Production Of Dyes Research Articles

Modular Cascade of Flow Reactors: Continuous Flow Synthesis of Water-Insoluble Diazo Dyes in Aqueous System.

Continuous flow synthesis is pivotal in dye production to address batch-to-batch variations. However, synthesizing water-insoluble dyes in an aqueous system poses a challenge that can lead to clogging. This study successfully achieved the safe and efficient synthesis of azo dyes by selecting and optimizing flow reactor modules for different reaction types in the two-step reaction and implementing cascade cooperation. Integrating continuous flow microreactor with continuous stirred tank reactor (CSTR) enabled the continuous flow synthesis of Sudan Yellow 3G without introducing water-soluble functional groups or using organic solvents to enhance solubility. Optimizing conditions (acidity/alkalinity, temperature, residence time) within the initial modular continuous flow reactor resulted in a remarkable 99.5% isolated yield, 98.6 % purity, and a production rate of 2.90 g h-1. Scaling-up based on different reactor module characteristics further increased the production rate to 74.4 g h-1 while maintaining high yield and purity. The construction of this small 3D-printing modular cascaded reactor and process scaling-up provide technical support for continuous flow synthesis of water-insoluble dyes, particularly high-market-share azo dyes. Moreover, this versatile methodology proves applicable to continuous flow processes involving various homogeneous and heterogeneous reaction cascades.

Green extraction and application of yellow natural curcumin colorant from Curcuma aromatica rhizomes for silk dyeing

Green products such as plant tints are becoming more and more well-known worldwide due to their superior biological and ayurvedic properties. In this work, colorant from Amba Haldi (Curcuma aromatica) was isolated using microwave (MW), and bio-mordants were added to produce colorfast shades. Response surface methodology was used to develop a central composite design (CCD), which maximizes coloring variables statistically. The findings from 32 series of experiments show that excellent color depth (K/S = 12.595) was established onto MW-treated silk fabric (RS = 4 min) by employing 65 mL of radiated aqueous extract (RE = 4 min) of 5 pH cutting-edge the existence of 1.5 g/100 mL used sodium chloride at 75 °C for 45 min. It was discovered that acacia (keekar) extract (1%), pomegranate extract (2%), and pistachio extract (1.5%) were present before coloring by the use of bio-mordants. On the other hand, upon dyeing, acacia extract (1.5%), pomegranate extract (1.5%), and pistachio extract (2%) have all shown extremely strong colorfast colors. Comparatively, before dyeing, salts of Al3+ (1.5%), Fe2+ (2%), and TA (1.5%) gave good results; after dyeing, salts of Al3+ (1%) and Fe2+ (1.5%) and TA (2%) gave good results. When applied to silk fabric, MW radiation has increased the production of dyes recovered from rhizomes. Additionally, the right amount of chemical and biological mordants have been added, resulting in color fastness ratings ranging from outstanding to good. Therefore, the natural color extracted from Amba Haldi can be a sustainable option for the dyeing of silk fabric in the textile dyeing and finishing industries.

Investigation of occurrence of aromatic amines in municipal wastewaters using passive sampling

Aromatic amines (AAs) are human-made compounds known for their mutagenic properties, entering surface waters from various sources, often originating as transformation products of dyes or pesticides. Despite their low concentrations in surface waters, AAs can exhibit mutagenicity. Our study focused on evaluating three passive samplers (PSs) for enriching these compounds from influent and effluent of a wastewater treatment plant (WWTP) in Brno, Czech Republic. The PSs tested included variants containing AttractSPE™ SDB-RPS sorbent disk, one with and one without a diffusive agarose hydrogel layer, and a modified Speedisk (Bakerbond Speedisk® H2O-Philic). PSs were deployed in wastewater (WW) for one to four weeks in various overlapping combinations, and the uptake of AAs to PSs was compared to their concentrations in 24-hour composite water samples. A targeted LC/MS analysis covered 42 amines, detecting 11 and 13 AAs in daily composite influent and effluent samples, respectively. In the influent, AAs ranged from 1.5 ng L−1 for 1-anilinonaphthalene to 1.0 μg L−1 for aniline, and the highest concentration among all measured amines was observed for cyclohexylamine at 2.9 μg L−1. In the effluent, concentrations ranged from 0.5 ng L−1 for 1-anilinonaphthalene to 88 ng L−1 for o-anisidine. PSs demonstrated comparable accumulation of amines, with integrative uptake up to 28 days in both influent and effluent and detection of up to 23 and 27 amines in influent and effluent, respectively; altogether 34 compounds were detected in the study. Sampling rates (Rs) were estimated for compounds present in at least 50 % of the samples and showing <40 % aqueous concentration variability, with robustness evaluated by comparing values for compounds in WWTP influent and effluent. Although all devices performed similarly, hydrogel-based PS exhibited superior performance in several criteria, including time integration and robustness of sampling rates, making it a suitable monitoring tool for AAs in WW.

Sustainable dye extraction: Annatto powder production in a fountain confined spouted bed

AbstractThis study proposes an efficient and sustainable process for annatto powder production using a fountain confined spouted bed. With widespread applications in industries such as food, pharmaceuticals, and cosmetics, conventional extraction methods face environmental and economic challenges. Our study explores a solvent‐free and eco‐friendly approach using mechanical attrition within a fountain confined spouted bed, offering a cost‐effective solution for annatto cultivation. We systematically investigated the impact of four parameters—fountain confiner position and length, draft tube diameter, and airflow velocity—employing experimental design, multiple regression analysis, particle swarm optimization, and computational fluid dynamics–discrete element method (CFD‐DEM) simulations. The proposed optimization condition shows significantly higher collision intensity, improving annatto powder production compared to other central composite design tests. This study contributes to developing of a sustainable and economically viable method for dye production, with potential implications for annatto‐producing regions globally.

Comparative study of graphene oxide and copper oxide nanoparticle as surface modifiers in microfiltration membranes and adsorbents for efficient removal of textile dyes from contaminated water

Despite technological development, the textile industry still generates effluents with a high content of emerging contaminants, which are harmful to the environment. Conventional wastewater treatment methods struggle to remove emerging contaminants, necessitating advanced techniques. One promising solution is the modification of membranes and adsorption methods. The same modifying agents were used to modify the surface of microfiltration membranes and to create an adsorbent, allowing a comparison of the two processes in water treatment contaminated with dyes. Copper oxide nanoparticles were produced through green synthesis, and polyethersulfone microfiltration membranes were surface-modified using graphene oxide and copper oxide nanoparticles via a pressure-assisted method. Among the tested membranes, MF_GO1.0 + CuO3.0 showed the best performance, demonstrating a synergistic effect between the modifying agents, efficiently removing 97.69 % of Levafix Blue CA dye and recovering 84.88 % of the flux. It also exhibited outstanding removal rates (>99 %) for other textile dyes, such as Solophenyl Blue and Reactive Black 5. Membrane characterization revealed a decrease in contact angle for membranes modified with CuO and GO-CuO, rendering them more hydrophilic and improving permeability. Scanning Electron Microscopy depicted a compacted membrane, characteristic of graphene oxide, with nanoparticles on the surface. Chemical stability tests, conducted at neutral pH for 7 days, demonstrated no significant variation in permeability and contaminant removal. Although adsorption had limited effectiveness in removing the Levafix Blue CA dye, it provided valuable insights into the underlying mechanisms. Comparing membrane modification with adsorption, membranes displayed more efficiency in dye removal and showed enhanced antifouling properties. These results indicate the potential of modified membranes in treating dye-containing wastewater. As dye production increases, these innovative technologies offer promising solutions to reduce the environmental impact of textile industry effluents. By employing such advanced methods, we can work towards safeguarding our water resources and ecosystems from the harmful effects of textile wastewater pollution.

Hues of risk: investigating genotoxicity and environmental impacts of azo textile dyes.

The textile industry, with its extensive use of dyes and chemicals, stands out as a significant source of water pollution. Exposure to certain textile dyes, such as azo dyes and their breakdown products like aromatic amines, has been associated with health concerns like skin sensitization, allergic reactions, and even cancer in humans. Annually, the worldwide production of synthetic dyes approximates 7 × 107 tons, of which the textile industry accounts for over 10,000 tons. Inefficient dyeing procedures result in the discharge of 15-50% of azo dyes, which do not adequately bind to fibers, into wastewater. This review delves into the genotoxic impact of azo dyes, prevalent in the textile industry, on aquatic ecosystems and human health. Examining different families of textile dye which contain azo group in their structure such as Sudan I and Sudan III Sudan IV, Basic Red 51, Basic Violet 14, Disperse Yellow 7, Congo Red, Acid Red 26, and Acid Blue 113 reveals their carcinogenic potential, which may affect both industrial workers and aquatic life. Genotoxic and carcinogenic characteristics, chromosomal abnormalities, induced physiological and neurobehavioral changes, and disruptions to spermatogenesis are evident, underscoring the harmful effects of these dyes. The review calls for comprehensive investigations into the toxic profile of azo dyes, providing essential insights to safeguard the aquatic ecosystem and human well-being. The importance of effective effluent treatment systems is underscored to mitigate adverse impacts on agricultural lands, water resources, and the environment, particularly in regions heavily reliant on wastewater irrigation for food production.

UV–visible spectroscopic exploratory insight into the long term photo-stability of the fast green FCF dye-fructose-sodium lauryl sulphate-NaOH electrolyte based photogalvanic cell

Photo-galvanic cells are organo-inorganic chemical based devices. These cells use chemicals like photo-sensitizer(s), reductant(s), surfactant(s), alkali, solvent, and electrodes. Photo-decay and sacrifice of the chemical materials is imminent leading to the limited electrical output, efficiency and life of these cells. For realizing practical applications, the scalability of electrical output and stability of these devices is of utmost importance. Therefore, the long term photo-stability of Fast Green FCF dye-Fructose-Sodium lauryl sulphate (SLS)-NaOH electrolyte based cells has been studied in present work. The electrical output of the cell has been monitored over long period of time. Further, the photo-stability of electrolyte has been determined and analyzed spectroscopically. It has been observed that the Fast Green FCF dye-Fructose-SLS-NaOH photogalvanic cell device is capable of producing power even after decay of electrolyte. In early 24 h, about 90.54 % of dye degradation is observed. The cell is capable of giving current with even left out concentration ∼0.2 × 10−4 M (i.e., 9.46 % of initial concentration) of sensitizer. Further, the photo-degradation products (organic sulfonates) of FCF dye and SLS are also potential candidates for current generation. Cell charged in sunlight is capable of generating current even after cutting-off the illumination of electrolyte.

Dynamic Scheduling of Multi-agent Electromechanical Production Lines based on Iterative Algorithms

In response to the optimization scheduling problem in the dyeing production process, the author proposes a hierarchical scheduling method for dyeing vats based on genetic algorithm and multi-agent. In this method, a hierarchical scheduling algorithm is used to decompose production scheduling into static and dynamic strategies. The static strategy adopts a genetic algorithm that supports batch processing of multiple products, non equality of equipment, order delivery time, switching cost, and other constraints: Dynamic strategy is a coordinated dynamic optimization algorithm that uses multi-agent systems to support the running status of dye tanks based on static strategies. By solving the algorithm with multiple constraints and dynamic factors in the production process, the final result of the dyeing tank operation task is obtained. The simulation compared pure genetic algorithm with manual scheduling, and the results showed that the hierarchical dynamic scheduling strategy based on data-driven achieved the goal of optimizing the production scheduling of dyeing vats. The practical application results also demonstrate the feasibility of this method.

EXTRACTION AND CHARACTERISATION OF NATURAL DYE FROM ORANGE PEEL FOR TEXTILE APPLICATIONS

Awareness of the need to protect the environment and people's health has led to an intensification of concerns for obtaining sustainable products and processes. Toxic waste created during the production and use of synthetic dyes has an impact on both human and environmental health. As a result, natural dyes are more secure and safer than synthetic dyes. This study is significant because it has the potential to help develop sustainable and environmentally friendly textile dyeing techniques. In this study, a natural dye was successfully extracted from orange peel (Citrus recticulata Rutaceae) which was applied on textile fibre and was found to be partly effective for eco-friendly dyeing applications. The extracted dye does not have a good wash fastness, which is the ability of the fabric to retain its colour after washing. This weakness is demonstrated by carrying out a Fourier transform infrared (FTIR) analysis where the potential binding mechanisms between the dye and the textile fibres was revealed. Different functional groups can interact with the fibre’s functional groups, affecting the dye's affinity for the fabric and its overall colour fastness properties. Findings show that dyes from orange peels showed promise in this study, but need to be improved further. Therefore, the study suggests that further research is needed to optimize the dyeing process and improve the fabric's resistance to washing and other environmental factors.

Examining the Effectiveness of Marketing Mix Components on Market Acceptance towards Natural Dye Products in Indonesia

Natural dye batik is a popular product in Indonesia, made using natural dyes derived from plants. This unique and authentic product attracts consumers who care about the environment and local culture, making it more preferred than chemical dyes. Research on the potential of natural dye products in Indonesia is important as it has great potential to develop the natural dye industry. Various marketing strategies have been used to market natural dye batik in Indonesia, but empirical testing is needed to understand how these strategies impact purchasing decisions. Studies have shown that consumer attitudes towards the environment, market competition, return rates, pricing strategies, and cultural influences impact optimal levels of environmental friendliness or greenness for products. This study examines the variable influence of marketing mix on the purchase intention of natural dye batik in Indonesia, aiming to contribute to the development of the natural dye industry and provide healthier and environmentally friendly alternatives for consumers using (PLS-SEM). The study concludes that product attributes, price, promotional approach, and place have significant impacts on consumer intention to buy with p-value 0.00, 0.00, and 0.033 below 0.05, and that executives should adopt green marketing strategies to improve consumer recommendations regarding purchase intention.

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.

Screening of azo dye biosorption efficacy of free, immobilized, indigenous bacterial strains associated with azo dye contaminated river water—An in vitro study

AbstractAzo dye degradation utilizing microorganisms has acquired significance over the last decades, owing to its beneficial properties such as rapid degradation, economic feasibility, and eco‐friendly. In this work, azo dyes (Methyl red and methylene blue) degradation efficacy using indigenous bacterial strains Pseudomonas sp. and Bacillus sp. as free and immobilized cells were investigated under in vitro batch decolorization setup was carried. Most importantly, the bacterial cells of both strains were immobilized with sodium alginate and the immobilized cells were evaluated for dye decolorization efficacy under laboratory conditions. An eco‐toxic assessment of the degraded products was done using in vitro phytotoxicity tests and in silico analyses. Among the free and immobilized cells, maximum decolorization efficacy was observed in the Pseudomonas sp. immobilized cells which exhibited 74.5% decolorization efficacy, and the maximum decolorization efficacy of free cells was 63% of was observed. Ecotoxicity of the dye‐degraded products was screened by determination of phytotoxicity. Seedlings emergence of groundnut seeds exposed to degraded dye products revealed phytotoxicity. Results indicated that degraded dye products of methyl red derived from Pseudomonas sp. showed 93.0% seedling emergence, and methylene blue‐degraded products Pseudomonas sp. degraded dye products supported 92.0% seedling emergence, respectively. Bacterial cells immobilized with biocompatible polymers can be effectively utilized in wastewater treatment without affecting the ecological components. The findings highlight the value of this work in contributing to the domain of sustainable and eco‐friendly wastewater treatment technology.

Chemical synthesis of ZnO, CuO, MnO and FeO Nano adsorbent and their application in anionic reactive blue turquoise 71 dye (RB-71 dye) and real effluents remediation: Batch adsorption and column studies

Industrial dye production chemicals contribute significantly to environmental pollution. This study explores the use of nanotechnology, specifically nano fertilizers and adsorption technology, for efficient removal of synthetic anionic dyes and enhancing agricultural production. Nano adsorbents (MnO, FeO, ZnO, and CuO) were generated using the co-precipitation method. Optimal conditions for Manganese oxide (MnO) were pH 2 (33.2 mg/g), dosage 0.01 g/50 mL, and adsorption capacity 77.2 mg/g. FeO optimal conditions were pH 2 (21.5 mg/g), dosage 0.01 g/50 mL, and qe 40.5 mg/g. CuO optimal conditions were pH 2 (28.2 mg/g), dosage 0.01 g/50 mL, and qe 71.3 mg/g. ZnO optimal conditions were pH 2 (25.4 mg/g), dosage 0.01 g/50 mL, and qe 64.2 mg/g. Pseudo 1st order and Freundlich sorption isotherms were best-fit models. Endothermic reactions were observed, indicating the sorption process’s nature and feasibility. Electrolyte concentrations affected the sorption potential. Surfactants/detergents reduced sorption efficiency. 0.5 N NaOH proved most effective for desorption. In column studies, optimal conditions for acidic RB-71 dye sorption were 3 cm bed height, 1.8 mL/min flow rate, and 70 mg/L inlet dye concentration. Metal oxide showed exhibited crystal and polymorphs structure. FT-IR spectra depicted metal-oxide peaks between 400 and 899 cm−1. SEM micrograph reveals a spherical shape with an approximate size of 10–50 μm. The adsorption method’s novelty lies in its easy handling, eco-friendliness, and cost-effectiveness, making it a promising technology for practical-scale application in addressing dye pollution.

Determination of nine aromatic amines in water by cloud point extraction-gas chromatography-mass spectrometry

Aromatic amines are a class of compounds bearing amino groups on their benzene rings; these compounds are important raw materials for the industrial production of rubber chemicals, pesticides, dyes, pharmaceuticals, photosensitive chemicals, and agricultural chemicals. Research has revealed that some aromatic amines teratogenetic, carcinogenic, and mutagenic properties. Given the high toxicity and potential harm caused by aromatic amines, monitoring their levels in water sources is critical. Aromatic amines are among the 14 strategic environmental pollutants blacklisted in China, and assessing their exposure levels is essential for protecting human health and the environment. At present, the standard method for detecting aromatic amines in water is liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS). However, this method has the disadvantages of large sample size requirement, complex operation, long analysis time, and high reagent consumption. In this study, instead of traditional LLE technology, cloud point extraction (CPE) technology was used in combination with GC-MS to establish an efficient, sensitive, and environment-friendly method for the detection of nine aromatic amines, namely, 2-chloramine, 3-chloramine, 4-chloramine, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 1-naphthylamine, 2-naphthylamine, and 4-aminobenzene, in water. Triton X-114 was used as the extraction agent. The main experimental parameters were optimized using a single-factor optimization method. The aromatic amines in various water samples were quantitatively analyzed using GC-MS. The nine aromatic amines were separated on a DB-35 MS capillary column (30 m×0.25 mm×0.25 μm). The mass spectrometer was operated in selected ion monitoring (SIM) mode, and quantitative analysis was performed using the internal standard method. The results demonstrated that all nine aromatic amines could be completely separated within 16 min and had good linearities within accurate mass concentration ranges, with correlation coefficients (R2) greater than 0.998. The limits of detection (LODs) and quantification (LOQs) of these aromatic amines in water were 0.12-0.48 and 0.40-1.60 μg/L, respectively. The accuracy and precision of the method were assessed via the determination of aromatic amines in surface water of drinking water sources, offshore seawater, wastewater of the typical printing and dyeing industry at levels of 2.0 and 10.0 μg/L. The recoveries of the aromatic amines in surface water of drinking water sources were 81.1%-109.8%, with intra-day and inter-day relative standard deviations (RSDs) of 0.7%-5.2% (n=6) and 1.6%-6.2% (n=3), respectively. The recoveries of the aromatic amines in offshore seawater were 83.0%-115.8%, with intra-day RSDs (n=6) of 1.5%-8.6% and inter-day RSDs (n=3) of 2.4%-12.2%. The recoveries of the nine aromatic amines in wastewater of the typical printing and dyeing industry were 91.0%-120.0%, with intra-day RSDs (n=6) of 2.9%-12.9% and inter-day RSDs (n=3) of 2.5%-13.1%. The established method was used to detect nine aromatic amines in actual water samples. No aromatic amines were detected in the surface water of drinking water sources or offshore seawater samples. However, 2-chloramine, 4-chloramine, and 4-aminobenzene, which are frequently used in the printing and dyeing industry, were detected in the wastewater of the typical printing and dyeing industry samples. The proposed method offers the advantages of simple operation, high sensitivity, low cost, low organic reagent requirement, and good repeatability. Thus, this method provides reliable technical support for studying the residual status and environmental behavior of aromatic amines in water.

In-situ hydrothermal synthesis of MoS2 /TiO2 nanocomposites for enhanced and stable photocatalytic performance: Methylene blue degradation pathway and mechanism

BackgroundIn recent years, nanocomposite photocatalytic has become more and more attractive and important since it has a great potential to contribute to such wastewater treatment and environmental problems. Pollutant dyes such as methylene blue (MB) have utilizations in manufacturing, paper, medicine and textiles. In addition, creating a Z-scheme nanocomposite illustrates a fitting approach for improving the photocatalytic performance of photocatalysts. Mott-Schottky curves demonstrate that MoS2 and TiO2 are combined to form Z-scheme nanocomposite. MethodsNovel MoS2/TiO2 nanocomposite photocatalysts were well synthesized by a simple hydrothermal process. The photodegradation intermediate products of MB dye are also identified by liquid chromatography-mass spectrometry (LC-MS) and the possible degradation pathway is proposed. Ultimately, the potential photocatalytic pathway mechanism of nanocomposites was verified according to the LC-MS analysis and trapping experiments. Significant findingsThe construction of a Z-scheme nanocomposite is a crucial factor in improving the photocatalytic activity of heterojunction photocatalysts. MoS2/TiO2 nanocomposites had photocatalytic activity within 120 min irradiation to visible light and achieved 98.5 % of MB. A stable heterostructure has been effort designed using MoS2/TiO2 with improved electron and hole migration. The photodegradation performance for MoS2/TiO2 is 3.8 folds that the bare photocatalysts. This nano-heterojunction significantly suppresses the recombination rate of photoexcited charge carriers and enhances the operation of solar energy. The Z-scheme nano-heterojunctions offer a potential strategy for promoting the utilization of photocatalysts in waste environmental purification and clean water.

Quantification of p-Phenylenediamine in Hair Dyes and Health Risk Implications in the UAE: Describing Discordances Between Regulations and Real-Life Practices.

p-Phenylenediamine (PPD) has been used over the past five decadesas a primary precursor in the production of oxidative hair dyes. Numerous health dangers are associated with the short- and long-term use of PPD, raising concerns about its safety. For instance, mounting data suggests that PPD is linked to dermatitis and allergy cases. To quantify the PPD content in hair dyes by measuring the PPD concentration after mixing the ingredients of commercial hair dyes. A total of 290 permanent hair dyes were tested. RP-HPLC-DAD analysis was performed to determine and quantify the PPD content. The estimated mean of the PPD limit was 0.89 (95% CI [0.81-0.96]). Of the 290 tested hair dyes, 7.2% (n = 21) exceeded the recommended PPD concentration after mixing. Significantly more hair dyes manufactured in India and China had a PPD content exceeding 2% after mixing compared to dyes from other regions (P = 0.001). Moreover, hair dyes manufactured in India and the UAE were more likely to have incomplete descriptions of the conditions of use and warnings on the label (P = 0.002). The effectiveness of the current regulations relevant to these products should be reevaluated. Moreover, through the use of good manufacturing procedures (GMPs), research, and the reporting of adverse reactions, hair dyes should be subjected to better control and monitoring in terms oftheir safety and quality.

Biowaste-alkaline lignin and GO integrated polysulfone ultrafiltration membrane fabrication for Pb2+ and Eosin Y dye removal

The textile industry uses a variety of lead compounds, including lead acetate for textile dyeing, lead chloride for lead salt manufacture, and lead molybdate for pigments. Furthermore, Eosin Y, a water-soluble red dye, is commonly used in textile dyeing and ink production. The presence of Eosin Y dye and lead metal ions in textile industry effluents is prevalent. Integrating adsorbent nanofillers into the membrane matrix serves a dual purpose of membrane filtration and adsorption functionalities. In this study, Lignin/GO incorporated polysulfone composite membranes were fabricated with the phase inversion method and with PEG 6000 as a pore-forming agent. Zeta potential, pure water flux, mechanical strength, and hydrophilicity of the membranes were all improved by the integration of lignin and GO into the membrane matrix. Filtration operations were carried out using an aqueous solution containing both lead (Pb) and Eosin Y dye. Additionally, the influence of their electrostatic interactions on membrane fouling and the regeneration process was examined. The electrostatic interaction, specifically the linking effect between Pb2+ ions and negatively charged Eosin Y molecules, formed larger Eosin-Pb complexes. This led to an enhanced Pb2+ removal through membrane filtration. During the second filtration cycle, the membrane, comprising 0.75 wt% lignin and 0.75 wt% GO, achieved 100 % removal of Pb2+ ions and an 81 % rejection of Eosin Y. A Pb2+ adsorption study was conducted using the optimized lignin/GO membrane. The adsorption process was investigated through Langmuir and Freundlich isotherms exhibiting a superior fit and assured R2 values of 0.977 and 0.994, respectively. According to the isotherm data the adsorption process involves multilayer physisorption. The developed Lignin/GO-incorporated polysulfone composite membranes hold the promise for tackling issues in a variety of domains, including water treatment and biomedical applications, demonstrating versatility and ability to make positive impacts across industries.

Groundwater conservation, and recycling and reuse of textile wastewater in a denim industry of Bangladesh

Bangladesh holds the 2nd position after China in the global apparel market in terms of denim export. In the textile industry clusters of Bangladesh, the groundwater level is depleting at an alarming rate due to overconsumption and mismanagement. The present study evaluates the groundwater conservation potential of a denim facility in Manikganj District through an effluent recycling and reuse approach. In this study, 100% treated wastewater and 10% treated wastewater mixed with softwater were utilized in the wet processing plant to dye and wash sample denim products and investigated for their fabric quality using seven parameters. The test results followed the requirements given by the North American and European fashion brands that source denim products from Bangladesh. The feasibility assessment of groundwater conservation through its high (100%) and low (10%) recycling rates indicated that the studied facility can potentially save around 619,230 m3 and 61,923 m3 of groundwater in a year, respectively.

Biotechnological Approach to Treat Textile Dyeing Effluents: A Critical Review Analysing the Practical Applications

Although the textile industry is one of the significant contributors to the global economy, approximately 10% of the annual global dye production, amounting to 7 × 106 tonnes and spanning a spectrum of 10,000 different dye variants, is wasted in the dyeing process and subsequently released into the environment. Following the dyeing and processing stages, this waste contributes to environmental pollution, making the textile industry account for 20% of the overall industrial water pollution worldwide. Traditional treatment of effluents is burdensome for the majority of textile units that are micro-scale enterprises. A significant challenge is that there isn't a single, commercially viable way to efficiently treat wastewater from textile industries. Scholars from several disciplines are working together to investigate novel approaches that are assiduously directed at addressing environmental issues by minimising waste, thereby promoting sustainability, circular economy, and industrial symbiosis. This study aims to address the challenges associated with the treatment process of textile dye-related effluents by conducting a comprehensive analysis of recent research on treatment processes and advancements and exploration of biotechnological treatment methods that are focused on achieving the reuse of treated water. The review covers different processes, traditional, current and emerging techniques, and it emphasises their use in practical situations. Also, the efficiency, specificity, and environmental friendliness of different biotechnological approaches are discussed offering a comparison of their benefits and drawbacks. A holistic remediation approach is advocated by harmonizing both conventional and non-conventional treatment methods for a more comprehensive solution.

Investigating the feasibility of utilizing &lt;i&gt;Pennisetum purpureum&lt;/i&gt; leaves waste as a sustainable dye: Extraction, characterization and application on textile

This study investigated the potential of Pennisetum purpureum (Elephant grass) leaves waste as a source of natural dyes. The objective was to extract, characterize and apply the natural dyes on textile fabrics. Elephant grass was chosen due to its abundant availability as agricultural waste, making it an environmentally sustainable alternative to synthetic dyes. The extraction process involved maceration, followed by filtration to obtain the dye extract. The dye components were isolated using vacuum liquid chromatography and then characterized using analytical tools such as UV-Visible Spectrophotometry, High-Performance Liquid Chromatography (HPLC) and Fourier-Transform Infrared Spectroscopy (FTIR) to identify the presence of specific compounds responsible for the dyeing potential. The perspiration fastness, rubbing fastness, light fastness and wash fastness properties were assessed to evaluate the durability and suitability of the natural dyes. The UV-Visible spectrum, HPLC and FTIR analysis confirmed the presence of chromophores such as conjugated systems, and provided information about chemical components namely rutin, quercetin, senecionine, hyoscyamine and tannic acid present in the dye, as well as the types of bond present in the molecules including C-H, O-H, C=O and C-O groups, which are characteristics of natural dyes. The dyed textile fabrics demonstrated somewhat fair to good with a rating of 3-7 for perspiration fastness, light fastness, rubbing fastness and wash fastness, indicating the potential of the natural dye for practical applications. The findings can inspire further research and development in utilizing agricultural waste for natural dye production, promoting sustainable practices in textile manufacturing.