CEL.LA UVEC per a la depuració d'aigües: una tecnologia neta per a l'eliminació de color

Peer Reviewe

Reciclado de aguas residuales textiles decoloradas con técnicas electroquímicas

En este trabajo se aborda la posibilidad de reciclar las aguas residuales textiles para su empleo en el proceso de tintura, previa eliminación del color causado por la presencia de colorantes reactivos mediante un tratamiento electroquímico con la celda ECO 75 (ELCHEM). También se describe detalladamente el funcionamiento y la estructura de esta celda. Se aplica el tratamiento electroquímico a la decoloración de diversas aguas residuales sintéticas. Se estudia el rendimiento de decoloración y el consumo eléctrico resultante. Posteriormente, se someten las aguas ya tratadas a un proceso de aereación para eliminar el cloro residual y se valoran los resultados obtenidos empleando dichas aguas en la tintura de algodón.This work deals with the possibility of recycling textile wastewater for use in the dyeing process. Until now, colour produced by the presence of reactive dyes was removed by means of an electrochemical treatment with cell ECO 75 (ELCHEM). The structure of the cell is described in detail. The electrochemical treatment is applied to the decolorisation of diverse synthetic wastewaters. Decolorisation yield and electrical consumption are studied. Later, treated waters are submitted to a stripping process in order to remove residual chlorine, and they are then employed for cotton dyeing. The dyed samples are compared.Ce travail étudie la possibilité de recycler les eaux résiduaires textiles pour les employer dans la teinture, après avoir éliminé la couleur due à la présence des colorants réactifs à l’aide d’un traitement électrochimique employant la cellule ECO 75 (ELCHEM). Le fonctionnement et la structure de cette cellule sont également décrits. Le traitement électrochimique est appliqué à la décoloration de diverses eaux résiduaires synthétiques. Le rendement de la décoloration et la consommation électrique sont étudiés. Postérieurement, les eaux traitées sont soumises à une aération pour enlever le chlore résiduaire et les résultats obtenus en employant ces eaux pour la teinture du coton sont discutés

Review on alternatives for the reduction of textile microfibers emission to water

The microplastics (MPs) are considered one of the most threatening pollutants. One of the main concerns is their continuous and cumulative flow to water environments, as they are very difficult to be removed. Microfibers (MFs) are a significant type of MPs, with textile articles as one of the most renowned sources. This review aims to provide the current status of these MFs as pollutants, discussing possible alternatives from the manufacturing until the final disposition of MFs. There are many alternatives to reduce these pollutants from reaching the environment but also gaps that need to be further evaluated and addressed. Besides, it should be noticed that alternatives could be complementary between them. Some viable and non-contaminating solutions to reduce this pollution are currently on the market. Also, one relevant aspect is the final disposition or usage of the retained MFs to avoid them from reaching aquatic environmentsThe authors acknowledge the support of the “Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya” for funding this projectPostprint (published version

Electrochemical techniques in textile processes and wastewater treatment

The textile industry uses the electrochemical techniques both in textile processes (such as manufacturing fibers, dyeing processes, and decolorizing fabrics) and in wastewaters treatments (color removal). Electrochemical reduction reactions are mostly used in sulfur and vat dyeing, but in some cases, they are applied to effluents discoloration. However, the main applications of electrochemical treatments in the textile sector are based on oxidation reactions. Most of electrochemical oxidation processes involve indirect reactions which imply the generation of hypochlorite or hydroxyl radical in situ. These electrogenerated species are able to bleach indigo-dyed denim fabrics and to degrade dyes in wastewater in order to achieve the effluent color removal. The aim of this paper is to review the electrochemical techniques applied to textile industry. In particular, they are an efficient method to remove color of textile effluents. The reuse of the discolored effluent is possible, which implies an important saving of salt and water (i.e., by means of the “UVEC Cell”)Postprint (published version

Reuse of textile wastewater after homogenization–decantation treatment coupled to PVDF ultrafiltration membranes

The textile industry is one of the largest consumers of water in the world and its wastewater is a serious problem when it is discharged without the proper treatment. In this work, wastewater generated by textile industry was treated coupling a homogenization–decantation treatment with polyvinylidene difluoride (PVDF) ultrafiltration membranes. Initially, the wastewater was aerated in a homogenization–decantation tank where 17% colour and 10% chemical oxygen demand (COD) were removed. The aerated effluent was treated with an ultrafiltration membrane in order to reuse the permeate in new dyeing processes. Firstly, the ultrafiltration treatment was performed in a laboratory plant. The permeate analysis showed 20% colour removal and 60% COD decrease. On the basis of these results, a semi-industrial system was built. With this plant, the permeate characterization showed similar results. The system was found to be scalable and suitable for the treatment of this kind of effluents. Finally, new dyeings were performed with both permeates. Monochromatic dyeings were carried out with 100% permeate whereas 50% permeate was reused for dyeings with a mixture of three dyes. The colour differences were found to be lower than 1.5, which was the acceptance value establishedPostprint (author's final draft

Development of a self-sustaining floating water treatment system with renewable energy supply ETAF

II International Congress on Watter and Sustainability. Terrassa – Barcelona, 24-25-26 March 2021. Most attractive Poster AwardAward-winnin

Chromatographie d’exclusion: analyse de la distribution des poids moléculaires dans les silicones par GPC

En el presente trabajo se explican los fundamentos de la cromatografía de exclusión o permeación en gel (GPC) y se aplica dicha técnica a la determinación de la distribución pesos moleculares de 4 polímeros de aminodimetilsiloxano con distintos grados de polimerización y diferente contenido del grupo funcional etilendiamino. A partir de los cromatogramas GPC obtenidos y de los correspondientes datos cromatográficos, se calculan los pesos moleculares promedio (MN y MW) de las 4 siliconas analizadas y la polidispersidad de las mismas, comparándose los resultados obtenidos frente al peso molecular teóricoIn this paper, the basis of the exclusion chromatography technique or gel permeation chromatography (GPC) are exposed and this technique is applied to the molecular weight distribution analysis of 4 polymers constituted by aminodimethylpolysiloxane with different polymerization degree and ethylenediamino functional group content. Their average molecular weights (MW and MN) were calculated. From the GPC chromatograms and the corresponding chromatographic results, the polydispersity of these samples was also calculated. Results were compared with the theoretical molecular weightDans ce travail, les bases de la technique de chromatographie d’exclusion ou chromatographie de perméation en gel (GPC) sont exposées et cette technique a été appliqué à l’analyse de la distribution des poids moléculaires de 4 polymères constitués par aminodimethylpolysiloxane avec des différents degrés de polymérisation et différente teneur de groupes fonctionnels ethylenediamino.Pour les 4 polymères sélectionnés, leurs poids moléculaires moyens (MW et MN) ont été calculés. La polydispersité des échantillons a aussi été calculée à partir des correspondants chromatogrammes et de leurs données chromatographiques. Les résultats ont été comparés avec le poids moléculaire théoriquePeer Reviewe

Comparison of different wastewater treatments for colour removal of reactive dye baths

The generation of high-coloured wastewater is one of the main environmental problems of the textile industry. Reactive dyes are widely used in the dyeing of cellulosic fibres. However, they have low exhaustion degree (70–90%). The degradation of residual dyes by aerobic biological treatment is very poor, being necessary the application of specific treatments. In this work, three different methods for the removal of reactive dyes were compared: electrochemical treatment, coagulation with Moringa oleifera waste and enzymatic treatment with laccase. Two azo bifunctional dyes with different reactive groups were selected: C.I. Reactive Black 5 (vinyl sulphone) and C.I. Reactive Red 231 (chlorotriazine). The influence of pH (5 and 9) and dye hydrolysis on the decolourisation yield was studied. The electrochemical treatment was the most efficient, with 95–100% colour removal yield. The coagulation with M. oleifera waste also achieved high colour removal efficiency (91–94%). Both methods showed an independent behaviour with respect to pH or dye hydrolysis. The enzymatic treatment should be performed at pH 5. This method was suitable to remove the chlorotriazine dye (92–93% efficiency), whereas the vinyl sulphone one showed a marked dependence on dye hydrolysis: moderately efficient for the hydrolysed dye and highly efficient without hydrolysis. The activity of laccase was not modified by the usual salinity of the reactive dyeing effluent (20 g/L NaCl). Nevertheless, the effluent salinity enhanced the electrochemical and M. oleifera treatment yield.Peer ReviewedPostprint (author’s final draft

Novel treatment to immobilize and use textiles microfibers retained in polymeric filters through their incorporation in composite materials

Microplastics (MPs, size < 5 mm) are among the most environmentally challenging pollutants. Their continuous and cumulative inflow or generation in the environment is what makes them drastically problematic. These pollutants can come from a wide variety of sources; hence, they are potential vectors that pose extensive risks to environmental and human health. Microfibers (MFs) are one type of MPs. Among the most well-known types of MFs are those detached from textile articles from household laundering or industrial processes. Currently, there are many ways to retain the MFs detached from textile articles. However, as far we know, there are no methods of valorizing the retained MFs. As such, we propose a novel and sustainable treatment method to immobilize MFs in a polymeric matrix, turning them into a composite. To determine the mechanical properties of the expected composites, different proportions of polyester MFs were mixed with low-density polyethylene, which is the material proposed for the immobilization of MFs. The results show that the optimum manufacturing composition was 10% (v/v) polyester MFs in the polymeric matrix. This composition improved some of the tensile mechanical properties of the polymeric matrix. Once the composites are obtained, these can be used for different purposesThis research was funded by the Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya (AGAUR 2018_DI_022)Postprint (published version

El rastro invisible y tóxico de billones de colillas

¿Sabía que anualmente se fuman 6 billones de cigarrillos? ¿Y que 4,5 billones de colillas terminan en el medio ambiente? ¡Son más de 8 millones por minuto! Es bien sabido que fumar tiene un impacto en la salud de los fumadores y sus acompañantes. Pero se habla menos del efecto que las colillas provocan en el medio ambiente y en nuestro organismoPostprint (published version