Engineering Commons^™

Influence Of Photoreactor Design Parameters On The Performance Of Ultraviolet Light-Induced Degradation Of Per-And Polyfluoroalkyl Substances By Bismuth Oxy Hydroxy Phosphate And Hexagonal Boron Nitride Photocatalystsinfluence Of Photoreactor Design Parameters On The Performance Of Ultraviolet Light-Induced Degradation Of Per-And Polyfluoroalkyl Substances By Bismuth Oxy Hydroxy Phosphate And Hexagonal Boron Nitride Photocatalysts, Mojtaba Qanbarzadeh

All Dissertations

The main objective of this study is to evaluate the practical applicability of heterogeneous photocatalysis technology powered by ultraviolet (UV) photons for the degradation of per and -polyfluoroalkyl substances (PFAS) in contaminated groundwater samples. For this purpose, bismuth oxyhydroxy phosphate (BOHP) and hexagonal boron nitride (hBN) were utilized as the main photocatalysts in slurry photodegradation systems. BOHP (Bi₃O(OH)(PO₄)₂) is a wide bandgap semiconductor with high activity for degrading long-chain perfluorocarboxylic acids (PFCAs) in mild operational conditions. Boron nitride (BN) is another wide bandgap semiconductor material that was used in this study due to its …

Nanobubble Technology For The Removal Of Mib And Geosmin From Drinking Water, Meryem Soyluoglu

All Dissertations

The presence of taste and odor (T&O) compounds in drinking water has been historically a major challenge for water utilities. They are difficult to remove using conventional water treatment processes, a combination of coagulation, flocculation, sedimentation, filtration, and chlorination. However, activated carbon (AC) adsorption, advanced oxidation processes, and biofiltration can be effective. The seasonal nature of T&O events makes it difficult to justify installing dedicated treatment technologies. Additionally, incorporating these technologies into existing water treatment plants can be expensive and require significant upgrades. Therefore, water utilities are always interested in exploring new approaches to minimize the occurrence and removal of …

The Cr(Iii) Exchange Mechanism Of Macroporous Resins: The Effect Of Functionality And Chemical Matrix, And The Statistical Verification Of Ion Exchange Data, Khizar Hussain Shah, Noor S. Shah, Gul Afshan Khan, Sadaf Sarfraz, Jibran Iqbal, Aneeqa Batool, Ahmad Jwuiyad, Shabnam Shahida, Changseok Han, Monika Wawrzkiewicz

All Works

This study focuses on investigating and comparing the influence of the surface functional groups and chemical matrices of macroporous resin on the Cr(III) exchange mechanism. The results discussed herein indicate that sulfonic resin removed Cr(III) ions with faster kinetics than carboxylic resin. Equilibrium was established within 15 and 7 min for the carboxylic and sulfonic resins, respectively, with a 99.5% removal efficiency at 333 K. The Langmuir exchange capacity was observed to be higher for the sulfonic resin (1.5 mmol∙g−1) than the carboxylic resin (0.80 mmol∙g−1) at 333 K. The adsorption isotherms obtained for the carboxylic and sulfonic resins were …

Enhancing Performance Of Gravity Driven Membranes For Water Purification In Small Rural Communities, Amr Ezzat Melligy Mr.

Theses and Dissertations

Due to the rapid population growth in Egypt, providing safe drinking water is becoming an ongoing challenge especially in rural scattered communities. It became more crucial than ever to find innovative and affordable solutions to purify water and reduce water-borne diseases. Ultrafiltration and micro-filtration membranes has been successful in large, centralized plants and is currently one of the popular solutions to provide high quality product water. However, using those membrane systems in rural areas is challenged by several parameters; among which are; the absence of skilled workers, stable energy sources and availability of chemicals. The goal of this thesis is …

Accessing The Relative Sustainability Of Point-Of-Use Water Disinfection Technologies Through Costs And Environmental Impacts, Bright C. Elijah

Electronic Theses and Dissertations

According to the World Health Organization, 785 million people lack access to basic drinking water facilities, and 144 million people rely on surface water which is prone to microbial contamination. Point-of-use (POU) water disinfection technologies can be adopted to help address these issues by treating water at the household level; however, navigating various POU disinfection technologies for a given water source or location can be difficult. While numerous conventional POU technologies exist (e.g., boiling water, POU chlorination), new emerging POU technologies (e.g., using novel materials or advanced processes) have been coined by developers to be lower cost with higher treatment …

Understanding The Interfacial Processes Of Reactive Nanobubbles Toward Agricultural Applications, Xiaonan Shi

Dissertations

There is a growing interest in nanobubble (NB) technology because of its diverse applications (e.g., detergent-free cleaning, water aeration, ultra-sound imaging and intracellular drug delivery, and mineral processing). NBs have a higher efficiency of mass transfer compared to bulk scale bubbles due to the high specific surface areas. The high specific surface also facilitates physical adsorption and chemical reactions in the gas liquid interface. Furthermore, the collapse of NBs creates shock waves and the formation of hydroxyl radicals (OH).

However, it remains elusive why or how NBs are stabilized in water and particularly, the states of internal pressures of NBs …

Silica-Based Materials For Water Treatment Applications: Adsorption And Supported Noble Metal-Based Catalysis, Xiaopeng Min

Theses and Dissertations

Various contaminants have been widely detected in aquatic systems due to both natural and anthropogenic activities, such as conventional and emerging organic pollutants (e.g., nitroarenes, per- and poly-fluoroalkyl substances (PFAS)), and toxic oxyanions (e.g., chlorate, selenate). The presence of these contaminants may pose negative effects on both human health and water systems. Therefore, it is of great desire to develop novel materials and technologies to treat these waterborne pollutants.Catalytic treatment using noble metal (e.g., Pd)-based catalysts has emerged as a promising method for reduction of waterborne contaminants. Silica-based supports may enhance the reactivity and sustainability of Pd-based catalysts by improving …

The Effect Of Molar Peroxide Ratio On The Oxidation Of Bisphenol A In An Ultraviolet Light Emitting Diode/Hydrogen Peroxide Advanced Oxidation Process, Megan C. Shade

Theses and Dissertations

Bisphenol A is a compound widely used in industry that is detrimental to human health and ecological systems. Ultraviolet light emitting diodes and hydrogen peroxide can be combined t produces hydroxyl radicals. These highly reactive radicals have the potential to degrade contaminants in water. This research utilized 50, 100, 250, 500, and 1000:1 H₂O₂:BPA molar ratios for analysis. These results illustrated that the reactions at the 50, 100, and 250:1 ratios were hydrogenperoxide limited. The 1000:1 results exhibited evidence of radical scavenging that limited the degradation of BPA.

The Effect Of Molar Peroxide Ratio On The Oxidation Of 2,4-Dinitroanisole In An Ultraviolet Light Emitting Diode Advanced Oxidation Process, Troy M. Searcy

Theses and Dissertations

Insensitive munitions (IMs) are increasingly employed by the U.S. military to prevent unintended detonations associated with conventional munitions. One IM used extensively is 2,4 dinitroanisole (DNAN). This research employed an ultraviolet light emitting diode (LED) and hydrogen peroxide advanced oxidation process (AOP) to treat DNAN-contaminated water at the laboratory scale. Five molar peroxide ratios (50:1, 100:1, 250:1, 500:1, 1000:1) were evaluated using the observed pseudo first-order rate constant as the performance metric. Both peroxide-limiting reactions and radical scavenging were observed over the range of ratios tested, with overall removal of DNAN decreasing above a ratio of 500:1.

Evaluation Of Efficient Water Reuse Technologies For Sustainable Forward Operating Bases, Kelsie L. Crouch

Theses and Dissertations

A secure water source is essential to the resiliency and readiness of military installations and contingency operation locations, especially those located in the dry climates the US military operates in today. There are multiple issues of concern when identifying water sources, such as security, cleanliness, accessibility, and sustainability. Water resources pose a potential vulnerability to mission readiness in a remote, agile environment, such as a forward operating base (FOB). Having a secure water resource helps facilitate mission readiness in the contingency environment, offering the opportunity to be more resilient and cost-effective. Current water treatment technologies present the possibility to perform …

Impact Of Artisanal And Small-Scale Mining On Water Bodies And Treatment: The Case Of Birim River Basin In Ghana, Adwoa Boadua Yirenkyi Fianko

Electronic Thesis and Dissertation Repository

Water bodies, the source of drinking water for many rural households in mining areas are at risk of contamination due to artisanal and small-scale mining (ASM) activities. Water quality, therefore, remains a topical issue for policymakers and researchers.

This research sought to achieve three objectives: firstly, to evaluate the effectiveness of existing policies and regulations about ASM in protecting waterbodies. Secondly, to determine the impact of ASM on waterbodies, health and livelihood of inhabitants in mining communities and thirdly, to remove heavy metals from water using locally available bio-adsorbents such as moringa seeds, coconut and corn husks.

A survey of …

Comparison Of The Pfas Adsorption Capabilities Of A Coconut Shell Based Granular Activated Carbon And A Bituminous Coal Based Granular Activated Carbon, Matthew D. Holliday

Theses and Dissertations

This research compares the ability of two granular activated carbons (GAC) from different material sources to adsorb perfluoroalkyl substances (PFAS) in deionized water. A bottle study design was used to conduct the research, which measured the reduction in perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). The carbons used were the bituminous coal based Calgon Filtrasorb 600 (F600) and the coconut shell based Evoqua AquaCarb 1230CX (AC1230CX). Additionally, the research focused on the rates at which the two contaminants were removed and compared them to previous research conducted with different forms of GAC. Results showed that both GACs were capable …

Fouling And Aging In Membrane Filtration : Hybrid Afm-Based Characterization, Modelling And Reactive Membrane Design, Wanyi Fu

Dissertations

Membrane filtration has been extensively used in water and wastewater treatment, desalination, dairy making, and biomass/water separation. However, membrane fouling, aging and insufficient removal efficiency for dissolved organic matters remain major challenges for wider industrial applications. In order to tackle these challenges, this doctoral dissertation investigates mechanisms of membrane fouling and development of antifouling membrane filtration technologies. Specifically, four major research areas are explored: (i) nanoscale physicochemical characterization of the chemically modified polymeric membranes; (ii) quantitative modelling between membrane properties and membrane fouling and defouling kinetics; (iii) development of quantitative structure-activity relationships for membranes that undergo thermal and chemical aging …

Assessment Of Uv Light For The Treatment Of Cyanotoxins In Small-Scale Drinking Water Treatment Systems, Ryan Spencer Mclintock

Cal Poly Humboldt theses and projects

Harmful Algal Blooms (HABs) are commonly caused by the rapid growth of cyanobacteria in fresh waterways, which many people rely on for drinking water. When a HAB occurs, a variety of cyanotoxins can be produced and released into sources of drinking water, which can make people sick or die if not properly treated. Two of the most common toxins are microcystin-LR (MC-LR) and anatoxin-a (A-a), for which the World Health Organization (WHO) recommends a maximum allowable concentration of 1 µg/L in drinking water to avoid health risks. The recommendation for maximum allowable concentration was calculated specifically for microcystins, but is …

Removal Of Carbamazepine From Drinking Water, Jordan Alex Gadberry, Adam Johnson, Juan Rodriguez, Paola Marrero-Rivera, Tom Krumpolc, Zach Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few decades, pharmaceuticals have accumulated in various water sources. This has become a public health concern because many pharmaceuticals have limited research on the effects of chronic low-level exposure. According to the World’s Health Organization (WHO), traces of pharmaceuticals products have been reported in different water sources such as surface waters, wastewater, groundwater, and drinking water.^[1] One pharmaceutical of interest that has been detected in water sources is carbamazepine. Carbamazepine (CBZ) is a common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic pain, and various psychological disorders. …

Reducing Costs While Maintaining Learning Outcomes Using Blended, Flipped, And Mastery Pedagogy To Teach Introduction To Environmental Engineering, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As part of a cost-savings initiative, an existing course of 'introduction to environmental engineering' offered using a 'traditional' format of didactic class meetings supplemented with hands-on laboratory sessions, was changed significantly. The 'modified' format uses 'blended', 'flipped', and 'mastery' approaches to teach "2601: Fundamentals of Environmental Engineering" to approximately 60 sophomores pursuing baccalaureate degrees in environmental, civil, or architectural engineering, each semester. This paper presents a summary of the results from eight course offerings over a period of four years to more than 450 total students. Assessments included student grades; open-ended invitations for anonymous feedback at the end of each …

Biologically Active Filters: An Advanced Treatment Process For Pharmaceuticals And Personal Care Products, Shuangyi Zhang

Dissertations

With the increasing concern of pharmaceuticals and personal care products (PPCPs) in source water, this study examines the hypothesis that existing filters and adsorbents in water treatment plants can be converted to biologically active filters (BAFs) to treat these compounds. Removals through bench-scale BAFs are evaluated as a function of media, granular activated carbon (GAC) and dual-media, empty bed contact time (EBCT), and pre-ozonation. For GAC BAFs, greater oxygen consumption, increased pH drop, and greater DOC removal normalized to adenosine triphosphate (ATP) are observed indicating a different microbial community compared to dual-media BAFs. ATP concentrations in the upper portion of …

Aqueous Photochemistry Of Glyoxylic Acid, Alexis J. Eugene, Sha-Sha Xia, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging …

Cal Poly On-Site Water Treatment Project Proposal, Tanner Wingo

Biomedical Engineering

This report is based off of a competition hosted by the Environmental Protection Agency (EPA): the 2015 Campus RainWorks Challenge. Student teams were encouraged to design an infrastructure that could manage storm water, benefit campus life, and promote sustainability. The report summarizes the engineering aspects that support the competition submittal. The design is to treat campus wastewater on-site and to a suitable level for either reuse or discharge into Brizzolara Creek.

Operational And Water Quality Analysis For The City Of Akron's Water Treatment Plant And Distribution System, Chelsea James

Williams Honors College, Honors Research Projects

Chlorination is one of the most common methods of treating pathogens and ensuring microbial water quality in water treatment and distribution. As chlorinated water leaves the source and travels through the water distribution system, the chlorine reacts with both the organic compounds (dissolved organic carbon, DOC) in the source water and the corrosion or biofilm of the pipe walls. The chlorine concentration, or chlorine residuals, at any point in the water distribution system is a good measure of water quality. At the same time, chlorination produces disinfection byproducts as the chlorine also reacts with other naturally-occurring materials in the water. …

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 …

Impacts Of Ozone Dose And Empty Bed Contact Time On Total Organic Carbon Removal Through Ozone-Biological Activated Carbon Treatment, Ashley Selvy

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the face of climate change, pollution, and population growth, water scarcity has become a global threat. Many populations have witnessed their drinking water sources dwindle to an unsustainable level. These severe conditions have sparked interest in potable reuse as an increasingly viable alternative to typical ‘pristine’ drinking water sources. Currently, the California Division of Drinking Water (DDW) provides the most stringent requirements for reuse water quality. The best way to meet these standards is through the use of full advanced treatment (FAT), which consists of reverse osmosis (RO) and an advanced oxidation process (AOP). Alternative treatment trains composed of …

Removal Of Trace Heavy Metals From Drinking Water By Electrocoagulation, Joe Heffron

Master's Theses (2009 -)

Geologic and anthropogenic heavy metals contaminate drinking water for hundreds of millions of people worldwide. Electrocoagulation -- the in situ generation of coagulant by electrolytic oxidation of metal electrodes -- is a century-old process gaining new traction for metal removal from water and wastewater. However, the low conductivity of drinking water and low target contaminant concentrations required for human consumption present challenges for electrocoagulation of drinking water. This study is unique in that it addresses seven different metal contaminants at the trace concentrations of concern to human consumption and investigates the wide range of possible source water matrices. The goal …

Trihalomethane Removal And Re-Formation In Spray Aeration Processes Treating Disinfected Groundwater, Cassandra Smith

Electronic Theses and Dissertations

Historically, chlorination has been widely utilized as a primary and secondary disinfectant in municipal water supplies. Although chlorine disinfection is effective in inactivating pathogenic microbes, the use of chlorine creates the unintentional formation of regulated chemicals. On January 4, 2006, the United States Environmental Protection Agency (EPA) promulgated the Stage 2 Disinfectants/Disinfection by-product rule (DBPR) that focuses on public health protection by limiting exposure to four trihalomethanes (THM) and five haloacetic acids (HAA5), formed when chlorine is used for microbial pathogen control. This thesis examines post-aeration TTHM formation when employing spray-aeration processes to remove semi-volatile TTHMs from chlorinated potable water …

Performance Evaluation Of Natural Iron-Rich Sandy Soil As A Low-Cost Adsorbent For Removal Of Lead From Water, Yee Sern Ng, Bhaskar Sen Gupta, Mohd Ali Hashim

Ng Yee-Sern

Technical feasibility of natural iron-rich sandy soil as a low-cost adsorbent for removal of lead from water was investigated . The soil, which had an iron content of 3,719 mg/kg, was collected from Hulu Langat, Malaysia, and was used for adsorption studies without any surface modification through chemical treatment. The effects of pH, solution: soil ratio and initial lead concentration on the adsorption efficiency were studied using response surface methodology based on Box–Behnken experimental design. The results showed that pH of the solution had the highest impact on the adsorption efficiency whereby adsorption efficiency of 97% could be achieved at …

Evaluación De La Calidad Del Agua De Abastecimiento Del Acueducto Rural - San Julián Del Municipio De Villamaría - Caldas Y Propuesta De Un Sistema De Potabilización, Jenny Lorena Leiva Leiva

Ingeniería Ambiental y Sanitaria

En este trabajo se evaluó la calidad del agua que abastece a la vereda de San Julián perteneciente a la zona rural del municipio de Villamaría. Esta zona cuenta con tres bocatomas a las cuales se les propuso el tratamiento de potabilización que más se ajustara a las condiciones reales de población, dotación y disponibilidad de recursos financieros. Se generaron las herramientas, fichas de control y de seguimiento de las operaciones unitarias empleadas en el tratamiento de las fuentes de abastecimiento propuesto, con el objetivo de lograr que los entes responsables de su funcionamiento puedan asegurar la calidad de agua …

Numerical Simulation Of Flow In Ozonation Process, Jie Zhang

USF Tampa Graduate Theses and Dissertations

In the last two decades, Computational Fluid Dynamics (CFD) has shown great potential as a powerful and cost-efficient tool to troubleshoot existing disinfection contactors and improve future designs for the water and wastewater treatment utilities.

In the first part of this dissertation two CFD simulation methodologies or strategies for computing turbulent flow are evaluated in terms of the predicted hydraulic performance of contactors. In the LES (large eddy simulation) methodology, the more energetic, larger scales of the turbulence are explicitly computed or resolved by the grid. In the less computationally intensive RANS (Reynolds-averaged Navier-Stokes) methodology, only the mean component of …

Computer Simulation Of Lime-Soda Water Softening Process, J. C. Y. Chen, I. W. Wei

Irvine W. Wei

No abstract provided.

Assessing Trichloromethane Formation And Control In Algal-Stimulated Waters Amended With Nitrogen And Phosphorus, Clinton Mash

Graduate Theses and Dissertations

Nitrogen (N) and phosphorus (P) enrichments can stimulate algal growth in drinking water sources, which can cause increased production of disinfection byproduct (DBP) precursors. However, the effect of systematic N and P enrichments on DBP formation and control has not been adequately studied. In this work, we enriched samples from a drinking water source - sampled on April 5, May 30, and August 19, 2013 - with N and P to stimulate algal growth at N:P ratios covering almost five orders of magnitude (0.2-4,429). To simulate DBP-precursor removal processes at drinking water treatment plants (DWTPs), the samples were treated with …

Assessing The Impact Of Chlorine Residual On Trihalomethane And Haloacetonitrile Formation Under Chlorination And Chloramination Disinfection Regimes, Thien Duc Do

Graduate Theses and Dissertations

A disinfection byproduct (DBP) formation potential (FP) test can be used to indirectly measure the concentration of DBP precursors in natural waters, permitting assessment of various DBP-related treatment processes and control strategies. While these tests require a 7-day chlorine residual (CR) between 3-5 mg L^-1 as Cl², it is not well known if this recommended residual corresponds to the true DBPFP (i.e., the maximum concentrations) for trihalomethanes (THMs) and haloacetonitriles (HANs). In this study, THMs and HANs were quantified as a function of CR under three common disinfection regimes: (1) free chlorine at pH 7.0 (FC7), (2) …