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Papers by Pilar Fernández-Ibañez
Catalysis Today, 2005
The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have b... more The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have been investigated under laboratory conditions (small vial, artificial light) and in large-scale photo-reactors under sunlight to achieve low-cost decontamination of textile and agrochemical industry effluent wastewater. Fe-ions deposited onto chemically treated C fabrics or encapsulated in Nafion thin films cast directly onto the carbon fabrics are efficient in decomposing H 2 O 2 used as an oxidant in the photo-assisted abatement of non-biodegradable azo-dyes used in textiles. The Orange II taken as a model pollutant quickly fades under solar irradiation even at an initial pH 6. This range of pH is not possible with the homogeneous photo-Fenton process. In contrast, the use of supported catalysts on C fabrics allows the costly pH adjustment to be avoided. This makes catalyst recovery and economical decontamination of wastewater containing non-biodegradable pollutants possible. #
Journal of Photochemistry and Photobiology B: Biology, 2008
Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compou... more Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compound parabolic collector (CPC) mirrors to enhance the efficiency of solar disinfection (SODIS) for batch reactors under real, solar radiation (cloudy and cloudless) conditions. On clear days, the system with CPC reflectors achieved complete inactivation (more than 5-log unit reduction in bacterial population to below the detection limit of 4 CFU/mL) one hour sooner than the system fitted with no CPC. On cloudy days, only systems fitted with CPCs achieved complete inactivation. Degradation of the mirrors under field conditions was also evaluated. The reflectivity of CPC systems that had been in use outdoors for at least 3 years deteriorated in a non-homogeneous fashion. Reflectivity values for these older systems were found to vary between 27% and 72% compared to uniform values of 87% for new CPC systems. The use of CPC has been proven to be a good technological enhancement to inactivate bacteria under real conditions in clear and cloudy days. A comparison between enhancing optics and thermal effect is also discussed.
Environmental Science & Technology, 2015
The sunlight/H2O2 process has recently been considered as a sustainable alternative option compar... more The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.
Environmental Science and Pollution Research, 2014
Catalysis Today, 1999
Large photoelectrochemical reactors of various sizes, made of cylindrical photoanodes surrounding... more Large photoelectrochemical reactors of various sizes, made of cylindrical photoanodes surrounding the counter electrode compartment, have been placed inside the glass tubes of either compound parabolic (CPC) or parabolic trough collectors (PTC, Helioman). Model pollutants have been destroyed at various solar light concentrations. Their oxidation rates have been found to be up to 1000-times higher than the values obtained with TiO 2 slurries. Separation of charges is much better when the photogenerated electrons are collected through an electrochemical bias and, moreover, the continuous measurement of photocurrents makes it possible to directly monitor the efficiency of the whole system and thereby improve it. (P. Fernandez-Ibañez) 0920-5861/99/$ -see front matter ©1999 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 0 -5 8 6 1 ( 9 9 ) 0 0 1 9 4 -7
Catalysis today, 2005
The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have b... more The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have been investigated under laboratory conditions (small vial, artificial light) and in large-scale photo-reactors under sunlight to achieve low-cost decontamination of textile and agrochemical industry effluent wastewater. Fe-ions deposited onto chemically treated C fabrics or encapsulated in Nafion thin films cast directly onto the carbon fabrics are efficient in decomposing H 2 O 2 used as an oxidant in the photo-assisted abatement of non-biodegradable azo-dyes used in textiles. The Orange II taken as a model pollutant quickly fades under solar irradiation even at an initial pH 6. This range of pH is not possible with the homogeneous photo-Fenton process. In contrast, the use of supported catalysts on C fabrics allows the costly pH adjustment to be avoided. This makes catalyst recovery and economical decontamination of wastewater containing non-biodegradable pollutants possible. #
Applied Catalysis B: Environmental, 2014
The occurrence of antibiotics in urban wastewater treatment plants (UWTPs) may result in the deve... more The occurrence of antibiotics in urban wastewater treatment plants (UWTPs) may result in the development of antibiotic resistance and subsequently in the release of multidrug resistant bacteria (MDR) and genes into the effluent. Conventional disinfection processes are only partially effective in controlling ARB spread, so advanced oxidation processes (AOPs) have been investigated as alternative option in this work. In particular, the aim of this work was to comparatively assess the efficiency of solar disinfection and solar driven AOPs (namely H 2 O 2 /sunlight, TiO 2 /sunlight, H 2 O 2 /TiO 2 /sunlight, natural photo-Fenton) for the inactivation of a multidrug (namely ampicillin, ciprofloxacin and tetracycline) resistant E. coli strain isolated from the effluent of the biological process of an UWTP. Different concentrations of H 2 O 2 (0.588-1.470-2.205 mM), TiO 2 (50-100 mg L −1 ), H 2 O 2 /TiO 2 (0.147 mM/50 mg L −1 , 0.588 mM/100 mg L −1 ) and Fe 2+ /H 2 O 2 (0.090/0.294, 0.179/0.588, 0.358/1.176 mM) were evaluated at pilot-scale (in compound parabolic collector reactor) in real biologically treated wastewater. All investigated processes resulted in a complete inactivation (5-log decrease) of bacteria until detection limit, but the best disinfection efficiency in terms of treatment time (20 min to reach the detection limit) and required energy (0.98 kJ L −1 ) was observed for photo-Fenton at pH 4 (Fe 2+ /H 2 O 2 :0.090/0.294 mM). Antimicrobial susceptibility was tested by Kirby-Bauer disk diffusion method. Ampicillin and ciprofloxacin (to which the selected strain is resistant), cefuroxime and nitrofurantoin were chosen as tested antibiotics. None of the investigated processes affected antibiotic resistance of survived colonies.
Journal of Chemical Technology & Biotechnology, 2014
Research on Chemical …, 2007
In this paper, we present pilot-scale solar Photo-Fenton and TiO 2 treatment of a model compound ... more In this paper, we present pilot-scale solar Photo-Fenton and TiO 2 treatment of a model compound (α-methylphenylglycine) dissolved in 500 mg/l concentration in water. Not only contaminant disappearance and mineralisation were evaluated, but also enhancement of biodegradability. The solar photoreactors, composed of 4.16 m 2 of compound parabolic collectors, had a total volume of 82 l (44.6 l illuminated). Treatment was successful with both Advanced Oxidation Processes (AOPs) tested, but photo-Fenton was shown to be by far more efficient from the kinetic and practical point of view. To find out the conditions for biocompatibility using the AOPs as a pre-treatment, waste water after certain degradation time, unacclimated municipal sludge and mineral nutrients were placed together and evaluated by the Zahn-Wellens (Z-W) test. Biodegradability was enhanced (70% biodegradable) by both AOPs, but photo-Fenton was demonstrated to be more efficient, requiring a treatment time one order of magnitude shorter than TiO 2 . Hydrogen peroxide management for reduced consumption and elimination prior to discharging water to the biotreatment step is also discussed in detail.
Applied Catalysis B: Environmental, 2006
Photo-Fenton experiments were performed using alachlor as a model compound (initial concentration... more Photo-Fenton experiments were performed using alachlor as a model compound (initial concentration 100 mg/L) in a compound parabolic collector solar pilot-plant. Three process parameters were varied following a central composite design without star points (temperature 20-50 8C, iron concentration 2-20 mg/L, illuminated volume 11.9-59.5% of total). Under all experimental conditions, complete alachlor degradation, mineralisation of chloride and 85-95% mineralisation of dissolved organic carbon (DOC) was achieved. An increase in temperature, iron concentration and illuminated volume from minimum to maximum value reduced the time required for 80% degradation of initial DOC by approximate factors of 5, 6 and 2, respectively. When process parameter changes were made simultaneously, these factors multiplied each other, resulting in degradation times between 20 and 1250 min.
Solar disinfection and solar-driven advanced oxidation processes (AOPs) (namely H2O2/sunlight, Ti... more Solar disinfection and solar-driven advanced oxidation processes (AOPs) (namely H2O2/sunlight, TiO2/sunlight, H2O2/TiO2/sunlight, solar photo-Fenton) were evaluated in the inactivation of indigenous antibiotic-resistant bacteria (ARB) in real urban wastewater. A multidrug resistant (MDR) Escherichia coli strain isolated from the effluent of the biological process of an urban wastewater treatment plant was the target ARB. The higher inactivation rates (residual density under detection limit, 2 CFU mL−1) were achieved with H2O2/TiO2/sunlight (cumulative energy per unit of volume (QUV) in the range 3–5 kJ L−1, depending on H2O2/TiO2 ratio) and H2O2/sunlight (QUV of 8 kJ L−1) processes. All investigated processes did not affect antibiotic resistance of survived colonies. Moreover, H2O2/sunlight was compared with conventional chlorination process to evaluate bacterial regrowth potential and particularly the proportion of indigenous MDR E. coli with respect to total indigenous E. coli population. Chlorination (1.0 mg Cl2 L−1) was more effective than H2O2/sunlight (50 mg H2O2 L−1) to achieve total inactivation of MDR E. coli (15 min Vs 90 min) but less effective in controlling their regrowth (24 h Vs 48 h). Interestingly, the percentage of MDR E. coli in H2O2/sunlight treated samples decreased as incubation time increased; the opposite was observed for chlorinated samples.
Catalysis Today, 2005
The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have b... more The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have been investigated under laboratory conditions (small vial, artificial light) and in large-scale photo-reactors under sunlight to achieve low-cost decontamination of textile and agrochemical industry effluent wastewater. Fe-ions deposited onto chemically treated C fabrics or encapsulated in Nafion thin films cast directly onto the carbon fabrics are efficient in decomposing H 2 O 2 used as an oxidant in the photo-assisted abatement of non-biodegradable azo-dyes used in textiles. The Orange II taken as a model pollutant quickly fades under solar irradiation even at an initial pH 6. This range of pH is not possible with the homogeneous photo-Fenton process. In contrast, the use of supported catalysts on C fabrics allows the costly pH adjustment to be avoided. This makes catalyst recovery and economical decontamination of wastewater containing non-biodegradable pollutants possible. #
Journal of Photochemistry and Photobiology B: Biology, 2008
Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compou... more Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compound parabolic collector (CPC) mirrors to enhance the efficiency of solar disinfection (SODIS) for batch reactors under real, solar radiation (cloudy and cloudless) conditions. On clear days, the system with CPC reflectors achieved complete inactivation (more than 5-log unit reduction in bacterial population to below the detection limit of 4 CFU/mL) one hour sooner than the system fitted with no CPC. On cloudy days, only systems fitted with CPCs achieved complete inactivation. Degradation of the mirrors under field conditions was also evaluated. The reflectivity of CPC systems that had been in use outdoors for at least 3 years deteriorated in a non-homogeneous fashion. Reflectivity values for these older systems were found to vary between 27% and 72% compared to uniform values of 87% for new CPC systems. The use of CPC has been proven to be a good technological enhancement to inactivate bacteria under real conditions in clear and cloudy days. A comparison between enhancing optics and thermal effect is also discussed.
Environmental Science & Technology, 2015
The sunlight/H2O2 process has recently been considered as a sustainable alternative option compar... more The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.
Environmental Science and Pollution Research, 2014
Catalysis Today, 1999
Large photoelectrochemical reactors of various sizes, made of cylindrical photoanodes surrounding... more Large photoelectrochemical reactors of various sizes, made of cylindrical photoanodes surrounding the counter electrode compartment, have been placed inside the glass tubes of either compound parabolic (CPC) or parabolic trough collectors (PTC, Helioman). Model pollutants have been destroyed at various solar light concentrations. Their oxidation rates have been found to be up to 1000-times higher than the values obtained with TiO 2 slurries. Separation of charges is much better when the photogenerated electrons are collected through an electrochemical bias and, moreover, the continuous measurement of photocurrents makes it possible to directly monitor the efficiency of the whole system and thereby improve it. (P. Fernandez-Ibañez) 0920-5861/99/$ -see front matter ©1999 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 0 -5 8 6 1 ( 9 9 ) 0 0 1 9 4 -7
Catalysis today, 2005
The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have b... more The physicochemical properties and photocatalytic behavior of Fe/C and Fe/Nafion/C fabrics have been investigated under laboratory conditions (small vial, artificial light) and in large-scale photo-reactors under sunlight to achieve low-cost decontamination of textile and agrochemical industry effluent wastewater. Fe-ions deposited onto chemically treated C fabrics or encapsulated in Nafion thin films cast directly onto the carbon fabrics are efficient in decomposing H 2 O 2 used as an oxidant in the photo-assisted abatement of non-biodegradable azo-dyes used in textiles. The Orange II taken as a model pollutant quickly fades under solar irradiation even at an initial pH 6. This range of pH is not possible with the homogeneous photo-Fenton process. In contrast, the use of supported catalysts on C fabrics allows the costly pH adjustment to be avoided. This makes catalyst recovery and economical decontamination of wastewater containing non-biodegradable pollutants possible. #
Applied Catalysis B: Environmental, 2014
The occurrence of antibiotics in urban wastewater treatment plants (UWTPs) may result in the deve... more The occurrence of antibiotics in urban wastewater treatment plants (UWTPs) may result in the development of antibiotic resistance and subsequently in the release of multidrug resistant bacteria (MDR) and genes into the effluent. Conventional disinfection processes are only partially effective in controlling ARB spread, so advanced oxidation processes (AOPs) have been investigated as alternative option in this work. In particular, the aim of this work was to comparatively assess the efficiency of solar disinfection and solar driven AOPs (namely H 2 O 2 /sunlight, TiO 2 /sunlight, H 2 O 2 /TiO 2 /sunlight, natural photo-Fenton) for the inactivation of a multidrug (namely ampicillin, ciprofloxacin and tetracycline) resistant E. coli strain isolated from the effluent of the biological process of an UWTP. Different concentrations of H 2 O 2 (0.588-1.470-2.205 mM), TiO 2 (50-100 mg L −1 ), H 2 O 2 /TiO 2 (0.147 mM/50 mg L −1 , 0.588 mM/100 mg L −1 ) and Fe 2+ /H 2 O 2 (0.090/0.294, 0.179/0.588, 0.358/1.176 mM) were evaluated at pilot-scale (in compound parabolic collector reactor) in real biologically treated wastewater. All investigated processes resulted in a complete inactivation (5-log decrease) of bacteria until detection limit, but the best disinfection efficiency in terms of treatment time (20 min to reach the detection limit) and required energy (0.98 kJ L −1 ) was observed for photo-Fenton at pH 4 (Fe 2+ /H 2 O 2 :0.090/0.294 mM). Antimicrobial susceptibility was tested by Kirby-Bauer disk diffusion method. Ampicillin and ciprofloxacin (to which the selected strain is resistant), cefuroxime and nitrofurantoin were chosen as tested antibiotics. None of the investigated processes affected antibiotic resistance of survived colonies.
Journal of Chemical Technology & Biotechnology, 2014
Research on Chemical …, 2007
In this paper, we present pilot-scale solar Photo-Fenton and TiO 2 treatment of a model compound ... more In this paper, we present pilot-scale solar Photo-Fenton and TiO 2 treatment of a model compound (α-methylphenylglycine) dissolved in 500 mg/l concentration in water. Not only contaminant disappearance and mineralisation were evaluated, but also enhancement of biodegradability. The solar photoreactors, composed of 4.16 m 2 of compound parabolic collectors, had a total volume of 82 l (44.6 l illuminated). Treatment was successful with both Advanced Oxidation Processes (AOPs) tested, but photo-Fenton was shown to be by far more efficient from the kinetic and practical point of view. To find out the conditions for biocompatibility using the AOPs as a pre-treatment, waste water after certain degradation time, unacclimated municipal sludge and mineral nutrients were placed together and evaluated by the Zahn-Wellens (Z-W) test. Biodegradability was enhanced (70% biodegradable) by both AOPs, but photo-Fenton was demonstrated to be more efficient, requiring a treatment time one order of magnitude shorter than TiO 2 . Hydrogen peroxide management for reduced consumption and elimination prior to discharging water to the biotreatment step is also discussed in detail.
Applied Catalysis B: Environmental, 2006
Photo-Fenton experiments were performed using alachlor as a model compound (initial concentration... more Photo-Fenton experiments were performed using alachlor as a model compound (initial concentration 100 mg/L) in a compound parabolic collector solar pilot-plant. Three process parameters were varied following a central composite design without star points (temperature 20-50 8C, iron concentration 2-20 mg/L, illuminated volume 11.9-59.5% of total). Under all experimental conditions, complete alachlor degradation, mineralisation of chloride and 85-95% mineralisation of dissolved organic carbon (DOC) was achieved. An increase in temperature, iron concentration and illuminated volume from minimum to maximum value reduced the time required for 80% degradation of initial DOC by approximate factors of 5, 6 and 2, respectively. When process parameter changes were made simultaneously, these factors multiplied each other, resulting in degradation times between 20 and 1250 min.
Solar disinfection and solar-driven advanced oxidation processes (AOPs) (namely H2O2/sunlight, Ti... more Solar disinfection and solar-driven advanced oxidation processes (AOPs) (namely H2O2/sunlight, TiO2/sunlight, H2O2/TiO2/sunlight, solar photo-Fenton) were evaluated in the inactivation of indigenous antibiotic-resistant bacteria (ARB) in real urban wastewater. A multidrug resistant (MDR) Escherichia coli strain isolated from the effluent of the biological process of an urban wastewater treatment plant was the target ARB. The higher inactivation rates (residual density under detection limit, 2 CFU mL−1) were achieved with H2O2/TiO2/sunlight (cumulative energy per unit of volume (QUV) in the range 3–5 kJ L−1, depending on H2O2/TiO2 ratio) and H2O2/sunlight (QUV of 8 kJ L−1) processes. All investigated processes did not affect antibiotic resistance of survived colonies. Moreover, H2O2/sunlight was compared with conventional chlorination process to evaluate bacterial regrowth potential and particularly the proportion of indigenous MDR E. coli with respect to total indigenous E. coli population. Chlorination (1.0 mg Cl2 L−1) was more effective than H2O2/sunlight (50 mg H2O2 L−1) to achieve total inactivation of MDR E. coli (15 min Vs 90 min) but less effective in controlling their regrowth (24 h Vs 48 h). Interestingly, the percentage of MDR E. coli in H2O2/sunlight treated samples decreased as incubation time increased; the opposite was observed for chlorinated samples.