In February 2014, a coal ash spill on Duke Energy's Dan River Plant in Eden, NC released approximately 39,000 tons of coal ash into the Dan River. It took approximately one week to stop the spill. Starting in February 2015, drinking water utilities using the Dan River experienced a series of taste and odor (TandO) events described as "earthy" or "musty". Similar TandO events were not documented before the coal ash spill. This research attempted to understand causes of the TandO events and if the coal ash spill was connected. A variety of water quality analyses were performed on twelve sites from August 2016 to September 2017 on the Dan and Smith Rivers. The Smith River served as the control. From concentrations of coal ash indicators (particularly Ba, Sr, As, V, and Br-), there was a signature of coal ash on the Dan River that was not present on the Smith River. The signature could not be attributed to the coal ash spill, as the signature was present upstream of the spill. Chronic ecosystem toxicity due to metals was low and not significantly different between the Dan and Smith Rivers. No substantial TandO events occurred during the period of this study. All monitored odorants were detected with varying frequencies in both the Dan and Smith Rivers. No significant change in odorant concentration was found above and below the location of the coal ash spill. / MS / In February 2014, a coal ash spill from Duke Energy’s Dan River Plant in Eden, NC released approximately 39,000 tons of coal ash into the Dan River. Starting in February 2015, drinking water utilities using the Dan River experienced a series of taste and odor (T&O) events described as smelling “earthy” or “musty”. Similar T&O events were not documented before the coal ash spill. This research attempted to understand underlying causes of these T&O events and to determine if the coal ash spill was connected. Analyses, including concentrations of coal ash indicators and odorants, were performed from August 2016 to September 2017 on a monthly basis for both the Dan and Smith Rivers. The Smith River served as a control river as it was not impacted by coal burning power plants and or a coal ash spill. There was a signature of coal ash metal contamination in the Dan River but not in the Smith River. The coal ash signature could not be attributed to the 2014 Duke Energy coal ash spill in Eden, NC because it was also found upstream of the area sampled and the location of the coal ash spill. Chronic ecosystem toxicity due to metals was low on the both the Dan and Smith Rivers and was not different between the rivers. No substantial drinking water taste and odor events occurred during the study period. All monitored earth-musty odorants were detected with varying frequency at concentrations mostly below and sometimes above their individual odor threshold concentration.

MIB e Geosmina são os principais agentes causadores de gosto e odor em águas de abastecimento. O carvão ativado em pó (CAP) desempenha um ótimo papel na remoção de MIB e Geosmina, entretanto, estudos tem comprovado que sua capacidade de adsorção é consideravelmente prejudicada quando em contato com concentrações residuais de agentes oxidantes empregados na etapa de pré-oxidação. Com o objetivo de avaliar o efeito da presença de permanganato de potássio na fase líquida no processo de adsorção de MIB e Geosmina pelo CAP, este estudo foi desenvolvido combinando diferentes dosagens do agente oxidante (zero, 1 e 2 mg L-1 ) e CAP (20 e 40 mg L-1) visando a remoção de MIB e Geosmina. Observou-se uma redução nas concentrações residuais do permanganato de potássio na água, o que evidencia a existência de uma interação entre o agente oxidante e o CAP. A utilização do permanganato de potássio conjuntamente ao CAP mostrou-se prejudicial à remoção de MIB e Geosmina sendo que para a aplicação de 20 mg L-1 de CAP, a presença de 2 mg L-1 de agente oxidante na fase líquida provocou uma redução na remoção de MIB e Geosmina de cerca de 50%. A presença do permanganato de potássio na água, no entanto, não provocou alteração no tempo de contato necessário para a adsorção dos micropoluentes estudados no CAP. Fica evidente, portanto, a necessidade do controle da dosagem do agente oxidante a ser aplicado a fim de se evitar concentrações residuais que possam interagir com o CAP reduzindo sua capacidade de remoção de MIB e Geosmina. / MIB and Geosmin are the main agents causing taste and odor in domestic water supply. Powdered activated carbon (PAC) plays an important role in the removal of MIB and Geosmin, however, studies have shown that its adsorption capacity is considerably impaired when in contact with residual concentrations of oxidizing agents used in the pre-oxidation stage. This study evaluated the effect of adding potassium permanganate in the liquid phase during the adsorption of MIB and Geosmin to PAC. The removal of MIB and Geosmin was evaluated with different dosages of the oxidizing agent, potassium permanganate (zero, 1 and 2 mg L-1) and PAC (20 and 40 mg L-1). The results showed a reduction in the residual permanganate in water, indicating an interaction between the oxidizing agent and the PAC. The use of potassium permanganate together with PAC reduced the MIB and Geosmin removal. The addition of 20 mg L-1 of PAC, in the presence of 2 mg L-1 of oxidizing agent in the liquid phase reduced the removal of MIB and Geosmin by 50%. The contact time required for the adsorption of the micropollutants to PAC, however, was not affected by the presence of potassium permanganate in the water. Therefore, the need to control the oxidizing agent\'s dosage is evident. Dosage control of the oxidizing agent can reduce its residual concentrations, which may interact with the PAC reducing its ability to remove MIB and Geosmin.

During 20th century main concern was to have sanitary water flowing through the tap. In 21st century constant supply of safe drinking water is common at any home in USA. Hence consumers pay attention to aesthetic quality of tap water. Odorous algal metabolites in source water and metals introduced to drinking water due to corrosion of pipes in the distribution system cause taste, odor and color problems, and result in complaints and perception of tap water as unhealthy. Millions of dollars are spent each year by water industry to address and prevent these issues. This research focused on some of the taste-and-odor issues associated with drinking water. First aim was to understand when geosmin, 2-MIB, and nonadienal become detectable, employing two-resistance mass transfer theory to determine the concentration of odorants in bathroom air. Results showed that water temperature and odorant concentration in water play an important role. Next focus was to develop an international odor standard to be used for training of sensory analysis panelists. There are many sensory methods to monitor drinking water to detect the off-flavors however an odor standard has been missing. Hexanal was studied with trained flavor profile analysis panels and was proposed as an ideal odor reference standard to be used for training and sensory assessment of water samples. Main focus was to understand metallic flavor of drinking water caused by iron and copper. It was shown that metallic sensation has taste and retronasal components creating the flavor and humans are very sensitive to it. Occurrence of lipid oxidation in the oral cavity was shown when metals were ingested, that produces carbonyls which are responsible for the metallic flavor. Antioxidants and chelators were investigated to study prevention of lipid oxidation and, chelators were determined to be more effective. Oral epithelial cell cultures were developed as a model for oral cavity to further investigate lipid oxidation and effectiveness of the antioxidants and chelators. This dissertation is a result of inter-disciplinary work and possibly a good example for how problems may be solved by incorporating different methods and point of views from several disciplines. / Ph. D.

As atividades humanas em bacias hidrográficas introduzem nos cursos de água nutrientes que aceleram o processo natural de eutrofização, favorecendo a ocorrência de florações de algas e cianobactérias. Estas florações se caracterizam por um crescimento explosivo destes microrganismos. Entre os diversos impactos negativos trazidos pelas florações está a emissão potencial dos compostos 2-metilisoborneol (MIB) e geosmina (GEO), os quais conferem gosto e odor de mofo e terra a água. Estes compostos não são totalmente removidos pelos processos convencionais de tratamento de água – clarificação química, filtração em meio granular e desinfecção com cloro, e permanecem na água até seu consumo, ocasionando alto índice de rejeição do produto por parte da população consumidora. Desta forma, a pesquisa foi planejada para avaliar alternativas de processos de tratamento visando à remoção de compostos odoríferos na água. Além de MIB e geosmina, foram feitas investigações relativas a remoção de ferro (Fe+2), manganês (Mn+2) e enxofre (H2S), nos processos estudados. Estas formas são normalmente encontradas em ambientes redutores, como águas subterrâneas e no hipolímnio de lagos e reservatórios, podendo contribuir para a deterioração das características organolépticas da água, ocasionando gosto e odores desagradáveis na água potável. Os processos estudados na pesquisa foram aeração em cascata, dessorção gasosa e nanofiltração. Os mecanismos do primeiro e segundo processos são: a oxidação de formas reduzidas e a dessorção de compostos voláteis e gases da água para o ar. O sistema de nanofiltração remove contaminantes da água através de retenção física imposta pelo tamanho dos poros da membrana. / Human activities in watersheds introduce nutrients to water bodies, accelerating the natural process of eutrophication and favoring the occurrence of algae and cyanobacterial blooms. The blooms are characterized by explosives growths of those microorganisms. Among the several negative impacts brought by the blooms is the potential emission of the compounds 2-methylisoborneol (MIB) and geosmin (GEO), which confer earthy and moldy taste and odor to drinking water. MIB and GEO are not completely removed by the conventional water treatment processes – chemical clarification, granular filtration and chorine disinfection, causing consumer’s rejection of the distributed drinking water This research was planned to evaluate the capability of alternative treatment processes to remove odorous compounds from water. Besides MIB and geosmin, the research encompassed tests with iron (Fe+²), manganese (Mn+²) and hydrogen sulfide (H2S). These species are usually found in reduced environments such as lake and reservoir hypolimnion and groundwater. They can cause problems associated with color, taste and odor in drinking water. Processes studied in the research were cascade aeration, air stripping and nanofiltration. Prevailing mechanisms in the first two processes are oxidation of the reduced forms by air oxygen and stripping of volatile compounds and gases dissolved in water to air. Nanofiltration systems remove contaminants dissolved in water by physical retention imposed by the membrane pore size.

As atividades humanas em bacias hidrográficas introduzem nos cursos de água nutrientes que aceleram o processo natural de eutrofização, favorecendo a ocorrência de florações de algas e cianobactérias. Estas florações se caracterizam por um crescimento explosivo destes microrganismos. Entre os diversos impactos negativos trazidos pelas florações está a emissão potencial dos compostos 2-metilisoborneol (MIB) e geosmina (GEO), os quais conferem gosto e odor de mofo e terra a água. Estes compostos não são totalmente removidos pelos processos convencionais de tratamento de água – clarificação química, filtração em meio granular e desinfecção com cloro, e permanecem na água até seu consumo, ocasionando alto índice de rejeição do produto por parte da população consumidora. Desta forma, a pesquisa foi planejada para avaliar alternativas de processos de tratamento visando à remoção de compostos odoríferos na água. Além de MIB e geosmina, foram feitas investigações relativas a remoção de ferro (Fe+2), manganês (Mn+2) e enxofre (H2S), nos processos estudados. Estas formas são normalmente encontradas em ambientes redutores, como águas subterrâneas e no hipolímnio de lagos e reservatórios, podendo contribuir para a deterioração das características organolépticas da água, ocasionando gosto e odores desagradáveis na água potável. Os processos estudados na pesquisa foram aeração em cascata, dessorção gasosa e nanofiltração. Os mecanismos do primeiro e segundo processos são: a oxidação de formas reduzidas e a dessorção de compostos voláteis e gases da água para o ar. O sistema de nanofiltração remove contaminantes da água através de retenção física imposta pelo tamanho dos poros da membrana. / Human activities in watersheds introduce nutrients to water bodies, accelerating the natural process of eutrophication and favoring the occurrence of algae and cyanobacterial blooms. The blooms are characterized by explosives growths of those microorganisms. Among the several negative impacts brought by the blooms is the potential emission of the compounds 2-methylisoborneol (MIB) and geosmin (GEO), which confer earthy and moldy taste and odor to drinking water. MIB and GEO are not completely removed by the conventional water treatment processes – chemical clarification, granular filtration and chorine disinfection, causing consumer’s rejection of the distributed drinking water This research was planned to evaluate the capability of alternative treatment processes to remove odorous compounds from water. Besides MIB and geosmin, the research encompassed tests with iron (Fe+²), manganese (Mn+²) and hydrogen sulfide (H2S). These species are usually found in reduced environments such as lake and reservoir hypolimnion and groundwater. They can cause problems associated with color, taste and odor in drinking water. Processes studied in the research were cascade aeration, air stripping and nanofiltration. Prevailing mechanisms in the first two processes are oxidation of the reduced forms by air oxygen and stripping of volatile compounds and gases dissolved in water to air. Nanofiltration systems remove contaminants dissolved in water by physical retention imposed by the membrane pore size.

As atividades humanas em bacias hidrográficas introduzem nos cursos de água nutrientes que aceleram o processo natural de eutrofização, favorecendo a ocorrência de florações de algas e cianobactérias. Estas florações se caracterizam por um crescimento explosivo destes microrganismos. Entre os diversos impactos negativos trazidos pelas florações está a emissão potencial dos compostos 2-metilisoborneol (MIB) e geosmina (GEO), os quais conferem gosto e odor de mofo e terra a água. Estes compostos não são totalmente removidos pelos processos convencionais de tratamento de água – clarificação química, filtração em meio granular e desinfecção com cloro, e permanecem na água até seu consumo, ocasionando alto índice de rejeição do produto por parte da população consumidora. Desta forma, a pesquisa foi planejada para avaliar alternativas de processos de tratamento visando à remoção de compostos odoríferos na água. Além de MIB e geosmina, foram feitas investigações relativas a remoção de ferro (Fe+2), manganês (Mn+2) e enxofre (H2S), nos processos estudados. Estas formas são normalmente encontradas em ambientes redutores, como águas subterrâneas e no hipolímnio de lagos e reservatórios, podendo contribuir para a deterioração das características organolépticas da água, ocasionando gosto e odores desagradáveis na água potável. Os processos estudados na pesquisa foram aeração em cascata, dessorção gasosa e nanofiltração. Os mecanismos do primeiro e segundo processos são: a oxidação de formas reduzidas e a dessorção de compostos voláteis e gases da água para o ar. O sistema de nanofiltração remove contaminantes da água através de retenção física imposta pelo tamanho dos poros da membrana. / Human activities in watersheds introduce nutrients to water bodies, accelerating the natural process of eutrophication and favoring the occurrence of algae and cyanobacterial blooms. The blooms are characterized by explosives growths of those microorganisms. Among the several negative impacts brought by the blooms is the potential emission of the compounds 2-methylisoborneol (MIB) and geosmin (GEO), which confer earthy and moldy taste and odor to drinking water. MIB and GEO are not completely removed by the conventional water treatment processes – chemical clarification, granular filtration and chorine disinfection, causing consumer’s rejection of the distributed drinking water This research was planned to evaluate the capability of alternative treatment processes to remove odorous compounds from water. Besides MIB and geosmin, the research encompassed tests with iron (Fe+²), manganese (Mn+²) and hydrogen sulfide (H2S). These species are usually found in reduced environments such as lake and reservoir hypolimnion and groundwater. They can cause problems associated with color, taste and odor in drinking water. Processes studied in the research were cascade aeration, air stripping and nanofiltration. Prevailing mechanisms in the first two processes are oxidation of the reduced forms by air oxygen and stripping of volatile compounds and gases dissolved in water to air. Nanofiltration systems remove contaminants dissolved in water by physical retention imposed by the membrane pore size.

Indiana University-Purdue University Indianapolis (IUPUI) / Eagle Creek Reservoir (ECR), located in the Midwestern U.S., is a freshwater limnic system plagued by seasonal Harmful Algal Blooms (HABs) which generate water-fouling Geosmin (GSM) and 2-Methylisoborneol (MIB) Taste and Odor (T&O) compounds. Past investigations of T&O event dynamics have identified Actinomycetes as responsible for MIB production and several genera of cyanobacteria for GSM production. During 2018, a temporally and spatially expansive sampling regimen of the reservoir was carried out and a battery of biological, chemical, physical, and hyperspectral experiments performed. The resulting data was analyzed using time series, cross-correlation, lag time, and multivariate analyses as well as machine learning algorithms to pick apart and interrogate any relationships between HABs, T&O events, and environmental parameters. The results show that local weather and watershed conditions exert significant control over the state of the reservoir and the behavior of the algal community. GSM and MIB peaked during early May under well-mixed, cold, and nutrient-rich water column conditions, then declined under summer thermal stratification before making a small resurgence during late season mixing. Bloom die-off and decay was effectively ruled out as a mechanism controlling T&O concentrations, and no links were found between T&O concentrations and algal biomass. Strong evidence was found that GSM/MIB concentrations were a response by bloom microbes to changing nutrient conditions within the reservoir, and it was determined that nutrient fluxes from the watershed 30-40 days prior to peak T&O concentrations are likely instrumental in the development of the slow- ix growing microbes characteristic of the reservoir. Attempts were made to assess spatial and temporal variability but no significant spatial differences were identified; differences between sampling sites were far smaller than differences between different sampling dates. The findings here add to the growing body of literature showing T&O and HAB dynamics are more closely linked to the relative abundance and speciation of nutrients than other parameters. Additionally, these findings carry important implications for the management of ECR and other similar freshwater reservoirs while highlighting the importance of reducing watershed eutrophication.

Indiana University-Purdue University Indianapolis (IUPUI) / In this research, Environmental Fluid Dynamic Code (EFDC) and Adaptive- Networkbased Fuzzy Inference System Models (ANFIS) were developed and implemented to determine the spatial-temporal distribution of cyanobacterial metabolites: 2-MIB and geosmin, in Eagle Creek Reservoir, IN. The research is based on the current need for understanding algae dynamics and developing prediction methods for algal taste and odor release events. In this research the methodology for prediction of 2-MIB and geosmin production was explored. The approach incorporated a combination of numerical and heuristic modeling to show its capabilities in prediction of cyanobacteria metabolites. The reservoir’s variable data measured at monitoring stations and consisting of chemical/physical and biological parameters with the addition of calculated mixing conditions within the reservoir were used to train and validate the models. The Adaptive – Network based Fuzzy Inference System performed satisfactorily in predicting the metabolites, in spite of multiple model constraints. The predictions followed the generally observed trends of algal metabolites during the three seasons over three years (2008-2010). The randomly selected data pairs for geosmin for validation achieved coefficient of determination of 0.78, while 2-MIB validation was not accepted due to large differences between two observations and their model prediction. Although, these ANFIS results were accepted, the further application of the ANFIS model coupled with the numerical models to predict spatio-temporal distribution of metabolites showed serious limitations, due to numerical model calibration errors. The EFDC-ANFIS model over-predicted Pseudanabaena spp. biovolumes for selected stations. The predicted value was 18,386,540 mm3/m3, while observed values were 942,478 mm3/m3. The model simulating Planktothrix agardhii gave negative biovolumes, which were assumed to represent zero values observed at the station. The taste and odor metabolite, geosmin, was under-predicted as the predicted v concentration was 3.43 ng/L in comparison to observed value of 11.35 ng/l. The 2-MIB model did not validate during EFDC to ANFIS model evaluation. The proposed approach and developed methodology could be used for future applications if the limitations are appropriately addressed.