TRATAMIENTO ELECTROQUÍMICO DE DISOLUCIONES DE TINTURAS OBTENIDAS A PARTIR DE LA MEZCLA DE COLORANTES REACTIVOS BIFUNCIONALES HIDROLIZADOS

ELECTROCHEMICAL TREATMENT OF DYE DISSOLUTIONS OBTAINED FROM THE MIXTURE OF HYDROLYZED BIFUNCTIONAL REACTIVE DYES In this Doctoral Thesis the degradation of the three reactive dyestuffs that make up the Tricromia Procion HEXL is studied by applying the oxidation-reduction electrochemical treatment to 125mA/cm2 in a filter-press cell using a stainless steel cathode, and as anode, an Ti / SnO2-Sb-Pt type DSA electrode are used. The degree of decolorization / mineralization is evaluated by Total Organic Carbon (TOC), Total Nitrogen (TN) and Chemical Oxygen Demand (COD), data that also allow us to know Average Oxidation State (AOS) at the end of each as well as information on the efficiency in each case through the Carbon Oxidation State (COS), State of Average Oxidation (EOP), Instantaneous Currente Efficiency (ICE) and Average Current Efficiency (ACE). The kinetics of discoloration and the evolution of the generated intermediates have been studied through measurements of High Resolution Liquid Chromatography (HPLC). The spectra obtained through UV-Visible Spectroscopy and FTIR allows us to follow the discoloration from the initial and final state of the solutions after the electrolysis. The main objective is to obtain discolored water with organic matter contents significantly lower than the initial values and to study the possibility of reuse of these purified waste water in subsequent dyeing processes. In this first part of the work we studied the electrochemical treatment for the degradation of these dyes using solutions with the hydrolyzed dyes. Na2SO4 is used as electrolyte. Next, we study the degradation and electrochemical behavior of baths containing the dyes: Procion Yellow HEXL, Procion Crimson HEXL and Procion Navy HEXL after the dyeing of cotton fabrics. Dyes are made at the laboratory level, subsequently the waters resulting from these dye baths are subjected to an electrochemical oxidation-reduction treatment at 125mA / cm2 in a filter-press cell. Proceed to study and to verify that these treated waters can be reused in later dyes obtaining acceptable values of equalization in the dyed tissues. We perform a color equalization study of the cotton fabrics tinted with the dyes of the Tricromia Procion HEXL, using solutions with different proportions of distilled water and recovery water and verify the equalization of the same, the data that we obtain from this study indicate us that good results are obtained from mixtures of 70% recovery water and 30% water. The color differences obtained in the fabrics dyed in the reuses are below the maximum limit of acceptance of color differences in the textile industry, which is one unit (DECMC(2:1) ¿ 1). Subsequently we study the degradation and mineralization of the bath resulting from the dyeing of cotton fabrics at the laboratory level with a mixture of the colorants the Tricromia Procion HEXL using NaCl as electrolyte by subjecting these baths to a treatment Oxide-reduction electrochemical at 125mA/cm2 in a filter-press cell. In all cases a decrease of COD, TOC and TN is obtained, AOS and COS data indicate that the oxidation state of Carbon in all solutions increases, the ACE and COS results show that the process takes place in a way efficient. The discoloration kinetics of all processes correspond to pseudo-first order, UV-Visible spectroscopy reveals that the bands corresponding to the chromophore group of the dyes are eliminated. This treatment of successive dyes and discolorations could be a viable alternative in the purification of actual textile effluents containing this type of dyes.TRATAMIENTO ELECTROQUÍMICO DE DISOLUCIONES DE TINTURAS OBTENIDAS A PARTIR DE LA MEZCLA DE COLORANTES REACTIVOS BIFUNCIONALES HIDROLIZADOS Se estudia la degradación de los tres colorantes reactivos bifuncionales que componen la Tricromía Procion HEXL mediante la aplicación del tratamiento electroquímico de óxido-reducción a 125mA/cm2 en una célula filtro-prensa empleando un cátodo de acero inoxidable, y como ánodo se utiliza un electrodo tipo DSA de Ti/SnO2-Sb-Pt. Se evalúa el grado de decoloración/mineralización mediante medidas de Carbono Orgánico Total (COT), Nitrógeno Total (TN) y Demanda Química de Oxigeno (DQO), datos que además nos permiten conocer el Estado de Oxidación Promedio (EOP) al final de cada electrolisis, así como información de la eficiencia en cada caso a través del Estado de Oxidación del Carbono (EOC), Eficiencia en Corriente Instantanea (ECI) y Eficiencia en Corriente Promedio (ECP). La cinética de decoloración y la evolución de los intermedios generados se han estudiado a través medidas de Cromatografía Liquida de Alta Resolución (HPLC). Los espectros obtenidos a través de Espectroscopia UV-Visible y FTIR nos permiten hacer un seguimiento de la decoloración desde el estado inicial y final de las disoluciones tras la electrolisis. El objetivo principal es obtener aguas decoloradas con contenidos en materia orgánica sensiblemente inferiores a los valores iniciales y estudiar la posibilidad de reutilización de esas aguas residuales depuradas en posteriores procesos de tintura. En la primera parte del trabajo se estudió el tratamiento electroquímico para la degradación de estos colorantes empleando disoluciones con los colorantes hidrolizados. Se utiliza Na2SO4 como electrolito. Seguidamente se estudia la degradación y comportamiento electroquímico de baños que contienen los colorantes: Procion Yellow HEXL, Procion Crimson HEXL y Procion Navy HEXL tras la tintura de tejidos de algodón. Se realizan tinturas a nivel de laboratorio, posteriormente las aguas resultantes de estos baños de tintura se someten a un tratamiento electroquímico de óxido-reducción a 125mA/ cm2 en una célula filtro-prensa. Se procede a estudiar y verificar que estas aguas tratadas pueden ser reutilizadas en posteriores tinturas obteniendo valores aceptables de igualación en los tejidos teñidos. Se realiza un estudio de igualación del color de los tejidos de algodón tintados con los colorantes de la Tricromía Procion HEXL, utilizando disoluciones con distintas proporciones de agua destilada y agua de recuperación y comprobando la igualación de las mismas, los datos obtenidos en este estudio nos indican que se consiguen buenos resultados a partir de mezclas de 70% agua de recuperación y 30% agua. Las diferencias de color obtenidas en los tejidos tintados en cuatro reutilizaciones son inferiores al límite máximo de aceptación de diferencias de color en la industria textil, que es de una unidad (DECMC(2:1) ¿ 1). Posteriormente hemos estudiado la degradación y mineralización del baño resultante de la tintura de tejidos de algodón a nivel de laboratorio con una mezcla de los colorantes de la Tricromía Procion HEXL utilizando NaCl como electrolito al someterlos a un tratamiento electroquímico de óxido-reducción a 125mA/ cm2 en una célula filtro-prensa. En todos los casos se obtiene una disminución de DQO, COT y TN, los datos de EOP y EOC nos indican que aumenta el Estado de Oxidación del Carbono en todas las disoluciones, los resultados de ECP y EOC demuestran que el proceso tiene lugar de forma eficiente. La cinética de decoloración de todos los procesos corresponde a pseudo-primer orden, la espectroscopia UV-Visible revela que las bandas correspondientes al grupo cromóforo de los colorantes son eliminadas. Este tratamiento de sucesivas tinturas y decoloraciones podría ser una alternativa viable en la depuración de efluentes textiles reales que contienen esTRACTAMENT ELECTROQUÍMIC DE DISSOLUCIONS DE TINTURES OBTINGUDES A PARTIR DE LA MESCLA DE COLORANTS REACTIUS BIFUNCIONALES HIDROLITZATS En la present Tesi Doctoral s'estudia la degradació dels tres colorants reactius bifuncionals que componen la Tricromia Procion HEXL mitjançant l'aplicació del tractament electroquímic d'òxid-reducció a 125mA/cm2 en una cèl¿lula filtre-premsa emprant un càtode d'acer inoxidable, i com a ànode s'utilitza un elèctrode tipus DSA de Ti/SnO2-Sb-Pt. S'avalua el grau de decoloració/mineralització mitjantçant mesures de Carboni Orgànic Total (COT), Nitrogen Total (TN) i Demanda Química d'Oxigen (DQO), dades que a més ens permeten conéixer l'Estat d'Oxidació Mitjana (EOM) al final de cada electròlisi, així com informació de l'eficiència en cada cas a través de l'Estat d'Oxidació del Carboni (EOC) , Eficiència en Corrent Instantània (ECI) i Eficiència en Corrent Mitjana (ECM). La cinètica de decoloració i l'evolució dels intermedis generats s'han estudiat a través de mesures de Cromatografia Liquida d'Alta Resolució (HPLC). Els espectres obtinguts a través d'Espectroscòpia UV-Visible i FTIR ens permet fer un seguiment de la decoloració des de l'estat inicial i final de les dissolucions després de l'electròlisi. L'objectiu principal és obtindre aigües decolorades amb continguts en matèria orgànica sensiblement inferiors als valors inicials i estudiar la possibilitat de reutilització d'eixes aigües residuals depurades en posteriors processos de tintura. A la primera part del treball es va estudiar el tractament electroquímic per a la degradació d'estos colorants emprant dissolucions amb els colorants hidrolitzats. S¿utilitza Na2SO4 com electròlit. A continuació s'estudia la degradació i comportament electroquímic de banys que contenen els colorants: Procion Yellow HEXL, Procion Crimson HEXL i Procion Navy HEXL després de la tintura de teixits de cotó. Es realitzen tintures a nivell de laboratori, posteriorment les aigües resultants d'estos banys de tintura se sotmeten a un tractament electroquímic d'òxid-reducció a 125mA/cm2 en una cèl¿lula filtre-premsa. Procedim a estudiar i verificar que estes aigües tractades poden ser reutilitzades en posteriors tintures aconseguint valors acceptables d'igualació en els teixits tenyits. Es realitza un estudi d'igualació del color dels teixits de cotó tintats amb els colorants de la Tricromia Procion HEXL, utilitzant dissolucions amb distintes proporcions d'aigua destil¿lada i aigua de recuperació i comprovant la igualació de les mateixes, les dades obtingudes en este estudi ens indiquen que s¿aconsegueixen bons resultats a partir de mescles de 70% aigua de recuperació i 30% aigua. Les diferències de color obtingudes en els teixits tintats en les quatre reutilitzacions són inferiors al límit màxim d'acceptació de diferències de color en la indústria tèxtil que és d'una unitat (DECMC(2:1) ¿ 1). Posteriorment hem estudiat la degradació i mineralització del bany resultant de la tintura de teixits de cotó a nivell de laboratori amb una mescla dels colorants de la Tricromia Procion HEXL, utilitzant NaCl com a electròlit al sotmetre'ls a un tractament electroquímic d'òxid-reducció a 125mA/cm2 en una cèl¿lula filtre-premsa. En tots els casos s'obté una disminució de DQO, COT i TN, les dades d'EOP i EOC ens indiquen que augmenta l'estat d'Oxidació del Carboni en totes les dissolucions, els resultats d'ECP i EOC demostren que el procés té lloc de forma eficient. La cinètica de decoloració de tots els processos correspon a pseudo-primer ordre, l'espectroscòpia UV-Visible revela que les bandes corresponents al grup cromóforo dels colorants són eliminades. Este tractament de successives tintures i decoloracions podria ser una alternativa viable en la depuració d'efluents tèxtils reals que contenen este tipus de colorants.Orts Maiques, FJ. (2017). TRATAMIENTO ELECTROQUÍMICO DE DISOLUCIONES DE TINTURAS OBTENIDAS A PARTIR DE LA MEZCLA DE COLORANTES REACTIVOS BIFUNCIONALES HIDROLIZADOS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86153TESI

On the behaviour of Atrazine removal from water using fabrics as anodes and Cathodes

[EN] This study examines the degradation of atrazine (ATZ) with Pt-modified textile electrodes using an electrochemical method that is comparatively studied in two electrochemical cell configurations: cells with separated anodic and cathodic compartments (divided configuration); and without any separation (undivided configuration). The influence of the presence of chloride ions was studied. The best results were obtained when an undivided cell was used. The morphology and composition of the dispersed Pt coatings were analyzed using field emission scanning electron microscopy (FESEM) and Energy Dispersive X-Ray Analysis. The FESEM analyses confirmed that the textile surface was effectively modified by the electrocatalytic material. High performance liquid chromatography, gas chromatography mass spectrometry, and spectroscopic methods were used to follow the evolution of major oxidation products. Total organic carbon, chemical oxygen demand, and total nitrogen were used to evaluate the degradation efficiency of treated aqueous solutions. The experimental results obtained indicate that the efficiency of the electrochemical treatment was high with a low energy consumption when using electrodes based on textile materials, such as anodes or as cathodes (in particular, in electrolysis without compartment separation). All these can be produced at very competitive pricesSpanish Agencia Estatal de Investigacion (AEI) and European Union (FEDER funds) are acknowledged for the financial support (contracts MAT 2016-77742-C2-1-P and CTQ 2017-90659-RED). Chemviron Carbon who kindly donated the FlexzorbTM FM10 activated carbon fabrics and Funding for open access charge, CRUE-Universitat Politècnica de València, are acknowledged tooHamous, H.; Khenifi, A.; Orts Maiques, FJ.; Bonastre Cano, JA.; Cases, F. (2022). On the behaviour of Atrazine removal from water using fabrics as anodes and Cathodes. Chemosphere. 291(Part 1):1-8. https://doi.org/10.1016/j.chemosphere.2021.132738S18291Part

Study of the Reuse of Industrial Wastewater After Electrochemical Treatment of Textile Effluents without External Addition of Chloride

[EN] The interference of human beings in the environment is causing rapid intense environmental damage which is particularly evident in the depletion of natural resources. Research into powerful practical treatments to decolorize and degrade colored textile wastewater is an important challenge nowadays for the textile industry due to environmental considerations, along with the potential water saving. It has been verified, in previous studies, that electrochemical oxidation-reduction treatment with doped SnO2 anodes was effective. In particular, those belonging to a trychromy (mix of three reactive dyes) achieved a significant reduction in Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC), as well as the decolorization of the treated solutions. Subsequently, the next step is to proceed to study and verify that these treated waters can be reused in subsequent dyes and that acceptable values of color equalization in the dyed fabrics can be achieved. The color differences obtained in the dyed fabrics in the four studied reuses are below the threshold of acceptance of color differences in the textile industry, which is one unit. The only electrolyte used was sodium sulphate. Chloride was not added externally in order to avoid as far as possible indirect oxidation. This allows a true test of the electrooxidantion power of the anodes. In these conditions, the Ti/SnO2-Sb-Pt DSA electrode is stable. The degree of mineralization is evaluated by measurements of TOC and COD. These data also allow the Average Oxidation State (AOS) at the end of each electrolysis, as well as information on the efficiency in each case through the Carbon Oxidation State (COS) and Average Current Efficiency (ACE) to be established. High Performance Liquid Chromatography (HPLC) was used to study the decolorization kinetics and the evolution of the generated intermediates. Comparison of the spectra obtained by UV-Visible Spectroscopy allows the decolorization from the initial state to the end of the electrolysis to be monitored.The authors wish to thank the Spanish Agencia Estatal de Investigación (AEI) and European Union (FEDER funds) for the financial support (contract MAT2016-77742-C2-1-P). The authors wish to acknowledge Tim Vickers for help with the English revision and Texcoy S.L. company (Spain) where the dyeing processes were done.Orts Maiques, FJ.; Del Río García, AI.; Molina Puerto, J.; Bonastre Cano, JA.; Cases, F. (2019). Study of the Reuse of Industrial Wastewater After Electrochemical Treatment of Textile Effluents without External Addition of Chloride. International Journal of Electrochemical Science. 14(2):1733-1750. https://doi.org/10.20964/2019.02.27S1733175014

Electrochemical treatment of real textile wastewater: Trichromy Procion HEXL

[EN] The electrochemical treatment of wastewaters from the textile industry is a promising technique for not easily biodegradable compounds. This work is aimed at studying the electrochemical degradation of bifunctional reactive dyes after a real dyeing process. These are: Procion Yellow HELX®, Procion Crimson HELX® and Procion Navy HELX®, which are widely used in dyeing processes of cellulose fibers. Their structure is mainly characterized by the presence of two azo groups as chromophore group and two monochlorotriazinic groups as reactive groups. Electrolyses were carried out under galvanostatic conditions in an undivided electrolytic cell. Ti/SnO2-Sb-Pt and stainless steel electrodes were used as anode and cathode, respectively. In all cases Na2SO4 was used as electrolyte without external addition of chloride. The degree of degradation was evaluated by means of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) measurements. The decolourization kinetics and the presence of the intermediates generated due to of the electrochemical treatment were studied by High Performance Liquid Chromatography (HPLC) and these studies were also carried out with UV¿Visible and Fourier Transform Infrared (FTIR) Spectroscopies. In all cases, a decrease in TOC and COD, and a complete decolourization were obtained after the electrochemical treatment. AOS and COS data proved the presence of oxidised intermediates in solution after the electrolyses. These results suggest the possibility of reusing the treated water in several dyeing processes.The authors wish to thank the Spanish Agencia Estatal de Investigacion (AEI) and European Union (FEDER funds) for the financial support (contract MAT2016-77742-C2-1-P). A.I. del Rio is grateful to the Spanish Ministerio de Ciencia y Tecnologia for her FPI fellowship. J. Molina is grateful to the Conselleria d'Educacio, Formacio i Ocupacio (Generalitat Valenciana) for the Programa VALi + D Postdoctoral Fellowship (APOSTD/2013/056). The authors wish to acknowledge to the Texcoy S.L. company (Spain) where the dyeing processes were done and Tim Vickers for help with the English revision.Orts Maiques, FJ.; Del Río García, AI.; Molina Puerto, J.; Bonastre Cano, JA.; Cases, F. (2018). Electrochemical treatment of real textile wastewater: Trichromy Procion HEXL. Journal of Electroanalytical Chemistry. 808:387-394. doi:10.1016/j.jelechem.2017.06.051S38739480

Electrochemical treatment of bifunctional dyes in a filter press reactor

[EN] In the present work, the electrochemical treatment of reactive bifunctional dyes is investigated. The selected dyes correspond to the tricromy HEXL. These dyes present two azo groups as chromophore groups and two monochlorotriazinic groups as reactive groups. This study has been carried out in two parts: in the fi rst part, synthetic solutions containing just one of these dyes, Procion HEXL, were studied (Solution (1)). Previous investigations have demonstrated that the best process to carry out this study is the oxidoreduction at 125 mA cm-2. Following to this fi rst part, the same study in the same working conditions was performed with solutions containing the three dyes of the tricromy H-EXL (Procion Yellow HEXL, Procion Crimson HEXL and Procion Navy HEXL). In this last case, the concentrations were selected considering the concentrations found in real effluents. In order to evaluate the decoloration/mineralization obtained, Total Organic Carbon (TOC) and the Chemical Oxygen Demand (COD) were measured. These parameters allowed to know the Average Oxidation State (AOS) after each electrolysis and the effi ciency at which the process takes place by means of calculating the Carbon Oxidation State (COS) and The Average Current Effi ciency (ACE). The UV-Visible spectroscopy permitted to observe the decoloration differences between the initial and fi nal stage. Moreover, the High Performance Liquid Chromatography (HPLC) gave information about the intermediates generated as well as the decoloration kinetics.[ES] En el presente trabajo se ha investigado el comportamiento electroquímico de colorantes reactivos bifuncionales. Los colorantes seleccionados son los correspondientes a la tricromía HEXL. Estos colorantes presentan dos grupos azo como cromóforos y dos grupos monoclorotriazínico como grupos reactivos. El estudio consta de dos partes: inicialmente, se han estudiado disoluciones sintéticas que contienen únicamente uno de estos colorantes, el Procion Yellow HEXL (Disolución 1). Investigaciones anteriores han demostrado que el proceso de oxido-reducción a 125 mA cm-2 es el que presenta mejores resultados. Posteriormente, se trasladó este estudio, en las mismas condiciones de trabajo, a disoluciones que contienen una mezcla de los tres colorantes correspondientes a la tricromía HEXL (Procion Yellow HEXL , Procion Crimson HEXL y Procion Navy HEXL) adaptando las concentraciones a condiciones reales (Disolución 2). Esta investigación se ha centrado en evaluar el grado de decoloración/mineralización mediante medidas de Carbono Orgánico Total (COT) y Demanda Química de Oxígeno (DQO). Esto ha permitido conocer el Estado de Oxidación Promedio (EOP) tras cada electrólisis además de la eficiencia en cada caso mediante análisis del Estado de Oxidación del Carbono (EOC) y Eficiencia en Corriente Promedio (ECP). La Espectroscopía UV-Visible ha permitido observar las diferencias de decoloración entre el estado inicial y final en todos los casos. Además, la Cromatografía Líquida de Alta Resolución (HPLC) ha permitido conocer la evolución de los intermedios generados así como la cinética de decoloración.Los autores desean agradecer agradecimiento al Ministerio de Ciencia e Innovación y los Fondos de la Unión Europea (FEDER) la financiación proporcionada (CTM2010-18842-C02-02 y CTM 2011-23583).Del Río García, AI.; Orts Maiques, FJ.; Molina Puerto, J.; Bonastre Cano, JA.; Cases Iborra, FJ. (2012). Tratamiento electroquímico de colorantes bifuncionales tipo Hexl en una célula filtro prensa. DYNA: Ingeniería e Industria. 87(6):679-688. https://doi.org/10.6036/4682S67968887

Carbon textiles electrodes modified with RGO and Pt nanoparticles used for electrochemical treatment of azo dye.

[EN] The efficiency of Orange G (OG) azo dye degradation using an electrochemical method under potentiostatic conditions has been comparatively studied in two electrolytic cells (divided and undivided cells) in the presence or absence of chloride ions with Pt-modified textile electrodes. The morphology of the carbon-based electrodes with nanoparticles of platinum electrochemically dispersed on their surface was analyzed using field emission scanning electron microscopy (FESEM) and EDX analysis. The FESEM analyses confirmed that the textile surface was coated by Pt nanoparticles. According to the experimental results obtained, when the same solutions are comparatively treated with the two cells, the undivided cell always gives a quicker decolorization than the divided cell ? and the decrease in total organic carbon (TOC), chemical oxygen demand (COD), and total nitrogen (TN) confirms this result. The degree of OG removal was monitored by spectroscopic methods and high-performance liquid chromatography (HPLC). The results indicate that that full best dye removal is obtained at a loaded charge of around 0.17 Ah L?1 which is associated with an electrical energy per order (EEO) of 0.189 kW h m?3 order?1. Based on the results obtained, the electrochemical process with TCRGO-Pt electrodes could be useful as a pretreatment technique or treatment for decolorizing wastewaters containing dyes.The authors wish to thank the Spanish Agencia Estatal de Investigaci?n (AEI) and European Union (FEDER funds) for the financial support (contract MAT2016-77742-C2-1-P) and Chemviron Carbon who kindly donated the FlexzorbTM FM10 activated carbon fabrics. The invitation by the E3TECH Spanish Network of Excellence (CTQ2017-90659-REDT (MEIC/AEI) ) is kindly acknowledgedHamous, H.; Khenifi, A.; Orts Maiques, FJ.; Bonastre Cano, JA.; Cases, F. (2021). Carbon textiles electrodes modified with RGO and Pt nanoparticles used for electrochemical treatment of azo dye. Journal of Electroanalytical Chemistry. 887:1-10. https://doi.org/10.1016/j.jelechem.2021.115154S11088