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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Iron Nanoparticles for In Situ Chemical Oxidation

Al-Shamsi, Mohammed 31 July 2013 (has links)
Recently, metal nanoparticles have attracted the attention of researchers in several fields of study due to their high surface area and other unique properties. Using metal nanoparticles as a component of an in situ chemical oxidation (ISCO) system is emerging and hence very little information is available. In this research, nano zero valent iron (nZVI) particles and iron-based bimetallic zero valent nanoparticles (BZVNs) were employed to activate some common peroxygens (hydrogen peroxide (H2O2), persulfate (S2O82-), and peroxymonosulfate (HSO5-)) to degrade hazardous organic compounds. Aqueous and soil slurry batch systems were used along with a one-dimensional physical model. The results from the aqueous batch systems showed that nZVI is a promising activator for S2O82- compared to other conventional iron activators (e.g., granular-ZVI and Fe2+). For example, the initial trichloroethylene (TCE) reaction rate by nZVI activated S2O82- was 1.11 x 10-4 M L-1 min-1 compared to an initial reaction rate of 6.25 x 10-5 M L-1 min-1, 5.18 x 10-6 M L-1 min-1, and 1.8 x 10-7 M L-1 min-1 for Fe2+ activated S2O82-, granular-ZVI activated S2O82-, and non-activated S2O82-, respectively. However, the surfaces of nZVI particles were passivated quickly following exposure to S2O82-, causing the reaction rate to reduce to a magnitude representative of an un-activated S2O82- system. An iron-sulfate (FeSO4) complex was formed on the surfaces of the nZVI particles following exposure to S2O82- compared to the iron oxyhydroxide (FeOOH) layer that was present on fresh nZVI surfaces. BZVNs showed better treatment effectiveness than nZVI particles as activators for H2O2, S2O82-, and HSO5-. For example, the TCE reaction rate constant for nano-Ag-Fe0 activated H2O2 was 9 to 18 fold higher than that for nZVI activated H2O2. Of the nine different BZVNs investigated as activators, the greatest TCE degradation was achieved by nano-Pd-Fe0 and nano-Zn-Fe0 activated S2O82- system, nano-Co-Fe0 activated HSO5- system, and nano-Ag-Fe0 activated H2O2 system. For all of these systems, an increase in the dosage of nanoparticles and peroxygens increased TCE degradation. The activated H2O2 system showed a lower TCE degradation rate compared to either the activated S2O82- or the activated HSO5- systems, suggesting that a bridged group complex is formed between the activators and H2O2. The dissolved TCE concentration remaining in the soil slurry batch systems after using the nano-Pd-Fe0 activated S2O82- system was two to three fold higher than that in an aqueous batch system. Furthermore, for five different aquifer materials used, the higher mass of aquifer materials the lower the TCE degradation, indicating that the aquifer materials compete with a target organic compound in the presence of activated S2O82-. A linear relationship was observed between the organic carbon (OC) content and the initial TCE decomposition rate. Although there is no direct evidence of the effect of OC on the treatment system, it is suggested that the OC may result in scavenging the generated free radicals or by directly consuming persulfate. In the one-dimensional physical model systems, bimetallic nanoparticles were mobile in a non-geological porous medium and relatively immobile in a geological porous medium. In the non-geological porous medium, we found that adding a second metal (e.g., Pd) to nano-Fe0 particles significantly improved their functionality and performance (e.g., mobility and suspension). For example, the results from mobility experiments using columns packed with glass beads showed that the effluent iron concentration was <6 % of the influent iron concentration for the nano-Fe0 particles, while it was ~100 % for the nano-Pd-Fe0 particles. In the geological porous medium, based on visual inspection, nano-Pd-Fe0 particles could not travel more than a few centimeters into columns packed with CFB Borden sand, and no iron was detected in the effluent. To overcome the delivery issue in porous media, nano-Pd-Fe0 particles were injected to create a zone of activation to activate S2O82- for the treatment of TCE source zone. However, we found that the TCE mass destruction was only 9 % higher in the nano-Pd-Fe0 activated S2O82- system compared to the non-activated S2O82- system as revealed by the effluent chloride concentration. In addition, the activation zone composed of nano-Pd-Fe0 particles was rapidly deactivated after exposure to persulfate as visually observed by color change, indicating that the longevity of the activation zone is limited. This research effort provides a contribution to the field of ISCO by evaluating the potential utility and applicability of a new class of activators for some common peroxygens.
2

Iron Nanoparticles for In Situ Chemical Oxidation

Al-Shamsi, Mohammed 31 July 2013 (has links)
Recently, metal nanoparticles have attracted the attention of researchers in several fields of study due to their high surface area and other unique properties. Using metal nanoparticles as a component of an in situ chemical oxidation (ISCO) system is emerging and hence very little information is available. In this research, nano zero valent iron (nZVI) particles and iron-based bimetallic zero valent nanoparticles (BZVNs) were employed to activate some common peroxygens (hydrogen peroxide (H2O2), persulfate (S2O82-), and peroxymonosulfate (HSO5-)) to degrade hazardous organic compounds. Aqueous and soil slurry batch systems were used along with a one-dimensional physical model. The results from the aqueous batch systems showed that nZVI is a promising activator for S2O82- compared to other conventional iron activators (e.g., granular-ZVI and Fe2+). For example, the initial trichloroethylene (TCE) reaction rate by nZVI activated S2O82- was 1.11 x 10-4 M L-1 min-1 compared to an initial reaction rate of 6.25 x 10-5 M L-1 min-1, 5.18 x 10-6 M L-1 min-1, and 1.8 x 10-7 M L-1 min-1 for Fe2+ activated S2O82-, granular-ZVI activated S2O82-, and non-activated S2O82-, respectively. However, the surfaces of nZVI particles were passivated quickly following exposure to S2O82-, causing the reaction rate to reduce to a magnitude representative of an un-activated S2O82- system. An iron-sulfate (FeSO4) complex was formed on the surfaces of the nZVI particles following exposure to S2O82- compared to the iron oxyhydroxide (FeOOH) layer that was present on fresh nZVI surfaces. BZVNs showed better treatment effectiveness than nZVI particles as activators for H2O2, S2O82-, and HSO5-. For example, the TCE reaction rate constant for nano-Ag-Fe0 activated H2O2 was 9 to 18 fold higher than that for nZVI activated H2O2. Of the nine different BZVNs investigated as activators, the greatest TCE degradation was achieved by nano-Pd-Fe0 and nano-Zn-Fe0 activated S2O82- system, nano-Co-Fe0 activated HSO5- system, and nano-Ag-Fe0 activated H2O2 system. For all of these systems, an increase in the dosage of nanoparticles and peroxygens increased TCE degradation. The activated H2O2 system showed a lower TCE degradation rate compared to either the activated S2O82- or the activated HSO5- systems, suggesting that a bridged group complex is formed between the activators and H2O2. The dissolved TCE concentration remaining in the soil slurry batch systems after using the nano-Pd-Fe0 activated S2O82- system was two to three fold higher than that in an aqueous batch system. Furthermore, for five different aquifer materials used, the higher mass of aquifer materials the lower the TCE degradation, indicating that the aquifer materials compete with a target organic compound in the presence of activated S2O82-. A linear relationship was observed between the organic carbon (OC) content and the initial TCE decomposition rate. Although there is no direct evidence of the effect of OC on the treatment system, it is suggested that the OC may result in scavenging the generated free radicals or by directly consuming persulfate. In the one-dimensional physical model systems, bimetallic nanoparticles were mobile in a non-geological porous medium and relatively immobile in a geological porous medium. In the non-geological porous medium, we found that adding a second metal (e.g., Pd) to nano-Fe0 particles significantly improved their functionality and performance (e.g., mobility and suspension). For example, the results from mobility experiments using columns packed with glass beads showed that the effluent iron concentration was <6 % of the influent iron concentration for the nano-Fe0 particles, while it was ~100 % for the nano-Pd-Fe0 particles. In the geological porous medium, based on visual inspection, nano-Pd-Fe0 particles could not travel more than a few centimeters into columns packed with CFB Borden sand, and no iron was detected in the effluent. To overcome the delivery issue in porous media, nano-Pd-Fe0 particles were injected to create a zone of activation to activate S2O82- for the treatment of TCE source zone. However, we found that the TCE mass destruction was only 9 % higher in the nano-Pd-Fe0 activated S2O82- system compared to the non-activated S2O82- system as revealed by the effluent chloride concentration. In addition, the activation zone composed of nano-Pd-Fe0 particles was rapidly deactivated after exposure to persulfate as visually observed by color change, indicating that the longevity of the activation zone is limited. This research effort provides a contribution to the field of ISCO by evaluating the potential utility and applicability of a new class of activators for some common peroxygens.
3

Alguns estudos da fluorescência e quimiluminescência de substâncias húmicas / Some studies on fluorescence and chemiluminescence of humic substances

Magdaleno, Giselle Baratti 14 December 2007 (has links)
Investigou-se a influência de íons metálicos Al(III), Ca(II), Fe(III), Pb(II), Cu(II) e Cr(III) (10-6 a 10 -3 mol L-1 na intensidade relativa de fluorescência (IRF) do ácido húmico (AH, 10 mg L-1). os íons Cu(ii), Pb(II) e Cr (III) produziram um efeito de supressão, enquanto os íons Fe(III), Al(III) e Ca(II) não influenciaram significativamente nos valores de IRF. A partir dos valores de IRF foram calculadas a constante de estabilidade (K) dos complexos e a capacidade complexante do AH com Cu(II), Pb(II) e Cr(III). Os valores de K seguiram a ordem: Cr(III)> Pb(II) > Cu(II) e a capacidade complexante: Cr(III) ~ Pb(II)> Cu(II). Desenvolveu-se um novo método analítico baseado na reação quimiluminescente da oxidação do AH com peroxomonosulfato de potássio (PMS; 0,6 mol L-1</SUP) ) em meio básico (NaOH 1,0 mol L-1 ). A intensidade máxima de radiação emitida (Imáx ) e a área em função do tempo foram lineares com a quantidade de AH em solução na faixa de 0,5 a 20 mg L-1, com o limite de detecção de 0,24 mg L-1 , com limite de detecção de 0,24 mg L-1 . Um estudo comparativo foi realizado utilizando-se H2O2 (0,58 mol L-1 na presença de CH2O (0,44 mol L-1) em meio básico (NaOH 0,16 mol L-1) com limite de detecção de 0,4 mg L-1. As adições dos íons Cl-, NO3- , PO43- , CO32- , Fe(III), Cu(II), Cr(III) e Ca(II) na reação quimiluminescente de AH com PMS, não interferiram significativamente no sinal. Adições de 50 mg L-1 de Co(II) ou Mn(II) à solução de AH Aldrich, na forma de complexos de EDTA ou cloretos, aumentaram o valor Imáx devido à formação de espécies fortemente oxidantes como SO5°-, SO4°- HO° durante a reação de decomposição do PMS. O método foi aplicado para determinar a concentração de AH em amostra de água do Rio Miranda - MS, obtendo-se valores entre 2,9 a 12,3 mg L-1 . As reações de oxidação, com emissão de radiação, de alguns compostos orgânicos com PMS em meio básico foram estudadas. Com os polifenóis obtiveram- se intensidades de radiação mais significativas e os valores de área seguiram a seguinte ordem: floroglucinol >> ácido fúlvico > ácido húmico > resorcinol > ácido pirogálico > catecol > hidroquinona. Desta forma, como polifenóis existem na estrutura de substâncias húmicas, acredita-se que essas porções da molécula devem ser as responsáveis pela produção de quimiluminescência. / The influence of Al(III), Ca(II), Fe(III), Pb(II), Cu(II), and Cr(III) metal ions (10-6 to 10-3 mol L-1) on the relative fluorescence intensity (RFI) of humic acid (HA, 10 mg L-1) was investigated. Cu(II), Pb(II), and Cr(III) ions produced a quenching effect, while Fe(III), Al(III), and Ca(II) ions did not significantly interfere with RFI values. Stability constants (K) and complexing capacities of HA with Cu(II), Pb(II), and Cr(III) were obtained using RFI values. Stability values of complexes followed the order: Cr(III)> Pb(II) > Cu(II) and the complexing capacity values: Cr(III) ~ Pb(II) > Cu(II). A new analytical method was developed based on the chemiluminescent oxidation of HA by peroxymonosulfate (PMS; 0.6 mol L-1) in basic medium (NaOH 1.0 mol L-1). The intensity of radiation emission (Imax) and area vs. time were linear functions of HA concentration range of 0.5-20 mg L-1. The detection limit was 0.24 mg L-1. A comparative study was conducted using H2O2 (0.58 mol L-1) in the presence of CH2O (0.44 mol L-1) in basic medium (NaOH 0.16 mol L-1). The detection limit was 0.4 mg L-1 of HA. The addition of Cl-, NO3-, PO43-, CO32-, Fe(III), Cu(II), Cr(III), and Ca(II) to the chemiluminescent reaction of HA with PMS did not interfere with the signal. The addition of 50 mg L-1 Co(II) or Mn(II) (as EDTA complexes or chloride salts) to the HA sample enhanced radiation emission, due to the formation of strong oxidant species such as SO5o-, SO4o-, and HOo during PMS decomposition reaction. This method was applied to determine HA concentration in a sample of river water (Miranda River - MS), obtaining values between 2.9 and 12.3 mg L-1. Oxidation reactions of some organic compounds by PMS in basic medium were studied, which produced radiation emission. Polyphenols produced the highest emissions and the area values followed the order: phloroglucinol> fulvic acid> humic acid> resorcinol> pyrogalic acid> cathecol> hydroquinone. Since polyphenolic groups are supposed to exist within humic acid structure, those portions of the molecule are most likely to be responsible for that chemiluminescence.
4

Alguns estudos da fluorescência e quimiluminescência de substâncias húmicas / Some studies on fluorescence and chemiluminescence of humic substances

Giselle Baratti Magdaleno 14 December 2007 (has links)
Investigou-se a influência de íons metálicos Al(III), Ca(II), Fe(III), Pb(II), Cu(II) e Cr(III) (10-6 a 10 -3 mol L-1 na intensidade relativa de fluorescência (IRF) do ácido húmico (AH, 10 mg L-1). os íons Cu(ii), Pb(II) e Cr (III) produziram um efeito de supressão, enquanto os íons Fe(III), Al(III) e Ca(II) não influenciaram significativamente nos valores de IRF. A partir dos valores de IRF foram calculadas a constante de estabilidade (K) dos complexos e a capacidade complexante do AH com Cu(II), Pb(II) e Cr(III). Os valores de K seguiram a ordem: Cr(III)> Pb(II) > Cu(II) e a capacidade complexante: Cr(III) ~ Pb(II)> Cu(II). Desenvolveu-se um novo método analítico baseado na reação quimiluminescente da oxidação do AH com peroxomonosulfato de potássio (PMS; 0,6 mol L-1</SUP) ) em meio básico (NaOH 1,0 mol L-1 ). A intensidade máxima de radiação emitida (Imáx ) e a área em função do tempo foram lineares com a quantidade de AH em solução na faixa de 0,5 a 20 mg L-1, com o limite de detecção de 0,24 mg L-1 , com limite de detecção de 0,24 mg L-1 . Um estudo comparativo foi realizado utilizando-se H2O2 (0,58 mol L-1 na presença de CH2O (0,44 mol L-1) em meio básico (NaOH 0,16 mol L-1) com limite de detecção de 0,4 mg L-1. As adições dos íons Cl-, NO3- , PO43- , CO32- , Fe(III), Cu(II), Cr(III) e Ca(II) na reação quimiluminescente de AH com PMS, não interferiram significativamente no sinal. Adições de 50 mg L-1 de Co(II) ou Mn(II) à solução de AH Aldrich, na forma de complexos de EDTA ou cloretos, aumentaram o valor Imáx devido à formação de espécies fortemente oxidantes como SO5°-, SO4°- HO° durante a reação de decomposição do PMS. O método foi aplicado para determinar a concentração de AH em amostra de água do Rio Miranda - MS, obtendo-se valores entre 2,9 a 12,3 mg L-1 . As reações de oxidação, com emissão de radiação, de alguns compostos orgânicos com PMS em meio básico foram estudadas. Com os polifenóis obtiveram- se intensidades de radiação mais significativas e os valores de área seguiram a seguinte ordem: floroglucinol >> ácido fúlvico > ácido húmico > resorcinol > ácido pirogálico > catecol > hidroquinona. Desta forma, como polifenóis existem na estrutura de substâncias húmicas, acredita-se que essas porções da molécula devem ser as responsáveis pela produção de quimiluminescência. / The influence of Al(III), Ca(II), Fe(III), Pb(II), Cu(II), and Cr(III) metal ions (10-6 to 10-3 mol L-1) on the relative fluorescence intensity (RFI) of humic acid (HA, 10 mg L-1) was investigated. Cu(II), Pb(II), and Cr(III) ions produced a quenching effect, while Fe(III), Al(III), and Ca(II) ions did not significantly interfere with RFI values. Stability constants (K) and complexing capacities of HA with Cu(II), Pb(II), and Cr(III) were obtained using RFI values. Stability values of complexes followed the order: Cr(III)> Pb(II) > Cu(II) and the complexing capacity values: Cr(III) ~ Pb(II) > Cu(II). A new analytical method was developed based on the chemiluminescent oxidation of HA by peroxymonosulfate (PMS; 0.6 mol L-1) in basic medium (NaOH 1.0 mol L-1). The intensity of radiation emission (Imax) and area vs. time were linear functions of HA concentration range of 0.5-20 mg L-1. The detection limit was 0.24 mg L-1. A comparative study was conducted using H2O2 (0.58 mol L-1) in the presence of CH2O (0.44 mol L-1) in basic medium (NaOH 0.16 mol L-1). The detection limit was 0.4 mg L-1 of HA. The addition of Cl-, NO3-, PO43-, CO32-, Fe(III), Cu(II), Cr(III), and Ca(II) to the chemiluminescent reaction of HA with PMS did not interfere with the signal. The addition of 50 mg L-1 Co(II) or Mn(II) (as EDTA complexes or chloride salts) to the HA sample enhanced radiation emission, due to the formation of strong oxidant species such as SO5o-, SO4o-, and HOo during PMS decomposition reaction. This method was applied to determine HA concentration in a sample of river water (Miranda River - MS), obtaining values between 2.9 and 12.3 mg L-1. Oxidation reactions of some organic compounds by PMS in basic medium were studied, which produced radiation emission. Polyphenols produced the highest emissions and the area values followed the order: phloroglucinol> fulvic acid> humic acid> resorcinol> pyrogalic acid> cathecol> hydroquinone. Since polyphenolic groups are supposed to exist within humic acid structure, those portions of the molecule are most likely to be responsible for that chemiluminescence.
5

Kinetic and Mechanistic Studies on the Removal of Cyanotoxins and Antibiotics with Hydroxyl and Sulfate Radical Based Advanced Oxidation Processes

He, Xuexiang 12 September 2014 (has links)
No description available.
6

Sulfate Radical-Based Environmental Friendly Chemical Oxidation Processes for Destruction of 2-Chlorobiphenyl (PCB) and Chlorophenols (CPs)

RASTOGI, ADITYA 22 April 2008 (has links)
No description available.
7

COBALT/PEROXYMONOSULFATE AND RELATED OXIDIZING REAGENTS FOR WATER TREATMENT

ANIPSITAKIS, GEORGIOS P. January 2005 (has links)
No description available.
8

Assessment of novel Advanced Oxidation Processes for the Simultaneous Disinfection and Decontamination of Water

Berruti, Ilaria 30 May 2022 (has links)
[ES] El mundo se enfrenta a una profunda crisis asociada al agua y la reutilización de aguas residuales urbanas (UWW), especialmente en agricultura, se presenta como una posible solución para abordar este problema. No obstante, la reutilización se debe promover dentro de unos límites mínimos de calidad del agua, los cuales pueden alcanzarse mediante la implementación de eficientes tratamientos terciaros en las actuales plantas de tratamiento de aguas residuales urbanas. En las últimas décadas, los Procesos de Oxidación Avanzada (POA), basados en la generación de especies reactivas del oxígeno altamente oxidantes y no selectivas, se han planteado como alternativa a los tratamientos convencionales para desinfección y descontaminación de agua residual. El objetivo general de este estudio es, por tanto, la evaluación de nuevos POA para desinfección y descontaminación simultánea de agua, investigando: (i) fotocatálisis heterogénea solar con ZnO modificado (Ce, Yb y Fe) y TiO2-P25 de referencia, (ii) peroximonosulfato (PMS) bajo radiación solar natural (PMS/Solar), (iii) POA basados en radical sulfato utilizando PMS y radiación UV-C (PMS/UV-C) y (iv) combinación de ZnO modificado con PMS como estrategia de tratamiento. Los objetivos biológicos y químicos analizados en este estudio fueron: tres patógenos de impacto en salud humana (dos bacterias gram-negativas Escherichia coli, Pseudomonas spp y una gram-positiva Enterococcus spp) y tres Contaminantes de Preocupación Emergente (CE) (Diclofenaco-DCF, Sulfametoxazol-SMX y Trimetoprim-TMP). La fotoactividad de ZnO modificado con Ce, Yb o Fe se evaluó a escala de laboratorio (200 mL), obteniendo buenas cinéticas de inactivación bacteriana y degradación de CE. El ZnO-Ce mostró el mejor rendimiento, no obstante, se descartó el escalado de este proceso tanto su aplicación directa, considerando su similar eficiencia en comparación con TiO2-P25 y por el alto coste del tratamiento, como en combinación con PMS, por la la liberación de Zn2+ al agua tratada. El uso directo de PMS como agente oxidante para el tratamiento de agua y UWW se ha demostrado en este estudio, aumentado su eficiencia al ser el sistema irradiado tanto con lámparas UV-C como con luz solar natural. Se han postulado diferentes mecanismos de inactivación y degradación de CE para cada tipo de irradiación: activación de PMS para generar radicales (con fotones UV-C) y la no activación o mecanismo de oxidación directo (con luz solar natural). La capacidad de los procesos PMS/Solar y PMS/UV-C se evaluó en UWW a escala de planta piloto en un Colector Parabólico Compuesto (10 L) y en una planta piloto de UV-C (80 L), respectivamente. El mejor rendimiento de tratamiento se alcanzó con una concentración de PMS de 1 mM en ambos casos, logrando una inactivación exitosa de todos los objetivos microbianos (incluyendo bacterias resistentes a antibióticos), sin observar recrecimiento bacteriano tras 48 h y eliminando de manera eficiente los CE. Por otro lado, la eliminación eficiente de genes de resistentes a antibióticos y productos de transformación se obtuvo con PMS/UV-C, mientras que éstos parámetros siguen siendo un reto a abordar en el caso del proceso PMS/Solar. En ningún caso se observó toxicidad del agua tratada para Aliivibrio fischeri, excluyendo un efecto nocivo para el medio ambiente receptor del efluente, y solo un leve efecto fitotóxico en el crecimiento de dos de las tres semillas analizadas (L. sativum y S. alba), indicando la idoneidad del efluente para su reutilización en riego. Finalmente, el análisis de costes demostró que este factor clave podría ser una barrera importante para la implementación del proceso PMS/Solar en plantas centralizadas de tratamiento de UWW. No obstante, su consideración como sistemas descentralizados asociados a pequeños volúmenes de agua en zonas con alta incidencia de radiación solar, ahorrando costes energéticos mediante el aprovechamiento de la luz solar, podría ser una opción real y asequible. / [CA] El món s'enfronta a una profunda crisi associada a l'aigua i la reutilització d'aigües residuals urbanes (UWW), especialment en agricultura, es presenta com una possible solució per a abordar aquest problema. No obstant això, la reutilització s'ha de promoure dins d'uns límits mínims de qualitat de l'aigua, els quals poden aconseguir-se mitjançant la implementació d'eficients tractaments terciaris en les actuals plantes de tractament d'aigües residuals urbanes. En les últimes dècades, els Processos Avançats d'Oxidació (PAO), basats en la generació d'espècies reactives d'oxigen altament oxidants i no selectives, s'han plantejat com a alternativa als tractaments convencionals per a desinfecció i descontaminació d'aigua residual. L'objectiu general d'aquest estudi és, per tant, l'avaluació de nous POA per a desinfecció i descontaminació simultània d'aigua, investigant: (i) fotocatàlisi heterogènia solar amb ZnO modificat (Ce, Yb i Fe) i TiO2-P25 de referència, (ii) peroximonosulfat (PMS) baix radiació solar natural (PMS/Solar), (iii) POA basats en radical sulfat utilitzant PMS i radiació UV-C (PMS/UV-C) i (iv) combinació de ZnO modificat amb PMS com a estratègia de tractament. Els objectius biològics i químics analitzats en aquest estudi van ser: tres patògens d'impacte en salut humana (dos bacteris gram-negatius Escherichia coli, Pseudomonas spp i un gram-positiu Enterococcus spp) i tres Contaminants de Preocupació Emergent (CE) (Diclofenac-DCF, Sulfametoxazol-SMX i Trimetoprim-TMP). La fotoactivitat de ZnO modificat amb Ce, Yb o Fe es va avaluar a escala de laboratori (200 mL), obtenint bones cinètiques d'inactivació bacteriana i degradació de CE. El ZnO-Ce va mostrar el millor rendiment, no obstant això, es va descartar l'escalat d'aquest procés tant mitançant la seua aplicació directa o com en combinació amb PMS, considerant la seua similar eficiència en comparació amb TiO2-P25, l'alt cost del tractament i l'alliberament de Zn2+ a l'aigua tractada. L'ús directe de PMS com a agent oxidant per al tractament d'aigua i UWW s'ha demostrat en aquest estudi, augmentat la seua eficiència quan el sistema és irradiat tant amb llums UV-C com amb llum solar natural. S'han postulat diferents mecanismes d'inactivació i degradació de CE per a cada tipus d'irradiació: activació de PMS per a generar radicals (amb fotons UV-C) i la no activació o mecanisme d'oxidació directe (amb llum solar natural). La capacitat dels processos PMS/Solar i PMS/UV-C es va avaluar en UWW a escala de planta pilot en un Col·lector Parabòlic Compost (10 L) i en una planta pilot d'UV-C (80 L), respectivament. El millor rendiment de tractament es va aconseguir amb una concentració de PMS d'1 mm en tots dos casos, aconseguint una inactivació reeixida de tots els objectius microbians (incloent bacteris resistents a antibiòtics), sense observar recreixement bacterià després de 48 h i eliminant de manera eficient els CE. D'altra banda, l'eliminació eficient de gens de resistents a antibiòtics i productes de transformació es va obtindre amb PMS/UV-C, mentre que aquests paràmetres continuen sent un repte a abordar en el cas del procés PMS/Solar. En cap cas es va observar toxicitat a l'aigua tractada per a Aliivibrio fischeri, excloent un efecte nociu per al medi ambient receptor de l'efluent, i només un lleu efecte fitotòxic en el creixement de dos de les tres llavors analitzades (L. sativum i S. alba), indicant la idoneïtat de l'efluent per a la seua reutilització en reg. Finalment, l'anàlisi de costos va demostrar que aquest factor clau podria ser una barrera important per a la implementació del procés PMS/Solar en plantes centralitzades de tractament de UWW. No obstant això, la seua consideració com a sistemes descentralitzats associats a xicotets volums d'aigua en zones amb alta incidència de radiació solar, estalviant costos energètics mitjançant l'aprofitament de la llum solar, podria ser una opció real i assequible. / [EN] It is well recognized that the world is facing a water crisis and the reuse of urban wastewater (UWW) in agriculture, has been gaining attention as a reliable solution to address this problem. It is mandatory to promote the safe water reuse and minimum water quality limits could be achieved by upgrading the Urban Wastewater Treatment Plants, through the addition of an efficient tertiary treatment. In the last decades, Advanced Oxidation Processes (AOPs), relying on the potential generation of highly oxidant, reactive and non-selective Reactive Oxygen Species (ROS), have been raised as alternative to conventional treatments for both water disinfection and decontamination. The general aim of this study is the assessment of novel AOPs for the simultaneous disinfection and decontamination of water, investigating (i) solar heterogeneous photocatalysis, involving modified ZnO with Ce, Yb and Fe and the benchmark TiO2-P25, (ii) peroxymonosulfate (PMS) under natural solar radiation (PMS/Solar), (iii) Sulfate radical-based AOPs (SR-AOPs) involving PMS and UV-C radiation (PMS/UV-C) and (iv) combination of the best-performing photocatalytic material with PMS (PMS/modified ZnO). The involved biological and chemical targets in this study were: three human health impact pathogens (two gram-negative bacteria Escherichia coli, Pseudomonas spp. and the gram-positive Enterococcus spp.) and three Contaminants of Emerging Concern (CECs, Diclofenac-DCF, Sulfamethoxazole-SMX and Trimethoprim-TMP). Photoactivity of modified ZnO with Ce, Yb or Fe was assessed in 200-mL vessel reactors, attaining good target's removal kinetic rates. Best performing material was ZnO-Ce, but its feasibility for a further up-scaling was discarded both as photocatalyst alone, considering the similar performances obtained, compared to TiO2-P25 and the high treatment cost, and in combination with PMS, due to the release of high amount of Zn2+. PMS alone has been proven to be an effective oxidant agent for water and UWW treatment, increasing its effectiveness when illuminated with photons from UV-C lamps and natural sunlight. Nevertheless, different inactivation and CECs degradation mechanisms have been postulated for each type of irradiation, and according to the activation of PMS (with UV-C photons) or non-activation (under natural sunlight). The capability of PMS/Solar and PMS/UV-C processes were evaluated in actual UWW at pilot plant scale in 10-L Compound Parabolic Collector and in 80L UV-C pilot plant, respectively. Optimal load of PMS was found to be 1 mM in both cases, achieving successful inactivation of natural occurring bacteria and their antibiotic resistant counterparts, without observing bacterial regrowth after 48h and efficiently eliminating CECs. Efficient removal of antibiotic resistant genes (ARGs) and transformation products (TPs) was obtained by PMS/UV-C, while their elimination is still a challenge to be addressed in PMS/Solar process. Reclaimed UWW obtained by both PMS/Solar and PMS/UV-C process showed no toxicity towards Aliivibrio fischeri, excluding a harmful effect towards the receiving aquatic environment after effluent discharge, and a very slightly phytotoxic effect for growth of two out of the three tested seeds (L. sativum and S. alba), indicating the suitability of this water for its subsequent reuse for agriculture. The analysis of the treatment cost revealed that this key factor could be an important barrier for implementation of PMS/Solar process in large centralized UWW treatment plants. Nevertheless, its consideration as decentralized systems associated to small volume of water in areas with a high solar radiation incidence, saving energy costs by using natural solar radiation, could be a real and affordable option. / Berruti, I. (2022). Assessment of novel Advanced Oxidation Processes for the Simultaneous Disinfection and Decontamination of Water [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/183052

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