<p>In the context of climate change, increasing demands for freshwater make it necessary to manage our water resources in a sustainable way and find innovative ways to extend their life. An integrated water management approach needs to consider anthropogenic water use and reuse which represent major components of the current water cycle. In particular, unplanned, or de facto, indirect water reuse occurs in most of the U.S. river systems; however, there is little real-time documentation of it. Despite the fact that there are national and state agencies that systematically collect data on water withdrawals and wastewater discharges, their databases are organized and managed in a way that limits the ability to combine reported water data to perform large scale analysis about water use and indirect reuse. To better document these issues and to demonstrate the utility of such an analysis, I studied the Wabash River Watershed located in the U.S. Midwest. Existing data for freshwater extraction, use, discharge, and river streamflow were collected, curated and reorganized in order to characterize the water use and reuse within the basin. Indirect water reuse was estimated by comparing treated wastewater discharges with stream flows at selected points within the watershed. Results show that during the low flow months of July-October 2007, wastewater discharges into the Wabash River basin contributed 82 to 121% of the stream flow, demonstrating that the level of water use and unplanned reuse is significant. These results suggest that intentional water reuse for consumptive purposes such as landscape or agricultural irrigation could have substantial ecological impacts by diminishing stream flow during vulnerable low flow periods. This research also completed a time series watershed-scale analysis of water use and unplanned indirect reuse for the Wabash River Watershed from 2009 to 2017. Results document the occurrence of indirect water reuse over time, ranging from 3% to 134% in a water-rich area of the U.S. The time series analysis shows that reported data effectively describe the water use trends through nine years, clearly reflecting both anthropogenic and natural events in the watershed, such as the retirement of thermoelectric power plants, and the occurrence of an extreme drought in 2012. Results demonstrate the feasibility and significance of using available water datasets to perform large scale water use analysis, describe limitations encountered in the process, and highlight areas for improvement in water data management.</p>

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Det är välkänt att klimatförändringar på grund av global uppvärmning är en av de största kriserna som hotar jorden. Det är en enorm utmaning för mänskligheten att minska koldioxidutsläppen, den främsta orsaken till global uppvärmning. Enkelt genomförbara åtgärder är inte tillräckliga och teknik för att ta bort koldioxid från atmosfären anses nödvändig för att temperaturökningen inte ska överstiga de 1,5 °C som anges i Parisavtalet. Direkt infångning av koldioxid från luft (vanligen kallad direkt luftinfångning, (Eng. Direct air capture - DAC)) är en ny teknik som kan ta bort koldioxid direkt från atmosfären. För närvarande är denna metod dyr; upp till 1000 USD per ton avlägsnad koldioxid. Denna höga kostnad beror främst på den relativt låga koldioxidkoncentrationen i luften, vilket leder till att en stor anläggning behövs för att fånga upp gasen och därmed stora investeringar. Tekniken är mycket energiintensiv, antingen elektrisk eller termisk, och för att göra en direkt infångning effektivare, måste anläggningen drivas med energi som inte har några eller mycket låga koldioxidutsläpp. Energin på Island är billig och dess produktion innebär ett mycket lågt koldioxidavtryck. Syftet med arbetet i denna avhandling är att utforska om metoden för direkt infångning av koldioxid från luft kommer att vara en mer genomförbar metod än koldioxidinfångning från punktkällor (eng. point source - PS) på Island på grund av god tillgång till billig och ren energi. Lärandekurvan för direkt luftfångning studerades tillsammans med scenarier för metodens tekniska utveckling. Tre olika fall med punktkällor på Island studerades för jämförelse. Två olika direkta luftinfångningstekniker analyserades också, en som drivs av en stor mängd elektricitet och en som drivs mestadels av termisk energi. Det resulterade i att i bästa fall, där inlärningshastigheten är hög och tekniska förbättringar är signifikanta, så skulle produktionskostnaden för direkt luftinfångning (levelized cost of energy, LCOC) vara lägre än motsvarande för infångning från en punktkälla. Energikostnaden påverkar LCOC för DAC idag men med teknisk utveckling förväntas energibehovet minska och därför kommer energikostnadens påverkan att bli lägre. Det är dock fortfarande viktigt, med tanke på bidraget till att minska globala uppvärmningen, att energin som driver DAC-anläggningen har ett lågt koldioxidavtryck, vilket kan garanteras på Island. Tvärtom, om inlärningshastigheten för DAC-tekniken är låg och inga tekniska förbättringar sker i lösningsmedel eller sorbenter, är och kommer DAC-tekniken att bli dyrare än infångning från punktkällor om båda anläggningarna finns på Island. En hög inlärningshastighet och teknikutveckling är beroende av trycket att nå målen i Parisavtalet. Det är därför mycket viktigt för DAC att efterfrågan på koldioxidinfångning ökar. Dessutom har DAC mer potential att påverka klimatförändringarna eftersom DAC kan vara en kolnegativ teknik om den kombineras med permanent lagring av koldioxid. PS-avskiljningen kan endast vara en kolneutral teknik och detta om den kombineras med permanent lagring av koldioxid. / It is well known that climate change due to global warming is one of the greatest crises facing the Earth. It is a huge challenge for mankind to reduce CO2 emissions, the major cause of global warming. Mitigation measures are not enough. Technologies to remove the CO2 from the atmosphere are considered necessary, so the temperature rise does not exceed 1.5°C as stated in the Paris Agreement. Direct air capture (DAC) is a new technology that can remove carbon dioxide directly from the atmosphere. Currently, this method is expensive, up to 1000 USD per ton CO2 removed. This high cost is mostly due to the relatively low concentration of CO2 in the ambient air, leading to a large unit to capture the gas and therefore high capital investment. The technology is very energy-intensive, either electrical or thermal, and to make direct air capture more efficient the plant needs to be powered with energy that has no or very low CO2 emissions. The energy in Iceland is low cost and its production has a very low carbon footprint. This thesis aims to find out if the direct air capture method will be more feasible than a point source CO2 capture in Iceland due to good access to low-cost and clean energy. The learning curve for direct air capture was studied along with scenarios for its technological development. Two different direct air capture technologies were analyzed, one that is powered by a large amount of electricity and one powered mostly by thermal energy. Three different point source cases in Iceland were studied for comparison. For the best-case scenario, where the learning rate is high and technological improvements are significant, the levelized cost of direct air capture is lower than levelized cost of point source capture. The cost of energy affects the levelized cost of direct air capture today but with technical development, the energy needed is expected to go down, and therefore the effect of energy cost will be lower.  However, it is still important, concerning contribution to reducing global warming, that the energy powering the direct air capture plant has a low carbon footprint, which can be assured in Iceland. On the contrary, if the learning rate of the direct air capture technology is low and no technical improvements occur in solvents or sorbents the direct air capture technology is and will be more expensive than point source capture considering both located in Iceland. The high learning rate and development in technology are dependent on the pressure to reach the goals of the Paris Agreement. It is therefore vital for direct air capture that the demand for carbon removal measures is enhanced due to pressure to reach the Paris Agreement goals. Furthermore, direct air capture has more potential to affect climate change than point source capture as direct air capture can be a carbon-negative technology if coupled with the permanent storage of CO2. The point source capture can only be a carbon-neutral technology if coupled with the permanent storage of CO2.

Urban environments have been identified as a non-point source contributor of nutrient loadings into watersheds. Interannual surges of nutrient loadings into local water systems are more damaging than mean interannual nutrient loadings. Virginia has outlined the need to reduce urban nutrient loadings. Mean interannual nutrient loadings and interannual nutrient loadings variability are expected to increase under climate change (CC). However, there are few studies that provide a predictive framework for abating nutrient loadings under CC. Thus, there is a lack of information regarding how effective water quality policy will be in the future. Using the Difficult Run watershed in Fairfax County, VA, as a site of study, we used mathematical programming to compare how the costs of abating nutrient loads differed under differing climates in the Mid-Atlantic. We first compared the costs of abating mean interannual nutrient loadings in the watershed based on historical climate conditions to those predicted for CC. We then evaluated how changes in the interannual variability of nutrient loadings for CC affect the costs of meeting watershed goals. We found that abating mean interannual nutrient loadings was substantially costlier for CC relative to meeting the same goals under historical climate conditions. Further, we found that the costs of abating interannual nutrient loadings variability increased under CC relative to meeting the same goals under historical climate. One implication of this study suggests that policy makers seeking to meet water quality goals over time must front-load supplemental BMPs today in order to offset the changes predicted for CC. / Master of Science

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Effluent from on-site sewage treatment and disposal systems (OSTDS) is generally known to impact groundwaters and surface waters with nitrogen (N) and phosphorus (P) and other contaminants. Little research has quantified this problem along the Indian River Lagoon (IRL), especially in Indian River County (IRC) where there are 26,660 active systems. This study assessed the effects of OSTDS on contamination of surface and groundwaters along three urbanized canals and the St. Sebastian River in IRC, all of which flow into the Central IRL. Multiple lines of evidence were used to define the source of the nutrient loadings including the novel approach of using the artificial sweetener, sucralose, as an indicator of human sewage impact. Results indicate that areas with high densities of OSTDS are contributing N to surface waters and elevating N:P ratios through submarine groundwater discharge and promoting eutrophication in the Central IRL. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

This study assessed the feasibility and suitability of a Water Quality Trading (WQT) program within the Kentucky River Basin (KRB). The study’s focal point was based on five success factors of a WQT program: environmental suitability, geospatial orientation, participant availability, regulatory incentive, and economic incentive. The study utilized these five success factors, geographical characteristics, and Discharge Monitoring Reports (DMR) to assess the feasibility of a WQT program. The assessment divided the KRB into five eight digit Hydrologic Unit Codes (HUC), North, Middle, and South Fork, Middle Basin, and Lower Basin, to determine regional impacts caused by the nutrient PSs. Individual nutrient profiles were generated to show the number of point sources (PS) operating in the KRB, their geospatial orientation to one another, and their permitted nutrient limits and nutrient discharges in form of total phosphorus (TP), total nitrogen (TN), and total nitrogen (as ammonia) (TA). Findings suggest trading is highly unlikely for TP and TN PSs due to the lack of regulatory standards, limited number of TN and TP PSs, and an inadequate demand for offset credits. Trading is also unlikely in all the HUC 8 watersheds except for the Lower Basin due to the lack of nutrient impaired waters. Key Words: Point Source, Non-Point Source, Water Quality Trading, TMDL, Impaired Waters

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-20T14:01:59Z No. of bitstreams: 1 VALÉRIO DE ARAÚJO GOMES - DISSERTAÇÃO PPGEQ 2007..pdf: 2306567 bytes, checksum: aa927c50f8346bfbe8e90901136c65fe (MD5) / Made available in DSpace on 2018-03-20T14:01:59Z (GMT). No. of bitstreams: 1 VALÉRIO DE ARAÚJO GOMES - DISSERTAÇÃO PPGEQ 2007..pdf: 2306567 bytes, checksum: aa927c50f8346bfbe8e90901136c65fe (MD5) Previous issue date: 2017 / A determinação de concentração de poluentes lançados na atmosfera é um elemento importante na previsão de impactos ambientais causados por emissões de efluentes industriais, sendo fundamental na avaliação de viabilidade de novas plantas, ou mesmo para plantas existentes. Em função da ampliação dos parques industriais e da aproximação dos centros urbanos, cada vez mais fica evidente a necessidade de dispor de dados de simulações da qualidade do ar, para tomar decisões em relação ao tipo de tratamento dos efluentes gasosos, posicionamento de plantas, projetos de chaminés (altura), e principalmente do tipo de controle e processo que será necessário para minimizar as concentrações lançadas no meio ambiente. O presente trabalho teve como objetivo, principalmente, desenvolver uma rotina aplicada as emissões de fluoreto gasoso proveniente de reduções eletrolíticas de alumínio. A referência adotada foi o modelo desenvolvido pela Environmental Research & Technology Inc. chamado BLP – Buoyant Line and Point Source (modelo fundamentado na distribuição gaussiana), aplicando algumas considerações específicas. A implementação foi realizada utilizando o Mathcad 11 Enterprise Edition. Posteriormente ao desenvolvimento foram feitas várias simulações com informações coletadas pelo programa de monitoramento de fontes estacionárias da Alumar e comparados com os dados coletados na estação de monitoramento contínuo de qualidade do ar localizada na vila de Coqueiro (intermediações do limite da fábrica, 2,500 Km). Complementarmente, também foi realizada uma simulação para comparar o resultado do modelo proposto com os resultados do CALPUFF (software comercial referendado pela EPA – Environmental Protection Agency) que foi utilizado durante a elaboração do estudo de impacto ambiental da complementação da sala de cubas – linha 3. O modelo proposto apresentou uma correlação de 82% com os dados históricos coletados na estação localizada na vila de Coqueiro e um erro de 4,35% quando comparado com as simulações do CALPUFF. / The determination of the pollutants concentration released into the atmosphere is an important element in the prediction of environmental impacts caused by emissions from industrial effluents, being fundamental in the feasibility evaluation of new plants, or even for existing plants. Due to the industrial parks expansion and the approximation of urban centers, it is increasingly evident that there is a need for air quality simulation data to make decisions regarding the type of treatment of gaseous effluents, plant positioning, chimneys dimensions (height), and especially of the type of control and process that will be necessary to minimize the concentrations released in the environment. The main objective of this work was to develop a routine applied to the emission of gaseous fluoride from electrolytic smelting of aluminum. The reference adopted was the model developed by Environmental Research & Technology Inc called BLP - Buoyant Line and Point Source (model based on the Gaussian distribution), applying some specific considerations. The implementation was performed using Mathcad 11 Enterprise Edition. After the development, several simulations were carried out with information collected by Alumar's stationary source monitoring program and compared to the data collected at the continuous air quality monitoring station located in the village of Coqueiro (distant 2,500 km). In addition, simulations were also carried out to compare the results of the proposed model with the results from CALPUFF (commercial software endorsed by the EPA - Environmental Protection Agency) that was used during the elaboration of the environmental impact study of the complementation of the potroom - line 3. The proposed model presented a correlation of 82% with the historical data collected at the station located in the village of Coqueiro and an error of 4.35% when compared to the simulations of the CALPUFF.