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Articles 1 - 16 of 16
Full-Text Articles in Environmental Engineering
An Investigation Into The Common Problems Of Lagoon Wastewater Treatment In Kentucky, Kaylee A. Jones
An Investigation Into The Common Problems Of Lagoon Wastewater Treatment In Kentucky, Kaylee A. Jones
Honors Theses
Lagoon wastewater treatment systems are commonly used in areas that do not have the available resources for typical mechanical wastewater treatment. Lagoon systems consist of multiple preliminary lagoons, but mainly rely on long-term facultative lagoons for most analyte removal. In this study, one particular lagoon wastewater treatment system (named Municipality A Wastewater Treatment Plant) is investigated due to noncompliance with governmental standards provided by the National Pollutant Discharge Elimination System (NPDES). Samples were collected by researchers at 4 different instances inside of the treatment systems. These samples were sent to an analytical laboratory for testing. The readings from these samples …
Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy
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 …
Environmental Assessment Of The Impact Of Land-Based Discharges On Marine Water And Sediment Quality In Dubai, Uae, Ayman Fathy Halawa
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 …
A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague
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 …
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. …
Application Of Cation Exchange And Nanofiltration To Treat Flue Gas Desulfurization Wastewater, Ayush R. Shahi
Application Of Cation Exchange And Nanofiltration To Treat Flue Gas Desulfurization Wastewater, Ayush R. Shahi
Civil Engineering ETDs
Flue gas emitted from coal-fired power plants is one of the major sources of sulfur and nitrogen oxides emissions to the atmosphere in the world today. Although coal use has decreased, it is still a major contributor to such emissions. The Clean Air Act in the United States established regulations for coal-fired power plants to limit SOx and NOx emissions into the atmosphere. To meet regulatory requirements, power plants have been using scrubbers to limit their air emissions. Flue-gas desulfurization (FGD) is a pollution prevention method that is employed to limit sulfur dioxide emissions directly in the environment …
Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler
Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler
Public Land & Resources Law Review
In Hawai’i Wildlife Fund v. County of Maui, the Ninth Circuit held that the plain language of the Clean Water Act provides jurisdiction over indirect discharges of pollutants from a point source into groundwater that is shown to be connected to navigable waters. The court found that studies confirmed pollutants entering the Pacific Ocean were fairly traceable to the County of Maui’s sewage disposal wells. In affirming the district court’s ruling, the Ninth Circuit held that Maui County violated the Clean Water Act by discharging pollutants into a navigable water without the required permit. The court also concluded the …
Viability Of Graywater Reuse In Lesotho’S Lowland Agricultural District, Ryan Wagner
Viability Of Graywater Reuse In Lesotho’S Lowland Agricultural District, Ryan Wagner
Dissertations, Master's Theses and Master's Reports
Water security has become a large issue with populations rising and weather patterns changing to drier and hotter conditions in southern Africa. Lesotho, a mountainous country landlocked by South Africa, is responsible for a large amount of the rainfall in southern Africa. As such, Lesotho provides water to South Africa in exchange for national economic growth. Lesotho, however, is also prone to droughts and with water reserves being sold to South Africa, water security has become a national issue. This study looked at Lesotho’s current water use habits and found that graywater reuse could lead to much more available water. …
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 …
Wastewater Treatment Improvement For Rush Strong School, Christina R. Sanford Utk, Kelli M. Grissom, Katie Gipson, Sharon Counts
Wastewater Treatment Improvement For Rush Strong School, Christina R. Sanford Utk, Kelli M. Grissom, Katie Gipson, Sharon Counts
Chancellor’s Honors Program Projects
No abstract provided.
Occurrence And Proliferation Of Antibiotics And Antibiotic Resistance In Wastewater Treatment Plants, Majid Neyestani
Occurrence And Proliferation Of Antibiotics And Antibiotic Resistance In Wastewater Treatment Plants, Majid Neyestani
UNLV Theses, Dissertations, Professional Papers, and Capstones
Solids retention time (SRT) is one of the most important factors in designing and operating activated sludge systems for biological wastewater treatment. Longer SRTs have been shown to alter the structure and function of microbial communities, thereby leading to improved treatment efficacy with respect to bulk and trace organics, nutrient removal, and membrane fouling. However, research has also shown that longer SRTs lead to increased prevalence of antibiotic resistant bacteria, perhaps due to increased exposure to antibiotics present in influent wastewater. The purpose of this study was to characterize changes in microbial community structure in a laboratory-scale activated sludge system …
Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts
Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts
Master's Theses
Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.
A pilot facility was operated with nine CO2-supplemented raceway ponds, each with a 33-m2 surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …
The Use Of Cod, Toc, Fluorescence, And Absorbance Spectroscopy To Estimate Biochemical Oxygen Demand In Wastewater, Evelyn Aramaine Christian
The Use Of Cod, Toc, Fluorescence, And Absorbance Spectroscopy To Estimate Biochemical Oxygen Demand In Wastewater, Evelyn Aramaine Christian
UNLV Theses, Dissertations, Professional Papers, and Capstones
All wastewater treatment facilities must obtain a National Pollution Discharge Elimination System (NPDES) permit, which regulates the quality of water that is discharged. Common to all NPDES permits is a limit on organic matter, as determined by the five-day biochemical oxygen demand (BOD5) test. More rapid methods, such as chemical oxygen demand (COD), total organic carbon (TOC), fluorescence, and absorbance spectroscopy are also capable of quantifying organic matter. Previous studies indicate it is possible to develop correlations between these parameters. This study explored the correlations using influent, primary clarifier effluent, and finished effluent samples from an operational wastewater treatment plant …
Recovery Of Nutrient Nitrogen From Municipal Wastewater Residuals By Gas Membrane Separation, Evelyn Rios
Recovery Of Nutrient Nitrogen From Municipal Wastewater Residuals By Gas Membrane Separation, Evelyn Rios
Open Access Theses & Dissertations
There are relatively high amounts of ammonia returned to the headworks of a municipal wastewater plant that are extracted from the dewatering process. This ammonia load contributes to a significant oxygen demand in the secondary treatment, requiring greater air blower energy costs. This goal of this research was to evaluate the feasibility of the recovery of an ammonium sulfate product from belt press filtrate. The objectives of this research were to: (1) analyze wastewater treatment average monthly data flows and constituents with respect to ammonia nitrification, (2) the evaluate the technical performance of a two sage gas-separation membrane for recovering …
Electrochemical Disinfection Of Municipal Wastewater Using Alternating Current, Xavier A. Chavez Reyes
Electrochemical Disinfection Of Municipal Wastewater Using Alternating Current, Xavier A. Chavez Reyes
University of New Orleans Theses and Dissertations
This research focused on chlorine-free disinfection of wastewater by complying with today's regulations. The equipment used was a continuous flow electrochemical reactor connected to an alternating current (AC) power supply. The electrodes used were made out of titanium coated with iridium oxide. To determine the inactivation of Escherichia Coli, a bacterial count method based on the USEPA method 1603 was used.
After several experiments it was determined that electrochemical disinfection using AC was not efficient and economic enough to be classified as a viable alternative to chlorine disinfection. It was demonstrated that chlorine can be produced by electrolysis using AC …
Regulation Issues And Prediction Of Natural Estrogen Loads For Wastewater Treatment Plants, Michelle E. Jarvie
Regulation Issues And Prediction Of Natural Estrogen Loads For Wastewater Treatment Plants, Michelle E. Jarvie
Dissertations, Master's Theses and Master's Reports - Open
No abstract provided.