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Full-Text Articles in Engineering
Emulsion Characterization Study For Improved Bilgewater Treatment And Management, Daniela Diaz Hernandez
Emulsion Characterization Study For Improved Bilgewater Treatment And Management, Daniela Diaz Hernandez
Electronic Theses and Dissertations, 2020-
The need for proper management of bilgewater to meet discharge regulations (e.g., 15 ppm oil) has revealed the necessity to expand the current understanding of bilgewater emulsions. This study proposed to evaluate emulsion stability under various environmental conditions and to identify governing parameters for emulsion formation. The stabilizing properties of eight-commercial cleaners and two-neat surfactants were evaluated. In situ characterization techniques were used for monitoring emulsion stability. Additionally, a needle-type pH microsensor and fluorescence spectroscopy were used for analyzing mass transfer at the oil-water interface. Water quality of extracted bilgewater showed to highly vary between vessels (e.g., conductivity: 1.74 -- …
Improving Air Pollution Exposure Estimation Using Cell Phone Location Data And Low-Cost Sensors, Xiaonan Yu
Improving Air Pollution Exposure Estimation Using Cell Phone Location Data And Low-Cost Sensors, Xiaonan Yu
Electronic Theses and Dissertations, 2020-
Human exposure estimation to air pollution plays an important role in epidemiological studies which are designed to reveal correlations between human exposures to certain air pollutants and certain diseases, such as asthma, cardiovascular disease and reproductive diseases. Traditionally, when people's mobile data is hard to get, home location is used to estimate people's exposures assuming that people stay at home all the time. Whereas, people move and it is more accurate to estimate people's exposures including people's mobility. In our study, we showcased two methods to obtain people's mobile data: Google Maps location history (GMLH) data and Call Detailed Record …
Water Reclamation Using Functionalized Forward Osmosis Membrane, Fnu Joshua
Water Reclamation Using Functionalized Forward Osmosis Membrane, Fnu Joshua
Electronic Theses and Dissertations, 2020-
This study investigated water reclamation from an impaired-quality water using forward osmosis (FO) membrane functionalized by nano zero valent iron (nZVI) loaded polyelectrolyte multilayer films. Stormwater runoff was selected as the impaired-quality water, which served as a feed solution (FS) and a NaCl salt solution at a concentration representing reverse osmosis (RO) concentrate was used a draw solution (DS). RO concentrate is another impaired-quality water that is discharged to the environmental with little or no treatment. A commercial cellulose triacetate (CTA) FO membrane was modified using poly allylamine hydrochloride (PAH) (a polycation) and poly acrylic acid (PAA) (a polyanion) following …
Evaluating The Performance And Impacts Of Seawater Regeneration In An Anion Exchange Process, Daniel Whalen
Evaluating The Performance And Impacts Of Seawater Regeneration In An Anion Exchange Process, Daniel Whalen
Electronic Theses and Dissertations, 2020-
This research investigated the use of seawater regeneration for anion exchange (AIX) processes. Seawater and salt-supplemented seawater regeneration of chloride-form anion resin were evaluated in regard to (1) operational performance efficiency of sulfate and natural organic matter removal, (2) competing exchange of bromide during regeneration, and (3) brominated disinfection by-product (DBP) formation due to bromide leakage. The first component involved bench-scale research that revealed that seawater-based regeneration led to bromide leakage that could be mitigated to an average of 1.82 mg/L using 1% salt-supplemented seawater, and 1.25 mg/L using 3% salt-supplemented seawater. Conceptual cost comparisons revealed that the use of …
Chemically Stabilized Oil-In-Water Emulsion Separation Using A Custom Aquaporin-Based Polyethersulfone (Pes) Forward Osmosis Membrane System, Annmarie Ricchino
Chemically Stabilized Oil-In-Water Emulsion Separation Using A Custom Aquaporin-Based Polyethersulfone (Pes) Forward Osmosis Membrane System, Annmarie Ricchino
Electronic Theses and Dissertations, 2020-
The stability of oil-in-water emulsions is enhanced by the presence of surfactants in the water, thereby increasing difficulty of remediation. In this study, mineral oil and a standard bilge mix (SBM) were used as model oils for forward osmosis (FO) performance evaluation and two different high-concentration feed solutions (FS) were tested: 10,000 and 100,000 ppm oil/surfactant (9:1 Oil/Surfactant, wt %). It was hypothesized that the charge-charge interactions between the surfactant portion of the micelles and the membrane would play an important role in membrane fouling. Therefore, the effects of both an anionic surfactant (sodium dodecyl sulfate [SDS]) and a nonionic …
Removal Of Chemicals Of Emerging Concern And Mass Transfer Modeling In A Nanofiltration Membrane Process, Carlyn Higgins
Removal Of Chemicals Of Emerging Concern And Mass Transfer Modeling In A Nanofiltration Membrane Process, Carlyn Higgins
Electronic Theses and Dissertations, 2020-
An investigation of 1,4-dioxane and enantiomeric ibuprofen mass transfer in a nanofiltration (NF) membrane process has been completed. Pilot-scale experiments using a 267 gallon per minute (gpm) split-feed, center-port NF process treating pH 6.5 groundwater revealed a consistent 12 percent removal of 1,4-dioxane despite the variable feed concentration (180 nanograms per liter (ng/L) to 38,400 ng/L) when the water flux and temperature were held constant. Bench-scale, flat-sheet NF membrane experiments treating pH 4.0 synthetic water displayed a 34.5 to 49.5 percent removal of racemic ibuprofen. Removal values were dependent on feedwater concentration (1 to 1,500 microgram per liter (µg/L)), pH, …
Removal Of Heavy Metals From Landfill Leachate Using Electrospun Polyelectrolyte Complex Fiber-Laminated Ultrafiltration Membrane, Amirsalar Rabbani Esfahani
Removal Of Heavy Metals From Landfill Leachate Using Electrospun Polyelectrolyte Complex Fiber-Laminated Ultrafiltration Membrane, Amirsalar Rabbani Esfahani
Electronic Theses and Dissertations, 2020-
Ultrafiltration (UF) is a low-pressure membrane process that yields higher permeate flux and saves significant operating costs compared to NF/RO. However, UF has not been applied as a primary method for landfill leachate treatment due to its large pore size. This research investigated the removal of heavy metals from landfill leachate using an UF membrane laminated with fiber mats produced from electrospinning of a polyelectrolyte complex. In this research, we modified the surface of the UF membrane with two polyelectrolytes including Polyacrylic Acid (PAA) and Polyallylamine Hydrochloride (PAH). The removal of heavy metals including Pb, Cd, and Cu from water …
Ultraviolet Irradiation Combined With Chlorine Dioxide Pre-Oxidation For Disinfection By-Product Control, Paula Campesino
Ultraviolet Irradiation Combined With Chlorine Dioxide Pre-Oxidation For Disinfection By-Product Control, Paula Campesino
Electronic Theses and Dissertations, 2020-
The use of ultraviolet (UV) light and chlorine dioxide (ClO2) as an advanced oxidation process (AOP) has been investigated at the bench-scale to understand the effects of their use on disinfection by-product (DBP) formation potential (FP) in chlorinated groundwater (GW) and surface water (SW) supplies. Two GWs and two SWs of varying qualities were subject to a series of AOP treatment sequences at the bench scale: sodium hypochlorite, to serve as a baseline; ClO2-Cl2, UV-Cl2, and UV-ClO2-Cl2. In these treatment sequences, Cl2 is used as a primary and secondary disinfectant. Several water quality parameters were measured throughout the experiments, including …