RESUMO
In this study, graphene oxide/N-halamine nanocomposite was synthesized through Pickering miniemulsion polymerization, which was then coated on cotton surface. The modified cotton exhibited excellent superhydrophobicity, which could effectively prevent microbial infestation and reduce the probability of hydrolysis of active chlorine, with virtually no active chlorine released in water after 72 h. Deposition of reduced graphene oxide nanosheets endowed cotton with ultraviolet-blocking properties, attributing to enhanced UV adsorption and long UV paths. Moreover, encapsulation of polymeric N-halamine resulted in improved UV stability, thus extending the life of N-halamine-based agents. After 24 h of irradiation, 85 % of original biocidal component (active chlorine content) was retained, and approximately 97 % of initial chlorine could be regenerated. Modified cotton has been proven to be an effective oxidizing material against organic pollutants and a potential antimicrobial substance. Inoculated bacteria were completely killed after 1 and 10 min of contact time, respectively. An innovative and simple scheme for determination of active chlorine content was also devised, and real-time inspection of bactericidal activity could be achieved to assure antimicrobial sustainability. Moreover, this method could be utilized to evaluate hazard classification of microbial contamination in different locations, thus broadening the application scope of N-halamine-based cotton fabrics.
Assuntos
Aminas , Antibacterianos , Fibra de Algodão , Gossypium , Látex , Nanoestruturas , Polimerização , Aminas/química , Aminas/efeitos da radiação , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/efeitos da radiação , Biofilmes/efeitos dos fármacos , Cloro/química , Corantes , Fibra de Algodão/microbiologia , Fibra de Algodão/efeitos da radiação , Desinfetantes/química , Desinfetantes/efeitos da radiação , Condutividade Elétrica , Contaminação de Equipamentos/prevenção & controle , Gossypium/química , Gossypium/microbiologia , Grafite/química , Halogenação , Interações Hidrofóbicas e Hidrofílicas , Látex/química , Látex/efeitos da radiação , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Indústria Têxtil/métodos , Raios Ultravioleta , Água/químicaRESUMO
Cotton produces natural fiber for the textile industry. The genetic effects of genomic structural variations underlying agronomic traits remain unclear. Here, we generate two high-quality genomes of Gossypium hirsutum cv. NDM8 and Gossypium barbadense acc. Pima90, and identify large-scale structural variations in the two species and 1,081 G. hirsutum accessions. The density of structural variations is higher in the D-subgenome than in the A-subgenome, indicating that the D-subgenome undergoes stronger selection during species formation and variety development. Many structural variations in genes and/or regulatory regions potentially influencing agronomic traits were discovered. Of 446 significantly associated structural variations, those for fiber quality and Verticillium wilt resistance are located mainly in the D-subgenome and those for yield mainly in the A-subgenome. Our research provides insight into the role of structural variations in genotype-to-phenotype relationships and their potential utility in crop improvement.
Assuntos
Fibra de Algodão/análise , Genoma de Planta/genética , Gossypium/genética , Gossypium/fisiologia , Agricultura/métodos , Ligação Genética , Variação Genética/genética , Genótipo , Gossypium/classificação , Fenótipo , Locos de Características Quantitativas/genética , Análise de Sequência de DNA , Indústria Têxtil/métodosRESUMO
Landmark and sustainable eco-friendly dye treatment processes are highly desirous to ameliorate their effect on the environment. The present study investigated the azo dye degradation efficiency of adapted Enterobacter hormaechei SKB 16 from textile effluent polluted soil in optimized culture conditions. The adapted bacteria strain was identified by standard microbiological and molecular techniques. E. hormaechei was tested individually for the decolourizing of Reactive Yellow 145 (RY 145) and Reactive Red F3B (RR 180) dyes under optimized conditions of pH, temperature and dye concentration on decolourization were studied. The adapted bacteria strain exhibited maximum decolourization (98 %) of Reactive yellow 145 and Reactive red 180 in 100 ppm concentration at pH 7, temperature 37 °C after 98 h of incubation. The enzyme analyses revealed that azo reductase and laccase played major roles in the cleavage of the azo bond and desulfonation respectively of both dyes during degradation. The metabolites were further characterized by Fourier Transform Infrared Spectroscopy (FT-IR), High-Performance Liquid Chromatography (HPLC), and Gas Chromatography-Mass Spectrometry (GCMS). Thereafter, degradation was deduced based on changes of the functional group, variation in retention times and mass/charge ratio and molecular weight. This study elucidated the promising potentials of adapted SKB 16 strain in the eco-friendly removal of textile azo dyes. In addition, repeatability and sustainability are enhanced due to effective management of time which would have been spent on rigorous and extensive screening process.
Assuntos
Compostos Azo/metabolismo , Biodegradação Ambiental , Enterobacter/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Temperatura , Indústria Têxtil/métodos , Têxteis , Águas Residuárias/microbiologiaRESUMO
In this study, we developed a novel method to prepare chemical fibers by plasticizing cotton with 1-allyl-3-methylimidazolium chloride (AMIMCl) under high temperature and pressure. Cotton was homogeneously mixed with AMIMCl by kneading in a certain mass proportion. It would be a sheet after hot-pressing and this process could be repeated several times. The morphologies of chemical fibers showed that cotton was successfully plasticized by AMIMCl with the crystallinity of the chemical fibers increased by about 15%. Differential scanning calorimetry (DSC) showed that the glass transition temperature (Tg) occurred in chemical fibers and we could further verify cotton was plasticized by AMIMCl. This simple and green method will be helpful to modify and broaden the application field of cotton.
Assuntos
Compostos Alílicos/química , Fibra de Algodão , Imidazóis/química , Plastificantes/química , Indústria Têxtil/métodos , Temperatura de Transição , VitrificaçãoRESUMO
The purpose of this work was to examine the influence of poly(sodium allyl sulfonate) (PSAS) branches on sizing properties of biological macromolecule (corn starch) for exploring a new anionic starch graft copolymer size (S-g-PSAS). Successful synthesis of S-g-PSAS samples was confirmed by energy dispersive X-ray spectrometer. Viscosity stability, adhesion, film properties and desizability of the samples were also investigated. Compared with HS, improved adhesion to cotton and viscose fibers, viscosity stability and desizability for S-g-PSAS as well as enhanced breaking elongation and bending endurance for S-g-PSAS film were exhibited. With the rise in grafting ratio, bonding forces to both fibers, viscosity stability and desizability of S-g-PSAS and its film properties such as breaking elongation and bending endurance, were gradually enhanced. These results indicated that S-g-PSAS showed potential for the use as a new starch-based size in the sizing of cotton and viscose warps.
Assuntos
Compostos Alílicos/química , Fibra de Algodão , Plastificantes/química , Amido/análogos & derivados , Adesivos/síntese química , Alcanossulfonatos/química , Elasticidade , Indústria Têxtil/métodos , Viscosidade , Zea mays/químicaRESUMO
As it is well known, the textile industry generates a large amount of wastewater with varied composition that need to be treated. In particular, the Sergipe state, in Brazil, is a region that requires attention due the presence of several local textile industries. In this study, the efficiency of electrochemical oxidation (EO) process applied in the samples of Brazilian textile industry effluents previously treated by physical-chemical process coagulation-flocculation (CF) was evaluated by the reduction in TOC parameter and by the ecotoxicity using Lactuca sativa and Raphidocelis subcapitata bioassays. The optimized experiments achieved for the CF ([Al2(SO4)3]0â¯=â¯1.5â¯mgâ¯L-1, pHâ¯=â¯6.0, alkalinityâ¯=â¯0.675â¯mgâ¯L-1, [flocculating agent]â¯=â¯61â¯mgâ¯L-1, rapid mixing = 100 rpm for 1 min, slow stage = 20-60 rpm for 20 min) a reduction of 20% on TOC. The best results obtained for EO was using the DSA electrode (I = 300 mA) reaching a TOC removal efficiency of 82% after an electrolysis time of 180 min. The ecotoxicity experiments indicated that the proposed treatment (CF + EO, I = 300 mA) was effective to decrease the dissolved pollutants presented in the treated samples. In comparison with raw samples, the treatment achieved a reduction of 52% for IC5072h value using R. subcapitata as bioindicator, and a 98% reduction of LC50 (Lactuca sativa).
Assuntos
Ecotoxicologia/métodos , Oxirredução/efeitos dos fármacos , Indústria Têxtil/métodos , Poluentes Químicos da Água/química , Floculação , Resíduos Industriais/análise , Poluentes Químicos da Água/análiseRESUMO
Chemical catalysts are being replaced by biocatalysts in almost all industrial applications due to environmental concerns, thereby increasing their demand. Enzymes used in current industries are produced in microbial systems or plant seeds. We report here five newly launched leaf-enzyme products and their validation with 15 commercial microbial-enzyme products, for detergent or textile industries. Enzymes expressed in chloroplasts are functional at broad pH/temperature ranges as crude-leaf extracts, while most purified commercial enzymes showed significant loss at alkaline pH or higher temperature, required for broad range commercial applications. In contrast to commercial liquid enzymes requiring cold storage/transportation, chloroplast enzymes as a leaf powder can be stored up to 16 months at ambient temperature without loss of enzyme activity. Chloroplast-derived enzymes are stable in crude-leaf extracts without addition of protease inhibitors. Leaf lipase/mannanase crude extracts removed chocolate or mustard oil stains effectively at both low and high temperatures. Moreover, leaf lipase or mannanase crude-extracts removed stain more efficiently at 70 °C than commercial microbial enzymes (<10% activity). Endoglucanase and exoglucanase in crude leaf extracts removed dye efficiently from denim surface and depilled knitted fabric by removal of horizontal fibre strands. Due to an increased demand for enzymes in the food industry, marker-free lettuce plants expressing lipase or cellobiohydrolase were created for the first time and site-specific transgene integration/homoplasmy was confirmed by Southern blots. Thus, leaf-production platform offers a novel low-cost approach by the elimination of fermentation, purification, concentration, formulation and cold-chain storage/transportation. This is the first report of commercially launched protein products made in leaves and validated with current commercial products.
Assuntos
Detergentes , Lipase , Folhas de Planta , Indústria Têxtil , Cloroplastos/enzimologia , Cloroplastos/genética , Detergentes/normas , Estabilidade Enzimática , Lipase/genética , Lipase/isolamento & purificação , Lipase/metabolismo , Lipase/normas , Folhas de Planta/enzimologia , Folhas de Planta/genética , Temperatura , Indústria Têxtil/métodos , beta-Manosidase/genética , beta-Manosidase/isolamento & purificação , beta-Manosidase/metabolismo , beta-Manosidase/normasRESUMO
OBJECTIVE: To determine the perceived health and safety needs identified by textile workers, managers and experts as well as direct observation of the prevailing health and safety practices in the textile industry. METHODS: The qualitative study using the needs assessment conceptual framework was conducted in July-August 2015 in Karachi, and comprised focus group discussions with textile workers, in-depth interviews with factory managers and health and safety officers, and key informant interviews with relevant stakeholders and experts. A walk-through survey was also conducted in selected mills for which the Checklist of hazards in textiles was used. RESULTS: A total of 6focus group discussions, 6 in-depth interviews and 5 key informant interviews were conducted. Workers were found to have limited knowledge of occupational hazards, preventions and diseases. They identified lack of awareness and non-existent safety mechanisms as areas for improvement. Managers thought preventive practices and health services were not standardised while influence of buyers in the form of international business regulations and legislations were thought to be the enabling factors for enforcing health and safety standards. Poor governance, lack of knowledge regarding labour rights, low literacy level, poor compliance and low wages were the barriers for health promotion at workplace, as identified by the experts. Walk-through survey found mechanisms in place for fire safety, but the workers and managers were generally not using Personal Protective Equipment despite the presence of several hazards at workplace. CONCLUSIONS: There was found a need for context-specific occupational health and safety interventions at individual, organisational and policy levels.
Assuntos
Exposição Ocupacional/prevenção & controle , Saúde Ocupacional/normas , Indústria Têxtil , Local de Trabalho/normas , Adulto , Feminino , Promoção da Saúde , Humanos , Masculino , Avaliação das Necessidades , Paquistão , Pesquisa Qualitativa , Indústria Têxtil/métodos , Indústria Têxtil/normasRESUMO
Abstract In this work we have assessed the decolorization of textile effluents throughout their treatment in a solid-state fermentation (SSF) system. SSF assays were conducted with peach-palm (Bactris gasipaes) residue using the white rot fungus Ganoderma lucidum EF 31. The influence of the dye concentration and of the amounts of peach-palm residue and liquid phase on both the discoloration efficiency and enzyme production was studied. According to our results, independently of experimental conditions employed, laccase was the main ligninolytic enzyme produced by G. lucidum. The highest laccase activity was obtained at very low effluent concentrations, suggesting the existence of an inhibitory effect of higher concentrations on fungal metabolism. The highest percentage of color removal was reached when 10 grams of peach palm residue was moistened with 60 mL of the final effluent. In control tests carried out with the synthetic dye Remazol Brilliant Blue R (RBBR) decolorization efficiencies about 20% higher than that achieved with the industrial effluent were achieved. The adsorption of RBBR on peach-palm residue was also investigated. Equilibrium tests showed that the adsorption of this dye followed both Langmuir and Freundlich isotherms. Hence, our experimental results indicate that peach-palm residue is suitable substrate for both laccase production and color removal in industrial effluents.
Resumo Neste trabalho, avaliamos a descoloração de efluentes têxteis durante seu tratamento em um sistema de fermentação em estado sólido (SSF). Os ensaios foram conduzidos com resíduo de pupunha (Bactris gasipaes) utilizando o fungo de podridão branca Ganoderma lucidum EF 31. A influência da concentração de corante, as quantidades de resíduo e da fase líquida foram estudadas tanto na eficiência de descoloração como na produção de enzima. De acordo com os resultados, independentemente das condições experimentais utilizadas, a lacase foi a principal enzima ligninolítica produzida por G. lucidum. A atividade de lacase mais elevada foi obtida em baixas concentrações de efluentes, sugerindo um efeito inibitório no metabolismo fúngico. A maior remoção de cor foi obtida com 10 gramas de resíduo da pupunha e 60 mL do efluente final. Nos ensaios de controle realizados com o corante sintético RBBR, foram atingidos cerca de 20% mais descoloração do que os obtidos com o efluente industrial. A adsorção de RBBR no resíduo de pupunha também foi investigada. Os testes de equilíbrio mostraram que a adsorção deste corante seguiu as isotermas de Langmuir e Freundlich. Assim, os resultados experimentais indicam que o resíduo de pupunha é um substrato adequado tanto para a produção de lacase quanto para a remoção de cor em efluentes industriais.
Assuntos
Indústria Têxtil/métodos , Biodegradação Ambiental , Reishi/enzimologia , Arecaceae/química , Lacase/química , Águas Residuárias/química , Antraquinonas , Cor , Adsorção , Corantes/química , FermentaçãoRESUMO
The effluent discharged by the textile dyehouses has a seriously detrimental effect on the aquatic environment. Some dyestuffs produce toxic decomposition products and the metal complex dyes release toxic heavy metals to watercourses. Of the dyes used in the textile industry, effluents containing reactive dyes are the most difficult to treat because of their high water-solubility and poor absorption into the fibers. A range of treatments has been investigated for the decolorization of textile effluent and the adsorption seems to be one of the cheapest, effective and convenient treatments. In this review, the adsorbents investigated in the last decade for the treatment of textile effluent containing reactive dyes including modified clays, biomasses, chitin and its derivatives, and magnetic ion-exchanging particles have been critically reviewed and their reactive dye binding capacities have been compiled and compared. Moreover, the dye binding mechanism, dye sorption isotherm models and also the merits/demerits of various adsorbents are discussed. This review also includes the current challenges and the future directions for the development of adsorbents that meet these challenges. The adsorption capacities of adsorbents depend on various factors, such as the chemical structures of dyes, the ionic property, surface area, porosity of the adsorbents, and the operating conditions. It is evident from the literature survey that decolorization by the adsorption shows a great promise for the removal of color from dyehouse effluent. If biomasses want to compete with the established ion-exchange resins and activated carbon, their dye binding capacity will need to be substantially improved.
Assuntos
Corantes/isolamento & purificação , Resíduos Industriais/prevenção & controle , Indústria Têxtil/métodos , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Corantes/química , Troca Iônica , Poluentes Químicos da Água/análiseRESUMO
In this study, pollutants from textile industry wastewater were transformed/oxidized using Ti/RuO2 electrode by Electro-Fenton (EF) method in a continuous reactor. The performance was evaluated in terms of % COD removal, % color removal and energy consumed. Electrolysis time, retention time, current, and ferrous sulphate concentration as Fenton catalyst were selected as EF process parameters. To determine the optimum operating conditions multiple response optimization with desirability approach based on central composite design under response surface methodology was used. Spectrophotometric and GC-MS analysis were performed to identify the degraded/transformation compounds, and on this basis degradation mechanism during EF process as well as disposability of treated wastewater was analyzed. Further, bioassay test of treated textile wastewater was conducted for toxicity analysis in view of its disposal quality. Results showed that all the components of textile wastewater were totally eliminated/transformed in lower molecular weight compounds after EF treatment of textile effluent. Further, bioassay test analysis confirmed the nontoxic nature of treated wastewater.
Assuntos
Peróxido de Hidrogênio/química , Resíduos Industriais/análise , Ferro/química , Indústria Têxtil/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Águas Residuárias/análise , Poluentes Químicos da Água/análiseRESUMO
Ginger peroxidase (GP) was entrapped into the hydrogels of guar gum (GG)-alginate/agarose and these immobilized GP preparations were employed for the treatment of textile effluent. GG is a natural hydrophilic polysaccharide, the average size of which increases in its hydrated form that helps in retaining the enzyme inside the entrapping support. Therefore, the activity retention by alginate-guar gum (ANGG) and agarose-guar gum (AGG) was higher than that of alginate and agarose alone. ANGG-GP and AGG-GP were highly stable against various physical and chemical denaturants during the decolorization of textile effluent. As compared to free GP, both the immobilized preparations were more efficient in the decolorization of textile effluent in batch processes. After 10th repeated use in batch processes, ANGG-GP and AGG-GP was quite effective in removing up to 68% and 55% of the color from textile effluent, respectively. Continuous packed bed reactors containing ANGG-GP and AGG-GP were able to decolorize around 80% and 69% of the effluent color, respectively, even after 30â¯days of their continuous operation at room temperature (30⯰C). Genotoxicity of textile effluent was significantly reduced after GP mediated decolorization.
Assuntos
Alginatos/química , Galactanos/química , Hidrogéis/química , Mananas/química , Peroxidase/química , Gomas Vegetais/química , Sefarose/química , Biodegradação Ambiental/efeitos dos fármacos , Corantes/química , Enzimas Imobilizadas/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Indústria Têxtil/métodos , TêxteisRESUMO
In this work we have assessed the decolorization of textile effluents throughout their treatment in a solid-state fermentation (SSF) system. SSF assays were conducted with peach-palm (Bactris gasipaes) residue using the white rot fungus Ganoderma lucidum EF 31. The influence of the dye concentration and of the amounts of peach-palm residue and liquid phase on both the discoloration efficiency and enzyme production was studied. According to our results, independently of experimental conditions employed, laccase was the main ligninolytic enzyme produced by G. lucidum. The highest laccase activity was obtained at very low effluent concentrations, suggesting the existence of an inhibitory effect of higher concentrations on fungal metabolism. The highest percentage of color removal was reached when 10 grams of peach palm residue was moistened with 60 mL of the final effluent. In control tests carried out with the synthetic dye Remazol Brilliant Blue R (RBBR) decolorization efficiencies about 20% higher than that achieved with the industrial effluent were achieved. The adsorption of RBBR on peach-palm residue was also investigated. Equilibrium tests showed that the adsorption of this dye followed both Langmuir and Freundlich isotherms. Hence, our experimental results indicate that peach-palm residue is suitable substrate for both laccase production and color removal in industrial effluents.
Assuntos
Arecaceae/química , Biodegradação Ambiental , Lacase/química , Reishi/enzimologia , Indústria Têxtil/métodos , Águas Residuárias/química , Adsorção , Antraquinonas , Cor , Corantes/química , FermentaçãoRESUMO
In this research, extraction of colouring matter from date pits powder was conferred by conventional and ultrasonic methods. Phenolic compounds present in the resulted extract were identified by HPLC analysis. Total phenolic, total flavonoid and total metallic contents were quantified; and the highest levels were obtained in case of ultrasonic extraction process at a frequency of 25 kHz. The different resultant extracts were diluted with distilled water and unified to a polyphenolic content of 48 mg per 100 mL. Dyeing results have been discussed as a function of the bio-metallic contents present in the extract. It was found that the highest colour strengths and the better fastness properties were registered in case of dyeing experiments developed using the ultrasonic extracts. Those above results could be due to the highest metallic content present in the ultrasonic extracts, which has functioned as a bio-mordant properly extracted from date pits powder.
Assuntos
Corantes/química , Fibra de Algodão , Extratos Vegetais/análise , Extratos Vegetais/química , Indústria Têxtil/métodos , Fracionamento Químico/métodos , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Metais/análise , Fenóis/análise , Phoeniceae/química , Sementes/química , UltrassomRESUMO
Microfibers have received much attention due to their promise for creating flexible and highly relevant tissue models for use in biomedical applications such as 3D cell culture, tissue modeling, and clinical treatments. A generated tissue or implanted material should mimic the natural microenvironment in terms of structural and mechanical properties as well as cell adhesion, differentiation, and growth rate. Therefore, the mechanical and biological properties of the fibers are of importance. This paper briefly introduces common fiber fabrication approaches, provides examples of polymers used in biomedical applications, and then reviews the methods applied to modify the mechanical and biological properties of fibers fabricated using different approaches for creating a highly controlled microenvironment for cell culturing. It is shown that microfibers are a highly tunable and versatile tool with great promise for creating 3D cell cultures with specific properties.
Assuntos
Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Nanofibras/química , Polímeros/química , Administração Tópica , Animais , Adesão Celular , Sistemas de Liberação de Medicamentos/métodos , Humanos , Injeções Subcutâneas , Microfluídica/métodos , Polieletrólitos/química , Propriedades de Superfície , Indústria Têxtil/métodos , Alicerces Teciduais/químicaRESUMO
Intensifying legislation and increased research on the toxicological and persistent nature of per- and polyfluoroalkyl substances (PFASs) have recently influenced the direction of liquid repellent chemistry use; environmental, social, and sustainability responsibilities are at the crux. Without PFAS chemistry, it is challenging to meet current textile industry liquid repellency requirements, which is a highly desirable property, particularly in outdoor apparel where the technology helps to provide the wearer with essential protection from adverse environmental conditions. Herein, complexities between required functionality, legislation and sustainability within outdoor apparel are discussed, and fundamental technical performance of commercially available long-chain (C8) PFASs, shorter-chain (C6) PFASs, and non-fluorinated repellent chemistries finishes are evaluated comparatively. Non-fluorinated finishes provided no oil repellency, and were clearly inferior in this property to PFAS-finished fabrics that demonstrated good oil-resistance. However, water repellency ratings were similar across the range of all finished fabrics tested, all demonstrating a high level of resistance to wetting, and several non-fluorinated repellent fabrics provide similar water repellency to long-chain (C8) PFAS or shorter-chain (C6) PFAS finished fabrics. The primary repellency function required in outdoor apparel is water repellency, and we would propose that the use of PFAS chemistry for such garments is over-engineering, providing oil repellency that is in excess of user requirements. Accordingly, significant environmental and toxicological benefits could be achieved by switching outdoor apparel to non-fluorinated finishes without a significant reduction in garment water-repellency performance. These conclusions are being supported by further research into the effect of laundering, abrasion and ageing of these fabrics.
Assuntos
Vestuário/normas , Fluorocarbonos/normas , Têxteis/normas , Adsorção , Indústria Têxtil/métodos , Água/químicaRESUMO
Effluents from textile industries are highly colored due to vast use of various azo dyes and color is the first visual indicator of pollution. Biological treatment of textile effluent is often hampered due to the alkaline pH and high salinity; a common characteristic of many textile industrial wastewaters. Considering this, the present study explores the potential of a newly isolated halotolerant and alkaliphilic bacterium Nesterenkonia lacusekhoensis EMLA3 for degradation of methyl red (MR) dye under alkaline condition. Strain EMLA3 showed 97% degradation of 50 mg L-1 MR after 16 h at initial pH of 11.5 in nutrient medium. Dye degradation by the isolate is supported by the formation of low-molecular weight metabolites as divulge through GC-MS & FTIR studies Optimum dye degradation was observed in the pH range of 8.0-11.5 and temperature range of 30-35 °C. Significant MR degrading activity of the strain could be achieved in the presence of very high salt level (100-120 g L-1 NaCl) and in co-presence of different heavy metals. Application of strain to alkaline pH, salt, and heavy metals laden-textile effluent resulted in overall 83% dye removal from the effluent after 120 h of treatment under static condition. Furthermore, the property of microbe to drop-down the pH of wastewater from 11.5 to 8.60 after treatment also lowers the need of additional neutralization treatment. The entire study thus comes out with novel application of N. lacusekhoensis-a less explored extremophilic bacterium-for treatment of alkaline and salt-rich azo dye-containing wastewaters.
Assuntos
Compostos Azo/metabolismo , Micrococcaceae/metabolismo , Salinidade , Álcalis/química , Compostos Azo/análise , Biodegradação Ambiental , Ambientes Extremos , Resíduos Industriais , Indústria Têxtil/métodos , Águas Residuárias/química , Águas Residuárias/microbiologiaRESUMO
Families of new hydrophobic and/or oleophobic triarylmethane dyes possessing long hydrocarbon or polyfluorinated chains have been prepared. When covalently grafted on to cotton fabric, these dyes give rise to a new type of colored superhydrophobic fibers.