902 research outputs found
A review on the present situation of wastewater treatment in textile industry with membrane bioreactor and moving bed biofilm reactor
Membrane bioreactor (MBR) is one of the advanced treatment technologies used in industrial wastewater treatment due to its various advantages over conventional biological processes. Recently, the application of MBR in treatment of textile wastewater has increased significantly with an effective removal of contaminants. Moving bed bioreactor (MBBR) has been efficiently used for the treatment of different municipal and industrial wastewater during the last decades and it is a relatively novel and effective technology applied in textile wastewater treatment. This review paper presents the situation of MBR and MBBR technology for textile wastewater purification under different conditions and collates results of previous studies during the past years about MBR and MBBR treatment technologies used in textile processes. Both of these two technologies have shown their efficiency, but they still have problems in textile wastewater treatment. To this end, MBR-MBBR hybrid system could be an attractive solution for textile wastewater purification because of the high efficiency and low consumption of energy and spacePostprint (author's final draft
Depuración de las aguas residuales en la industria de los tensioactivos.
Se indican los procesos de depuración más adecuados, para eliminar los distintos tipos de contaminantes del agua según sus caracterÃsticas quÃmicas y fÃsicas. De forma breve se comentan algunas aplicaciones prácticas de las técnicas respirométricas, para la segregación de efluentes poco biodegradables o inhibidores, que podrÃan dificultar el tratamiento biológico.
Se menciona la utilidad de los pretratamientos, para el buen funcionamiento de los procesos biológicos. Se describe la aplicación de la oxidación electroquÃmica para disminuir la carga orgánica y aumentar la biodegradabilidad del agua antes de su depuración biológica. A modo de referencia se indican algunos ejemplos recientes de depuradoras instaladas en industrias quÃmicas (fabricación de detergentes, cosmética, fábricas de aromas, industria farmacéutica).The most adequate depuration processes to eliminate the different types of water contaminants, according to their physical and chemical characteristics, are indicated. Some practical applications of the respirometric techniques for the segregation of not very biodegradable effluents or inhibitors, which could hinder the biological treatment, are briefly described.
The usefulness of pretreatments to attain a good behaviour of biological processes is mentioned. The application of the electrochemical oxidation to lower the organic charge and increase the water biodegradability before its biological depuration is also described. Some recent examples of water treatment plants installed in chemical industries (manufacture of detergents, cosmetics, essences,
pharmaceuthicals) are given as a reference.L'étude indique les procédures d'épuration des eaux qui conviennent le mieux à l'élimination des différentes sortes de polluants, d'après leurs caractéristiques chimiques et physiques. Elle présente ensuite brièvement quelques applications pratiques de techniques respirométriques, pour la ségrégation des effluents faiblement biodégradables ou inhibiteurs, qui pourraient entraver le traitement biologique.
On y cite l'utilité des prétraitements, pour le bon fonctionnement des processus biologiques. Vient ensuite la description de l'application de l'oxydation électrochimique pour diminuer la charge organique et augmenter la biodégradabilité de l'eau avant son épuration biologique. Quelques exemples récents de stations d'épuration, installées dans certaines industries chimiques, illustrent ces principes (fabrication de lessives, cosmétique, fabriques d'arômes, industrie pharmaceutique).Peer Reviewe
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
Depuración de las aguas residuales procedentes de la tintura con transportadores.
En este trabajo, se describe la técnica de extracción-cromatografÃa de gases utilizada para la valoración cuantitativa de los carriers (transportadores de tintura) en las aguas residuales.
A continuación se determinan las cinéticas de biodegradación de seis transportadores de tintura. Utilizando dos de estos carriers se han preparado unos efluentes sintéticos, estudiándose su depuración en una planta piloto de fangos activados y mediante procedimientos fisicoquÃmicos.Peer Reviewe
CaracterÃsticas contaminantes y posibilidades de reutilización de los baños residuales del blanqueo del algodón.
Este trabajo ha consistido en la realización de varios procesos de descrudado y blanqueo de artÃculos de algodón en aparatos piloto de laboratorio en las condiciones usuales de la industria. Con un doble objetivo: determinar la carga contaminante generada en cada proceso y establecer la posibilidad de reutilización de algunos efluyentes.Cette communication décrit la réalisation de plusieurs processus d'ébouillissage et de blanchiment d'articles en coton dans des appareils de laboratoire pilote dans les conditions usuelles de l'industrie. On visait a un double objectif: la détermination de la charge pollutionnante générée dans chaque processus et l'établissement de la possibilité de la réutilisation de quelques eaux résiduaires.This paper describes various scouring and bleaching processes of cotton articles carried out in laboratory pilot plants under usual industrial conditions. The aims were twofold: to determine the polluting charge generated in each process and to establish the possibility of the yield of some of the effluents.Peer Reviewe
Algunos aspectos sobre la contaminación debida a la tintura de poliéster a alta temperatura.
En este trabajo se analiza la biodegradabilidad de dos productos dispersantes, y un igualador, empleados en la tintura del poliéster a alta temperatura. Y se comentan los métodos analÃticos empleados.
También se estudia la depuración en una planta piloto de fangos activados, de dos efluentes preparados con los productos estudiados anteriormente, analizándose la influencia que la biodegradabilidad de estos productos ejerce sobre el rendimiento de la depuración.Dans ce travail on analyse la biodégradabilité de deux produits dispersants, ainsi que d'un agent d'unisson, employés dans la teinture du polyester à haute température. Et l'on commente les méthodes analytiques employées.
On étudie aussi l'épuration de boues activées dans una installation pilote, de deux eaux résiduaires préparées avec les produits étudiés antérieurement; on analyse l'influence que la biodégradabilité de ces produits exerce sur le rendement de l'épuration.The biodegradability of two dispersing agents and a levelling agent used in high temperature dyeing of polyester is studied in this paper. The analytical methods used are also mentioned.
Depuration in an activated sludge pilot plant of two effluents made with the products studied is also considered as well as the influence on the depuration rate exerted by the biodegradability of the above products.Peer Reviewe
Reciclado de aguas residuales textiles decoloradas con técnicas electroquÃmicas
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 electroquÃmico con la celda ECO 75 (ELCHEM). También se describe detalladamente el funcionamiento y la estructura de esta celda. Se aplica el tratamiento electroquÃmico 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
One gene, many proteins: mapping cell-specific alternative splicing in plants
Pre-mRNA alternative splicing (AS) generates protein variants from a single gene that can create novel regulatory opportunities. In this issue of Developmental Cell, Li et al. (2016) present a high-resolution expression map of AS events in Arabidopsis root tissues, giving insight into cell-type- and stage-specific AS mechanisms in plants
Long non-coding RNAs reveal new regulatory mechanisms controlling gene expression
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