Colored nanoparticles for ecological dyeing of cellulosic fibers

Dyeing cellulosic fibres with reactive dyes wastes great quantities of salt and water. The objective of this work is to dye cellulosic fibers using colored nanoparticles (CNPs) as an alternative to dyeing with reactive dyes. CNPs do not need salt nor soaping after dyeing, consuming less than 50% of water

Adsorptive stripping voltammetric determination of reactive dyes

The present study was mainly devoted to evaluate the applicability of differential pulse adsorptive stripping voltammetry (DPAdSV) for the determination of ultra-trace concentration levels of a range of reactive dyes. The studied reactive dyes were found to adsorb effectively onto the hanging mercury drop electrode (HMDE). This applied electroanalytical method was primarily based on the nonelectrolytic accumulation (adsorption) of the analyte of interest (reactive dye), followed by a cathodic reduction scan measurement. Consequently, the adsorptive stripping voltammograms of the analysed reactive dyes exhibited several useful electrochemical signals, corresponding to the cathodic reduction of the anthraquinone, azo and halo-striazine groups... cont'd

Sol-gel technology for ecological dyeing cellulosic of fibres

Dyeing cellulosic fibres with reactive dyes wastes great quantities of salt and water. The objective of this work is to dye cellulosic fibers using coloured nanoparticles (CNPs) as an alternative to dyeing with reactive dyes, without salt and with only a short washing-off procedure at the end of dyeing. Samples of cotton were dyed by exhaustion with CNPs at light to medium colours. Washfastness results are given. Complete Washing-off sequence after dyeing was not necessary for the red and yellow colours, only one rinsing. The blue colour needs some washing off since the fastness is lower than for the other colours even though soaping is not necessary, saving energy and time relative to dyeing with reactive dyes

An evaluation of the environmental fate of reactive dyes

Merged with duplicate record 10026.1/697 on 01.02.2017 by CS (TIS)Dyestuffs are widely used industrial chemicals, yet surprisingly little is known about their fate in the environment. The potential modes of transformation and removal of reactive dyes in treatment and in the environment are principally through anaerobic and aerobic biodegradation and photodegradation. The research herein describes the use of LC-MS analysis with laboratory simulations to develop a better understanding of the occurrence and fate of reactive dyes and their degradation products in the aquatic environment. One reason for the lack of information on the environmental fate of reactive dyes has been the paucity of robust analytical methods suitable for the determination of dyes in aqueous samples. Robust analytical methods were optimised to provide LC-MS and MSMS identification of degradation products. Additionally, interpretation of the MSMS spectra of known reactive dyes provided novel characteristic fragment ions indicative of the triazine reactive group of reactive dyes . Fibre reactive dyes are designed to have a degree of photostability and therefore their photodegradation behaviour has not been widely investigated. Little is known of their stability to daylight over prolonged periods of irradiation in dilute aqueous solutions and in the presence of humic substances. The kinetics of photodegradation of an anthraquinone dye (Reactive Blue H4R) and azo dye (Reactive Yellow P5G) were evaluated. The former underwent rapid and extensive degradation 01/2 1.5 h). The major products formed were identified using LC-MSMS and a photodegradation pathway proposed. By comparison, the photodegradation of the azo dye was significantly slower, 01/2 30 h). The addition of humic substancesa ppearedt o have little effect on the rate of photodegradationu nder the conditions used. The reduction of azo dyes under anaerobic treatment has been extensively studied, but the subsequent fate of the initial reduction products when exposed to air are not understood. Three relatively simple azo dyes, Amaranth, Sunset Yellow and Naphthol Blue-Black, were reduced and their autoxidation products identified by LC-MS. These were subsequently used to predict the autoxidation products of a more complex azo reactive dye: Reactive Red 3.1. Additionally, a persistent degradation product from the anaerobicaerobic treatment of Reactive Red 3.1 was identified from LC-MS data. Azo reactive dyes are generally regarded as being resistant to aerobic degradation and there are few published data regarding degradation pathways for reactive anthraquinone dyes. Pure cultures of Pseudomonas docunhae, A 9046 and A texaco and mixed bacterial consortia (semi-continuous activated sludge, SCAS) aerobic degradation of azo and anthraquinone reactive dyes was studied. Two azo dyes were degraded by pure cultures of A docunhae and A 9046, suggesting that azo dyes can be aerobically degraded given favourable conditions. The antraquinone dye was extensively degraded by SCAS and pure culture biodegradation. Metabolites were identified by LC-MS and a degradation pathway proposed.AstraZeneca Brixharn Environmental Laboratory Freshwater Quarry Brixharn, Devo

Removal of reactive dyes by quaternized coconut husk

Coconut husk modified through the use of N-(3-chloro-2-hydroxypropyl)- trimethylammonium chloride was evaluated for its ability to remove reactive dyes from aqueous solution. Sorption of dyes was pH dependent and favorable sorption occurred at low pH. In contrast, natural coconut husk showed very little uptake of these reactive dyes. The maximum sorption capacities of the modified coconut husks for Reactive Blue 2, Reactive Yellow 2, Reactive Orange 16 and Reactive Blue 4 were 128.9, 182.2, 254.5 and 423.7 mg/g respectively. Column experiments using textile effluent showed that the reactive and disperse dyes in the effluent could be successfully removed

Application of biotechnology in the coloration of jute fabric using bis–triazinyl type of reactive dyes

Two sets of processed jute fabric, viz. alkaline scoured-bleached and bioscoured -bleached jute fabrics, have been dyed separately with two neucleophilic substitution type (bis- triazinyl type) of reactive dyes, namely Procion Blue HERD and Procion Green HE4BD dyes. It is observed that bioscoured - bleached- reactive dyed jute fabric shows higher dye uptake than that produced by alkaline scoured-bleached-reactive dyed jute fabric in case of both the reactive dyes. Bio-treatment results in improvement of handle and wash fastness properties of jute fabric. Brightness of the shade is also improved in case of biotreated-bleached-reactive dyed jute fabric. 

Synthesis and Characterization of Some Mono Chloro-S- Triazine Vinyl Sulphone Reactive Dyes

A series of ten bifunctional mono-chloro-s-triazine vinyl sulphone reactive dyes were synthesized based on Hacid with varied substituents coded as (BRD). These dyes were characterized by IR spectroscopy. The results revealed an incorporation of various substituents. The visible absorption spectra of these dyes were examined in various solvents and results shows positive and negative salvatochromism as the solvent polarity; changes, melting point, percentage yield and molar extinction co-efficient of these dyes were also evaluated and the results obtained are within a reasonable range acceptable for commercial dyeing.Keywords: Bifunctional Reactive Dyes, Characterization, Synthesi

Isotherm And Kinetics Of Reactive Dye Adsorption On Palm Kernel Shell-Based Activated Carbon

The adsorptions of two reactive dyes, Reactive Black 5 and Reactive Red E onto Palm Kernel Shell-based activated carbon (granule form) and commercial grade coal-based activated carbons (powder form) were studied. The experiment was carried out to investigate the effect of the presence of more than one type dye in solution on equilibrium and kinetic of adsorption. Equilibrium isotherm models were applied to describe the adsorption capacities of both single and binary systems. All batch experiments were carried out at a constant temperature of 28°C (+2°C) using an incubator shaker that was operated at 150 rpm. The results showed that adsorption of reactive dyes onto commercial coal-AC from single system can be successfully described by Langmuir model. The adsorptions onto Palm Kernel Shell-AC in single and binary systems can be successfully described by Freundlich and the Redlich-Peterson models and by Modified Extended Freundlich model, respectively. Experimental data showed that competitive adsorption for active sites on the carbon surface reduces overall uptake capacity of the reactive dyes. The rate of adsorptions of two reactive dyes, Reactive Black 5 and Reactive Red E onto Palm Kernel Shell-AC were studied. The sorption kinetics was well described by pseudo-second-order kinetic model in single system. In addition, the experiment was carried out to investigate three models: film resistance model, film-surface and film-pore diffusion models. The results showed that the external coefficients of mass transfer, Kf, decreased with increasing of initial adsorbate concentration. Variations of Kf values, indicated that adsorption was controlled by both external and intraparticle diffusion. Furthermore, simulation results showed that the rate of the kinetic process was controlled by two resistance models. It was found that the adsorption process was better described by film-surface diffusion model. Finally, the Chemical Oxygen Demand (COD) of the treated reactive dyes solutions from single and binary systems showed that a minimum of 4g/L dosage of PKS was needed to reduce the COD to acceptable level according to the United State Water Quality Guidelines and Pollutant Fact Sheets guidelines. From the work, it was clearly shown that PKS-AC had good adsorption capacity on reactive dye. This study provides information on adsorption mechanism of binary reactive dye system which is useful in adsorption column desig

Monoazo reactive dyes: Synthesis and application on cotton, silk and wool fibers

Mono azo reactive dyes are mostly used in textiles industries. The current study was developed to synthesize and apply mono azo reactive dyes. The primary goal of this research article is to highlight synthesized dyes with outstanding fixing properties for the dyeing and printing sectors to invent in future. Diazotized o-anisidine was coupled with several 4-amino-4ʼ-hydroxy benzilidene acetophenone cyanurated coupling component including H-acid, Gamma acid, J-acid, N-methyl J-acid, N-phenyl J-acid, K- acid and peri acid, to create a variety of monoazo reactive dyes. IR and elemental analyses were used to describe them. Moreover, the dyeing capabilities of each of these dyes on silk, wool, and cotton have been evaluated. The wet fastness properties also evaluated. Synthesized mono azo reactive dyes have excellent fixation values as well as fastness properties.Os corantes reativos monoazo são usados principalmente nas indústrias têxteis. O presente estudo foi desenvolvido para sintetizar e aplicar corantes reativos mono azo. O objetivo principal deste artigo de pesquisa é destacar corantes sintetizados com excelentes propriedades de fixação para os setores de tingimento e estamparia investirem ainda mais. A o-anisidina diazotizada foi acoplada a vários componentes de acoplamento cianuratados de 4-amino-4'-hidroxi benzlideno acetofenona, incluindo ácido H, ácido gama, ácido J, ácido N metil J, ácido N-fenil J, ácido K e peri ácido, para criar uma variedade de corantes reativos monoazo. Análises elementares de IR e nitrogênio foram usadas para descrevê-los. Além disso, as capacidades de tingimento de cada um desses corantes em seda, lã e algodão foram avaliadas. As propriedades de resistência à umidade também foram avaliadas. Os corantes reativos monoazo sintetizados têm excelentes valores de fixação, bem como propriedades de solidez