This page has only limited features, please log in for full access.
This work studied the removal of phenol from industrial effluents through catalytic ozonation in the presence of granular activated carbon in a continuous fixed-bed reactor. Phenol was chosen as model pollutant because of its environmental impact and high toxicity. Based on the evolution of total organic carbon (TOC) and phenol concentration, a kinetic model was proposed to study the effect of the operational variables on the combined adsorption–oxidation (Ad/Ox) process. The proposed three-phase model expressed the oxidation phenomena in the liquid and the adsorption and oxidation on the surface of the granular activated carbon in the form of two kinetic constants, k1 and k2 respectively. The interpretation of the constants allow to study the benefits and behaviour of the use of activated carbon during the ozonisation process under different conditions affecting adsorption, oxidation, and mass transfer. Additionally, the calculated kinetic parameters helped to explain the observed changes in treatment efficiency. The results showed that phenol would be completely removed at an effective contact time of 3.71 min, operating at an alkaline pH of 11.0 and an ozone gas concentration of 19.0 mg L−1. Under these conditions, a 97.0% decrease in the initial total organic carbon was observed.
Cristian Ferreiro; Ana de Luis; Natalia Villota; Jose María Lomas; José Ignacio Lombraña; Luis Miguel Camarero. Application of a Combined Adsorption−Ozonation Process for Phenolic Wastewater Treatment in a Continuous Fixed-Bed Reactor. Catalysts 2021, 11, 1014 .
AMA StyleCristian Ferreiro, Ana de Luis, Natalia Villota, Jose María Lomas, José Ignacio Lombraña, Luis Miguel Camarero. Application of a Combined Adsorption−Ozonation Process for Phenolic Wastewater Treatment in a Continuous Fixed-Bed Reactor. Catalysts. 2021; 11 (8):1014.
Chicago/Turabian StyleCristian Ferreiro; Ana de Luis; Natalia Villota; Jose María Lomas; José Ignacio Lombraña; Luis Miguel Camarero. 2021. "Application of a Combined Adsorption−Ozonation Process for Phenolic Wastewater Treatment in a Continuous Fixed-Bed Reactor." Catalysts 11, no. 8: 1014.
The objective of this study is to evaluate the turbidity generated during the Fenton photo-reaction applied to the oxidation of waters containing carbamazepine as a function of factors such as pH, H2O2 concentration and catalyst dosage. The results let establish the degradation pathways and the main decomposition byproducts. It is found that the pH affects the turbidity of the water. Working between pH = 2.0 and 2.5, the turbidity is under 1 NTU due to the fact that iron, added as a catalyst, is in the form of a ferrous ion. Operating at pH values above 3.0, the iron species in their oxidized state (mainly ferric hydroxide in suspension) would cause turbidity. The contribution of these ferric species is a function of the concentration of iron added to the process, verifying that the turbidity increases linearly according to a ratio of 0.616 NTU L/mg Fe. Performing with oxidant concentrations at (H2O2) = 2.0 mM, the turbidity undergoes a strong increase until reaching values around 98 NTU in the steady state. High turbidity levels can be originated by the formation of coordination complexes, consisting of the union of three molecules containing substituted carboxylic groups (BaQD), which act as ligands towards an iron atom with Fe3+ oxidation state.
Natalia Villota; Cristian Ferreiro; Hussein Qulatein; Jose Lomas; Jose Lombraña. Turbidity Changes during Carbamazepine Oxidation by Photo-Fenton. Catalysts 2021, 11, 894 .
AMA StyleNatalia Villota, Cristian Ferreiro, Hussein Qulatein, Jose Lomas, Jose Lombraña. Turbidity Changes during Carbamazepine Oxidation by Photo-Fenton. Catalysts. 2021; 11 (8):894.
Chicago/Turabian StyleNatalia Villota; Cristian Ferreiro; Hussein Qulatein; Jose Lomas; Jose Lombraña. 2021. "Turbidity Changes during Carbamazepine Oxidation by Photo-Fenton." Catalysts 11, no. 8: 894.
The oxidation of aqueous solutions of carbamazepine is conducted using the Fenton reagent, combined with the photolytic action of a 150 W medium pressure UV lamp, operating at T = 40 °C. The effect of acidity is analysed at an interval pH = 2.0–5.0, verifying that operating at pH = 5.0 promotes colour formation (Colour = 0.15 AU). The effect of iron is studied, finding that the colour of the water increases in a linear way, Colour = 0.05 + 0.0075 [Fe]0. The oxidising action of hydrogen peroxide is tested, confirming that when operating with [H2O2]0 = 2.0 mM, the maximum colour is generated (Colourmax = 0.381 AU). The tint would be generated by the degradation of by-products of carbamazepine, which have chromophoric groups in their internal structure, such as oxo and dioxocarbazepines, which would produce tint along the first minutes of oxidation, while the formation of acridones would slowly induce colour in the water.
Natalia Villota; Cristian Ferreiro; Hussein Qulatein; Jose Lomas; Luis Camarero; José Lombraña. Colour Changes during the Carbamazepine Oxidation by Photo-Fenton. Catalysts 2021, 11, 386 .
AMA StyleNatalia Villota, Cristian Ferreiro, Hussein Qulatein, Jose Lomas, Luis Camarero, José Lombraña. Colour Changes during the Carbamazepine Oxidation by Photo-Fenton. Catalysts. 2021; 11 (3):386.
Chicago/Turabian StyleNatalia Villota; Cristian Ferreiro; Hussein Qulatein; Jose Lomas; Luis Camarero; José Lombraña. 2021. "Colour Changes during the Carbamazepine Oxidation by Photo-Fenton." Catalysts 11, no. 3: 386.
The water–development nexus is essential for the advancement and progress of cities in the face of problems such as climate change, water security and increasing environmental stress in the agricultural sector. Aiming for a circular economy and, at the same time, improving the resilience of water supply alternatives and achieving a goal of zero waste, this work presents a technical–economic study of a novel continuous ultrafiltration (c-UF) system with self-cleaning capacity coupled to an ozonation process, for the treatment of urban WWTP effluent. The removal efficiencies achieved were analysed both through macroscopic parameters (suspended solids, turbidity) and for the most frequently occurring contaminants of emerging concern (CECs). Consequently, an effluent suitable for irrigation was obtained, with a total recovery factor of 97.92%, a concentration of suspended solids (SS) below 1 mg L−1, 0.06 NTU turbidity and toxicity free, complying with the new European Regulation on Water Reuse (EU 2020/741). A comparative analysis of the proposed process with regard to conventional tertiary treatment revealed that the proposed process was 39.1% more economic, with a cost of 0.0325 € m−3. This alternative treatment will be of great interest because of its favourable technical–economic characteristics, being postulated as a basic process for implementation in modern water reuse plants.
Cristian Ferreiro; Natalia Villota; Ana de Luis; José Lombraña; Nestor Etxebarria; Jose Lomas. Water Reuse Study from Urban WWTPs via c-Ultrafiltration and Ozonation Technologies: Basis for Resilient Cities and Agriculture. Agronomy 2021, 11, 322 .
AMA StyleCristian Ferreiro, Natalia Villota, Ana de Luis, José Lombraña, Nestor Etxebarria, Jose Lomas. Water Reuse Study from Urban WWTPs via c-Ultrafiltration and Ozonation Technologies: Basis for Resilient Cities and Agriculture. Agronomy. 2021; 11 (2):322.
Chicago/Turabian StyleCristian Ferreiro; Natalia Villota; Ana de Luis; José Lombraña; Nestor Etxebarria; Jose Lomas. 2021. "Water Reuse Study from Urban WWTPs via c-Ultrafiltration and Ozonation Technologies: Basis for Resilient Cities and Agriculture." Agronomy 11, no. 2: 322.
This work aims to study the sustainable catalytic ozonation of aniline promoted by granular active carbon (GAC) doped with TiO2. Aniline was selected as a model compound for the accelerator manufacturing industries used in the manufacture of rubber due to its environmental impact, low biodegradability, and harmful genotoxic effects on human health. Based on the evolution of total organic carbon (TOC), aniline concentration measured using high performance liquid chromatography (HPLC), pH and ozone concentration in liquid and gas phase, and catalyst loading, a three-phase reaction system has been modelled. The proposed three-phase model related the ozone transfer parameters and the pseudo-first order kinetic constants through three coefficients that involve the adsorption process, oxidation in the liquid, and the solid catalyst. The interpretation of the kinetic constants of the process allowed the predominance of the mechanism of Langmuir–Hinshelwood or modified Eley–Rideal to be elucidated. Seven intermediate aromatic reaction products, representative of the direct action of ozone and the radical pathway, were identified and quantified, as well as precursors of the appearance of turbidity, with which two possible routes of degradation of aniline being proposed.
Cristian Ferreiro; Natalia Villota; José Ignacio Lombraña; María J. Rivero. Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC. Water 2020, 12, 3448 .
AMA StyleCristian Ferreiro, Natalia Villota, José Ignacio Lombraña, María J. Rivero. Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC. Water. 2020; 12 (12):3448.
Chicago/Turabian StyleCristian Ferreiro; Natalia Villota; José Ignacio Lombraña; María J. Rivero. 2020. "Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC." Water 12, no. 12: 3448.
This paper presents an intensification study of an ozonation process through an ultrasonic pre-treatment for the elimination of humic substances in water and thus, improve the quality of water treatment systems for human consumption. Humic acids were used as representative of natural organic matter in real waters which present low biodegradability and a high potential for trihalomethane formation. Ultrasonic frequency (98 kHz, 300 kHz and 1 MHz), power (10-40 W) and sonicated volume (150-400 mL) was varied to assess the efficiency of the ultrasonic pre-treatment in the subsequent ozonation process. A direct link between OH radical (●OH) formation and fluorescence reduction was observed during sonication pre-treatment, peaking at 300 kHz and maximum power density. Ultrasound, however, did not reduce total organic carbon (TOC). Injected O3 dose and reaction time were also evaluated during the ozonation treatment. With 300 kHz and 40 W ultrasonic pre-treatment and the subsequent ozonation step (7.4 mg O3/Lgas), TOC was reduced from 21 mg/L to 13.5 mg/L (36% reduction). ●OH attack seems to be the main degradation mechanism during ozonation. A strong reduction in colour (85%) and SUVA254 (70%) was also measured. Moreover, changes in the chemical structure of the macromolecule were observed that led to the formation of oxidation by-products of lower molecular weight.
Pello Alfonso-Muniozguren; Cristian Ferreiro; Elodie Richard; Madeleine Bussemaker; José Ignacio Lombraña; Judy Lee. Analysis of ultrasonic pre-treatment for the ozonation of humic acids. Ultrasonics Sonochemistry 2020, 71, 105359 .
AMA StylePello Alfonso-Muniozguren, Cristian Ferreiro, Elodie Richard, Madeleine Bussemaker, José Ignacio Lombraña, Judy Lee. Analysis of ultrasonic pre-treatment for the ozonation of humic acids. Ultrasonics Sonochemistry. 2020; 71 ():105359.
Chicago/Turabian StylePello Alfonso-Muniozguren; Cristian Ferreiro; Elodie Richard; Madeleine Bussemaker; José Ignacio Lombraña; Judy Lee. 2020. "Analysis of ultrasonic pre-treatment for the ozonation of humic acids." Ultrasonics Sonochemistry 71, no. : 105359.
Analysis of phenol ozonation using a G–L–S model: through mass transfer, chemical reaction and adsorption parameters.
Cristian Ferreiro; Natalia Villota; Ana de Luis; Jose Ignacio Lombraña. Analysis of the effect of the operational conditions in a combined adsorption–ozonation process with granular activated carbon for the treatment of phenol wastewater. Reaction Chemistry & Engineering 2020, 5, 760 -778.
AMA StyleCristian Ferreiro, Natalia Villota, Ana de Luis, Jose Ignacio Lombraña. Analysis of the effect of the operational conditions in a combined adsorption–ozonation process with granular activated carbon for the treatment of phenol wastewater. Reaction Chemistry & Engineering. 2020; 5 (4):760-778.
Chicago/Turabian StyleCristian Ferreiro; Natalia Villota; Ana de Luis; Jose Ignacio Lombraña. 2020. "Analysis of the effect of the operational conditions in a combined adsorption–ozonation process with granular activated carbon for the treatment of phenol wastewater." Reaction Chemistry & Engineering 5, no. 4: 760-778.
This work presents a case study of a wastewater treatment plant (WWTP), located in Biscay (Spain), in which the removal of high-occurrence contaminants of emerging concern (CEC) was studied. The existing biological treatment in the WWTP was complemented with a continuous ultrafiltration (c-UF) pilot plant, as a tertiary treatment. Thus, the effect on CEC removal of both treatments could be analyzed globally and after each operation. A total of 39 CEC were monitored, including pharmaceutical products, industrial additives, food additives, herbicides and personal care products. For evaluation of the efficiencies, the removal rates of the biological and of the c-UF treatments, including their variability over a day and a week in relation to the ammonium content, were examined in the influent of the WWTP. In the biological treatment, a wide range of different removal rates was obtained due to the different CEC’s biodegradability and concentration. In UF, lower, but more constant removal rates, were achieved. In addition, the reduction of the general toxicity by the UF treatment in terms of the Microtox® toxicity assay was also evaluated. After UF, all of the samples yielded values of TU50 lower than 1, confirming this result the UF effectiveness for toxicity removal.
Cristian Ferreiro; Iker Gómez-Motos; José Ignacio Lombraña; Ana De Luis; Natalia Villota; Oihana Ros; Nestor Etxebarria. Contaminants of Emerging Concern Removal in an Effluent of Wastewater Treatment Plant under Biological and Continuous Mode Ultrafiltration Treatment. Sustainability 2020, 12, 725 .
AMA StyleCristian Ferreiro, Iker Gómez-Motos, José Ignacio Lombraña, Ana De Luis, Natalia Villota, Oihana Ros, Nestor Etxebarria. Contaminants of Emerging Concern Removal in an Effluent of Wastewater Treatment Plant under Biological and Continuous Mode Ultrafiltration Treatment. Sustainability. 2020; 12 (2):725.
Chicago/Turabian StyleCristian Ferreiro; Iker Gómez-Motos; José Ignacio Lombraña; Ana De Luis; Natalia Villota; Oihana Ros; Nestor Etxebarria. 2020. "Contaminants of Emerging Concern Removal in an Effluent of Wastewater Treatment Plant under Biological and Continuous Mode Ultrafiltration Treatment." Sustainability 12, no. 2: 725.
Alginate microcapsules containing cell yeasts of the species Saccharomyces cerivisae, were studied to improve the protection of cell activity during drying. Dehydration is a common operation to stabilize microencapsulated microorganisms. Here, a promising process using microwaves on a particle bed under near fluidizing conditions (NFMD) was proposed. The dehydration of microcapsules by NFMD allows performing dehydration employing lower temperatures with high survival levels of dried microorganism cells and a high quality end product. Different thermal gradients and processing temperatures of NFMD were analyzed to select the most adequate operating strategy. The obtained results were compared to those obtained by freeze-drying, assumed as reference quality drying process. The results showed that the encapsulation system, joined with the selection of favorable conditions during dehydration by NFMD, allows a post drying viability higher than 90%, with an adequate control of the process temperature. To obtain the best results regarding both, the duration of drying and quality, product temperatures of about 30 °C in the microcapsules and 5–20 °C in the air are recommended.
Janire Mardaras; José Ignacio Lombraña; María Carmen Villarán. Effect of the thermal level on the viability of microencapsulated living cells dehydrated by near fluidizing microwave drying. Drying Technology 2019, 39, 219 -233.
AMA StyleJanire Mardaras, José Ignacio Lombraña, María Carmen Villarán. Effect of the thermal level on the viability of microencapsulated living cells dehydrated by near fluidizing microwave drying. Drying Technology. 2019; 39 (2):219-233.
Chicago/Turabian StyleJanire Mardaras; José Ignacio Lombraña; María Carmen Villarán. 2019. "Effect of the thermal level on the viability of microencapsulated living cells dehydrated by near fluidizing microwave drying." Drying Technology 39, no. 2: 219-233.
This work presents an efficient catalytic ozonation process for the treatment of aniline wastewater as a model pollutant. The process uses a granular activated carbon-supported titanium dioxide catalyst with environmentally-friendly and sustainable characteristics. Titanium dioxide composites were prepared by precipitation of alcoholic titanium tetrachloride solutions on two different carbon supports: Norit® GAC 1240 Plus and Norit® ROX 0.8. This method is an improvement on other composite preparation methods such as hydrothermal and impregnation by immersion techniques, which were also carried out for comparison. It characterised our composites by Brunauer–Emmett–Teller analysis, scanning electron microscopy-energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy to assess the influence of the carbon support. Composites synthesised via this novel precipitation method presented a 25% increase in their initial specific surface area and a 9.1% increase in titanium dioxide loading. It compared the catalytic activity of the different titanium dioxide composites on different aniline solutions, and studied the optimal pH and ozone dose. Norit® GAC 1240 Plus-supported titanium dioxide composite prepared by the precipitation method gave the highest removal yield with 80.24% mineralisation of total organic carbon in 45 min. With respect to the costs associated with the treatment, the composite achieved a removal yield of 26.8 mg ozone/mg total organic carbon.
C. Ferreiro; N. Villota; J.I. Lombraña; María J. Rivero. An efficient catalytic process for the treatment of genotoxic aniline wastewater using a new granular activated carbon-supported titanium dioxide composite. Journal of Cleaner Production 2019, 228, 1282 -1295.
AMA StyleC. Ferreiro, N. Villota, J.I. Lombraña, María J. Rivero. An efficient catalytic process for the treatment of genotoxic aniline wastewater using a new granular activated carbon-supported titanium dioxide composite. Journal of Cleaner Production. 2019; 228 ():1282-1295.
Chicago/Turabian StyleC. Ferreiro; N. Villota; J.I. Lombraña; María J. Rivero. 2019. "An efficient catalytic process for the treatment of genotoxic aniline wastewater using a new granular activated carbon-supported titanium dioxide composite." Journal of Cleaner Production 228, no. : 1282-1295.
In this work, a study of the main operating variables affecting TiO2/UV photocatalysis was carried out. The treatment of an industrial effluent containing aniline and benzothiazole from the manufacture of accelerants for vulcanization was performed in a TiO2-supported commercial photoreactor. The degradation of both contaminants was monitored by GC-MS analysis. The proposed experiments were able to properly identify the phenomenon of adsorption, as well as to improve the performance of the commercial photoreactor by adding small amounts of TiO2 in suspension. The removal performance, durability of the photocatalytic material, and energy costs were analysed. The results showed that the use of suspensions intensifies the degradation obtaining an improvement of 23.15% with respect to the use of the supported catalyst. For an aniline and benzothiazole solution, the best operating conditions were found at pH = 12.0, introducing 60.0 mg L−1 of suspended TiO2 together with the existing supported catalyst.
Cristian Ferreiro; Natalia Villota; José Ignacio Lombraña; María J. Rivero; Verónica Zúñiga; José Miguel Rituerto. Analysis of a Hybrid Suspended-Supported Photocatalytic Reactor for the Treatment of Wastewater Containing Benzothiazole and Aniline. Water 2019, 11, 337 .
AMA StyleCristian Ferreiro, Natalia Villota, José Ignacio Lombraña, María J. Rivero, Verónica Zúñiga, José Miguel Rituerto. Analysis of a Hybrid Suspended-Supported Photocatalytic Reactor for the Treatment of Wastewater Containing Benzothiazole and Aniline. Water. 2019; 11 (2):337.
Chicago/Turabian StyleCristian Ferreiro; Natalia Villota; José Ignacio Lombraña; María J. Rivero; Verónica Zúñiga; José Miguel Rituerto. 2019. "Analysis of a Hybrid Suspended-Supported Photocatalytic Reactor for the Treatment of Wastewater Containing Benzothiazole and Aniline." Water 11, no. 2: 337.
Ozonation is an efficient process for the primary degradation of most substrates but not for their mineralisation. In this work, the ozonation enhanced with the addition of H2O2 was studied for two substrates with very different oxidation resistances: the dye rhodamine 6G (R6G) and the surfactant linear alkylbenzene sulfonate (LAS). With O3 only, the primary degradation of R6G was completed in less than 10 min but its TOC removal only reached 45% in 1 h. By adding H2O2, TOC removal was increased to 70% with a molar ratio (mol H2O2/mol substrate) of 10. The analysis of pH decrease served to define the specific basicity loss (SBL). The optimum conditions for the R6G mineralisation were found to be associated with a SBL value between 1 and 10 ((min/g)/L)−1, through an adequate addition of H2O2. Moreover, in the case of LAS, the addition of H2O2 for a greater efficiency should occur after the foaming period, above all formed at acid pH. LAS degradation was also considerably improved, and the optimum for primary degradation achieved in 10 min with a TOC removal of over 65% with a molar ratio (mol H2O2/mol substrate) of 20.
Ana De Luis; José Ignacio Lombraña. pH-Based Strategies for an Efficient Addition of H2O2 During Ozonation to Improve the Mineralisation of Two Contaminants with Different Degradation Resistances. Water, Air, & Soil Pollution 2018, 229, 372 .
AMA StyleAna De Luis, José Ignacio Lombraña. pH-Based Strategies for an Efficient Addition of H2O2 During Ozonation to Improve the Mineralisation of Two Contaminants with Different Degradation Resistances. Water, Air, & Soil Pollution. 2018; 229 (11):372.
Chicago/Turabian StyleAna De Luis; José Ignacio Lombraña. 2018. "pH-Based Strategies for an Efficient Addition of H2O2 During Ozonation to Improve the Mineralisation of Two Contaminants with Different Degradation Resistances." Water, Air, & Soil Pollution 229, no. 11: 372.
Janire Mardaras; José Ignacio Lombraña; María Carmen Villarán. Near-fluidizing microwave drying to stabilize encapsulated material: Analysis of kinetic, energy and quality elements. Drying Technology 2018, 37, 976 -987.
AMA StyleJanire Mardaras, José Ignacio Lombraña, María Carmen Villarán. Near-fluidizing microwave drying to stabilize encapsulated material: Analysis of kinetic, energy and quality elements. Drying Technology. 2018; 37 (8):976-987.
Chicago/Turabian StyleJanire Mardaras; José Ignacio Lombraña; María Carmen Villarán. 2018. "Near-fluidizing microwave drying to stabilize encapsulated material: Analysis of kinetic, energy and quality elements." Drying Technology 37, no. 8: 976-987.
BACKGROUNDThe advanced oxidation includes a high range of technologies, all of them appropriate to achieve environmental remediation. One of them is the organic compounds degradation by ozonation. The ozonation of rhodamine 6G (R6G) was investigated to study the effect of pH and subsequent predominance of the control stage, whether mass transfer from gas to liquid phase or chemical reaction, during oxidation. Several pH conditions are studied to achieve a greater efficiency of the process.RESULTSA mathematical model enables the analysis of the controlling stage. It was satisfactorily verified, showing that, initially, the process is controlled by the G-L mass transfer stage but, as the R6G ozonation progresses, the process becomes controlled by the kinetic reaction. While 99% of the rhodamine dye is removed during the mass transfer control stage regardless of the pH value, the percentage of TOC removal is only increased during the kinetic reaction control stage.CONCLUSIONThe most favourable pH, given the mass transfer characteristics of this case, was found to be an intermediate values around 6.0 where a minimum value for coefficient for R6G mineralization zav of about 23 mol O3/mol R6G mineralized, and near its theoretical value, was obtained.
Cristina Rodríguez; José Ignacio Lombraña; Ana De Luis; Josu Sanz. Oxidizing efficiency analysis of an ozonation process to degrade the dye rhodamine 6G. Journal of Chemical Technology & Biotechnology 2016, 92, 674 -683.
AMA StyleCristina Rodríguez, José Ignacio Lombraña, Ana De Luis, Josu Sanz. Oxidizing efficiency analysis of an ozonation process to degrade the dye rhodamine 6G. Journal of Chemical Technology & Biotechnology. 2016; 92 (3):674-683.
Chicago/Turabian StyleCristina Rodríguez; José Ignacio Lombraña; Ana De Luis; Josu Sanz. 2016. "Oxidizing efficiency analysis of an ozonation process to degrade the dye rhodamine 6G." Journal of Chemical Technology & Biotechnology 92, no. 3: 674-683.
Advanced oxidation processes (AOP) are able to degrade pollutants into harmless substances. To demonstrate the successful application of AOP to real, polluted effluents, ozonation has been applied for the removal of linear alkylbenzene sulfonates (LAS), a surfactant mixture commonly used in detergent formulation. LAS can be identified in a wide range of concentrations, i.e., in domestic wastewater or in the raw effluent of detergent-processing plants. The strongly tensoactive nature of LAS results in a foaming effect that eventually discourages AOP application, especially in the case of ozonation. The primary goal of this research is to analyze the LAS ozonation kinetics, considering the simultaneous effect of foam formation, by the development of a semiempirical model that is mainly based on the foaming phenomenon. Along with foaming, the proposed model also considers LAS removal by ozonation and the inverse phenomenon of LAS formation by redissolution of LAS. To the best of our knowledge, such a finding has not been previously reported. The proposed foaming model has been developed within various pH and LAS concentration values, primarily examining the initial pH value of the effluent due to its significant effect on foaming. The developed model adequately predicts the LAS concentration profiles measured in the liquid during ozonation. Moreover, this approach makes it possible to quantify the incidence of foaming and LAS redissolution during ozonation comparatively, leading to being able to propose the most desirable operating conditions for LAS removal.
Cristina Rodríguez; Ana De Luis; Jose Ignacio Lombraña; Josu Sanz. Kinetic Analysis of the Ozonation Process of the Surfactant LAS Considering the Simultaneous Foaming Effect. Journal of Surfactants and Detergents 2014, 17, 1229 -1239.
AMA StyleCristina Rodríguez, Ana De Luis, Jose Ignacio Lombraña, Josu Sanz. Kinetic Analysis of the Ozonation Process of the Surfactant LAS Considering the Simultaneous Foaming Effect. Journal of Surfactants and Detergents. 2014; 17 (6):1229-1239.
Chicago/Turabian StyleCristina Rodríguez; Ana De Luis; Jose Ignacio Lombraña; Josu Sanz. 2014. "Kinetic Analysis of the Ozonation Process of the Surfactant LAS Considering the Simultaneous Foaming Effect." Journal of Surfactants and Detergents 17, no. 6: 1229-1239.
This study demonstrates the importance of reaction temperature on the UV/H2O2 process. Oxidation reactions have been carried out on 1 g L−1 solutions of linear alkylbenzene sulphonates (LASs) in the range from ambient to 80 °C. Use of these conditions could be justified as they often represent the thermal conditions in which some polluted effluents are discharged. At an intermediate temperature of 60 °C and using small amounts of hydrogen peroxide LAS removal is significantly improved due to a more efficient use of the oxidant. This is mainly due to the enhancement of the radical reaction rate constant, as it does the quantum yield of the LAS. The use of more severe operating conditions, temperatures of 80 °C and high amounts of peroxide is necessary if the aim is to improve biodegradability. Only in that case intensified oxidation makes possible the removal of aromatic intermediates.
Josu Sanz; José Ignacio Lombraña; Ana de Luis. Temperature-assisted UV/H2O2 oxidation of concentrated linear alkylbenzene sulphonate (LAS) solutions. Chemical Engineering Journal 2012, 215-216, 533 -541.
AMA StyleJosu Sanz, José Ignacio Lombraña, Ana de Luis. Temperature-assisted UV/H2O2 oxidation of concentrated linear alkylbenzene sulphonate (LAS) solutions. Chemical Engineering Journal. 2012; 215-216 ():533-541.
Chicago/Turabian StyleJosu Sanz; José Ignacio Lombraña; Ana de Luis. 2012. "Temperature-assisted UV/H2O2 oxidation of concentrated linear alkylbenzene sulphonate (LAS) solutions." Chemical Engineering Journal 215-216, no. : 533-541.
A. M. De Luis; Jose Ignacio Lombraña; A. Menéndez; J. Sanz. Analysis of the Toxicity of Phenol Solutions Treated with H2O2/UV and H2O2/Fe Oxidative Systems. Industrial & Engineering Chemistry Research 2011, 50, 1928 -1937.
AMA StyleA. M. De Luis, Jose Ignacio Lombraña, A. Menéndez, J. Sanz. Analysis of the Toxicity of Phenol Solutions Treated with H2O2/UV and H2O2/Fe Oxidative Systems. Industrial & Engineering Chemistry Research. 2011; 50 (4):1928-1937.
Chicago/Turabian StyleA. M. De Luis; Jose Ignacio Lombraña; A. Menéndez; J. Sanz. 2011. "Analysis of the Toxicity of Phenol Solutions Treated with H2O2/UV and H2O2/Fe Oxidative Systems." Industrial & Engineering Chemistry Research 50, no. 4: 1928-1937.
The combination of H2O2 with UV radiation was applied to study the degradation of Rhodamine 6G dye (Rh-6G). The lumped kinetic model proposed in this work is a reaction-system scheme to describe the degradation of dye using lumps of intermediate compounds grouped by their chemical and colorimetric behavior. Rate constants obtained by application of the model were shown to predict the progress of dye oxidation. The effects of pH and oxidant dosage on these rate constants were also analyzed. Finally, photodecoloration was studied considering the absorption at 528 nm (the maximum absorption wavelength of the dye) as the sum of all compounds absorbing at this wavelength: Rhodamine itself and the colored intermediates produced.
Amaia Menendez; Jose Ignacio Lombraña; Ana De Luis. Lumped-intermediates analysis in the photooxidation of Rhodamine 6G in the H2O2/UV system. Korean Journal of Chemical Engineering 2011, 28, 388 -395.
AMA StyleAmaia Menendez, Jose Ignacio Lombraña, Ana De Luis. Lumped-intermediates analysis in the photooxidation of Rhodamine 6G in the H2O2/UV system. Korean Journal of Chemical Engineering. 2011; 28 (2):388-395.
Chicago/Turabian StyleAmaia Menendez; Jose Ignacio Lombraña; Ana De Luis. 2011. "Lumped-intermediates analysis in the photooxidation of Rhodamine 6G in the H2O2/UV system." Korean Journal of Chemical Engineering 28, no. 2: 388-395.
J.I. Lombraña; R. Rodríguez; U. Ruiz. Microwave-drying of sliced mushroom. Analysis of temperature control and pressure. Innovative Food Science & Emerging Technologies 2010, 11, 652 -660.
AMA StyleJ.I. Lombraña, R. Rodríguez, U. Ruiz. Microwave-drying of sliced mushroom. Analysis of temperature control and pressure. Innovative Food Science & Emerging Technologies. 2010; 11 (4):652-660.
Chicago/Turabian StyleJ.I. Lombraña; R. Rodríguez; U. Ruiz. 2010. "Microwave-drying of sliced mushroom. Analysis of temperature control and pressure." Innovative Food Science & Emerging Technologies 11, no. 4: 652-660.
The characterization of radical oxidation in the degradation of phenolic compounds with H2O2/UV has been studied. A kinetic model was developed to estimate the concentration of different radical species. Radical concentration defines a determined oxidative level whose changes are analyzed for different oxidizing conditions involving pH and hydrogen peroxide dosage. This study has been developed to extend a previous radical model, only for simple phenolic solutions, to phenolic mixtures consisting of phenol and different cresols. In a mixture, the effects of composition and total amount of phenolics have a great influence on the degradation of each compound markedly modifying the behavior found in a simple solution. The application of a new extended radicalary model requires the characterization of the phenolic mixture solution through two fundamental parameters. The first one is the equivalent phenol in the mixture or phenol concentration, which gives the same oxidative level as that of the mixture case. Besides, additional information must be considered to characterize the deviation of the radical level between each compound and the mixture through the corresponding coefficient of radicalary activity. The model has been applied and verified to estimate the degradation of the different phenolics of a mixture, whatever the composition of phenolics, with good fitting to the experimental data. © 2010 American Institute of Chemical Engineers Environ Prog, 2011
Ana De Luis; José Ignacio Lombraña; Amaia Menéndez. Modeling of the radicalary state in the H2O2/UV oxidation system to predict the degradation kinetics of phenolic mixture solutions. Environmental Progress & Sustainable Energy 2010, 30, 196 -207.
AMA StyleAna De Luis, José Ignacio Lombraña, Amaia Menéndez. Modeling of the radicalary state in the H2O2/UV oxidation system to predict the degradation kinetics of phenolic mixture solutions. Environmental Progress & Sustainable Energy. 2010; 30 (2):196-207.
Chicago/Turabian StyleAna De Luis; José Ignacio Lombraña; Amaia Menéndez. 2010. "Modeling of the radicalary state in the H2O2/UV oxidation system to predict the degradation kinetics of phenolic mixture solutions." Environmental Progress & Sustainable Energy 30, no. 2: 196-207.