Textile Dyeing Processes Research Articles

Kandungan Fitokimia pada Ekstrak Kulit Kayu Tingi (Ceriops tagal) dengan Proses Ultrasonikasi

Tingi (Ceriops tagal) is considered as one of the natural dyes used in textile dyeing process. The purpose of this study was to determine the effect of extraction duration (20, 40, 60, 80 and 100 minutes) on ultrasonic extraction of tingi bark on yield value, total phenolics content, total flavonoids content, and total tannins content. The yield was calculated by drying the solution with a freezer dryer, while the phytochemical content was calculated by reading method on UV-vis spectrophotometry. The results of the experiment showed that the yield value of the duration treatment was in the range of 1.8 to 2.7%. Total phenolic content ranged from 268.1-314.1 mgGAE/g sample, total flavonoid content in the range of 68.3-87.1 mgQE/g sample, and total tannin content in the value between 244.8-338.1 mgTAE/g sample. The highest compound content was in the duration of 20 minutes.

Sustainable Textile Manufacturing with Revolutionizing Textile Dyeing: Deep Learning-Based, for Energy Efficiency and Environmental-Impact Reduction, Pioneering Green Practices for a Sustainable Future

The textile industry, a substantial component of the global economy, holds significant importance due to its environmental impacts. Particularly, the use of water and chemicals during dyeing processes raises concerns in the context of climate change and environmental sustainability. Hence, it is crucial from both environmental and economic standpoints for textile factories to adopt green industry standards, particularly in their dyeing operations. Adapting to the green industry aims to reduce water and energy consumption in textile dyeing processes, minimize waste, and decrease the carbon footprint. This approach has become crucial in achieving sustainability in textiles following the signing of the Paris Climate Agreement. Important elements of this transformation include the reuse of washing waters used in the dyeing process, the recycling of wastewater, and the enhancement of energy efficiency through necessary methodological and equipment changes. This study analyzes the energy, labor, production, and consumption data since 2011 for a textile factories with four branches located in the Adana Organized Industrial Zone. Among these factories, the one designated as UT1, which has the highest average energy and water consumption compared to the other three branches, is selected. In recent years, the use of artificial intelligence and machine learning technologies in predicting industrial processes has been increasingly observed. The data are analyzed using LSTM (Long Short-Term Memory) and ANN (Artificial Neural Networks) forecasting methods. Particularly, the LSTM algorithms, which provided the most accurate results, have enabled advanced forecasting of electricity consumption in dyeing processes for future years. In 2020, electricity consumption was recorded as 3,717,224 kWh and this consumption was reflected in the total energy cost as TRY 1,916,032. Electricity consumption accounts for 22.34% of total energy consumption, while the share of this energy type in the cost is 43.25%. In the light of these data, the MAPE value for energy consumption forecasts using the LSTM model was 0.45%, which shows that the model is able to forecast with high accuracy. As a result, a solar power plant was installed to optimize energy consumption, and in 2023 60% energy savings were achieved in summer and 25% in winter. The electricity consumption forecasting results have been an essential guide in planning strategic initiatives to enhance factory efficiency. Following improvement efforts aimed at reducing energy consumption and lowering the carbon footprint, significant optimizations in processes and layouts have been made at specific bottleneck points within the facility. These improvements have led to savings in labor, time, and space, and have reduced unit production costs.

Environmentally sound recycling of agricultural waste: A sustainable approach to develop bio-functional art textile

The agricultural processing industry produces a large amount of waste on a global scale whose disposal is simultaneously a nuisance and of special interest. The by-products are rich in bioactive phytoconstituents that might be beneficial to the production of bio-functional textiles. The present work uses agricultural wastes for the eco-friendly dyeing of woolen yarns. Response surface methodology based on 23- Central Composite Design was used to design experiments, evaluate the main dyeing parameters, develop efficient mathematical models to predict the dyeing process, and optimize the procedure. The quadratic regression models developed were found to be statistically significant using ANOVA, with R2 -value of 0.9734 and 0.9820 for color strength and lightness responses, respectively. Also, eye-soothing tone and hues with a good resistance to durability (4–5) and light (4) were achieved. The banana shell and gallnut bio-mordants improved UV protection by up to 25.33% and 59.79%, respectively. Generally speaking, the results showed that C. Oblonga leaf as well as gallnut and banana shells could be used as whole crop products in an ecologically sound textile dyeing process through a sustainable approach and that the proposed innovative application might serve as an attractive procedure for recycling and green waste management.

Comparing Color Strength Results through Analysis of Rinse Water between Wool Dyed with Onion Skins and Mordants and Synthetic Dye

The textile industry is one of the biggest global polluters releasing chemicals into the air, land, and water. The majority of these emissions are due to the chemicals that enter the water stream from the textile dyeing process. While synthetic dye effluents are very hard to remove from the wastewater, natural dyes have a very minimal effect on the environment due to their biodegradability. One major issue that prevents the textile industry from using natural dyes is the differences in colorfastness between the synthetic dyes and natural dyes. Because of this, this study will evaluate if the use of a mordant before fiber dyeing could increase the colorfastness of a natural dye so that the use of natural dyes can be increased in the textile industry. Harvesting a dye from yellow onion skins has proved to be an attractive dye product not only due to its color performance but since it is a natural waste product, not interfering in the food supply chain. Dye from onion skins was compared to a synthetic dye counterpart, Rit brand dye. One wool sample was dyed with Rit, and three others with the onion dye without a mordant, and with lemon juice or iron ferrous sulfate as mordants. These samples were then washed until the rinse water became clear. The rinse water was then evaluated with a UV-visible spectrophotometer. The KubelkaMunk theory was used to solve for color strength of the rinse water or how much dye bled from the wool during washing. In conclusion the Rit dye and the onion dye with the lemon mordant performed better than the onion dyes without a mordant and with an iron mordant.

Emerging pollutants in textile wastewater: an ecotoxicological assessment focusing on surfactants.

Water and several chemicals, including dyestuffs, surfactants, acids, and salts, are required during textile dyeing processes. Surfactants are harmful to the aquatic environment and induce several negative biological effects in exposed biota. In this context, the present study aimed to assess acute effects of five surfactants, comprising anionic and nonionic classes, and other auxiliary products used in fiber dyeing processes to aquatic organisms Vibrio fischeri (bacteria) and Daphnia similis (cladocerans). The toxicities of binary surfactant mixtures containing the anionic surfactant dodecylbenzene sulfonate + nonionic fatty alcohol ethoxylate and dodecylbenzene sulfonate + nonionic alkylene oxide were also evaluated. Nonionic surfactants were more toxic than anionic compounds for both organisms. Acute nonionic toxicity ranged from 1.3mg/L (fatty alcohol ethoxylate surfactant) to 2.6mg/L (ethoxylate surfactant) for V. fischeri and from 1.9mg/L (alkylene oxide surfactant) to 12.5mg/L (alkyl aryl ethoxylated and aromatic sulfonate surfactant) for D. similis, while the anionic dodecylbenzene sulfonate EC50s were determined as 66.2mg/L and 19.7mg/L, respectively. Both mixtures were very toxic for the exposed organisms: the EC50 average in the anionic + fatty alcohol ethoxylate mixture was of 1.0mg/L ± 0.11 for V. fischeri and 4.09mg/L ± 0.69 for D. similis. While the anionic + alkylene oxide mixture, EC50 of 3.34mg/L for D. similis and 3.60mg/L for V. fischeri. These toxicity data suggested that the concentration addition was the best model to explain the action that is more likely to occur for mixture for the dodecylbenzene sulfonate and alkylene oxide mixtures in both organisms. Our findings also suggest that textile wastewater surfactants may interact and produce different responses in aquatic organisms, such as synergism and antagonism. Ecotoxicological assays provide relevant information concerning hazardous pollutants, which may then be adequately treated and suitably managed to reduce toxic loads, associated to suitable management plans.

A response surface model to examine the reactive red 239 sorption behaviors on Rhizoclonium hieroglyphicum: isotherms, kinetics, thermodynamics and toxicity analyses.

The present study is an attempt to investigate the potentiality of Rhizoclonium hieroglyphicum in the removal of reactive red 239 (RR239) from aqueous solution and to assess the toxicity of the treated dye solution. Optimisation of the process variables namely dye and biosorbent concentrations, pH, temperature and incubation time for RR239 removal was performed using Response Surface Methodology (RSM) assisted Box Behnken Design (BBD) model. The recycling and regeneration efficiency of the dye adsorbed alga was evaluated using different eluents under optimized conditions. Further to understand the adsorption mechanism, isotherms, kinetics and thermodynamic studies were performed. UV-vis and FT-IR spectroscopy was employed to confirm the interaction between the adsorbate and biosorbent. The nature of the treated dye solution was assessed using phyto, microbial and brine shrimp toxicity studies. On the basis of quadratic polynomial equation and response surfaces given by RSM, 90% decolorization of RR239 was recorded at room temperature under specified optimal conditions (300mg/L of dye, 500mg/L of biosorbent, pH 8 and 72h of contact time). Desorption experiments demonstrated 88% of RR239 recovery using 0.1N acetic acid as an eluent and 81% of dye removal in regeneration studies. The data closely aligned with Freundlich isotherm (R2 - 0.98) and pseudo-second-order kinetic model (R2 - 0.9671). Thermodynamic analysis revealed that the process of adsorption was endothermic, spontaneous, and favorable. UV-Vis and FT-IR analyses provided evidence for adsorbate-biosorbent interaction, substantiating the process of decolorization. In addition, the results of phyto, microbial and brine shrimp toxicity assays consistently confirmed the non-toxic nature of the treated dye. Thus, the study demonstrated that R. hieroglyphicum can act as a potent bioremediation agent in alleviating the environmental repercussions of textile dyeing processes.

A novel environmental friendly and sustainable process for textile dyeing with sulphur dyes for cleaner production

This investigation herein primarily focuses on developing a new textile dyeing process with sulphur dye class at room temperature using bacterial Lysate. Sulphur dyes are applied on cotton to produce dark shades at a lower cost, primarily providing excellent colour fastness, except against chlorinating agents. The insoluble sulphur dyes, like vat dyes, are first reduced and then applied as soluble leuco compounds that need to be kept under alkaline conditions, along with a reducing agent. The conventionally followed method of dying process involves the process of reduction of dyes using hazardous chemicals as reducing agent and alkali at higher temperature as well as subsequent dyeing at higher temperatures (60–80 °C) varying with the nature of dyes and processes. It eventually eliminates traditional heating arrangements and achieving easier control of the dyeing process at room temperature than at high temperatures. This investigation compares the newly designed processing route with the followed traditional process in the context of exhaust dyeing and rope dyeing methods with padding mangle. In addition, it involves in substituting the conventional reducing agent i. e. sodium sulphide partially with sodium hydrosulphite for sulphur dyeing. In nut-shell, this process comprises of reduction of dyes in the presence of an alkali agent, a reducing agent and a catalytic agent, wherein the reducing catalytic agent is a bacterial Lysate, establishing it to be environmentally viable, energy and cost effective, and sustainable dying process along with promising improvement quality in terms of dye uptake and comparable fastness properties.

Acryloyl esters of emodin for waterless dyeing and toxicological studies

AbstractTraditional textile dyeing processes usually require large quantities of water and energy and generate wastewater that can be harmful to the environment. Dyeing in supercritical carbon dioxide (sc‐CO2) media is promising in textile coloration due especially to it providing a waterless process and eliminating the need for an energy intensive drying step. The natural anthraquinone emodin showed promising results for dyeing different fibres through sc‐CO2 process. However, emodin is mutagenic. The aim of this study was to develop non‐mutagenic derivatives of emodin that can be applied to textiles using sc‐CO2. Emodin structure was modified incorporating acryloyl groups, which are considered suitable for decreasing potential for DNA intercalation, and thus mutagenicity. The presence of acryloyl groups would also enable atmospheric plasma induced bonding with fibres. Molecular modelling studies showed that emodin derivatives became less planar with increasing number of attached acryloyl groups, making intercalation unlikely. The derivatives produced were tested to assess mutagenicity in vitro (Salmonella/microsome assay, TA1537, 10% S9) and in vivo (micronucleus test in hemocytes of aquatic crustacean). We found that emodin can be derivatised using acryloyl chlorides to give mono‐ and di‐acrylate esters suitable for dyeing polyester fibres in sc‐CO2. However, the new dyes presented mutagenicity for both in vitro and in vivo. Although the derivatives provided greenish‐yellow alternatives to emodin for dyeing synthetic fibres, they do not appear to be viable alternatives from the point of view of preserving human and environmental health. Plasma bonding studies are underway.

DYEING AT HOME FROM KITCHEN WASTE - TEA AND COFFEE RESIDUE

Food and Textile industries are considered to be the most vital industries for human survival. The food industry generates an enormous amount of waste which is used as animal feed or undergoes composting or just go as landfills. Some of these organic wastes contains colouring pigments which can be effectively used to colour textiles. Hence there is a possibility to bridge the gap utilizing the waste from food industry to colour textile materials. Chemical dyes are easier to use and produce bright shades but on the other hand it causes pollution to the environment. Natural dyes from plant sources are required in large amounts which may cause depletion of natural resources. Considering these factors, the waste material from food industry, which is available at little, or no cost can be effectively used to colour textiles, this would make natural dyeing affordable and bring about sustainability in textile dyeing process. This kind of sustainable approach protects the environment by utilizing the waste produced by one industry and creating a value-added item for another industry. This study was carried out considering the sustainability aspect which is mutually beneficial to food and textile industries.Natural dyes can be found in the kitchen or in one’s garden can produce beautiful hues. A simple dyeing process can be used to colour the fabric at home utilising available resources in the home kitchen. Decoction waste after extracting two widely used beverages - tea dust and filter coffee dust which are part of everyday kitchen waste were used for the study. Instead of these wastes going directly as landfills, dye was extracted prior to its disposal. Cotton fabric, mordanted with Alum, was dyed with the extracted dye. These dyed fabrics showed good to excellent colour fastness to perspiration, rubbing, washing, and pressing. Since these dyes are natural in origin, they are safe and eco-friendly. This study proves that throw-away kitchen waste can be utilized to extract dyes that can be used to create value-added products.

The Sustainable Bioactive Dyeing of Textiles: A Novel Strategy Using Bacterial Pigments, Natural Antibacterial Ingredients, and Deep Eutectic Solvents.

The textile industry stands as a prominent contributor to global environmental pollution, primarily attributable to its extensive reliance on synthetic dyes, hazardous components, and solvents throughout the textile dyeing and treatment processes. Consequently, the pursuit of sustainable textile solutions becomes imperative, aimed at replacing these environmentally unfriendly constituents with biobased and bioactive pigments, antibacterial agents, and, notably, natural solvents. Achieving this goal is a formidable yet indispensable challenge. In this study, the dyeing ability of the crude gel prodigiosin, produced by non-pathogenic bacteria Serratia plymuthica, was investigated on various multifiber fabrics at different conditions (temperature and pH) and by using salts and alternative mordants (the conventional Ferrous Sulphate (FeSO4) and a new bio-mordant, L-Cysteine (L-Cys)). Additionally, a novel gel-based Choline chloride (ChCl)/Lactic acid (LA) (1:2) deep eutectic solvent (DES) dyeing medium was studied to replace the organic solvents. Nylon fabrics dyed with 3.0% over the weight of the fiber (owf) L-Cys at pH = 8.3 had improved color fastness to washing, while the gel-based ChCl/LA (1:2) DES dyebath provided a better color fastness to light. Moreover, nylon fabrics under these conditions exhibited remarkable antimicrobial activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In conclusion, the utilization of the crude gel-based prodigiosin pigment demonstrates a distinct advantage in dyeing textile materials, aligning with the growing consumer demand for more eco-friendly and sustainable products. Additionally, the application of the natural reducing agent L-Cys, previously untested as a bio-mordant, in conjunction with the use of gel-based DES as a dyeing medium, has showcased improved colorimetric and antibacterial properties when applied to nylon that is dyed with the crude gel prodigiosin pigment.

A green approach of vat dyeing of cotton fabric with natural reducing agents

This study focuses on an eco-friendly approach to vat dyeing of cotton fabric using natural reducing agents and compare their performance with a conventional reducing agent. Natural reducing agents derived from pineapple barks, watermelon, and carambola extracts were investigated as alternatives. The reduction potential and FTIR of these natural extracted reducing agents were evaluated to assess their dyeing capability. Different colorimetric properties, color strength, colorfastness, bursting strength and pilling resistance of the dyed fabrics were analyzed. The environmental impact of the dyeing process was assessed by measuring parameters such as BOD, COD, TDS, DO and pH values. The results indicated that the natural reducing agents exhibited comparable reduction potential to sodium dithionite. Colorimetric analysis revealed that the optimal concentrations of the reducing agents for dyeing were 500–600 ml/l. The carambola extract showed the best colorimetric properties among the three reducing agents tested. The study demonstrates the potential of natural reducing agents as eco-friendly alternatives for vat dyeing of cotton fabric, contributing to sustainable and green textile dyeing processes.

Textile dyes effluents: A current scenario and the use of aqueous biphasic systems for the recovery of dyes

The textile industry is one of the most important industries in the world, but it is also one of the largest wastewater generators responsible for water depletion and ecotoxicity due to the inefficient fixation of textile dyes in fabrics. Although various studies have focused on the physicochemical and biological treatments of wastewater, these processes can be expensive and/or not environmentally sustainable, mainly focusing on the degradation of dyes rather than their valorisation. Aiming at the circularity of textile industries, Aqueous Biphasic Systems (ABS) have been proposed as circular, cost-effective, and sustainable platforms for the recovery of textile dyes. Thus, an overview of the use of ABS in the extraction and concentration of textile dyes is provided in this study, along with the main aspects of the textile dyeing process, the types of dyes used, their fixation efficiency, textile effluent composition, and commonly studied treatment methods. Overall, this study allows us to understand the influence of dye characteristics and ABS phase-forming compounds on the recovery efficiency of dyes, demonstrating the advantages of using this type of system in the design of a circular and sustainable extraction platform for the recovery and concentration of these compounds, as well as identifying the necessary improvements to successfully implement ABS-based processes at an industrial scale.

Optimization and prediction of the cotton fabric dyeing process using Taguchi design-integrated machine learning approach

The typical textile dyeing process calls for a wide range of operational parameters, and it has always been difficult to pinpoint which of these qualities is the most important in dyeing performance. Consequently, this research used a combined design of experiments and machine learning prediction models’ method to offer a sustainable and beneficial reactive cotton fabric dyeing process. To be more precise, we built a least square support vector regression (LSSVR) model based on Taguchi's statistical orthogonal design (L27) to predict exhaustion percentage (E%), fixation rate (F%), and total fixation efficiency (T%) and color strength (K/S) in the reactive cotton dyeing process. The model's prediction accuracy was assessed using many measures, including root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2). Principal component regression (PCR), partial least square regression (PLSR), and fuzzy modelling were some of the other types of regression models used to compare results. Our findings reveal that the LSSVR model greatly outperformed competing models in predicting the E%, F%, T%, and K/S. This is shown by the LSSVR model's much smaller RMSE and MAE values. Overall, it provided the highest possible R2 values, which reached 0.9819.

Evaluating the efficacy of wood decay fungi and synthetic fungal consortia for simultaneous decolorization of multiple textile dyes.

Wastewater from the textile industry dyeing process containing high loads of synthetic dyes leads to pollution of water with these toxic and genotoxic dyes. Much effort has been put towards developing biological systems to resolve this issue. Mycoremediation is a well-known approach using fungi to remove, degrade, or remediate pollutants and can be applied to decolorize textile dyes in industrial effluent. Fungal strains from four genera of Polyporales, namely Coriolopsis sp. TBRC 2756, Fomitopsis pinicola TBRC-BCC 30881, Rigidoporus vinctus TBRC 6770, and Trametes pocas TBRC-BCC 18705, were studied for decolorization efficiency, and R. vinctus was found to exhibit the greatest activity in removing all seven tested reactive dyes and one acid dye with a decolorization efficiency of 80% or more within 7 days under limited oxygen. This fungus simultaneously degraded multiple dyes in synthetic wastewater as well as industrial effluent from the dyeing process. To enhance the decolorization rate, various fungal consortia were formulated for testing. However, these consortia only trivially improved efficiency compared with using R. vinctus TBRC 6770 alone. Evaluation of R. vinctus TBRC 6770 decolorization ability was further performed in a 15-L bioreactor to test its ability to eliminate multiple dyes from industrial effluent. The fungus took 45 days to adapt to growth in the bioreactor and subsequently reduced dye concentration to less than 10% of the initial concentration. The following six cycles required only 4-7 days to reduce dye concentrations to less than 25%, demonstrating that the system can run efficiently for multiple cycles without the need for extra medium or other carbon sources.

Efficient and environmentally friendly removal of azo textile dye using a low-cost adsorbent: Kinetic and reuse studies with application to textile effluent

Recently, there has been an increasing interest in environmentally friendly methods for the removal of toxic dyes to enable sustainable textile dyeing processes. In this study, a highly efficient, non-toxic, low-cost MgO particles were prepared by sol-gel technique and utilized for the removal of Reactive Red 21 azo dye by adsorption process. The prepared MgO particles were characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, and Particle Size Analysis. The batch adsorption studies were performed for optimizing the parameters affecting adsorption. The adsorption behavior of Reactive Red 21 was accurately characterized by the Langmuir model. The adsorption process was found to be thermodynamically spontaneous at room temperatures as indicated by the negative Gibbs free energy change (∆G) value of −30.65 kj/mol. The kinetic studies indicate that the pseudo-second-order model provides a good fit to the adsorption of Reactive Red 21. The adsorption capacity of the prepared MgO particles for Reactive Red 21 was determined to be 355 mg/g at room temperature over a wide pH range of 5–9, with a contact time of 20 min. The regeneration of dye-adsorbed MgO particles was conducted at 500 °C for 2 h. The regenerated MgO particles were then utilized for adsorbing Reactive Red 21 five times with a sufficiently high dye removal efficiency. The prepared MgO particles provided a 98 % dye removal in real textile wastewater containing Reactive Red 21 dye.

A framework for environmental production of textile dyeing process using novel exhaustion-rate meter and multi-layer perceptron-based prediction model

In textile industries, a lot of wastewater are discharged which are one of the major environmental pollution problems, because they release undesirable dye effluents. Owing to re-dyeing procedures performed to meet customized color specifications, environmental pollution is a serious problem because of the emission of large volumes of wastewater. To solve the environmental problems caused by re-dyeing, the right-first-time (RFT) %, which is the rate at which the target quality is obtained with just one dyeing, must be increased by considering the dyeing conditions that affect product quality. Here, this study suggests a framework for cleaner production of textile dyeing process using novel exhaustion-rate meter (NERM) and multi-layer perceptron-based prediction model to solve the environmental problems caused by re-dyeing procedure by controlling the exhaustion-rate outliers. The proposed NERM measures the exhaustion-rate based on absorbance of the dyeing solution and is composed of measuring and analysis section. The dyeing solution absorbance is metered in the measuring component through a detector, which performs high-resolution measurement (0.3–1.5 nm full width at half maximum) via a 25-μm slit in the 200–1100-nm wavelength range; the absorbance is then converted to the exhaustion-rate based on Beer's law in the analysis section. Using the NERM, an exhaustion rate dataset according to the Na2SO4 and Na2CO3 consumption is acquired and a surrogate model that augments the exhaustion rate data is developed. The MLP-based prediction model is then developed using the augmented data to control the real-time exhaustion-rate outliers. As a results, the model performance as regards Na2SO4 and Na2CO3 prediction is indicated by R2 values of approximately 0.985 and 0.998, respectively, and root mean squared errors (RMSE) of approximately 1.477 and 1.000, respectively. In addition, the effectiveness of the proposed framework is demonstrated through application to several scenarios in which the real-time exhaustion rate outliers are detected.

Hydrogen-Bond-Assisted Dye-Incorporated Waterborne Poly( urethane-urea) (WPU) for an Environment-Friendly Textile Dyeing Process

To propose a green dyeing strategy permitting the incorporation of chromophores via the promotion of physical bonding and a simple sewage processing procedure, a strategy for increasing the reactivity of a conventional disperse dye, namely, 1-amino-4-hydroxy-2-phenoxyanthraquinone (Disperse Red 60, R60), to isocyanate groups and miscibility with waterborne poly(urethane-urea) (WPU) was reported. The modified dye R60-OH was prepared by the alkylation of 3-bromopropan-1-ol. Subsequently, R60-OH was reacted with the trifunctional isocyanate (named R60-O-THDI), which provided additional hydrogen bonds between the dye and the polymer chain and rendered better color fastness. Polyester, nylon, and cotton fabric coated with R60 and R60-O-THDI-incorporated WPUs were investigated by colorimetric analysis, washing tests, and rubbing color fastness. R60-O-THDI exhibited the best rubbing and washing color fastness, indicative of a simple method to fabricate a water-based dye ink without grafting a chromophore onto a polymer backbone via the promotion of physical bonding. The proposed green dyeing strategy also permitted a simple sewage processing procedure to recover polyurethane from the suspension by changing the pH, rendering better color fastness on textiles, as well as less wastewater production.

Production of a novel laccase from Ceratorhiza hydrophila and assessing its potential in natural dye fixation and cytotoxicity against tumor cells

BackgroundFlavonoid natural dyes have gained attention because they are nontoxic and eco-friendly. However, they do not work effectively with artificial fibers and require the use of mordants, which are considered as hazardous chemicals. Laccase enzyme catalyzes the oxidation of phenols, forming phenoxyl radicals that undergo a further polymerization process. So, laccase can oxidize flavonoid dyes, and it can be used instead of harmful mordants in flavonoid dye fixation on cotton fabrics. Laccases also are involved in a variety of metabolic processes, and they have anti-proliferative effects toward HepG2 and MCF-7 tumor cells. ResultsAmong fifteen fungal isolates, the fungus Ceratorhiza hydrophila isolated from the submerged plant Myriophyllum spicatum was selected as the most potent laccase producer. Optimization of the production medium resulted in a 9.9-fold increase in laccase productivity. The partially purified Ceratorhiza hydrophila laccase could successfully improve the affinity of cotton fabrics toward quercetin (flavonoid) dye with excellent color fastness properties. The partially purified laccase also showed anti-proliferative activity against HepG2 and MCF-7 tumor cells. However, high laccase concentration is required to estimate IC50. ConclusionsCeratorhiza hydrophila MK387081 is an excellent laccase producer. The partially purified laccase from Ceratorhiza hydrophila can be used in textile dyeing and printing processes as a safer alternative to the conventional hazardous mordants. Also, it can be used in preparation of cancer treatment drugs. However, further studies are needed to investigate IC50 for both cell types at higher laccase concentrations.

In Situ Adsorption of Red Onion (Allium cepa) Natural Dye on Cellulose Model Films and Fabrics Exploiting Chitosan as a Natural Mordant.

Synthetic dyes and chemicals create an enormous impact on environmental pollution both in textile manufacturing and after the product's lifetime. Biobased plant-derived colorants and mordants have great potential for the development of more sustainable textile dyeing processes. Colorants isolated from biomass residues are renewable, biodegradable, and usually less harmful than their synthetic counterparts. Interestingly, they may also bring additional functions to the materials. However, the extraction and purification of the biocolorants from biomass as well as their dyeing efficiency and color fastness properties require a more thorough examination. Here, we extracted red onion (Allium cepa) skins to obtain polyphenolic flavonoids and anthocyanins as biocolorants, characterized the chemical composition of the mixture, and used a quartz crystal microbalance and thin films of cellulose nanofibrils to study the adsorption kinetics of dyes onto cellulose substrates in situ. The effect of different mordants on the adsorption behavior was also investigated. Comparison of these results with conventional dyeing experiments of textiles enabled us to determine the interaction mechanism of the dyes with substrates and mordants. Chitosan showed high potential as a biobased mordant based both on its ability to facilitate fast adsorption of polyphenols to cellulose and its ability to retain the purple color of the red onion dye (ROD) in comparison to the metal mordants FeSO4 and alum. The ROD also showed excellent UV-shielding efficiency at low concentrations, suggesting that biocolorants, due to their more complex composition compared to synthetic ones, can have multiple actions in addition to providing aesthetics.

Optimization of a Textile Effluent Treatment System and Evaluation of the Feasibility to Be Reused as Influents in Textile Dyeing Processes

Textile effluents derived from azo-reactive dyeing processes represent a severe problem for aquatic ecosystems and human health. The large amounts of water used in this process and the poor quality of the discharges urge the need to develop treatment systems that involve reusing treated water. In this research, we present the optimization of a feasible, simple, and efficient treatment system that improves the quality of the effluents from the cotton fabric dyeing process. Through the characterization of the influents and effluents, we have identified seven parameters that have allowed the optimization of the treatment. Analytical techniques, such as nephelometry, EDTA, gravimetry, and BOD5, among others, and specialized equipment, such as the spectrophotometer, have been used for these purposes. The results showed that using combustion gases in the neutralization stage and new flocculant-coagulant reagents improved parameters, such as pH, total solids, hardness, and conductivity. The quality of the effluents thus obtained allowed their reuse only in the stages before the dyeing bath without affecting the final quality of the cotton fabrics in dark colors. This effort implies savings in water and supplies, and opens the door to future research on the treatment of textile effluents that help improve the environmental conditions of our region.