Engineering Commons^™

Α-Fe2o3/Graphene Oxide Powder And Thin Film Nanocomposites As Peculiar Photocatalysts For Dye Removal From Wastewater, Mahsa Khoshnam, Javad Farahbakhsh, Masoumeh Zargar, Abdul Wahab Mohammad, Abdelbaki Benamor, Wei Lun Ang, Ebrahim Mahmoudi

Research outputs 2014 to 2021

In this study, hematite graphene oxide (αFe2O3-GO) powder nanocomposites and thin-film hematite graphene oxide (αFe2O3-GO) were synthesized for application in the removal of Rhodamine B (RhB) from textile wastewater. αFe2O3-GO nanomaterials were placed onto the FTO substrate to form a thin layer of nanocomposites. Different analysis including XRD, FTIR, Raman spectra, XPS, and FESEM were done to analyze the morphology, structure, and properties of the synthesized composites as well as the chemical interactions of αFe2O3 with GO. The photocatalytic performance of two synthesized composites was compared with different concentrations of αFe2O3-GO. The results showed that powder nanocomposites are more effective …

Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection of drinking water is crucial for providing a safe potable water supply. Some of the most common disinfectants employed are chlorine, chloramines and ozone. While these disinfectants successfully inactivate pathogenic microorganisms, they simultaneously react with inorganic or organic precursors to form toxic byproducts, most commonly referred to as disinfection byproducts (DBPs). While there is a wide variety of organic matter and disinfection byproducts known, in this study we have looked into the potential of certain quaternary ammonium compounds (QACs) to act as precursors to form DBPs, namely trihalomethanes (THMs), haloacetonitriles (HANs) and nitrosamines.

The ubiquitous nature of QACs in …

Coal Fly Ash Beneficiation For Reuse And Removal Of Boron, Cadmium, Chromium, Copper, And Selenium In Wastewater Treatment., Joseph E. Cahill

Electronic Theses and Dissertations

New regulations on coal-fired power plants make previously used wastewater treatment methods aimed to remove heavy metals obsolete. Therefore, there has been increased interest and investment into new technologies to treat coal-fired power plants effluent in the past few years. Traditionally, heavy metal removal technologies have been broken into three categories: physical, chemical or biological. However, with new regulations, each category by itself does not offer an ideal solution to removing acceptable concentrations of heavy metals found in the effluents at the coal-fired power plants. Here we report a novel proof-of-concept utilizing adsorption through ion-exchange/co-precipitation - chemical and physical - …

Progress And Prospect Of Anodic Oxidation For The Remediation Of Perfluoroalkyl And Polyfluoroalkyl Substances In Water And Wastewater Using Diamond Electrodes, Sean T. Mcbeath, Adrián Serrano Mora, Fatemeh Asadi Zeidabadi, Brooke K. Mayer, Patrick J. Mcnamara, Madjid Mohseni, Michael R. Hoffman, Nigel J. D. Graham

Civil and Environmental Engineering Faculty Research and Publications

Although diamond electrodes are widely used in the field of electroanalysis and sensing, their application in the field of environmental engineering has yet to be fully realized. Many research studies have considered their potential application in water and wastewater treatment, where the in-situ electrochemical process can avoid the need for chemical additives by facilitating the oxidation of pollutants on the electrode surface or mediated by electrochemically synthesized oxidants in solution. Diamond-based electro-oxidation can effectively treat a number of organic micropollutants and is now being evaluated for the abatement of perfluoroalkyl and polyfluoroalkyl substances, which pose health concerns and are ubiquitous …

An Introductory Study Of Coal Fly Ash Enhancement For Heavy Metal Removal In Wastewater Treatment., Samuel T. Romes

Electronic Theses and Dissertations

Coal Combustion Products are the materials that remain after pulverized coal is burned to generate electricity. The fine portion, fly ash, has many re-use capabilities across various industries. Most recent data shows that approximately 60% of fly ash produced in the United States was used with the largest re-use being concrete additives. This work aims to enhance fly ash via hydrothermal treatment in order to expand the re-use capabilities of the material. These materials were tested as adsorbents for heavy metal removal from wastewater samples. The metals tested for removal were Copper (II) Acetate, Cadmium Chloride, Boric Acid, Sodium Selenite, …

The Impact Of Wastewater Chemistry And Flow Characteristics On Hydrogen Sulfide Concentration, Mohsina Muhammed Sherief

Theses

Hydrogen sulfide (H₂S) is a naturally occurring, highly toxic gas that is formed from the decomposition of sulfur compounds. At low concentrations, H₂S is an irritant for the eyes, respiratory and gastrointestinal tract. At higher H₂S concentrations, it produces neurological impairment with dizziness, headache, and loss of consciousness. Mortality was reported to reach 6 percent following exposure to elevated concentrations. H₂S is generated in different industrial processes. In wastewater collection and treatment plants, H₂S is a common source of concrete and metal corrosion that has resulted in huge economic loss. …

Co-Carriage Of Metal And Antibiotic Resistance Genes In Sewage Associated Staphylococci, Atena Amirsoleimani, Gail M. Brion, Patrice Francois

Civil Engineering Faculty Publications

Controlling spread of resistance genes from wastewater to aquatic systems requires more knowledge on how resistance genes are acquired and transmitted. Whole genomic sequences from sewage-associated staphylococcus isolates (20 S. aureus, 2 Staphylococcus warneri, and 2 Staphylococcus delphini) were analyzed for the presence of antibiotic resistance genes (ARGs) and metal resistance genes (MRGs). Plasmid sequences were identified in each isolate to investigate co-carriage of ARGs and MRGs within. BLASTN analysis showed that 67% of the isolates carried more than one ARG. The carriage of multiple plasmids was observed more in CC5 than CC8 S. aureus strains. Plasmid …

Environmental Assessment Of The Impact Of Land-Based Discharges On Marine Water And Sediment Quality In Dubai, Uae, Ayman Fathy Halawa

Theses

The current seawater and Creek – Canal waterway in the Emirate of Dubai, UAE, is under tremendous pressure because of continuous urban water discharges from land-based sources. Therefore, the impact of urban water discharges on marine water and sediment quality in the Emirate requires a thorough assessment. The main objective of this study is to assess the impacts of effluent discharges on the quality of water and sediment in the open sea and Dubai Creek. The land-based sources include the power and desalination plants, industrial sector, sewage treatment plant, and stormwater runoff. To achieve the stated objective, relevant data on …

Modeling Of Hydrogen Sulfide Generation And Rates Of Microbial Induced Concrete Corrosion In Manhole Shafts, Sunakshi Hada

Civil Engineering Dissertations

Manhole shafts can undergo infrastructure failure due to microbially induced concrete corrosion (MICC). Deterioration of the sewer systems by MICC process occurs due to the volatilization of hydrogen sulfide into the gas phase. The volatized hydrogen sulfide gas reacts with oxygen to form sulfuric acid, resulting in concrete corrosion. If optimum conditions are present, 24 mm of concrete loss can occur in 31 months, and the cost of fixing can range from $10-$30 per square foot. Also, if the manholes are not properly maintained, they can cause serious safety hazards, such as manhole lids falling through the structure, streets giving …

Wastewater Remediation Technologies Using Macroscopic Graphene-Based Materials: A Perspective, Rajan Arjan Kalyan Hirani, Abdul Hannan Asif, Nasir Rafique, Lei Shi, Shu Zhang, Hong Wu, Hongqi Sun

Research outputs 2014 to 2021

Three-dimensional (3D) graphene-based macrostructures are being developed to combat the issues associated with two-dimensional (2D) graphene materials in practical applications. The 3D macrostructures (3DMs), for example, membranes, fibres, sponges, beads, and mats, can be formed by the self-assembly of 2D graphene-based precursors with exceptional surface area and unique chemistry. With rational design, the 3D macrostructures can then possess outstanding properties and exclusive structures. Thanks to various advantages, these macrostructures are competing in a variety of applications with promising performances unlike the traditional activated carbons, biochars and hydrochars, which have less flexibilities for modifications towards versatile applications. However, despite having such …

Exploration Of The Sludge Biodiesel Pathway, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wastewater sludge is an overlooked source of fat, oil, and grease (FOG) that could be converted into biodiesel. The United States produces about 8 million tons of sludge per year. The disposal cost for this amount of sludge is about 2 billion US dollars. The widespread availability and low cost of sludge compared to other biodiesel raw materials make it an economical choice for a renewable fuel. Using sludge as a raw material can produce 25 to 30 mg per gram of fatty acid methyl ester (FAME); the main component of biodiesel. Sludge biodiesel has the potential of transforming a …

Annealing Of Encapsulated Heavy Metals From Brine Water Utilizing Microwave Enabled Sol-Gel Process, Adam Michael Flynn

Electronic Theses and Dissertations

Various waste encapsulation strategies have been investigated to solidify and stabilize heavy metal wastewater for proper long-term storage. This work aims to enhance a method of novel sol-gel encapsulation of heavy metals from mock brine waters using tetramethyl orthosilicate with the addition of an annealing step at various temperatures in order to reduce leaching of metals from the silica monoliths when exposed to water. The metals tested for encapsulation and leaching were mercury (II) chloride, potassium dichromate, sodium selenite, boric acid, cadmium chloride, and copper (II) acetate. The annealing of the silica monoliths led to an increased degree of for …

Modeling Study Of Electrocoagulation System For Treating Wastewater, Swachwa Dey

Graduate Research Theses & Dissertations

Effective treatment of wastewater from households, communities, and industries is vital to preserve our environment. Chemical treatment to add coagulants into the wastewater is the most popular treatment method, but due to the high operating cost and secondary contamination issue, a novel method to solve those issues is required. In this study, we revisited the electro-coagulation (EC) system which has promising features of low system/operating cost and environment friendly process. EC was actively developed once, but due to the low efficiency and scaling-up issues, it could not be fully utilized. In this study, physics-based mathematical model was developed to elucidate …

Co2 Biocapture By Scenedesmus Sp. Grown In Industrial Wastewater, Itzel Y. López-Pacheco, Eduardo Israel Castillo-Vacas, Lizbeth Castañeda-Hernández, Angie Gradiz-Menjivar, Laura Isabel Rodas-Zuluaga, Carlos Castillo-Zacarías, Juan Eduardo Sosa-Hernández, Damià Barceló, Hafiz M.N. Iqbal, Roberto Parra-Saldívar

Panhandle Research and Extension Center

Greenhouse gases (GHG) emissions are widely related to climate change, triggering several environmental problems of global concern and producing environmental, social, and economic negative impacts. Therefore, global research seeks to mitigate greenhouse gas emissions. On the other hand, the use of wastes under a circular economy scheme generates subproducts from the range of high to medium-value, representing away to help sustainable development. Therefore, the use of wastewater as a culture medium to grow microalgae strains that biocapture environmental CO₂, is a proposal with high potential to reduce the GHG presence in the environment. In this work, Scenedesmus sp. …

Development Of Phagotrophic Algae-Based Process For Conversion Of Waste Organics To Algae Lipids As Potential Feedstock For Biofuel, Hannah Nelson

Williams Honors College, Honors Research Projects

Interest in sustainable feedstock for biofuel has encouraged research on the production of phagotrophic algae from bacteria using a two-staged continuous-flow system. Bacteria cultures were fed the content of a waste stream from The J.M. Smuckers Company containing high concentrations of sugar. In the design, the bacteria effluent overflowed into the algae tank which was kept at a set volume. Several methods were developed to assist in maintaining the system at steady state and minimize the impact from contaminants. A rigorous cleaning protocol was implemented for both tanks, effectively eliminating protozoa from the bacteria system. The protozoa were decreased in …

A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague

Electronic Theses and Dissertations

Microplastics are an emerging concern due to their harmful effect to organisms and their ability to facilitate transport of contaminants including heavy metals. Microplastics can enter the environment through wastewater treatment plants, landfill leachate, and littering. Once in the environment microplastics can be distributed throughout rivers, the ocean, and lakes. In order to understand the adsorption of heavy metals to microplastics a geochemical modeling study was completed using Visual Minteq. Lab tests were completed to better understand what constituents are available in wastewater at four different locations: influent, clarifiers, digesters, and effluent. These constituents were then used to observe how …