Browsing by Subject "Water treatment"
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Item The energy-water nexus : an examination of the water quality impacts of biofuels(2010-05) Twomey, Kelly Marie; Webber, Michael E., 1971-; Lawler, Desmond F.Water and energy share an important relationship since it takes water to produce energy, and likewise, energy to pump, treat, and distribute water. This thesis explores the energy-water nexus in regards to electricity and transportation fuel production, as well as water treatment. It investigates how the Energy Independence and Security Act of 2007 might affect this interrelationship in the future since increases in corn cultivation for biofuels production are likely to lead to higher nitrate concentrations in US water reservoirs, which could trigger the requirement for additional energy consumption for drinking water treatment. The analysis indicates that advanced drinking water treatment might require an additional 2360 million kWh annually to treat drinking water currently exceeding the Environmental Protection Agency’s maximum contaminant level (MCL) limit of 10 mg per liter of nitrate-nitrogen. This is a 2100% increase in energy consumption for advanced water treatment to meet this MCL in comparison with surface water treatment alone. Although results indicate that most large surface and groundwater drinking water resources are not likely to exceed safe drinking water standards due to the expansion of corn-starch based ethanol production, smaller water reservoirs in agricultural regions are susceptible to nitrate contamination in the future. Consequently, these sources might require energy-intensive drinking water treatment to reduce nitrate levels below 10 mg per liter of nitrate-nitrogen. Based on these results, I conclude that projected increases in nitrate contamination in water may impact the energy consumed in the water treatment sector, because of the convergence of several related trends: (1) increasing cornstarch-based ethanol production, (2) increasing nutrient loading in surface water and groundwater resources as a consequence of increased corn-based ethanol production, (3) additional drinking water sources that exceed the MCL for nitrate, and (4) potentially more stringent drinking water standards for nitrate.Item Fluoride, natural organic matter, and particles : the effect of ligand competition on the size distribution of aluminum precipitates in flocculation(2016-05) Herrboldt, Jonathan Philip; Lawler, Desmond F.; Katz, Lynn EllenFluoride occurs at elevated concentrations naturally in surface and ground waters around the world. If consumed at low concentrations in drinking water (< 1.5 mg/L), fluoride is shown to reduce the occurrence of dental caries and the Centers for Disease Control and Prevention named fluoridation of public water systems one of the 10 Great Public Health Achievements of the 20th Century (CDC, 1999). However, prolonged exposure to high concentrations of fluoride (> 2.0 mg/L) causes adverse health effects to teeth and bones. For this reason the United State Environmental Protection Agency (USEPA) enacted a maximum contaminant level (MCL) for fluoride at 4.0 mg/L. This rule is currently under review following a recent risk assessment and may be lowered. If the MCL were lowered, water systems previously meeting treatment standards would suddenly find themselves out of compliance and will need to implement additional treatment to meet the new standard. Defluoridation by alum coagulation is a proposed defluoridation method. However, the interaction between fluoride and natural organic matter (NOM) and their effects on the particle size distribution of aluminum precipitates is not well understood. Because the particle size distribution of aluminum precipitates is an important parameter in the efficiency of sedimentation and filtration systems, a thorough understanding of these interactions and their potential effect on sedimentation and filtration is needed to inform the implementation of defluoridation by alum coagulation. This work utilized a series of jar tests on synthetic surface water to determine the effect of fluoride and NOM on the particle size distribution of aluminum precipitates. It was found that fluoride caused the volume distribution of aluminum precipitates to shift toward smaller particle sizes. However, NOM caused the formation of a larger number of aluminum precipitates, which resulted in a dramatic increase in the total volume of precipitates. When both fluoride and NOM were in the system, a combination of the two effects was observed: the volume distribution shifted toward smaller particle sizes but the peak of the distribution shifted toward a greater volume, indicating both smaller particles were being formed and a greater overall volume of particles precipitated.Item Kinetics of ciprofloxacin degradation by ozonation : effects of natural organic matter, the carbonate system, and pH(2010-08) Marron, Corin Ann; Katz, Lynn EllenThe presence of pharmacologically active and persistent compounds in drinking water sources is an environmental and public health concern. Sources of pharmaceuticals in the aquatic environment include wastewater treatment plant effluents and veterinary use. Antibiotics are of special concern because of their role in the spread of bacterial resistance. Conventional drinking water treatment processes are often ineffective for removing trace organic contaminants. Ozonation processes have demonstrated the ability to remove pharmaceutical compounds from drinking water supplies. During the ozonation of drinking water, the primary oxidants are ozone and hydroxyl radicals formed during the decomposition of ozone. Both oxidants contribute to the removal of pharmaceutical compounds; however, the relative rates of destruction by these two oxidants depends on the treatment operating conditions, the background water chemistry and the structure and reactivity of the target compound. This study investigated the relative impact of natural water characteristics, such as pH, the carbonate system, and natural organic matter, on the removal of the fluoroquinolone antibiotic ciprofloxacin by ozonation processes. Rate constants for k"O3, Cip obtained at pH 7 were approximately one order of magnitude higher than at pH 5 because ciprofloxacin changes from a positively charged cation to a neutral species over this pH range. The results showed that there was very little variation of the rate constants for ciprofloxacin oxidation by O₃ or hydroxyl radicals regardless of the carbonate concentration or the presence of the two organic matters studied in this research. Typical values for k"O3, Cip and k"HO°, Cip obtained at pH 7 ranged between 1.49x10⁴ and 1.64x10⁴ M⁻¹s⁻¹ and 1.29x10¹⁰ to 1.80x10¹⁰ M⁻¹s⁻¹, respectively. However, the presence of carbonate and other hydroxyl radical scavengers did have an impact on O₃ and hydroxyl radical exposure. The relative impact of these two oxidants changed depending on the pH of the system and the presence of carbonate and natural organic matter.Item Oxidation of pharmaceuticals : impacts of natural organic matter and elimination of residual pharmacological activity(2011-08) Blaney, Lee Michael; Lawler, Desmond F.; Katz, Lynn Ellen; Liljestrand, Howard M.; Richburg, John H.; Speitel Jr., Gerald E.; Kirisits, Mary JoAnthropogenically-derived substances, including pharmaceuticals and personal care products, endocrine-disrupting chemicals, and pesticides, are increasingly being detected in drinking water supplies and wastewater effluents. Concerns over the presence of these compounds in water supplies include their ability to impart toxicological activity, their capacity to spread antibiotic resistance, and their potential to affect cell-signaling processes. For these reasons, water treatment processes geared towards removal of these trace organic contaminants are vital. In this work, ozone was used to treat four pharmaceutical contaminants: ciprofloxacin, cyclophosphamide, erythromycin, and ifosfamide. Ciprofloxacin and erythromycin are antibiotic/antimicrobial compounds, and cyclophosphamide and ifosfamide are chemotherapy agents. Ozone effectively transformed all four pharmaceuticals, even in the presence of background natural organic matter, which exerts a considerable ozone demand. The apparent rate constants for the reaction of the pharmaceuticals with ozone at pH 7 were determined: 3.03 M-1s-1 for cyclophosphamide; 7.38 M-1s-1 for ifosfamide; 1.57×104 M-1s-1 for ciprofloxacin; and 7.18×104 M-1s-1 for erythromycin. Cyclophosphamide and ifosfamide, which do not react quickly with ozone, exhibited high rate constants (2.7×109 M-1s-1) for transformation by hydroxyl radicals, which are formed through ozone decomposition. Nevertheless, complete removal of cyclophosphamide and ifosfamide was achievable using a novel continuous aqueous ozone addition reactor and an ozone-based advanced oxidation process (peroxone). In ozone-based processes, pharmaceuticals are systematically transformed via complex oxidative pathways towards CO2, H2O, and the oxidized forms of other elements. Intermediate oxidation products containing oxygen atoms or hydroxyl groups substituted into the chemical structure of the parent pharmaceutical were identified using liquid chromatography-mass spectrometry (LC-MS). Given the structural similarity of intermediate oxidation products to the parent pharmaceuticals, an antimicrobial activity assay was employed to monitor the removal of pharmacological activity associated with ciprofloxacin, erythromycin, and their respective intermediate oxidation products throughout treatment. For solutions containing ciprofloxacin or erythromycin, ozone was able to completely eliminate the corresponding antimicrobial activity. Ciprofloxacin intermediate oxidation products were pharmacologically active; however, erythromycin’s intermediate products did not contribute to the residual antimicrobial activity. These results suggest that the design of conventional and advanced ozone-based processes must incorporate ozone demand from background organic matter and account for destruction of pharmacologically active intermediates.Item The potential of desalination as an alternative water supply in the United States(2009-05) Naini, Anjali Nina; Butler, Kent S.Many parts of the United States are facing water shortages. Planners have to ensure that there will be an adequate water supply to meet the needs of the growing population. Though many places encourage water conservation, and some even enforce water restrictions, this is not always enough to make up for the shortages. Thus, alternative water sources need to be considered in some cases. The states of Texas and Florida both face uncertainties with their future water supply. To meet the needs of their current and future populations, both states have recently been using desalination at a large scale to supplement their water supplies. This report examines the desalination facilities in El Paso, Texas and Tampa Bay, Florida to determine if desalination is a feasible water supply and to explore the consequences of pursuing the development of this water resource.Item The impact of biological pretreatment on reverse osmosis performance in space flight applications(2007-12) Crawley, Jason; Morse, Audra; Jackson, Andrew W.; Song, Lianfa; Anderson, ToddRO is a treatment technology likely to be used for the recovery of wastewater on board long duration, manned space flights. As with terrestrial RO applications, concentration polarization and fouling lead to decreasing productivity and increasing energy demands with time. These problems are further complicated in a closed loop environment that demands a high level of recovery and quality. Physiochemical and biological pretreatment options can enhance the performance of the RO system. Physiochemical pretreatment is not always desirable in the application of long duration space flight because the transport and stowage of consumables can be cost prohibitive. Also, the transport and stowage of hazardous materials such as strong acids and bases is not desirable. Biological pretreatment is a low energy option that requires only a limited supply of consumables. Additionally, biological pretreatment is a proven terrestrial technology that is well understood. To determine the degree to which the incorporation of biological treatment enhances RO performance, a series of bench scale experiments were performed. The RO performance was measured in terms of permeate flux decline, solute rejection, and flow resistances. A mass balance and observed solute concentrations also helped to determine the fate of selected solutes. The gel layer model was used to evaluate the permeate flux for each of the experiments. Observed resistances also indicate that biological pretreatment alleviates the degree of fouling. Results indicate that enhanced urea hydrolysis, pH decrease, and carbon oxidation serve as the primary benefits of biological pretreatment.Item Water treatment system for bottled water(2013-08) Kopzhanova, Aiym; Sanchez, Isaac C., 1941-Without water, as is known, there is no life. A person uses about 75 tons of water for the whole life. Thereby, about 80% of diseases come with water people drink because it is simply dirty, according to Louis Pasteur. The fact is that consuming tap water leads to 85 known diseases that result in twenty-five million deaths each year. In addition, dirty water consumption accelerates the aging process by 30%. Tap water is drinkable, but not necessarily beneficial. The fact that the dirty water flows out of the tap means that the water contains a large quantity of chemical and mechanical impurities as well as a variety of viruses and bacteria. For example, if a person drinks water with high content of iron for a long time, the possibility of getting liver disease is high. The tap water quality that has always been consumed by people from Zhezkazgan, Republic of Kazakhstan violates even the required standards for tap water. Therefore, any kind of water business is encouraged in that area. The most viable way to help this problem is bottled water production. The great number of papers and materials was used, analyzed and delivered in this report. In addition, a Russian company, Ecodar LLP, was contacted to acquire information about the most advanced technology in water treatment field. This report provides general description of water treatment technology to start a bottled water production business in Zhezkazgan