Abstract Heavy metals and organics are always presented an important rule in the pollution control. In Taiwan, there are large amounts of toxic wastewater produced from electrical plating, metal surface-treating, steel, IC, electrics, photo-electrics, printed PC board, refinery, medicals, oil painting and foods manufactory industries. Those wastewater are contained toxic and hazardous materials materials to human body or environment quality. Thus, we believe it need immediately to develop the innovative process on removal of wastewater containing heavy metals and organic compounds. This study uses the strong oxidation of Fenton¡¦s Process to first remove the organic pollutant, EDTA, and then uses Ferrite Process to incorporate heavy metal ions into spinel structure for facilitating removal of heavy metal ions, and through this work, the best operation model of series treatment ¡§Fenton/Ferrite Process¡¨ is established. With respect to batch reaction in Fenton¡¦s Process, the emphasis in this work is placed the effect on EDTA removal by pH, ferrous ions concentration, and hydrogen peroxide . The results show that the best removal of EDTA occurs when Fenton is under acid condition (pH=2); and the removal of EDTA increase as the ferrous ions and hydrogen peroxide increase adequately, but when its quantity exceeds a certain value, the removal of EDTA would decrease as follows. Such a result may be caused by the excess of ferrous ions and hydrogen peroxide which could restain generation of hydroxyl radicals. As followed the Fenton¡¦s process, Ferrite Process is next used for treatment of wastewater in series; Ferrite Process has three stages, and the operating conditions are controlled temperature and pH. For the first stage, the operating condition is 70¢J, and pH is 9.0; and the operating condition is 90¢J, and pH is 9.0 in the second stage; and the operating condition is 80¢J, and pH is 10.0 in the last stage. From the results of series experiments, with respect to reaction time, each concentration of heavy metal in supernatant could meet the standards of discharge water when the total time of A-4 experimental condition is 90 minutes; if Hg ion is not included in wastewater, then the reaction time could be reduced to 50 minutes. I shows benefit for short reaction it the time. Under A-3 experimental condition, the reaction time is 56 minutes when Cd and Hg ions are not included in the wastewater, then each ions concentration of heavy metal could also reach the standards of discharge water, and this experiment need of ferrous ions is least of all. Thus, this experiment in this work has the economic benefits both for regarding time and cost-effectiveness. Keywords¡GFenton¡¦s Process¡BFerrite Process¡BEDTA¡BHeavy metal

La escasez de agua se presenta como uno de los mayores retos para asegurar el desarrollo sostenible. Entre otras actuaciones, se deben investigar e implementar sistemas eficientes de tratamiento de aguas biorecalcitrantes, que necesitan ser condicionadas antes de su depuración biológica. Uno de los posibles pre-tratamientos es el proceso Fenton de oxidación avanzada, que presenta dos principales inconvenientes: la utilización de sales de hierro como catalizador homogéneo, que abandonan continuamente la etapa de oxidación, y el elevado consumo de oxidante, en parte desaprovechado. La presente tesis se centra en el estudio de la mejora del proceso Fenton de aguas fenólicas mediante su acoplamiento con tecnologías de membrana como la nanofiltración, la emulsificación con membranas o los reactores de membrana. El acoplamiento de dichas tecnologías con el proceso Fenton permite el confinamiento del catalizador y el aumento de la eficiencia de oxidación, mejorando así el tratamiento en términos ambientales y económicos. / Water scarcity is one of the major challenges for assuring a sustainable development. Among other measures, research into efficient wastewater treatment systems to deal with biorefractory wastewaters, which need to be amended before their biological degradation, is required. The Fenton process is an advanced oxidation process that can be used as potential pre-treatment for this purpose. However, the pre-treatment presents two main limitations: the use of iron salts as homogeneous catalyst, which are continuously thrown away in the reactor effluent, and the high consumption of oxidant, which is partially wasted. The present thesis aims at studying the improvement of the Fenton process applied on phenolic wastewater through its coupling with membrane technologies such as nanofiltration, membrane emulsification or membrane reactors. The coupling allows confining the catalyst and increasing the oxidation efficiency, thus enhancing the treatment efficiency in environmental and economic terms.

Abstract This research was to evaluate the treatment efficiency for in-situ treatment of pentachlorophenol (PCP) contaminated soil by electrokinetics-Fenton process combined with biodegradation. An electric gradient of 1V/cm, and graphite electrodes were employed in all experiments. Soil types, catalyst types and dosage, hydrogen peroxide concentration, cathode reservoir liquid species and reaction time were employed as the experimental factors in this study. In this study, no matter electrokinetics-Fenton process or the electrokinetics-biodegradation in the latter, prolong the reaction time can promote the removal and destruction efficiency (DRE) of target pollutant from soil. By using 0.0196 M FeSO4 with 3.5% H2O2, the DRE was only lower 2% than 0.098 M FeSO4 with 3.5% H2O2.It showed that using 0.0196 M FeSO4 can provide enough Fe2+ to react with H2O2. By increasing H2O2 concentration from 0.35% to 3.5%, a DRE rised from 68.34% to 79.77%. When iron powder was used as catalyst, the residual pentachloroplenol concentration near to anode reservoir lower than 0.0196 M FeSO4 was used. But the DRE was 56.58% lower than the 68.34% of using 0.0196 M FeSO4.As the influences of soil types to electrokinetics-Fenton process, the residual concentration of pollutant for Soil No. 2 was higher than Soil No. 1. A DRE of only 59.22% was obtained. It is postulated that a much higher content of organic matter with Soil No. 2 whereas lower the treatment efficiency because of consumption of hydroxyl radicals by the organic matter of soil. For the influence of different reservoir liquid species, in this study 0.1M acetic buffer solution was used as cathode reservoir liquid, expected to promote the removal efficiency. From the result of experiment that could not reach the expected treatment efficiency of increasing the removal efficiency from soil. From the experiment of electrokinetics process combined with cometabolism, a treatment efficiency of only 25.67% was obtained. The content of pollutant within every section of soil column were still higher than predict. But by using electrokinetics-Fenton process to pretreat the pollutant within soil first, the increasing efficiency of biodegradation was found. Even when reaction time was prolonged, the pollutant could be completely eliminated from soil. If only used iron minerals to proceed electrokinetics-Fenton process naturally exited in the soil, a DRE of only 20

This research was to evaluate the treatment efficiency of a chlorinated hydrocarbons contaminated site by combined technologies of electrokinetic processing-Fenton process-catalytic iron wall. The L9 orthogonal arrays were utilized to investigate the effects of four experimental factors (i.e., H2O2 concentration, size fraction of iron particles, mass of iron particles and elapsed time) on the treatment efficiency. The experimental results were further subjected to the analysis of variance (ANOVA) and regular analysis. According to the ANOVA of results of nine experiments conducted under an electric gradient of 1 V/cm, the H2O2 concentration, mass of iron particles and elapsed time were determined to be very significant parameters for the destruction and removal efficiency (DRE) of 1,1,2,2-tetrachloroethane (TeCA) . In this system, the optimal conditions with respect to the DRE of TeCA would be 2¢MH2O2, 50-100 mesh iron, 0.2 wt% iron and 20-day treatment time. Under this optimal conditions, it was able to obtain a DRE of 69.56% and the corresponding operating cost would be 672.9 NT$/m3. Aside from the constant voltage operation, the constant current operation also was employed in this study. The latter was found to be superior to the former in terms of electroosmotic flow quantity and DRE. Experimental results of soil column tests showed that TeCA was transformed to trichloroethylene (TCE). TCE could be regarded as a daughter product of TeCA degradation. Results of Tests 17 and 18 showed that destruction dominated the DRE of TeCA, whereas removal played a much more important role in the DRE of Test 19. Regarding the treatment efficiency of a 9-day pilot test using the same combined treatment technologies, it was found to be very satisfactory. DREs of vinyl chloride, dichloroethane, and TCE were found to be >96%, >96%, and >94%, respectively in the anode and cathode wells. The concentrations of TCE in both anode and cathode wells were found to be lower than the regulatory threshold (i.e., 2£gg/L) and the operating cost was determined to be about NT$57.5/m3.

Durante o processo metalúrgico de usinagem de uma peça ocorre a geração de calor proveniente do atrito ferramenta/peça e cavaco/ferramenta. Para que ocorra uma menor geração de calor possibilitando o manuseio, bem como a minimização na deformação da peça, utilizam-se fluidos, que são soluções lubrificantes à base de óleos, água ou polímeros, podendo ser sintéticos ou não, diminuindo, assim, o coeficiente de atrito reduzindo-se a quantidade de calor gerado no processo. Há uma grande variedade de fluidos de corte disponíveis no mercado que são constituídos por diversos compostos como: aminas, compostos clorados e/ou aromáticos, glicóis, nitrosaminas além da presença de metais provenientes do processo de manufatura, portanto, sem tratamento, não podem ser lançados na rede de esgoto convencional. Atualmente não há um método de tratamento para os fluidos de corte nas indústrias. Nesse contexto, propõe-se um estudo sobre a viabilidade dos tipos de tratamento dos fluidos de corte para uma disposição adequada. Os processos de tratamento propostos neste trabalho compreendem hidrolise ácida e Processo Oxidativo Avançado (POA), mais especificamente, Sistema Fenton, além de propor um tratamento baseado na fotodegradação. A caracterização do fluido antes e após seu tratamento foi realizada por técnicas analíticas e espectrométricas. Os processos oxidativos mostraram-se satisfatórios para o tratamento dos efluentes, reduzindo os níveis de contaminantes aos permitidos pela legislação. O processo foto-Fenton mostrou-se mais eficiente que o processo Fenton na degradação de todos os parâmetros avaliados, incluindo BTEX e HPAs. Os processos de hidrólise ácida não apresentaram resultados satisfatórios, reduzindo apenas os metais aos níveis permitidos para descarte. / During the cutting process, part of the heat generation results from tool-part and chip-tool friction. So that it happens a smaller generation of heat making possible the handling, as well as minimization in the tool deformation, cutting fluids are used, that are the oils base, water or polymeric lubricating solutions, could be synthetic or no, decreasing the attrition coefficient being reduced the amount of heat generated in the process. There is a great variety of cutting fluids that are constituted for several composed as: amines, chlorinated and/or aromatic composed, glycols and nitrosamines besides the presence of metals proceeding of manufacture process, therefore, without a treatment, they cannot be discarded in the conventional sewerage system. At the moment there isn\'t a treatment method for the cut fluids in the industries. In that context, intends a study about the viability types of cutting fluids treatment for appropriate disposition. Treatment processes proposed in this work understand acid hydrolysis and Advanced Oxidative Process (AOP), more specifically, Fenton System, in addition proposing a treatment based on the photodegradation (photo-Fenton process). The characterization of fluid before and after treatment it was accomplished by analytical and spectrometry techniques. Oxidative processes were exposed satisfactory for cutting fluids treatment, reducing the levels of pollutants to the allowed by the legislation. Photo-Fenton process was shown more efficient than Fenton process in the oxidation of BTEX and PAHs. Acid hydrolysis processes didn\'t present satisfactory results, just reducing the metals at the levels allowed for discard.

Durante o processo metalúrgico de usinagem de uma peça ocorre a geração de calor proveniente do atrito ferramenta/peça e cavaco/ferramenta. Para que ocorra uma menor geração de calor possibilitando o manuseio, bem como a minimização na deformação da peça, utilizam-se fluidos, que são soluções lubrificantes à base de óleos, água ou polímeros, podendo ser sintéticos ou não, diminuindo, assim, o coeficiente de atrito reduzindo-se a quantidade de calor gerado no processo. Há uma grande variedade de fluidos de corte disponíveis no mercado que são constituídos por diversos compostos como: aminas, compostos clorados e/ou aromáticos, glicóis, nitrosaminas além da presença de metais provenientes do processo de manufatura, portanto, sem tratamento, não podem ser lançados na rede de esgoto convencional. Atualmente não há um método de tratamento para os fluidos de corte nas indústrias. Nesse contexto, propõe-se um estudo sobre a viabilidade dos tipos de tratamento dos fluidos de corte para uma disposição adequada. Os processos de tratamento propostos neste trabalho compreendem hidrolise ácida e Processo Oxidativo Avançado (POA), mais especificamente, Sistema Fenton, além de propor um tratamento baseado na fotodegradação. A caracterização do fluido antes e após seu tratamento foi realizada por técnicas analíticas e espectrométricas. Os processos oxidativos mostraram-se satisfatórios para o tratamento dos efluentes, reduzindo os níveis de contaminantes aos permitidos pela legislação. O processo foto-Fenton mostrou-se mais eficiente que o processo Fenton na degradação de todos os parâmetros avaliados, incluindo BTEX e HPAs. Os processos de hidrólise ácida não apresentaram resultados satisfatórios, reduzindo apenas os metais aos níveis permitidos para descarte. / During the cutting process, part of the heat generation results from tool-part and chip-tool friction. So that it happens a smaller generation of heat making possible the handling, as well as minimization in the tool deformation, cutting fluids are used, that are the oils base, water or polymeric lubricating solutions, could be synthetic or no, decreasing the attrition coefficient being reduced the amount of heat generated in the process. There is a great variety of cutting fluids that are constituted for several composed as: amines, chlorinated and/or aromatic composed, glycols and nitrosamines besides the presence of metals proceeding of manufacture process, therefore, without a treatment, they cannot be discarded in the conventional sewerage system. At the moment there isn\'t a treatment method for the cut fluids in the industries. In that context, intends a study about the viability types of cutting fluids treatment for appropriate disposition. Treatment processes proposed in this work understand acid hydrolysis and Advanced Oxidative Process (AOP), more specifically, Fenton System, in addition proposing a treatment based on the photodegradation (photo-Fenton process). The characterization of fluid before and after treatment it was accomplished by analytical and spectrometry techniques. Oxidative processes were exposed satisfactory for cutting fluids treatment, reducing the levels of pollutants to the allowed by the legislation. Photo-Fenton process was shown more efficient than Fenton process in the oxidation of BTEX and PAHs. Acid hydrolysis processes didn\'t present satisfactory results, just reducing the metals at the levels allowed for discard.

Substâncias tóxicas como o fenol e outros compostos aromáticos dificultam o tratamento de efluentes via digestores biológicos. Estes compostos tóxicos em altas concentrações são nocivos aos lodos biológicos, podendo inviabilizar por completo o tratamento. Nas últimas décadas, os Processos Oxidativos Avançados (POAs), como os processos Fenton e foto- Fenton, surgiram como alternativa para o tratamento de compostos tóxicos. Os POAs degradam os compostos orgânicos pela geração de compostos oxidantes fortes, como o radical hidroxila, a partir de reagentes como peróxido de hidrogênio. Os processos Fenton e foto-Fenton fazem uso de ferro (II), um catalisador relativamente barato, para catalisar a decomposição do peróxido de hidrogênio, reação denominada como reação de Fenton. Em virtude dos complexos mecanismos presentes nos processos Fenton e foto-Fenton, torna-se necessária uma compreensão da cinética do processo, que envolve reações térmicas e fotoquímicas, por meio de sua modelagem matemática fenomenológica. A modelagem da degradação do fenol via processos Fenton e foto-Fenton proposta por este trabalho começa pela estequiometria dos dois processos, que descreve as reações químicas, térmicas e fotoquímicas existentes. A partir destas, é possível desenvolver o modelo cinético dos processos Fenton e foto-Fenton, no qual se determina a velocidade com que estas reações ocorrem. O passo seguinte é o da modelagem hidráulica (ou de escoamento) dos reatores de processo Fenton e foto-Fenton, sendo que para o segundo processo, o modelo deve levar em conta a propagação da radiação por dentro de reator. Foram realizados 3 experimentos de degradação de fenol via processo Fenton para análise das variações das concentrações de fenol, catecol e hidroquinona. Os dados experimentais são comparados com resultados simulados com intuito do ajuste das constantes cinéticas do modelo. Com as constantes ajustadas, são realizadas comparações entre os processos Fenton e foto-Fenton para análise de suas eficiências. A partir dos modelos matemáticos dos reatores de processos Fenton e foto-Fenton, é desenvolvido um modelo de otimização baseado em superestrutura de redes de reatores para a síntese de uma planta de tratamento de efluentes contaminados com fenol. Objetivou-se a redução dos custos de capital, operação e depreciação desta planta, sujeitos às restrições de projeto e ao modelo da superestrutura, resultando em modelos de programação não-linear inteira mista. Foram geradas soluções ótimas para o tratamento de efluentes contaminados com fenol em redes de um, dois e três reatores de POAs. / Toxic substances such as phenol and other aromatic compounds make the wastewater treatment by biological (aerobic or anaerobic) digestors more difficult. These toxic compounds in high concentrations are harmful for the biological sludge and they may render the treatment impractical. In recent decades, Advanced Oxidative Processes (AOPs) appeared as an alternative for the treatment of toxic compounds. AOPs degrade the organic compounds by generating strong oxidizing compounds, such as the hydroxyl radical, from reactants such as hydrogen peroxide. The Fenton and photo-Fenton processes make use of iron (II), a relatively inexpensive catalyst, to catalyze the hydrogen peroxide decomposition, reaction known as the Fenton reaction. Because of the complex nature of the mechanisms that take place in the Fenton and photo-Fenton processes, the understanding of the process kinetics, which involves thermal and photochemical reactions, becomes necessary through its first-principle mathematical modeling. The modeling of phenol degradation by the Fenton and photo-Fenton processes proposed in this work starts with the stoichiometry of the two processes that enumerates the existing thermal and photochemical reactions. Furthermore, it is possible to develop the Fenton and photo- Fenton kinetic model, which determines the reaction rates. The next step is to model the hydraulic (or flow) behavior of the Fenton and photo-Fenton process reactor, whereas the model for the latter must consider how the radiation propagates inside the reactor. Three experiments of the phenol degradation by the Fenton process were carried out to analyze the concentration variation for phenol, catechol and hydroquinone. The experimental data are compared with simulated results aiming the estimation of the kinetic constants of the model. Using the adjusted constants, the Fenton and photo-Fenton processes were compared to analyze their efficiencies. From the mathematical models of the Fenton and photo-Fenton process reactors, an optimization model based on reactor network superstructure is developed for the synthesis of a phenol contaminated wastewater treatment plant. The objective is to minimize the plant capital, operation and depreciation costs, subject to design constraints and to the superstructure model, thus resulting in mixed integer nonlinear programming models. Optimal solutions were generated for the phenol contaminated wastewater treatment in networks with one, two and three AOP reactors.

Substâncias tóxicas como o fenol e outros compostos aromáticos dificultam o tratamento de efluentes via digestores biológicos. Estes compostos tóxicos em altas concentrações são nocivos aos lodos biológicos, podendo inviabilizar por completo o tratamento. Nas últimas décadas, os Processos Oxidativos Avançados (POAs), como os processos Fenton e foto- Fenton, surgiram como alternativa para o tratamento de compostos tóxicos. Os POAs degradam os compostos orgânicos pela geração de compostos oxidantes fortes, como o radical hidroxila, a partir de reagentes como peróxido de hidrogênio. Os processos Fenton e foto-Fenton fazem uso de ferro (II), um catalisador relativamente barato, para catalisar a decomposição do peróxido de hidrogênio, reação denominada como reação de Fenton. Em virtude dos complexos mecanismos presentes nos processos Fenton e foto-Fenton, torna-se necessária uma compreensão da cinética do processo, que envolve reações térmicas e fotoquímicas, por meio de sua modelagem matemática fenomenológica. A modelagem da degradação do fenol via processos Fenton e foto-Fenton proposta por este trabalho começa pela estequiometria dos dois processos, que descreve as reações químicas, térmicas e fotoquímicas existentes. A partir destas, é possível desenvolver o modelo cinético dos processos Fenton e foto-Fenton, no qual se determina a velocidade com que estas reações ocorrem. O passo seguinte é o da modelagem hidráulica (ou de escoamento) dos reatores de processo Fenton e foto-Fenton, sendo que para o segundo processo, o modelo deve levar em conta a propagação da radiação por dentro de reator. Foram realizados 3 experimentos de degradação de fenol via processo Fenton para análise das variações das concentrações de fenol, catecol e hidroquinona. Os dados experimentais são comparados com resultados simulados com intuito do ajuste das constantes cinéticas do modelo. Com as constantes ajustadas, são realizadas comparações entre os processos Fenton e foto-Fenton para análise de suas eficiências. A partir dos modelos matemáticos dos reatores de processos Fenton e foto-Fenton, é desenvolvido um modelo de otimização baseado em superestrutura de redes de reatores para a síntese de uma planta de tratamento de efluentes contaminados com fenol. Objetivou-se a redução dos custos de capital, operação e depreciação desta planta, sujeitos às restrições de projeto e ao modelo da superestrutura, resultando em modelos de programação não-linear inteira mista. Foram geradas soluções ótimas para o tratamento de efluentes contaminados com fenol em redes de um, dois e três reatores de POAs. / Toxic substances such as phenol and other aromatic compounds make the wastewater treatment by biological (aerobic or anaerobic) digestors more difficult. These toxic compounds in high concentrations are harmful for the biological sludge and they may render the treatment impractical. In recent decades, Advanced Oxidative Processes (AOPs) appeared as an alternative for the treatment of toxic compounds. AOPs degrade the organic compounds by generating strong oxidizing compounds, such as the hydroxyl radical, from reactants such as hydrogen peroxide. The Fenton and photo-Fenton processes make use of iron (II), a relatively inexpensive catalyst, to catalyze the hydrogen peroxide decomposition, reaction known as the Fenton reaction. Because of the complex nature of the mechanisms that take place in the Fenton and photo-Fenton processes, the understanding of the process kinetics, which involves thermal and photochemical reactions, becomes necessary through its first-principle mathematical modeling. The modeling of phenol degradation by the Fenton and photo-Fenton processes proposed in this work starts with the stoichiometry of the two processes that enumerates the existing thermal and photochemical reactions. Furthermore, it is possible to develop the Fenton and photo- Fenton kinetic model, which determines the reaction rates. The next step is to model the hydraulic (or flow) behavior of the Fenton and photo-Fenton process reactor, whereas the model for the latter must consider how the radiation propagates inside the reactor. Three experiments of the phenol degradation by the Fenton process were carried out to analyze the concentration variation for phenol, catechol and hydroquinone. The experimental data are compared with simulated results aiming the estimation of the kinetic constants of the model. Using the adjusted constants, the Fenton and photo-Fenton processes were compared to analyze their efficiencies. From the mathematical models of the Fenton and photo-Fenton process reactors, an optimization model based on reactor network superstructure is developed for the synthesis of a phenol contaminated wastewater treatment plant. The objective is to minimize the plant capital, operation and depreciation costs, subject to design constraints and to the superstructure model, thus resulting in mixed integer nonlinear programming models. Optimal solutions were generated for the phenol contaminated wastewater treatment in networks with one, two and three AOP reactors.

<p>Cilj&nbsp; ovog&nbsp; rada&nbsp; bio&nbsp; je&nbsp; ispitivanje&nbsp; mogućnosti&nbsp; primene&nbsp; modifikovanog&nbsp; bentonita&nbsp; kao katalizatora&nbsp; (ferioksalat&nbsp; i&nbsp; Al,&nbsp; Fe-bentonit&nbsp; katalizatori)&nbsp; u&nbsp; Fenton&nbsp; i&nbsp; foto-Fenton&nbsp; procesu&nbsp; uklanjanja tekstilne&nbsp; reaktivne&nbsp; boje&nbsp; Reactive&nbsp; Red&nbsp; 120.&nbsp; Do&nbsp; sada&nbsp; su&nbsp; objavljene&nbsp; studije&nbsp; primene&nbsp; heterogenog Fenton procesa sa različitim koncentracijama gvožđau katalizatorima i sa kompleksom ferioksalata,međutim, njihovo poređenje u smislu efikasnosti obezbojavanja nije istraženo, &scaron;to je bio jedan od fokusa&nbsp; istraživanja&nbsp; u&nbsp; ovom&nbsp; radu.&nbsp; Osim&nbsp; toga,&nbsp; potencijal&nbsp; sunčeve&nbsp; energije&nbsp; predstavlja&nbsp; 16,7%&nbsp; od ukupno&nbsp; iskoristivog&nbsp; potencijala&nbsp; obnovljivih&nbsp; izvora&nbsp; energije&nbsp; u&nbsp; Srbiji,&nbsp; dok&nbsp; je&nbsp; prosečno&nbsp; sunčevo zračenje&nbsp; u&nbsp; Srbiji&nbsp; oko&nbsp; 40%&nbsp; vi&scaron;e&nbsp; od&nbsp; evropskog&nbsp; proseka,&nbsp; čineći&nbsp; ga&nbsp; vrlo&nbsp; zanimljivim&nbsp; za&nbsp; primenu&nbsp; u ovom tipu tretmana. U cilju &scaron;to boljeg iskori&scaron;ćenjasunčevog zračenja i unapređenja fotokatalitičkih performansi&nbsp; procesa&nbsp; primenjen&nbsp; je&nbsp; parabolični&nbsp; koncentri&scaron;ući&nbsp; reaktor,&nbsp; koji&nbsp; je&nbsp; za&nbsp; ovu&nbsp; vrstu&nbsp; procesa prvi put upotrebljavan. Proučavano je u kojoj meri je solarna fotokataliza značajan segment tehnike za tretman otpadnih voda tokom degradacije perzistentnih jedinjenja, kao &scaron;to je organska azo boja. Takođe, utvrđen je i potencijal fotolize vodonik-peroksida za obezbojavanjem sintetičkog rastvora date&nbsp; boje.&nbsp; Prva&nbsp; faza&nbsp; imala&nbsp; je&nbsp; za&nbsp; cilj&nbsp; sintezu&nbsp; materijala&nbsp; primenom&nbsp; različitih&nbsp; metoda&nbsp; pripreme&nbsp; i<br />konstrukciju solarnog paraboličnog reaktora, koji će se koristiti u Fenton i foto-Fenton procesima degradacije boje Reactive Red 120. Druga faza je podrazumevala karakterizaciju novosintetisanih materijala i optimizaciju procesa fotokatalize primenom Fenton i foto-Fenton procesa i određivanje postignutih efikasnosti primenjenih procesa. Takođe, vr&scaron;eno je određivanje stepena mineralizacije i identifikacija degradacionih produkata nakon procesa degradacije tekstilne boje Reactive Red 120, kao&nbsp; i&nbsp; primena&nbsp; foto-Fenton&nbsp; procesa&nbsp; na&nbsp; realnom&nbsp; efluentu.&nbsp; Na&nbsp; osnovu&nbsp; dobijenih&nbsp; rezultata&nbsp; tokom primene Fenton procesa i kori&scaron;ćenjem oba tipa katalizatora u periodima niskog i visokog intenziteta zračenja,&nbsp; sa&nbsp; aspekta&nbsp; postizanja&nbsp; visoke&nbsp; efikasnosti&nbsp; obezbojavanja&nbsp; i&nbsp; najmanjeg&nbsp; izluživanja&nbsp; gvožđa,<br />može&nbsp; se&nbsp; zaključiti&nbsp; da&nbsp; je&nbsp; Fenton&nbsp; proces&nbsp; najefikasniji&nbsp; na&nbsp; pH&nbsp; vrednosti&nbsp; 3.&nbsp; AlFeB&nbsp; je&nbsp; pokazao&nbsp; veću reaktivnost čak i pri manje upotrebljenim dozama od0,05 g u odnosu na CuOFeB (0,2 g), kao i mogućnost&nbsp; manje&nbsp; upotrebe&nbsp; vodonik-peroksida&nbsp; od&nbsp; 2,5&nbsp; mM,&nbsp; za&nbsp; postizanje&nbsp; visoke&nbsp; efikasnosti obezbojavanja i postignut visok stepen mineralizacije. Vi&scaron;i intenzitet sunčevog zračenja omogućava odvijanje reakcije obezbojavanja na vi&scaron;im pH vrednostima primenom oba katalizatora tokom fotoFenton&nbsp; procesa.&nbsp; Ovo&nbsp; je&nbsp; posebno&nbsp; izraženo&nbsp; kod&nbsp; CuOFeB&nbsp; tokom&nbsp; letnjeg&nbsp; perioda&nbsp; (pH&nbsp; 7),&nbsp; čak&nbsp; i&nbsp; pri nižim dozama katalizatora. Međutim, najveći udeo u&nbsp; procesu obezbojavanja pri upotrebi CuOFeB katalizatora ima fotoliza vodonik-peroksida (80%). Suprotno ovim rezultatima, pri istim reakcionim uslovima,&nbsp; potrebna&nbsp; je&nbsp; veća&nbsp; količina&nbsp; AlFeB&nbsp; katalizatora&nbsp; (0,1&nbsp; g)&nbsp; i&nbsp; niža&nbsp; pH&nbsp; vrednost&nbsp; reakcije,&nbsp; a efikasnost&nbsp; procesa&nbsp; značajno&nbsp; zavisi&nbsp; od&nbsp; početne&nbsp; koncentracije&nbsp; H₂O₂.&nbsp; Činjenica&nbsp; da&nbsp; se&nbsp; u&nbsp; pripremi katalizatora koristio bentonit kao prirodan, &scaron;irokorasprostranjen i jeftin materijal i solarno zračenje kao obnovljiv i alternativni izvor fotona, gore navedene rezultate bi trebalo uzeti u obzir prilikom analize tro&scaron;kova efikasnosti primenjenog procesa. Takođe, primena unapređenih procesa oksidacije se&nbsp; razmatra&nbsp; kao&nbsp; predlog&nbsp; za&nbsp; najbolju&nbsp; dostupnu&nbsp; tehniku&nbsp; kada&nbsp; je&nbsp; u&nbsp; pitanju&nbsp; tretman&nbsp; otpadne&nbsp; vode tekstilne industrije, dok se kao dodatne nove tehnike uzimaju u obzir foto-oksidacije i ispitivanje mogućnosti&nbsp; njihove&nbsp; primene&nbsp; u&nbsp; preči&scaron;ćavanju&nbsp; otpadne&nbsp; vode&nbsp; u&nbsp; tercijarnom&nbsp; tretmanu&nbsp; na poluindustrijskim sistemima.<br />&nbsp;</p> / <p>The aim of this study was to investigate the decolorization efficiency of Reactive Red 120&nbsp; (RR120) synthetic solution using ferrioxalate (CuOFeB) and Al, Fe-bentonite (AlFeB) catalysts in&nbsp; Fenton&nbsp; and&nbsp; photo-Fenton&nbsp; process.&nbsp; So&nbsp; far,&nbsp; studies&nbsp; of the&nbsp; application&nbsp; of&nbsp; a&nbsp; solar-assisted&nbsp; heterogeneous Fenton process with various Fe loaded catalysts and with ferrioxalate complex have&nbsp; been published, but according to&nbsp;&nbsp; the author&rsquo;s knowledge, their comparison in terms of efficacy of&nbsp; decolorization&nbsp; has&nbsp; not&nbsp; been&nbsp; performed,&nbsp; which&nbsp; was&nbsp; one&nbsp; of&nbsp; the&nbsp; focus&nbsp; of&nbsp; research&nbsp; in&nbsp; this&nbsp; paper.&nbsp; In addition, the potential of solar energy represents&nbsp; 16.7% of the total utilized&nbsp; potential of renewable&nbsp; energy sources in Serbia, while the average solar radiation in&nbsp; Serbia is&nbsp; about 40% higher than the&nbsp; European average, making it very interesting for&nbsp; application in this type of treatment. In order to&nbsp; optimize the use of solar radiation and to improve&nbsp; the photocatalytic performance of the process, parabolic&nbsp; concentrating&nbsp; reactor&nbsp; was&nbsp; used&nbsp; for&nbsp; the&nbsp; first&nbsp; time.&nbsp; As&nbsp; a&nbsp; significant&nbsp; segment&nbsp; of&nbsp; the&nbsp; wastewater&nbsp; treatment&nbsp; technique&nbsp; during&nbsp; the&nbsp; degradation&nbsp; of&nbsp; persistent&nbsp; compounds,&nbsp; such&nbsp; as&nbsp; organic azo dye, solar photocatalysis was studied. Also, the potential of photolysis of hydrogen peroxide for&nbsp; decolorization of the synthetic dye solution was determined. Aim of the first phase of the study was synthesizing&nbsp; materials&nbsp; by&nbsp; using&nbsp; different&nbsp; methods&nbsp; of&nbsp; preparation,&nbsp; and&nbsp; construction&nbsp; of&nbsp; a&nbsp; solar&nbsp; parabolic reactor, which will be used in Fenton andphoto-Fenton dye degradation processes. The second phase involved the characterization of newlysynthesized materials and the optimization of the&nbsp; photocatalytic&nbsp; process&nbsp; by&nbsp; applying&nbsp; Fenton&nbsp; and&nbsp; photo-Fonton&nbsp; processes,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; determination&nbsp; of&nbsp; achieved efficiency&nbsp; of&nbsp; the&nbsp; appliedprocesses.&nbsp; Also, the degree&nbsp; of mineralization and the identification of degradation products after applied processes were determined. Application&nbsp; of the photo-Fenton process on a real effluent was conducted as well. Based on the obtained results&nbsp; during&nbsp; Fenton&nbsp; process&nbsp; and&nbsp; using&nbsp; both&nbsp; types&nbsp; of&nbsp; catalysts&nbsp; in&nbsp; periods&nbsp; of&nbsp; low&nbsp; and&nbsp; high&nbsp; intensity&nbsp; of&nbsp; radiation, from the aspect of achieving high efficiency of decolorization and smallest iron leaching,&nbsp; it&nbsp; can&nbsp; be&nbsp; concluded&nbsp; that&nbsp; the&nbsp; Fenton&nbsp; process&nbsp; is&nbsp; most effective&nbsp; at&nbsp; pH&nbsp; 3.&nbsp; AlFeB&nbsp; showed&nbsp; greater&nbsp; reactivity even at less used doses of 0.05&nbsp; g, compared to CuOFeB (0.2 g), and the possibility of using&nbsp; less&nbsp; hydrogen&nbsp; peroxide&nbsp; (2.5&nbsp; mM),&nbsp; achieving&nbsp; high&nbsp; efficiency&nbsp; and&nbsp; a&nbsp; high&nbsp; degree&nbsp; of mineralization. Higher intensity of solar radiationallows the reaction to be carried out at higher pH values when using both catalysts during the photo-Fenton process. This is particularly pronounced largest part in the decolorization process using the CuOFeB catalyst has&nbsp; a photolysis of hydrogen peroxide&nbsp; (80%).&nbsp; Contrary&nbsp; to&nbsp; these&nbsp; results,&nbsp; under&nbsp; the&nbsp; same&nbsp; reaction&nbsp; conditions,&nbsp; a&nbsp; higher&nbsp; doses&nbsp; of AlFeB catalyst (0.1 g) is needed at lower pH value&nbsp; of the reaction, and the process efficiency is significantly dependent on the initial concentration of H ₂O₂. The fact that in the preparation of the catalysts bentonite as a natural, abundant, inexpensive material was used and solar&nbsp; radiation as a renewable and alternative source of photons, the above results should&nbsp; be taken into account in the cost-effectiveness&nbsp; analysis&nbsp; of&nbsp; the&nbsp; applied&nbsp; process. Also,&nbsp; the&nbsp; application&nbsp; of&nbsp; advanced&nbsp; oxidation processes is considered as a proposal&nbsp; for the best available technique when it comes to the treatment of&nbsp; wastewater&nbsp; from&nbsp; the&nbsp; textile&nbsp; industry,&nbsp; while&nbsp; as&nbsp; additional&nbsp; new&nbsp; techniques,&nbsp; photooxidation&nbsp; is considered as a candidate and the possibility of their application in the treatment of wastewater in tertiary treatment on semi-industrial systems.</p>

The global population is constantly rising and with the consequent increase in demand for clean water, the planet is facing a looming freshwater shortage. At the current rate, cities around the globe could lose as much as two thirds of their freshwater supply by 2050. To tackle this, there has been a huge surge on the investigation of novel wastewater treatment technologies. Advanced oxidation processes (AOPs) have shown great promise in this regard. Recently using microwaves with AOPs has been proven to exhibit improved reaction rates and thus there is a push towards developing processes involving microwaves and AOPs to achieve high water treatment efficiencies. However no methodical studies have been conducted to the best of our knowledge, to take the lab scale improvements successfully on to the pilot scale wastewater treatment system. To design such a system by coupling microwaves with Fenton process is the objective of this microwave assisted catalytic treatment of wastewater (MICROCAT) research project. Multiphysics simulation was used for cavity design optimisation and common pesticides found in agricultural wastewater were used as candidate impurities. A heterogeneous Fenton catalyst was prepared by a multi-stage thermal and chemical treatment of polyacrylonitrile (PAN) mesh on polypropylene support structure in collaboration with De Montfort University (DMU). The PAN meshes, after each stage of the treatment process, have been characterised using the field emission gun scanning electron microscope (FEGSEM) and electron dispersive X-ray spectroscopy (EDX) for microstructure and composition. The catalyst was used to study the decomposition of a model compound (e.g., carbetamide) using microwave radiation as well as conventional heating. Two kinds of trials were carried out constant power and constant temperature to observe the effect of variation of process parameters on the reaction rates. It was seen that the use of microwave heating enhanced the rate of decomposition compared to conventional heating in both scenarios. Attempts were also made to modify the composition of the catalyst and the support structure using polyvinylidene fluoride (PVDF) and carbon based additives (graphite and carbon black) to improve the microwave absorption characteristics. The combination of additive and PAN/PVDF mixtures has the potential to help in designing a suitable fabric support for catalyst that could be more receptive to microwaves, thereby helping to improve the energy efficiency of the process. Thorough investigation of dielectric properties and microwave absorption characteristics of the catalyst and support materials were performed independently. The heating rates of the meshes were monitored using an infrared thermal imaging camera. The absorption efficiencies of materials commonly used to build water treatment reactors such as polypropylene (PP), Fibreglass reinforced plastic (FRP), polyvinyl chloride (PVC), glass, PTFE, and fused quartz were assessed by subjecting them to constant microwave power experiments to ascertain their utility for making the reactor parts To take the successful lab scale results (100 ml) to scalable levels (80000 ml) for field trails, a new microwave reactor system was designed and tested. The cavity design was aided by multiphysics simulation of the electromagnetic field and temperature distribution inside the cavity. The model was created using COMSOL and provided valuable insight in making several design choices and improvements. The material data used in the model was determined both from our characterisation results and from corroborative literature data. The cavity itself was fully constructed using aluminium and the internal components were made using polypropylene and PTFE within the project timeline. The cavity was commissioned and initial testing at end user sites involved experiments measuring the rate of decomposition of carbetamide and other pesticides the results again emphasising that microwave treatment improves the reaction rates both from lab scale and in pilot scale water treatment situations in comparison to conventional treatment systems. This augers well for the generic applicability of the microwave assisted catalytic reactor system and its potential for the efficient treatment of contaminated water from hard to treat agricultural. Industrial, medical and defence waste/pollutants in future. An added advantage is that the developed microwave treatment system is mobile (on an ISO-container) and hence can reach the remote, contaminated site and treat it then and there rather than transporting the contaminated fluid to the treatment plant in a faraway location.