due to increased watershed urbanization and climate change. Changes in source water quality may affect public perceptions, treatment effectiveness, and ultimately costs to treat water to drinking standards. Although there are increased threats to current and future drinking water quality, current approaches to managing these threats are typically reactionary. Prior detailed modeling efforts of hypothetical events that may impair raw water quality allow for an understanding of constituent fate and transport, including potential maximum concentrations and travel times to the drinking water …
Investigation Of Effluent Nitrogen Derived From Conventional Activated Sludge (Cas) And Biological Nutrient Removal (Bnr) Systems And Its Impact On Algal Growth In Receiving Waters, Heonseop Eom
Doctoral Dissertations
The main objective of this research was to evaluate the effects of effluent nitrogen from conventional activated sludge (CAS) and biological nutrient removal (BNR) processes on eutrophication in receiving estuaries. To investigate differences in effluent nitrogen from CAS and BNR processes, lab-scale wastewater treatment systems having identical influent were operated under controlled conditions. This reactor study showed that the BNR system decreased nitrogen discharge by removing dissolved inorganic nitrogen (DIN) from wastewater but generated more effluent dissolved organic nitrogen (DON) than did the CAS system. The transition of treatment conditions from anoxic to oxic within the BNR process facilitated the …
Evaluation Of Ferrate Preoxidation For Drinking Water Treatment, Joseph E. Goodwill
Evaluation Of Ferrate Preoxidation For Drinking Water Treatment, Joseph E. Goodwill
Doctoral Dissertations
Ferrate (Fe(IV)) has been proposed as a viable alternative for pre-oxidation in drinking water treatment (Jiang & Lloyd, 2002; Sharma, Kazama, Jiangyong, & Ray, 2005). The primary advantages of ferrate include a strong oxidation potential without the formation of halogenated by-products. In addition, the by-product of ferrate oxidation, ferric iron (Fe(III)), may have beneficial impacts on downstream particle destabilization and removal processes. Also, ferrate has disinfectant properties and may also provide pathogen inactivation in drinking water (Sharma et al., 2005). However, despite these advantages, there is a dearth of research experience that examines the implications of using ferrate for treating …