Search Results (836)

The increasing demand for safer and environmentally sustainable products has intensified the search for natural alternatives to synthetic dyes. Filamentous fungi are promising sources of natural pigments due to their metabolic diversity and the feasibility of large-scale production. In this study, filamentous fungi isolated from Amazonian freshwater environments were evaluated for their potential to produce natural pigment-associated metabolites under different nutritional conditions. Forty-five fungal isolates were screened in solid media and subsequently cultivated in submerged fermentation using three media: potato dextrose broth supplemented with yeast extract (BD + YE); malt extract broth (ME); and yeast extract–sucrose broth supplemented with magnesium sulfate (YES). Among the 39 pigment-producing isolates, seven were selected for further investigation. Sucrose favored the highest absorbance values of pigment extracts, particularly for isolates identified as Talaromyces amestolkiae. In addition, the extract of T. amestolkiae TA10P5-3 exhibited the highest absorbance value (6.83 abs. units at 400 nm) when cultivated in YES medium, indicating stronger chromophore-associated spectral signals. This extract also showed antimicrobial activity against Pseudomonas aeruginosa (625 μg/mL), Staphylococcus epidermidis (312 μg/mL), and Candida tropicalis (625 μg/mL). Finally, the TA10P5-3 extract presented high total phenolic content (246.30 mg GAE/g) and antioxidant activity (EC₅₀ = 5470 μg/mL). These findings highlight Amazonian freshwater fungi as promising sources of natural pigments with potential industrial applications. Full article

The uncontrolled discharge of synthetic azo dyes such as methyl orange (MO) into water bodies has become a major environmental concern because of their strong chemical stability, limited biodegradability, and harmful effects on aquatic ecosystems. In this study, MgNiFe layered double hydroxides (LDHs) were synthesized through a co-precipitation route using a molar ratio of (Mg + Ni)/Fe equal to 3, and their adsorption ability toward MO in aqueous media was investigated. The prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), Fourier-transform infrared spectroscopy (FTIR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The characterization results revealed the successful formation of a hydrotalcite-like layered structure with good crystallinity, a relatively uniform distribution of metallic species, and the incorporation of carbonate anions within the interlayer galleries. In addition, the adsorption performance was evaluated by studying the effects of several operational factors, namely adsorbent dosage, initial pH, and contact time. To better understand the interaction between these parameters and identify the optimum operating conditions, a Box–Behnken response surface design was applied. The results indicate solution pH is the most influential parameter in the adsorption process. Under optimized conditions, a maximum removal efficiency of 86.86% was obtained, corresponding to an adsorption capacity of approximately ~86.86 mg·g⁻¹ (based on 100 mL solution volume). The enhanced adsorption performance may be attributed to the combined effect of the multivalent metal cations (Mg²⁺, Ni²⁺, and Fe³⁺), likely increases the surface positive charge density of the LDH and promotes interactions with anionic dye molecules. These interactions are suggested to involve electrostatic attraction and possible surface adsorption processes. However, in the absence of post-adsorption characterization, the exact adsorption mechanism remains hypothetical. Overall, the results demonstrate the promising potential of MgNiFe LDHs as efficient adsorbent materials for the treatment of dye-contaminated wastewater. Full article

The emerging demand for water pollution control has driven a significant interest in advanced porous materials for sustainable and effective wastewater treatment technologies. Metal–organic frameworks (MOFs) have been employed as promising substrates due to their versatile properties, especially their high surface area, tunable properties, and chemical functionality. However, their practical applications are often limited by poor aqueous stability, instability during recovery, and high production costs. Lignocellulosic biomass (LCB) is an abundant, low-cost, and renewable resource, primarily composed of cellulose, hemicellulose, and lignin, offering a sustainable solution for these challenges. This review critically examines the recent advances in design and applications of LCB-MOF materials for wastewater remediation. Several synthesis strategies, including in situ growth, ex situ impregnation, and post-synthetic modification, are systematically discussed in relation to their significance in enhancing stability, recyclability, and dispersibility of MOFs. The key, structural, morphological, and physicochemical properties of these LCB-MOFs were analyzed, along with their performance in removing organic dyes and heavy metal ions. Current drawbacks in long-term stability, scalability, and real-world wastewater performance are highlighted. Overall, LCB-MOFs demonstrate a promising class of sustainable materials that align with the principles of the circular economy and green chemistry, making them ideal for next-generation wastewater remediation technologies. Full article

Replacing artificial dyes with natural pigments in foods, especially carotenoids, has proven to be technologically feasible. This study developed a high-performance pitanga carotenoid extraction process using ionic liquids (ILs) and a factorial design to identify a potential substitute for artificial azo dyes, specifically Allura Red AC and Sunset Yellow FCF. 1-Hexyl-3-methyl-imidazolium chloride [C6mim]Cl was the most efficient IL. The optimized process conditions included a solid–liquid ratio R(S/L) of 1:10 m/m, an IL to ethanol co-solvent ratio R(IL/E) of 1:1 m/m, ultrasound power of 350 W, and six extraction cycles of 7 min each. These conditions yielded a total carotenoid content of 100.40 ± 3.71 μg/g (dry matter), demonstrating effective pigment recovery and a concentration suitable for practical use as a natural colorant alternative to synthetic azo dyes. The reuse of ILs and carotenoid purification were achieved through solid-phase extraction (SPE) using XAD-7HXP adsorbent, resulting in recovery rates of 89.2–76.2% for [C6mim]Cl and 108.9–23.2% for carotenoids. The major carotenoids identified were all-trans-β-cryptoxanthin, all-trans-rubixanthin, and all-trans-lycopene, whose combined presence contributed to a yellowish-orange hue similar to that of Sunset Yellow FCF, as confirmed by CIELAB parameters. Additionally, the [C6mim]Cl carotenoid extract exhibited high antioxidant activity, with an antioxidant capacity of 23.54 µmol of α-tocopherol equivalent. Full article

The utilization of plant isolates as dyes in applied fields has gained considerable interest due to growing environmental concerns associated with the toxic synthetic dyes. In the present work, the agro-waste (such as grape leaves) has been valorized as a rich source of flavonoid-based natural dye for sustainable dyeing of woolen yarn. Microwave irradiation was further applied to dye molecules and wool yarn to enhance the dye uptake and process efficiency. Processing parameters for dyeing were optimized using Box–Behnken as a statistical design, and the results of the analysis revealed that the processing parameters, including temperature (80 °C), time (25 min), pH 5, and salt concentration (3 g/100 mL), significantly influence the color strength. The microwave irradiation of both flavonoid-based grape leaf extract and yarns up to 4 min, followed by dyeing, has given improved color yield up to a K/S value of 5.38. Metal mordants and bio-mordants were analyzed to improve dye fixation and sustainability. The pretreatment of yarn with Fe²⁺-salt, post-treatment with Al³⁺-salt, and addition of tannic acid during the dyeing process improved the color strength and dye fixation. Furthermore, the addition of red sumac extract during the dyeing of yarns and the pretreatment of yarn with myrobalan as bio-mordants increased the color depth. The colorfastness rating shows that mordanting has improved color stability and has offered maximum resistance to color fading. It is concluded that agro-waste valorization, statistical modeling coupled with radiation treatment, has not only added value in process optimization but also mordanting in the coloring of yarn with grape leaf extract has valorized the green dyeing. Full article

This research paper examines the environmental impact of natural and synthetic fur coats, focusing exclusively on the processing and manufacturing stages. Using one coat weighing approximately 5 kg as the functional unit, a comparative Life Cycle Assessment (LCA) is conducted from raw material processing to final garment production, explicitly excluding animal farming. The analysis includes key processes such as cleaning, tanning, dyeing, and sewing for natural fur, and polymer production, fabric formation, dyeing, and finishing for synthetic fur. Data from international academic literature (Google Scholar and Scopus) are used to evaluate CO₂ emissions, energy and water consumption, chemical inputs, and waste generation. Results indicate that synthetic fur production is energy-intensive but requires relatively low water use, whereas natural fur processing involves high water consumption and chemical treatments, resulting in significantly higher emissions—often reaching hundreds to thousands of kg CO₂e per coat. The study further investigates the role of embedded IoT systems in improving efficiency within tanneries and textile manufacturing. Real-time monitoring and automated dosing systems can reduce emissions and chemical use by approximately 10–20%. Case studies of a smart tannery and an IoT-enabled synthetic fur production line illustrate potential implementation pathways. Although such optimizations can reduce environmental impacts, the findings clearly show that natural fur processing remains considerably more carbon-intensive than synthetic alternatives. This research highlights the importance of integrating digital technologies into industrial processes and suggests directions for future work based on real-world operational data. Full article

The textile industry has contributed significantly to global microplastic pollution, generating both primary and secondary microplastics. Primary microplastics, released during the manufacturing process of textiles, are the main concern due to their long-chain structure and persistence, while secondary microplastics are generated from the degradation of synthetic or blended textile products, which have already been in service or use. This review provides a comprehensive overview of methods for investigating fibrous primary microplastics generated throughout the major stages of the textile value chain, including yarn production, fabric manufacturing, garment processing, finishing, and packaging. In fact, there is an urgent need to deal with fibrous primary microplastics, as they are particularly hazardous due to their form (thin, long and often needle-like) and long-lasting life (can sustain in the environment over hundreds of years). Each manufacturing stage produces measurable microfiber losses. For example, pre-consumer production emits approximately 0.12 million metric tons of microplastics per year. High-speed yarn spinning releases additional MP (microplastics); rotor-spun polyester yarns shed 2000–8000 MFPs/g (microplastic fibers/g). The mechanical stresses such as friction, abrasion, and yarn breakage during weaving and knitting operations contribute significantly up to 10⁴–10⁶ microfibers per m² of fabric during production. Wet processing (dyeing, printing, and finishing) is another major hotspot for primary microplastic generation, with dye house effluents reporting up to 54,100 microfibers per liter. Moreover, during mechanical and chemical finishing operations, the generated nanoplastics (NPs) rose significantly, exceeding 10¹¹ particles per gram of material. Subsequently, the garments manufacturing units are estimated to produce 10,000 garments per day (5 tons of fabric), which equates to 5–25 kg/day of microplastic fiber waste. Targeted schemes for the study of primary microplastics at the earliest stages of textile production could significantly reduce environmental release and strengthen progress toward a more circular and sustainable textile economy. Full article

This study addresses the need for sustainable approaches in textile wastewater treatment by investigating laccase production with the white-rot fungus Schizophyllum commune TMF3 using agro-industrial waste as a substrate. Laccase was produced via solid-state fermentation on brewery spent grain under optimized conditions (1.75 g malt extract, 75% moisture, 7 days, 25 °C), reaching a maximum activity of 21.06 IU/g dry substrate. The crude enzyme was applied for the decolorization of azo and triphenylmethane dyes (50 mg/L). Decolorization efficiencies above 80% were achieved within 60 min without redox mediators, while chemical oxygen demand (COD) was reduced by more than 50% for all tested dyes. HPLC analysis showed parent dye peaks decreasing and the transformation products’ appearance. Antimicrobial activity testing showed no increase in inhibitory effects against Escherichia coli, Lactobacillus rhamnosus, Candida albicans, and Saccharomyces cerevisiae, while slight growth stimulation was observed in selected cases. Phytotoxicity assays using Triticum aestivum showed no inhibitory effects, with germination index values of 77–124%. Cytotoxicity assessment showed no effects for azo dyes, while cytotoxicity of the triphenylmethane dye decreased by 30% after treatment. These findings support the potential of agro-industrial laccase production as an effective approach for dye removal in sustainable wastewater strategies. Full article

This review analyzes the advances over a five-year period in the development of polymeric sorbents for the purification of aqueous media from key classes of pollutants: hydrocarbons (crude oil, diesel fuel), organic dyes, pharmaceuticals (antibiotics), pesticides, herbicides, volatile organic compounds, and polycyclic aromatic hydrocarbons. Attention is paid to the analysis of structure-property-performance relationships, with an emphasis on comparing materials derived from renewable natural feedstocks (such as cellulose, chitosan, terpenes, vegetable oils, and aloe vera) with synthetic polymers. The analysis reveals that biopolymer-based sorbents exhibit comparable or superior sorption capacities combined with environmental safety, biodegradability, and low cost. The key sorption mechanisms include physical adsorption, hydrophobic interactions, and electrostatic interactions. Despite persisting challenges related to scalability, stability in real-world environments, and the need for efficient regeneration protocols, a convergent approach that combines the advantages of modified natural polymers and functional synthetic components appears to be the most promising strategy for developing cost-effective and sustainable technologies for the restoration of water quality. Full article

Lubricants based on fatty acid ester (FAE) mixtures are widely used in the textile industry, e.g., in spin finishes applied during the production of synthetic fibres, or in sizes added to fibres before weaving. FAE lubricants can significantly impact the dyeing quality of a textile due to their hydrophobicity and must therefore be removed before dyeing. However, the solvents currently used for their removal pose an environmental risk, and biobased solutions are thus sought. A lipase-assisted pre-dyeing treatment for synthetic fibre textiles was developed in this study. Six lipases were tested for their ability to hydrolyse FAEs from a polyamide-with-elastane textile, and all were found to be active. The conditions for the washing of lipase-treated textiles were found to be crucial for the performance of the process. Among the possible lipid hydrolysis products of tripalmitin (selected as a model FAE), only palmitic acid removal improved during washing, in comparison with the original FAE. This improvement only occurred with washing solutions containing a monovalent base. A combination of lipase treatment and washing with a non-ionic surfactant and monovalent base was found to be effective in the removal of FAEs, with a performance similar to a current solvent-based pre-treatment process. Full article

Titanium-based perovskites have garnered significant attention for photocatalytic applications, particularly in the field of environmental remediation through the degradation of synthetic dyes and pharmaceuticals in aqueous solutions. This review paper aims to explore the synthesis methods, crystal structures, photoactivity, and photocatalytic performance of titanium-based perovskites in degrading synthetic dye and pharmaceutical effluents in water. The unique advantages of titanium-based perovskites as photocatalysts, associated with their high redox potentials and excellent optical and electrical properties, are highlighted. Their limitations in visible light absorption and photocatalytic efficiency due to rapid charge carrier recombination are also discussed. Several strategies to overcome these limitations, such as surface modifications of the photocatalysts, metal and non-metal doping, the introduction of structure defects, the formation of heterojunctions with electron-accepting materials, and the deposition of plasmonic metal nanoparticles are systematically examined. This review also provides an overview of the photocatalytic degradation of dyes and pharmaceuticals as emerging contaminants, utilizing titanium-based perovskites as photocatalysts, to highlight their efficiency and potential for real-word applications. By covering research findings, current knowledge, and future perspectives, this review aims to stimulate advancements in the design and application of titanium-based perovskite photocatalysts. Full article

In recent years, increasing consumer demand for healthier and more natural foods has driven the food industry to replace artificial additives. Among these, colorants play a crucial role, as they influence the sensory perception and acceptance of food products. However, the widespread use of synthetic colorants has raised growing concerns due to their potential association with adverse health effects. In addition, several regulatory agencies have restricted or banned the use of certain synthetic colorants, requiring their replacement with natural alternatives. In this context, anthocyanins have emerged as a promising substitute for artificial colorants, owing to their similar color properties. Despite their potential, their use as a food colorant still faces several challenges, particularly regarding stability, incorporation into food matrices, and regulatory constraints. Therefore, this review examines the challenges and current trends in natural colorants, highlighting the potential of anthocyanins as substitutes for synthetic red colorants in food products. Full article

This review examines how plant polyphenols enable multifunctional textiles, offering a sustainable alternative to synthetic dyes and nanomaterial-based treatments. A literature search (2001–2025) identified 105 peer-reviewed studies across eight functional areas. Abundant in agricultural and industrial byproducts, plant polyphenols act as natural colorants, bio-adhesives, and performance enhancers—providing coloration, antibacterial activity, UV protection, flame retardancy, deodorization, antioxidant capacity, superhydrophobicity, and more. Their catechol and pyrogallol groups bind strongly to natural and synthetic fibers via hydrogen bonding, π–π stacking, and metal chelation, ensuring durable, nontoxic functionality. We analyze structure–function links and scalable methods, including pad-dry-cure and metal–phenolic network (MPN) assembly, which were validated against ISO, ASTM, and AATCC standards. Polyphenol-based textiles match or exceed conventional ones in key metrics, with added benefits: full biodegradability, low ecotoxicity, and skin compatibility. Key advances include enzymatic polymerization for wash-stable color, MPN tuning for customizable functions, and using waste-derived polyphenols. However, major challenges remain: narrow color range (mostly yellow, brown, black) and poor wash/UV resistance, leading to rapid fading and loss of antibacterial/UV protection after laundering. Solving these is a top priority for future work. Overall, this review delivers a practical, science-based roadmap for high-performance, sustainable textiles that align with the Sustainable Development Goals and meet real-world needs in healthcare, sportswear, and smart wearables. Full article

Canities results from a progressive decline in melanocyte activity and melanin synthesis and is commonly associated with aesthetic concerns that motivate the use of cosmetic products for hair color correction. Shampoo, due to its frequent use, represents a suitable vehicle for the gradual deposition of pigments on the hair fiber. This study aimed to design and develop a shampoo containing dark synthetic semi-permanent dyes for the gradual coverage of gray hair. Four shampoo formulations were developed and evaluated through in vitro tests using bleached hair tresses to assess color deposition and performance. The selected formulation was subsequently subjected to accelerated stability studies and color sustainability evaluation. The results showed that the formulation maintained organoleptic, physicochemical, microbiological, and functional stability. Color sustainability assays indicated that the gray–black coloration persisted on hair tresses containing approximately 90% canities after eight washing cycles. The formulation incorporating the semi-permanent dyes Basic Blue 124, Basic Yellow 87, Basic Orange 31, and Basic Red 51 achieved a gradual gray–black tonal effect. In conclusion, the developed shampoo demonstrated stability and effectiveness for the gradual cosmetic coverage of gray hair. Full article

Textile wastewater contains recalcitrant dyes and organic matter, requiring efficient, scalable treatment technologies. This study optimized an aluminum-based electrocoagulation (EC) process to maximize color removal (Y₁) and chemical oxygen demand (COD) reduction (Y₂) using synthetic textile wastewater (SWW), and evaluated the practical transferability of the optimized conditions using real textile wastewater (RTW). A rotatable central composite design (CCD) coupled with response surface methodology (RSM) was used to assess the effects of treatment time, NaCl concentration, and applied voltage on both responses. From a modeling perspective, the results reveal the coexistence of symmetric and asymmetric response behaviors; quadratic effects define locally symmetric regions around the optimum, while interaction terms introduce asymmetry due to coupled electrochemical phenomena. Under the optimized conditions (16.5 min, 2.9 g·L⁻¹ NaCl, 18 V), removal efficiencies reached 99% for color and 97% for COD reduction, with a specific energy consumption of 6.6 kWh·m⁻³ and sludge moisture content of 92–94%. To assess applicability beyond bench scale, the optimized voltage, current, and electrolyte concentration were applied to a 50 L batch of RTW collected from the final rinsing stage of a denim dyeing process. Treatment time was extended to 84 min to compensate for the lower current density at the larger scale; under these conditions, 95% color removal and 80% COD reduction were achieved. Full article