Geruchsstoffe in Trinkwassergewinnungsanlagen stellen ein weltweit auftretendes Problem dar und führen in der Regel zu einer Kostenintensivierung bei der Aufbereitung des Rohwassers. Die den erdig-muffigen Geschmack des Wassers verursachenden, hauptsächlichsten Substanzen Geosmin und 2-Methylisoborneol (2-MIB) sind schon in einem Konzentrationsbereich von 1-10 ng/L wahrnehmbar. Da das Trinkwasser Geruchs- und Geschmacksneutral sein soll, müssen im Zuge der Rohwasseraufbereitung die Geruchsstoffe entfernt werden. Geruchsstoffe können durch verschiedene Mikroorganismen wie Cyanobakterien, Aktinomyceten, Streptomyceten oder auch Algen gebildet werden. Das Ziel dieser Arbeit stellte daher die Identifikation von cyanobakteriellen Geruchsstoffbildnern in den drei sächsischen Trinkwassertalsperren Klingenberg, Cranzahl und Saidenbach dar. Das Hauptaugenmerk lag auf der Charakterisierung der vorkommenden benthischen Cyanobakterien. Neben deren Abhängigkeit von der Trophie des Gewässers sollte das Artenspektrum der benthischen Cyanobakterien untersucht werden sowie eine Identifikation erfolgen, welche Geruchsstoffe sie synthetisieren bzw. freisetzen. Dazu erfolgte die Gewinnung von Isolaten benthischer Cyanobakterien anhand von Proben, die aus den Talsperren entnommen wurden. Die anschließende Charakterisierung der Isolate wurde sowohl auf morphologischer als auch auf molekularbiologischer Ebene durch die partielle Sequenzierung der rbcL- und geoA-Gene durchgeführt. Ein weiteres Ziel bestand darin, die Fähigkeit zur Bildung von Geosmin und 2-MIB nachzuweisen. Dazu sollten ausgewählte Isolate, zur Abschätzung des Geruchsstoff-Bildungspotentials der Cyanobakterien in der Talsperre, unter verschiedenen Laborbedingungen kultiviert und auf die Bildung und Freisetzung von Geruchsstoffen hin untersucht sowie der Einfluss der Beleuchtung durch verschiedene Lichtfarben bzw. Spektren und des Mediums bestimmt werden. Zusätzliche Fragestellungen stellten die Identifikation spezifischer Gene sowie die Entwicklung eines geeigneten Primersystems und gegebenenfalls der Nachweis einer Korrelation zur Geruchsstoffbildung dar. Anhand der Klima- und der physikalischen Daten sollten mögliche Einflussgrößen auf die Geruchsstoffproduktion durch benthische Cyanobakterien aufgezeigt werden. Durch regelmäßige Probenahmen wie auch Kamerabefahrungen in Zusammenarbeit mit der Landestalsperrenverwaltung Sachsen wurde die Entwicklung des von Cyanobakterien dominierten Phytobenthos in drei Talsperren verfolgt und dokumentiert. Dabei konnte gezeigt werden, dass dieses durch Vertreter der Gattungen Oscillatoria und Phormidium dominiert wurde. Im Verlauf der Untersuchungen konnten mehrere Massenentwicklungen von Cyanobakterien verfolgt werden. Die Abnahme des Staupegels ist in Verbindung mit der Sonneneinstrahlung die möglicherweise wichtigste Stellgröße für eine Massenentwicklung benthischer Cyanobakterien und einem damit verbundenen Anstieg des Geruchsstoff-Gehalts im Roh- bzw. Oberflächenwasser. Die Analyse der Entwicklung der Cyanobakterien unter natürlichen Bedingungen stellt aufgrund der großen Varianz der Einfluss nehmenden Parameter eine sehr komplexe Aufgabe dar. Daher wurden zur umfangreicheren Analyse der Herkunft der Geruchsstoffe Cyanobakterien isoliert. Dadurch wurde es möglich, das Geruchsstoff-Bildungspotential näher zu charakterisieren. Die erhaltenen Isolate wurden durch morphologische Merkmale bestimmt und molekularbiologisch durch partielle Sequenzierung des rbcL-Gens klassifiziert. Weiterhin erfolgte der analytische Nachweis von Geruchsstoffen in der Biomasse der Cyanobakterien sowie im Kultivierungsmedium. Der Nachweis von Geosmin in der Biomasse konnte hoch signifikant mit dem PCR-Nachweis von geoA korreliert werden. Es konnte gezeigt werden, dass der Besitz von geoA zu einer deutlich stärkeren Bildung und Freisetzung des Geruchsstoffs führt. Für das unter natürlichen Bedingungen ebenfalls auftretende 2-MIB konnten dagegen keine gesicherten cyanobakteriellen Produzenten identifiziert werden. 2003 wurde die Funktionalität des Gens cyc2 in Streptomyceten durch Gust et al. beschrieben. Auf dieser Grundlage konnte ein degeneriertes Primersystem zum Nachweis eines Stoffwechselgens (geoA) bei Cyanobakterien entwickelt werden. Die Biomasse des Isolats Phormidium sp. P2r aus der Talsperre Saidenbach enthielt einerseits in besonders großen Mengen intrazelluläres Geosmin. Andererseits konnten aber auch im Kultivierungsmedium hohe Geosminkonzentrationen ermittelt werden. Durch die Anwendung des etablierten Primersystems konnte mit der isolierten, genomischen DNA dieses Cyanobakteriums ein Amplifikat erhalten und sequenziert werden. Durch die Anwendung weiterer Protokolle, wie beispielsweise degenerierte Primersysteme oder des Vectorette-Ansatzes konnte der bekannte Sequenzbereich deutlich vergrößert werden. Dabei stellte es sich heraus, dass Phormidium sp. P2r zwei sehr ähnliche Gene (geoA1 und geoA2) besitzt, die vermutlich koreguliert werden. Die mRNA-Expressionsuntersuchungen bestätigten die Expression beider Gene bei Licht und einer Temperatur im Bereich von 10 - 20 °C. Nach einer 24stündigen Dunkelphase konnte die Bildung der geoA-mRNA hingegen nicht mehr nachgewiesen werden, was die Vermutung bestätigt, dass die Aktivität der Gene reguliert und nicht konstitutiv ist. Eine Verbindung der Synthese von Geosmin zur Photosysnthese ist aber dennoch fraglich. Die molekularbiologische Bestimmung der Diversität von geoA in Proben des Phytobenthos aus der Talsperre Klingenberg offenbarte eine große Vielfalt unterschiedlicher Sequenzen. Dies könnte auf vielfältigste Geosmin produzierende Mikroorganismen hinweisen. Das Geruchsstoff-Bildungspotential der isolierten und charakterisierten Cyanobakterien wurde unter verschiedenen Testbedingungen ermittelt. Dabei wurde vor allem der Einfluss unterschiedlicher Nährstoffkonzentrationen sowie Lichtfarben einschließlich UV-Strahlung untersucht. Es hat sich gezeigt, dass alle getesteten Stämme zur Geosmin-Freisetzung befähigt waren und sich das Freisetzungsniveau massiv in Abhängigkeit des Besitzes von geoA unterschied. Bei grünem Licht, welches auch in den untersuchten Talsperren den dominierenden Spektralanteil im Wasserkörper darstellt, wurde neben dem Tageslicht das beste Wachstum benthischer Cyanobakterien ermittelt. Letztendlich konnte durch die Laborexperimente eine variable Geosminbildung sowie ein unterschiedlicher Einfluss der Testbedingungen festgestellt werden. In der Talsperre Klingenberg konnte im Juni 2007 ein Gehalt von bis zu mehr als 70 ng Geosmin/L Oberflächenwasser bei einer Geruchsschwellenkonzentration von 1 ng/L (Young et al., 1996) ermittelt werden. Die Herkunft dieses Geruchsstoffs kann mit den Ergebnissen dieser Arbeit eindeutig den benthischen Cyanobakterien zugeordnet werden. Von besonderer Bedeutung war die Feststellung, dass der Besitz von geoA unter den benthischen Cyanobakterien der drei untersuchten Talsperren mit etwa 33 % der unterschiedlichen rbcL-Genotypen nicht weit verbreitet war. Die Rolle der anderen Cyanobakterien darf jedoch nicht unterschätzt werden, da z. B. hohe Geruchsstoff-Konzentrationen in der Talsperre Klingenberg bei einer deutlichen Dominanz von Oscillatoria sp. zustande kamen, aber alle als Oscillatoria klassifizierten Isolate geoA negativ waren. Eine Vorhersage der Entwicklung benthischer Cyanobakterien in den Talsperren kann auch mit den Ergebnissen dieser Arbeit nicht getroffen werden. Dazu ist die Reaktion der Cyanobakterien auf unterschiedliche Umweltfaktoren wie diese bei der Geruchsstoff-Bildung getestet wurden zu mannigfaltig. Wenn Cyanobakterien im Phytobenthos der Talsperren nachweisbar sind, könnte eine Prognose zur weiteren Entwicklung unter Berücksichtigung der zu erwartenden Veränderungen der Rahmenbedingungen, wie vor allem des Staupegels gegeben werden. Zur Ausbildung stabiler Cyanobakterien-Matten wie diese in der Talsperre Cranzahl 2007 vorhanden waren, ist sicherlich eine längerfristige Stabilität verschiedener und bislang noch unbekannter Rahmenbedingungen nötig. Obwohl die Dominanz der Cyanobakterien bei der Bildung von Geruchsstoffen im Phytobenthos in ähnlichen Habitaten auf Grund dieser Untersuchungen nicht mehr in Frage gestellt werden wird, ist dennoch die Möglichkeit gegeben, dass möglicherweise unter anderen Voraussetzungen und Bedingungen auch andere, nicht näher untersuchte Mikroorganismengruppen wie Aktinomyceten intensiv Geruchsstoffe in Talsperren bilden könnten.

Algae and cyanobacteria occur naturally in source waters and are known to cause extensive problems in the drinking water treatment industry. Cyanobacteria (especially Anabaena sp. and Microcystis sp.) are responsible for many water treatment problems in drinking water treatment works (DWTW) all over the world because of their ability to produce organic compounds like cyanotoxins (e.g. microcystin) and taste and odour compounds (e.g. geosmin) that can have an adverse effect on consumer health and consumer confidence in tap water. Therefore, the monitoring of cyanobacteria in source waters entering DWTW has become an essential part of drinking water treatment management. Managers of DWTW, rely heavily on results of physical, chemical and biological water quality analyses, for their management decisions. But results of water quality analyses can be delayed from 3 hours to a few days depending on a magnitude of factors such as: sampling, distance and accessibility to laboratory, laboratory sample turn-around times, specific methods used in analyses etc. Therefore the use of on-line (in situ) instruments that can supply real-time results by the click of a button has become very popular in the past few years. On-line instruments were developed for analyses like pH, conductivity, nitrate, chlorophyll-a and cyanobacteria concentrations. Although, this real-time (on-line) data has given drinking water treatment managers a better opportunity to make sound management decisions around drinking water treatment options based on the latest possible results, it may still be “too little, too late” once a sudden cyanobacterial bloom of especially Anabaena sp. or Microcystis sp. enters the plant. Therefore the benefit for drinking water treatment management, of changing the focus from real-time results to future predictions of water quality has become apparent. The aims of this study were 1) to review the environmental variables associated with cyanobacterial blooms in the Vaal Dam, as to get background on the input variables that can be used in cyanobacterial-related forecasting models; 2) to apply rule-based Hybrid Evolutionary Algorithms (HEAs) to develop models using a) all applicable laboratory-generated data and b) on-line measureable data only, as input variables in prediction models for harmful algal blooms in the Vaal Dam; 3) to test these models with data that was not used to develop the models (so-called “unseen data”), including on-line (in situ) generated data; and 4) to incorporate selected models into two cyanobacterial incident management protocols which link to the Water Safety Plan (WSP) of a large DWTW (case study : Rand Water). During the current study physical, chemical and biological water quality data from 2000 to 2009, measured in the Vaal Dam and the 20km long canal supplying the Zuikerbosch DWTW of Rand Water, has been used to develop models for the prediction of Anabaena sp., Microcystis sp., the cyanotoxin microcystin and the taste and odour compound geosmin for different prediction or forecasting times in the source water. For the development and first stage of testing the models, 75% of the dataset was used to train the models and the remaining 25% of the dataset was used to test the models. Boot-strapping was used to determine which 75% of the dataset was to be used as the training dataset and which 25% as the testing dataset. Models were also tested with 2 to 3 years of so called “unseen data” (Vaal Dam 2010 – 2012) i.e. data not used at any stage during the model development. Fifty different models were developed for each set of “x input variables = 1 output variable” chosen beforehand. From the 50 models, the best model between the measured data and the predicted data was chosen. Sensitivity analyses were also performed on all input variables to determine the variables that have the largest impact on the result of the output. This study have shown that hybrid evolutionary algorithms can successfully be used to develop relatively accurate forecasting models, which can predict cyanobacterial cell concentrations (particularly Anabaena sp. and Microcystis sp.), as well as the cyanotoxin microcystin concentration in the Vaal Dam, for up to 21 days in advance (depending on the output variable and the model applied). The forecasting models that performed the best were those forecasting 7 days in advance (R2 = 0.86, 0.91 and 0.75 for Anabaena[7], Microcystis[7] and microcystin[7] respectively). Although no optimisation strategies were performed, the models developed during this study were generally more accurate than most models developed by other authors utilising the same concepts and even models optimised by hill climbing and/or differential evolution. It is speculated that including “initial cyanobacteria inoculum” as input variable (which is unique to this study), is most probably the reason for the better performing models. The results show that models developed from on-line (in situ) measureable data only, are almost as good as the models developed by using all possible input variables. The reason is most probably because “initial cyanobacteria inoculum” – the variable towards which the output result showed the greatest sensitivity – is included in these models. Generally models predicting Microcystis sp. in the Vaal Dam were more accurate than models predicting Anabaena sp. concentrations and models with a shorter prediction time (e.g. 7 days in advance) were statistically more accurate than models with longer prediction times (e.g. 14 or 21 days in advance). The multi-barrier approach in risk reduction, as promoted by the concept of water safety plans under the banner of the Blue Drop Certification Program, lends itself to the application of future predictions of water quality variables. In this study, prediction models of Anabaena sp., Microcystis sp. and microcystin concentrations 7 days in advance from the Vaal Dam, as well as geosmin concentration 7 days in advance from the canal were incorporated into the proposed incident management protocols. This was managed by adding an additional “Prediction Monitoring Level” to Rand Waters’ microcystin and taste and odour incident management protocols, to also include future predictions of cyanobacteria (Anabaena sp. and Microcystis sp.), microcystin and geosmin. The novelty of this study was the incorporation of future predictions into the water safety plan of a DWTW which has never been done before. This adds another barrier in the potential exposure of drinking water consumers to harmful and aesthetically unacceptable organic compounds produced by cyanobacteria. / PhD (Botany), North-West University, Potchefstroom Campus, 2015

Algae and cyanobacteria occur naturally in source waters and are known to cause extensive problems in the drinking water treatment industry. Cyanobacteria (especially Anabaena sp. and Microcystis sp.) are responsible for many water treatment problems in drinking water treatment works (DWTW) all over the world because of their ability to produce organic compounds like cyanotoxins (e.g. microcystin) and taste and odour compounds (e.g. geosmin) that can have an adverse effect on consumer health and consumer confidence in tap water. Therefore, the monitoring of cyanobacteria in source waters entering DWTW has become an essential part of drinking water treatment management. Managers of DWTW, rely heavily on results of physical, chemical and biological water quality analyses, for their management decisions. But results of water quality analyses can be delayed from 3 hours to a few days depending on a magnitude of factors such as: sampling, distance and accessibility to laboratory, laboratory sample turn-around times, specific methods used in analyses etc. Therefore the use of on-line (in situ) instruments that can supply real-time results by the click of a button has become very popular in the past few years. On-line instruments were developed for analyses like pH, conductivity, nitrate, chlorophyll-a and cyanobacteria concentrations. Although, this real-time (on-line) data has given drinking water treatment managers a better opportunity to make sound management decisions around drinking water treatment options based on the latest possible results, it may still be “too little, too late” once a sudden cyanobacterial bloom of especially Anabaena sp. or Microcystis sp. enters the plant. Therefore the benefit for drinking water treatment management, of changing the focus from real-time results to future predictions of water quality has become apparent. The aims of this study were 1) to review the environmental variables associated with cyanobacterial blooms in the Vaal Dam, as to get background on the input variables that can be used in cyanobacterial-related forecasting models; 2) to apply rule-based Hybrid Evolutionary Algorithms (HEAs) to develop models using a) all applicable laboratory-generated data and b) on-line measureable data only, as input variables in prediction models for harmful algal blooms in the Vaal Dam; 3) to test these models with data that was not used to develop the models (so-called “unseen data”), including on-line (in situ) generated data; and 4) to incorporate selected models into two cyanobacterial incident management protocols which link to the Water Safety Plan (WSP) of a large DWTW (case study : Rand Water). During the current study physical, chemical and biological water quality data from 2000 to 2009, measured in the Vaal Dam and the 20km long canal supplying the Zuikerbosch DWTW of Rand Water, has been used to develop models for the prediction of Anabaena sp., Microcystis sp., the cyanotoxin microcystin and the taste and odour compound geosmin for different prediction or forecasting times in the source water. For the development and first stage of testing the models, 75% of the dataset was used to train the models and the remaining 25% of the dataset was used to test the models. Boot-strapping was used to determine which 75% of the dataset was to be used as the training dataset and which 25% as the testing dataset. Models were also tested with 2 to 3 years of so called “unseen data” (Vaal Dam 2010 – 2012) i.e. data not used at any stage during the model development. Fifty different models were developed for each set of “x input variables = 1 output variable” chosen beforehand. From the 50 models, the best model between the measured data and the predicted data was chosen. Sensitivity analyses were also performed on all input variables to determine the variables that have the largest impact on the result of the output. This study have shown that hybrid evolutionary algorithms can successfully be used to develop relatively accurate forecasting models, which can predict cyanobacterial cell concentrations (particularly Anabaena sp. and Microcystis sp.), as well as the cyanotoxin microcystin concentration in the Vaal Dam, for up to 21 days in advance (depending on the output variable and the model applied). The forecasting models that performed the best were those forecasting 7 days in advance (R2 = 0.86, 0.91 and 0.75 for Anabaena[7], Microcystis[7] and microcystin[7] respectively). Although no optimisation strategies were performed, the models developed during this study were generally more accurate than most models developed by other authors utilising the same concepts and even models optimised by hill climbing and/or differential evolution. It is speculated that including “initial cyanobacteria inoculum” as input variable (which is unique to this study), is most probably the reason for the better performing models. The results show that models developed from on-line (in situ) measureable data only, are almost as good as the models developed by using all possible input variables. The reason is most probably because “initial cyanobacteria inoculum” – the variable towards which the output result showed the greatest sensitivity – is included in these models. Generally models predicting Microcystis sp. in the Vaal Dam were more accurate than models predicting Anabaena sp. concentrations and models with a shorter prediction time (e.g. 7 days in advance) were statistically more accurate than models with longer prediction times (e.g. 14 or 21 days in advance). The multi-barrier approach in risk reduction, as promoted by the concept of water safety plans under the banner of the Blue Drop Certification Program, lends itself to the application of future predictions of water quality variables. In this study, prediction models of Anabaena sp., Microcystis sp. and microcystin concentrations 7 days in advance from the Vaal Dam, as well as geosmin concentration 7 days in advance from the canal were incorporated into the proposed incident management protocols. This was managed by adding an additional “Prediction Monitoring Level” to Rand Waters’ microcystin and taste and odour incident management protocols, to also include future predictions of cyanobacteria (Anabaena sp. and Microcystis sp.), microcystin and geosmin. The novelty of this study was the incorporation of future predictions into the water safety plan of a DWTW which has never been done before. This adds another barrier in the potential exposure of drinking water consumers to harmful and aesthetically unacceptable organic compounds produced by cyanobacteria. / PhD (Botany), North-West University, Potchefstroom Campus, 2015

A significant issue affecting the aquaculture and water industries is the presence of off-flavour compounds in water, which cause problems by imparting an undesirable earthy/musty flavour and smell to water and fish. Two predominant off-flavour compounds are geosmin (GSM) and 2-methylisoborneol (MIB). These compounds are produced by several varieties of cyanobacteria and actinomycetes as metabolic products and can be detected by humans at concentrations as low as 0.015 mg L-1. Removal of GSM and MIB from potable waters has proven to be inefficient using standard water treatment such as filtration, coagulation, flocculation, sedimentation and chlorination. Activated carbon and membrane processes can physically remove GSM and MIB, but do not destroy them, and ozone treatment can be expensive. Titanium dioxide (TiO2) photocatalysis has recently been demonstrated to rapidly degrade GSM and MIB. When the semiconductor catalyst is illuminated with ultraviolet light simultaneous oxidation and reduction reactions occur. Pollutants are broken down into mineral acids, carbon dioxide and water. This study was conducted to determine if TiO2 photocatalysis, using a pelleted form of TiO2 called Hombikat K01/C, was a suitable method for the treatment of potable water. Additionally an analytical method was developed to rapidily analyse the large number of samples generated. Two reactors, a bench scale batch reactor and pilot scale flow reactor, were developed and used to evaluate the efficacy of Hombikat K01/C TiO2 photocatalysis in degrading GSM. The batch reactor, containing Hombikat K01/C, was used to investigate the effect of numerous experimental variables on the photocatalysis of GSM, including initial substrate concentration, pH, light intensity, aeration rate, the presence of additional reactants, and catalysis conducted in deuterated water. GSM was rapidly degraded using the TiO2 batch reactor, with the rate of GSM degradation most affected by light intensity and additional reactants, though pH also had a notable effect. A kinetic isotope effect of 1.61 was observed for the destruction of GSM using Hombikat K01/C TiO2. The flow reactor was also found to efficiently degrade GSM in raw waters. The rate of GSM destruction was found to be significantly lowered by UV shielding of the catalyst, caused by constituents of raw the water used, and the presence of additional reactants. The pilot scale flow reactor was also successfully evaluated in Denmark using gesomin contaminated water from an eel farm

This thesis deals with different optimization problems encountered in organic synthesis. The use of response surface, sequential simplex and PLS techniques, for simultanious optimization of yield and suppression of side reactions is investigated. This is illustrated by an example of enamine synthesis, were a side reaction was a serious problem. The problem of efficient screening to find suitable catalysts and solvents in new reactions is also investigated. Here, the use of principal properties as selection criterion, is demonstrated with a new process for the silylation of a,ß-unsaturated ketones. The extension of the new method to bis silylation of 1,2- and 1,3-diketones is demonstrated. The total synthesis of (±)-geosmin is investigated by an approach aimed to reduce the number of necessary steps involved. The suggested strategy, is to find compatible solvents through several transformations in the sequence to accomplish one-pot multistep reactions. In this context an improved method for the preparation of 1,10-dimethyl-l(9)-octalone-2 was established. Comparison with previously reported total syntheses of (±)-geosmin was done. / digitalisering@umu

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.

A presente tese trata do desenvolvimento de uma língua eletrônica (LE) e da avaliação de seu uso na detecção de 2-metilisoborneol (MIB), geosmina (GEO) e isoborneol (ISO) em amostras de água. A água abastecida à região metropolitana de São Paulo provém de mananciais, os quais estão sujeitos à ploriferação de algas (eutrofização). Muitas delas podem ser tóxicas e ainda produzir compostos, como MIB e GEO, substâncias reconhecidas por provocar gosto e odor desagradáveis na água que consumimos. De fato, a presença de MIB e GEO na água é uma das maiores fontes de reclamação por parte dos consumidores junto à companhia de saneamento e abastecimento de São Paulo (SABESP). Apesar disso, ainda não existem tecnologias que possam ser aplicadas para a detecção in locu dessas substâncias. A LE usada nesta tese foi baseada em um arranjo de sensores químicos não-específicos, formados por microeletrodos interdigitados de ouro recobertos com filmes poliméricos nanoestruturados depositados pela técnica de automontagem e interrogados sob regime de corrente alternada. A calibração da LE foi realizada com soluções de concentração determinada de GEO, MIB e ISO preparadas em água destilada, mineral e de torneira. Foram avaliadas tanto soluções individuais contendo um único contaminante, quanto misturas contendo MIB e GEO. A resposta elétrica dos sensores (medidas de capacitância), foram interpretadas por análise das componentes principais (PCA) e por lógica Fuzzy, com as quais a LE consegue discriminar as diversas amostras com relativa facilidade e confiabilidade. Dentre as principais observações dessa investigação, notou-se que a LE desenvolvida consegue detectar MIB e GEO em amostras de água reais em concentrações tão baixas quanto 20 ng L-1. Os gráficos de PCA mostram a separação das amostras em clusters relativamente pequenos, bem separados e sem sobreposição. A LE é capaz de identificar de forma direta, a partir de variações na primeira componente principal, variações na razão molar nGEO/nMIB em misturas de MIB e GEO. Em um caso mais próximo da realidade, a LE consegue discriminar com relativa facilidade, amostras de água fornecidas pela SABESP, coletadas do sistema Guarapiranga antes e após a estação de tratamento. As taxas de acerto da LE usando os controladores Fuzzy desenvolvidos são próximas de 100% para a maioria das amostras. A menor taxa de acerto (93,33%) ocorreu com as amostras preparadas em água de torneira. Adicionalmente, nenhuma amostra de água pura foi classificada como contendo algum contaminante, ou seja, não houve falsos positivos. Conclui-se, portanto que a LE desenvolvida, tanto em termos de sensores quanto de análise de dados, apresenta potencial para monitoramento de MIB e GEO nos reservatórios de água, fornecendo em tempo real e in loco informações sobre a qualidade da água provinda da estação de tratamento. A tese também apresenta alguns resultados da preparação de filmes poliméricos com impressão molecular para aplicação em sensores específicos, obtidos durante o estágio na Universidade Autônoma de Barcelona. / Water from São Paulo metropolitan area comes from water reservoirs, which are prone to algae bloom (eutrophication). These algae can be toxic and produce compounds, such as geosmin (GEO) and 2-methylisoborneol (MIB) that give unpleasant taste and odour to the water supplied to consumers. In fact, their presence in water is one of the major complains of consumers to São Paulo\'s water company (SABESP). Despite that, technologies that can be applied for monitoring these substances in real time and in locu are still not available. In this sense, the present thesis work has focused on the development of an electronic tongue system (ET) and evaluate its performance on detecting MIB, GEO and isoborneol (ISO) in water samples. The ET is based on an array of non-specific chemical sensors, which are made of gold interdigitated microelectrodes covered with nanostructured polymeric films deposited via the layer-by-layer technique and interrogated in alternate current regime. The ET calibration was conducted by analyzing distilled, mineral and tap water samples tainted with known concentrations of MIB, GEO and ISO. The samples were solutions with a single tainting compound and solutions containing MIB and GEO mixed together. The sensors\' electrical response (capacitance measurements) was interpreted by principal component analysis (PCA) and Fuzzy logic. Among the main features of this work, the present ET presents a detection limit of about 20 ng L-1 for both tainting compounds. The ET can also discriminate with great easiness and confiability individual and mixture samples. PCA plots show that samples are grouped into relatively small and well-separeted clusters (no overlapping). The ET is also capable of detect, based on changes on the first principal component, changes in the nGEO/nMIB molar ratio of mixed samples. Also, the ET can discriminate with great easiness, water samples supplied by SABESP, collected at Guarapiranga\'s reservoir, before and after the water treatment plant. The influence of the water type on the sensors\' response has little significance when the Fuzzy controller is employed. The ET with the Fuzzy controller presents an excellent performance with very low error rates: 0.25% (distilled water), 5% (mineral water) and 6.66% (tap water). Besides that, Fuzzy logic results can be displayed in simpler plots which ensures easier readings of hit and error rates of the ET. Also, the numeric values (compound concentration) can be replaced by linguistic variables such as proper and improper. Finally, it can be concluded that the ET developed herein, when considering sensor and data analysis, shows a great potential for monitoring MIB and GEO in water reservoirs, providing in real time and in locu information about water quality in treatment stations. This thesis also presents the study on the assembly of molecularly imprinted polymeric films to be used in specific chemical sensors, carried out during the internship at the Universidade Autonoma de Barcelona.

A presente tese trata do desenvolvimento de uma língua eletrônica (LE) e da avaliação de seu uso na detecção de 2-metilisoborneol (MIB), geosmina (GEO) e isoborneol (ISO) em amostras de água. A água abastecida à região metropolitana de São Paulo provém de mananciais, os quais estão sujeitos à ploriferação de algas (eutrofização). Muitas delas podem ser tóxicas e ainda produzir compostos, como MIB e GEO, substâncias reconhecidas por provocar gosto e odor desagradáveis na água que consumimos. De fato, a presença de MIB e GEO na água é uma das maiores fontes de reclamação por parte dos consumidores junto à companhia de saneamento e abastecimento de São Paulo (SABESP). Apesar disso, ainda não existem tecnologias que possam ser aplicadas para a detecção in locu dessas substâncias. A LE usada nesta tese foi baseada em um arranjo de sensores químicos não-específicos, formados por microeletrodos interdigitados de ouro recobertos com filmes poliméricos nanoestruturados depositados pela técnica de automontagem e interrogados sob regime de corrente alternada. A calibração da LE foi realizada com soluções de concentração determinada de GEO, MIB e ISO preparadas em água destilada, mineral e de torneira. Foram avaliadas tanto soluções individuais contendo um único contaminante, quanto misturas contendo MIB e GEO. A resposta elétrica dos sensores (medidas de capacitância), foram interpretadas por análise das componentes principais (PCA) e por lógica Fuzzy, com as quais a LE consegue discriminar as diversas amostras com relativa facilidade e confiabilidade. Dentre as principais observações dessa investigação, notou-se que a LE desenvolvida consegue detectar MIB e GEO em amostras de água reais em concentrações tão baixas quanto 20 ng L-1. Os gráficos de PCA mostram a separação das amostras em clusters relativamente pequenos, bem separados e sem sobreposição. A LE é capaz de identificar de forma direta, a partir de variações na primeira componente principal, variações na razão molar nGEO/nMIB em misturas de MIB e GEO. Em um caso mais próximo da realidade, a LE consegue discriminar com relativa facilidade, amostras de água fornecidas pela SABESP, coletadas do sistema Guarapiranga antes e após a estação de tratamento. As taxas de acerto da LE usando os controladores Fuzzy desenvolvidos são próximas de 100% para a maioria das amostras. A menor taxa de acerto (93,33%) ocorreu com as amostras preparadas em água de torneira. Adicionalmente, nenhuma amostra de água pura foi classificada como contendo algum contaminante, ou seja, não houve falsos positivos. Conclui-se, portanto que a LE desenvolvida, tanto em termos de sensores quanto de análise de dados, apresenta potencial para monitoramento de MIB e GEO nos reservatórios de água, fornecendo em tempo real e in loco informações sobre a qualidade da água provinda da estação de tratamento. A tese também apresenta alguns resultados da preparação de filmes poliméricos com impressão molecular para aplicação em sensores específicos, obtidos durante o estágio na Universidade Autônoma de Barcelona. / Water from São Paulo metropolitan area comes from water reservoirs, which are prone to algae bloom (eutrophication). These algae can be toxic and produce compounds, such as geosmin (GEO) and 2-methylisoborneol (MIB) that give unpleasant taste and odour to the water supplied to consumers. In fact, their presence in water is one of the major complains of consumers to São Paulo\'s water company (SABESP). Despite that, technologies that can be applied for monitoring these substances in real time and in locu are still not available. In this sense, the present thesis work has focused on the development of an electronic tongue system (ET) and evaluate its performance on detecting MIB, GEO and isoborneol (ISO) in water samples. The ET is based on an array of non-specific chemical sensors, which are made of gold interdigitated microelectrodes covered with nanostructured polymeric films deposited via the layer-by-layer technique and interrogated in alternate current regime. The ET calibration was conducted by analyzing distilled, mineral and tap water samples tainted with known concentrations of MIB, GEO and ISO. The samples were solutions with a single tainting compound and solutions containing MIB and GEO mixed together. The sensors\' electrical response (capacitance measurements) was interpreted by principal component analysis (PCA) and Fuzzy logic. Among the main features of this work, the present ET presents a detection limit of about 20 ng L-1 for both tainting compounds. The ET can also discriminate with great easiness and confiability individual and mixture samples. PCA plots show that samples are grouped into relatively small and well-separeted clusters (no overlapping). The ET is also capable of detect, based on changes on the first principal component, changes in the nGEO/nMIB molar ratio of mixed samples. Also, the ET can discriminate with great easiness, water samples supplied by SABESP, collected at Guarapiranga\'s reservoir, before and after the water treatment plant. The influence of the water type on the sensors\' response has little significance when the Fuzzy controller is employed. The ET with the Fuzzy controller presents an excellent performance with very low error rates: 0.25% (distilled water), 5% (mineral water) and 6.66% (tap water). Besides that, Fuzzy logic results can be displayed in simpler plots which ensures easier readings of hit and error rates of the ET. Also, the numeric values (compound concentration) can be replaced by linguistic variables such as proper and improper. Finally, it can be concluded that the ET developed herein, when considering sensor and data analysis, shows a great potential for monitoring MIB and GEO in water reservoirs, providing in real time and in locu information about water quality in treatment stations. This thesis also presents the study on the assembly of molecularly imprinted polymeric films to be used in specific chemical sensors, carried out during the internship at the Universidade Autonoma de Barcelona.

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.