Diploma thesis is focused on changes of organic carbon (OC) in surface waters in headwater areas. Thesis is in its theoretical part focused on the literature study of currently published research results of the issue. The important part is finding the possible causes of OC variability, especially landcover and soil environment. The practical part is devoted to research in experimental basins of KFGG, namely in the upper Vydra, Blanice and Rolava. The aim of this work is to clarify the relationships between organic matter concentrations and discharge rates regarding to hydrological extremes. Furthermore, the influence of river basin size and various landcover and variability of concentrations and relationship with other indicators of biogeochemism is studied. The relationship between OC and discharge rate is positive and in most river basins strong or very strong. The weakest relationship was monitored on the profiles with the highest proportion of peatlands in the river basin. In these catchments, the highest average concentrations of OC were determined in autumn, in catchments with the lower proportion of peatlands it is in summer. Analysis of rainfall-runoff events confirmed the positive relationship of OC and discharge. The lag time of the maximum OC concentration beyond the maximum discharge...

A indústria têxtil gera grandes volumes de efluentes com elevada carga orgânica, forte coloração e toxicidade. Neste trabalho, estuda-se o tratamento de solução aquosa contendo o corante Solophenyl Yellow Arle 154% por meio dos processos O3-H2O2/UV e foto-Fenton, avaliando-se as repostas: remoção de cor em 5 minutos, remoção de cor em 60 minutos, taxa máxima de remoção de cor e remoção de COT em 60 minutos. Os experimentos foram realizados em semibatelada com circulação usando um reator fotoquímico com campo de radiação anular coaxial, constituído de corpo cilíndrico em aço com refletor interno de alumínio para 12 lâmpadas fixadas simetricamente na superfície refletora e um tubo reator em quartzo de 0,7 L, posicionados verticalmente no eixo do refletor. Para o processo O3-H2O2/UV foram utilizadas lâmpadas Phillips TUV (36 W, 254 nm). A corrente gasosa contendo O3 foi introduzida no reator por meio de um difusor. Para o processo foto-Fenton foram utilizadas lâmpadas Sylvania (12 W cada, 300 400 nm) e concentração de Fe(II) de 0,25 mmol/L. Em ambos os processos, solução de peróxido de hidrogênio foi adicionada durante os 30 minutos iniciais de tratamento. As amostras foram analisadas por medidas de carbono orgânico total (COT) e remoção de cor (absorbância medida em 405 nm em espectrofotômetro UV-visível). Em ambos os processos utilizou-se o planejamento experimental Doehlert, definindo os valores mínimo e máximo para cada variável adotada. No caso do processo O3- H2O2/UV (ETAPA I), foram estudados os efeitos da potência elétrica total das lâmpadas (144 432 W), concentração de H2O2 (5 30 mmol/L), concentração inicial de corante (20 100 mg/L), concentração de ozônio (10 40 mg/L) e pH (3 10). No processo foto-Fenton (ETAPA II), estudaram-se os efeitos da potência (160 480 W), concentração de H2O2 (5 30 mmol/L) e concentração inicial de corante (20 100 mg/L). Os resultados da ETAPA I indicaram que o aumento da concentração do corante, em meio ácido, aumenta a remoção de cor em 5 e 60 minutos, sugerindo a eficiência da ação via ozônio molecular sob o grupo cromóforo do corante. Os melhores resultados apresentaram remoção acima de 95% em 5 e 60 minutos de tratamento. Entretanto, para a remoção de COT em 60 minutos o processo não foi eficiente, apresentando resultado máximo de 35,6%. Na ETAPA II obtiveram-se resultados menos satisfatórios para remoção de cor se comparados aos da ETAPA I (56,1% em 5 minutos e 78% em 60 minutos de tratamento), mas melhores em relação à remoção de COT em 60 minutos atigindo 45,1% de remoção. As maiores taxas de remoção de cor foram observadas nos 5 primeiros minutos de tratamento para todos os experimentos. Experimentos complementares realizados em uma terceira etapa (ETAPA III) mostraram que a aplicação do processo O3 seguido do processo foto-Fenton permitiu resultados satisfatórios tanto para remoção de cor (97,2%), quanto para remoção de COT (69,5%). O estudo da ação do processo O3 em modo contínuo e a avaliação econômica preliminar do processo integrado O3 - foto-Fenton sugerem o potencial de aplicação do tratamento integrado a indústrias têxteis. / The textile industry generates large volumes of wastewater with high organic load, strong coloration and toxicity. In this work, the treatment of an aqueous solution containing the dye Solophenyl Yellow Arle 154% was studied by the O3-H2O2/UV and photo-Fenton processes, in order to evaluate the responses color removal after 5 minutes; color removal after 60 minutes; maximum rate of color removal; and TOC removal after 60 minutes. The experiments were carried out in the semi-batch mode with circulation using a photochemical reactor with annular coaxial radiation field, consisting of a cylindrical stainless steel support with an aluminum internal reflector with 12 lamps fixed symmetrically in the internal reflecting surface, and a quartz tube reactor of 0.7 L, positioned vertically along the axis of the reflector. For the O3- H2O2/UV process, Phillips TUV lamps (36 W, 254 nm) were used; the gas stream containing zone was introduced into the reactor through a diffuser. For the photo- Fenton process, Sylvania lamps (12 W each, 300 - 400 nm) and a concentration of Fe (II) of 0.25 mmol/L were used. In both cases, the hydrogen peroxide solution was added in the first 30 minutes of treatment. The samples were analyzed by the measurement of total organic carbon (TOC) and color removal (absorbance measured at 405 nm in a UV-visible spectrophotometer). In both cases the Doehlert experimental design was used, defining the minimum and maximum values of each variable adopted. In the case of O3-H2O2/UV process (PHASE I), the effects of the total electric power of the lamps (144 - 432 W), H2O2 concentration (5 - 30 mmol/L), initial dye concentration (20 - 100 mg/L), ozone concentration (10 - 40 mg/L), and pH (3 - 10) were studied. For the photo-Fenton process, the studied variables were: total electric power of the lamps (160 - 480 W), H2O2 concentration (5 - 30 mmol/L), and initial dye concentration (20 - 100 mg/L). The results of PHASE I indicated that the increase of dye concentration in acidic conditions increases color removal after 5 and 60 minutes, thus suggesting the efficiency of molecular ozone action upon the chromophore group of the dye. The best results showed color removal above 95% after 5 and 60 minutes of treatment. However, for the TOC removal the process was not efficient, with maximum removal after 60 minutes of only 35.6%. In PHASE II less satisfactory results for color removal were obtained in comparison with PHASE I (56.1% after 5 minutes and 78% after 60 minutes of treatment), but with higher TOC removal after 60 minutes, achieving over 45.1%. The highest color removal rates were observed within the first 5 minutes of treatment for all runs. Additional experiments carried out in PHASE III showed that the oxidation by O3 followed by the photo-Fenton process enabled to achieve suitable results for both color (97.2%) and TOC removals (69.5%). The study of the O3 process in the continuous mode and a preliminary economic evaluation suggests a high potential for the use of the integrated O3-photo-Fenton process in textile industries.

A indústria têxtil gera grandes volumes de efluentes com elevada carga orgânica, forte coloração e toxicidade. Neste trabalho, estuda-se o tratamento de solução aquosa contendo o corante Solophenyl Yellow Arle 154% por meio dos processos O3-H2O2/UV e foto-Fenton, avaliando-se as repostas: remoção de cor em 5 minutos, remoção de cor em 60 minutos, taxa máxima de remoção de cor e remoção de COT em 60 minutos. Os experimentos foram realizados em semibatelada com circulação usando um reator fotoquímico com campo de radiação anular coaxial, constituído de corpo cilíndrico em aço com refletor interno de alumínio para 12 lâmpadas fixadas simetricamente na superfície refletora e um tubo reator em quartzo de 0,7 L, posicionados verticalmente no eixo do refletor. Para o processo O3-H2O2/UV foram utilizadas lâmpadas Phillips TUV (36 W, 254 nm). A corrente gasosa contendo O3 foi introduzida no reator por meio de um difusor. Para o processo foto-Fenton foram utilizadas lâmpadas Sylvania (12 W cada, 300 400 nm) e concentração de Fe(II) de 0,25 mmol/L. Em ambos os processos, solução de peróxido de hidrogênio foi adicionada durante os 30 minutos iniciais de tratamento. As amostras foram analisadas por medidas de carbono orgânico total (COT) e remoção de cor (absorbância medida em 405 nm em espectrofotômetro UV-visível). Em ambos os processos utilizou-se o planejamento experimental Doehlert, definindo os valores mínimo e máximo para cada variável adotada. No caso do processo O3- H2O2/UV (ETAPA I), foram estudados os efeitos da potência elétrica total das lâmpadas (144 432 W), concentração de H2O2 (5 30 mmol/L), concentração inicial de corante (20 100 mg/L), concentração de ozônio (10 40 mg/L) e pH (3 10). No processo foto-Fenton (ETAPA II), estudaram-se os efeitos da potência (160 480 W), concentração de H2O2 (5 30 mmol/L) e concentração inicial de corante (20 100 mg/L). Os resultados da ETAPA I indicaram que o aumento da concentração do corante, em meio ácido, aumenta a remoção de cor em 5 e 60 minutos, sugerindo a eficiência da ação via ozônio molecular sob o grupo cromóforo do corante. Os melhores resultados apresentaram remoção acima de 95% em 5 e 60 minutos de tratamento. Entretanto, para a remoção de COT em 60 minutos o processo não foi eficiente, apresentando resultado máximo de 35,6%. Na ETAPA II obtiveram-se resultados menos satisfatórios para remoção de cor se comparados aos da ETAPA I (56,1% em 5 minutos e 78% em 60 minutos de tratamento), mas melhores em relação à remoção de COT em 60 minutos atigindo 45,1% de remoção. As maiores taxas de remoção de cor foram observadas nos 5 primeiros minutos de tratamento para todos os experimentos. Experimentos complementares realizados em uma terceira etapa (ETAPA III) mostraram que a aplicação do processo O3 seguido do processo foto-Fenton permitiu resultados satisfatórios tanto para remoção de cor (97,2%), quanto para remoção de COT (69,5%). O estudo da ação do processo O3 em modo contínuo e a avaliação econômica preliminar do processo integrado O3 - foto-Fenton sugerem o potencial de aplicação do tratamento integrado a indústrias têxteis. / The textile industry generates large volumes of wastewater with high organic load, strong coloration and toxicity. In this work, the treatment of an aqueous solution containing the dye Solophenyl Yellow Arle 154% was studied by the O3-H2O2/UV and photo-Fenton processes, in order to evaluate the responses color removal after 5 minutes; color removal after 60 minutes; maximum rate of color removal; and TOC removal after 60 minutes. The experiments were carried out in the semi-batch mode with circulation using a photochemical reactor with annular coaxial radiation field, consisting of a cylindrical stainless steel support with an aluminum internal reflector with 12 lamps fixed symmetrically in the internal reflecting surface, and a quartz tube reactor of 0.7 L, positioned vertically along the axis of the reflector. For the O3- H2O2/UV process, Phillips TUV lamps (36 W, 254 nm) were used; the gas stream containing zone was introduced into the reactor through a diffuser. For the photo- Fenton process, Sylvania lamps (12 W each, 300 - 400 nm) and a concentration of Fe (II) of 0.25 mmol/L were used. In both cases, the hydrogen peroxide solution was added in the first 30 minutes of treatment. The samples were analyzed by the measurement of total organic carbon (TOC) and color removal (absorbance measured at 405 nm in a UV-visible spectrophotometer). In both cases the Doehlert experimental design was used, defining the minimum and maximum values of each variable adopted. In the case of O3-H2O2/UV process (PHASE I), the effects of the total electric power of the lamps (144 - 432 W), H2O2 concentration (5 - 30 mmol/L), initial dye concentration (20 - 100 mg/L), ozone concentration (10 - 40 mg/L), and pH (3 - 10) were studied. For the photo-Fenton process, the studied variables were: total electric power of the lamps (160 - 480 W), H2O2 concentration (5 - 30 mmol/L), and initial dye concentration (20 - 100 mg/L). The results of PHASE I indicated that the increase of dye concentration in acidic conditions increases color removal after 5 and 60 minutes, thus suggesting the efficiency of molecular ozone action upon the chromophore group of the dye. The best results showed color removal above 95% after 5 and 60 minutes of treatment. However, for the TOC removal the process was not efficient, with maximum removal after 60 minutes of only 35.6%. In PHASE II less satisfactory results for color removal were obtained in comparison with PHASE I (56.1% after 5 minutes and 78% after 60 minutes of treatment), but with higher TOC removal after 60 minutes, achieving over 45.1%. The highest color removal rates were observed within the first 5 minutes of treatment for all runs. Additional experiments carried out in PHASE III showed that the oxidation by O3 followed by the photo-Fenton process enabled to achieve suitable results for both color (97.2%) and TOC removals (69.5%). The study of the O3 process in the continuous mode and a preliminary economic evaluation suggests a high potential for the use of the integrated O3-photo-Fenton process in textile industries.

This dissertation describes electrochemical oxidation of Padan 95 SP on Boron-doped diamond (BDD) electrode mainly by •OH radicals (which was measured by indirect method, i.e: the formation of 2-Hydroxylterephthalic acid (2-HTA)), Electro-Fenton and the combination with adsorption technology for increasing total organic carbon (TOC) removal efficiency. In this study, the formation of 2-HTA on BDD electrode via the reaction between terephthalic acid (TA) and •OH as a method to quantify hydroxyl radical formation was investigated. The degradation of Cartap in Padan 95SP (95 % Cartap) on BDD was investigated. Operating parameters such as applied current density, types of electrolyte and initial concentration of Padan 95SP were varied in order to determine their effect on the degradation efficiency of Cartap. The concentration of Cartap was determined by UV-Vis spectroscopy according to 5,5-Dithiobis-(2-nitrobenzoic acid) (DTNB) procedure. High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC-MS) were used to characterize the commercial Padan 95SP and the formation of by-products. The optimal conditions for Cartap degradation by electrochemical process have been established: concentration of electrolyte: 0.05 M Na2SO4, initial concentration of Padan 95SP: 300 mg·L-1, pH = 3, current density: j = 20 mA·cm-2. At this condition, Cartap decreases to 41 %, TOC decay reaches 8 %. To increase TOC decay at higher Padan 95 SP concentration in aqueous solution, the combination technique of electrochemical process with other techniques was proposed, e.g.: Electro-Fenton technique, pre-oxidizing by NaOCl or the Electro-Adsorption combination. In the Electro-Fenton technique, we investigated the influence of factors such as the presence of NaOCl in pretreatment of process, affects of H2O2 concentration, Fe2+ dosage, co-catalysts metals ion and pH. The efficiency shows approximately 80 % of TOC removed at 700 mg·L-1 Padan 95 SP. The combination of electrochemical with adsorption method shows the efficient removals of TOC and Padan 95SP (95 % Cartap) based on reagents oxidation in electrochemical process and adsorption of granular activated carbon (GAC), respectively. The influence of factors such as supporting electrolytes, flow rate, bed height, recycling number as well as initial concentration were investigated in order to determine their effects on TOC removal. The efficiency of this combination shows approximately 75 % of TOC and more than 90 % of Cartap removed at 700 mg·L-1 Padan 95 SP. Fourier Transform Infrared (FT-IR) and (Brunauer–Emmett–Teller) BET surface analysis were applied to investigate GAC before and after usage. The results have shown that the application of electrochemical technique with other methods can be the potential option for treatment of wastewater containing Padan 95 SP. / Diese Dissertation befasst sich mit der Reduktion des gesamten organischen Kohlenstoffs (TOC) aus wässriger Lösung, die Padan 95 SP enthält. Als Methoden zur Minimierung von TOC wurden die elektrochemische Oxidation von Padan 95 SP auf Bor-dotierter Diamant (BDD) Elektroden durch •OH Radikale, Elektro-Fenton und die Kombination mit Adsorptionstechnologien verwendet. Die •OH Radikale wurden dabei durch indirekte Methoden, z. B. die Bildung von 2-HTA gemessen. Zur Quantifizierung der Hydroxylradikalbildung wurde in dieser Studie die Bildung von 2-Hydroxylterephthalsäure (2-HTA) an BDD-Elektroden über die Reaktion zwischen Terephthalsäure (TA) und •OH untersucht. Weiterhin befasst sich die Arbeit mit dem Abbau von Cartap in Padan 95SP (95% Cartap) auf BDD über die Reaktion zwischen Cartap und Hydroxylradikalen. Betriebsparameter wie die angewandte Stromdichte, die Elektrolytarten und die Anfangskonzentration von Padan 95SP wurden variiert, um ihre Wirkung auf die Abbaueffizienz von Cartap zu bestimmen. Die Konzentration von Cartap wurde mittels UV-Vis-Spektroskopie mit dem 5,5-Dithiobis-(2-Nitrobenzoesäure) (DTNB) Verfahren bestimmt. Hochleistungs-Flüssigkeitschromatographie (HPLC) und Gaschromatographie/Massenspektrometrie (GC-MS) wurden verwendet, um das kommerziell erhältliche Padan 95SP und die Bildung von Nebenprodukten beim Abbau von Cartap zu charakterisieren. Die optimalen Bedingungen für die Cartap-Degradation durch den elektrochemischen Prozess wurden festgelegt: Konzentration des Elektrolyten: 0.05 M Na2SO4, Padan 95SP Anfangskonzentration: 300 mg·L-1, pH = 3, Stromdichte: j = 20 mA·cm-2. Unter diesen Bedingungen sinkt Cartap auf 41% und der TOC erreicht 8 % des jeweiligen Ausgangswertes. Um den TOC-Zerfall bei höher Padan 95 SP Konzentration in Wasser zu erhöhen, wurde die Kombination des elektrochemischen Prozesses mit anderen Techniken vorgeschlagen, z.B.: Elektro-Fenton-Technik, Oxidation mit NaOCl, oder die Kombination des elektrochemischen Prozesses mit einem Adsorptionsprozess. Bei der Elektro-Fenton-Technik wurde der Einfluss von Faktoren wieder Anwesenheit von NaOCl in der Prozessvorbehandlung, Auswirkungen der H2O2-Konzentration, Fe2+-Dosierung, Metallionen als Cokatalysatoren und der pH-Wert der Lösung untersucht, um die Wirkung auf die Abbau-Effizienz für Cartap zu bestimmen. Es konnten mit dieser Methode rund 80 % TOC, ausgehend von 700 mg·L-1Padan 95SP, entfernt werden. Die Kombination des elektrochemischen Prozesses mit einer Adsorptionsmethode ermöglicht eine effiziente Entfernung von TOC und Padan 95SP (95% Cartap). Dies basiert auf der Oxidation und anschließender Adsorption auf granularer Aktivkohle (GAC). Der Einfluss von Faktoren wie Leitelektrolyten, Flussrate, Betthöhe, Recyclingzahl sowie die Anfangskonzentration von Padan 95 SP wurde untersucht, um deren Auswirkungen auf die TOC Entfernung zu bestimmen. Durch die Kombination konnten so 75% desTOC und mehr als 90% Cartap bei 700 mg·L-1Padan 95 SP entfernt werden. Fourier-Transformations-Infrarot (FT-IR) und BET-Oberflächenanalyse wurden angewendet, um GAC vor und nach der Verwendung zu untersuchen. Die Ergebnisse haben gezeigt, dass die Kombination des elektrochemischen Prozesses mit anderen Methoden eine potentielle Option für die Behandlung von Abwasser, das Padan 95 SP enthält, sein kann.