Dyeing Research Articles

Valorization of Parthenium hysterophorus weed into biochar for adsorptive removal of industrial dyes from multi-pollutant aqueous systems

Valorization of Parthenium hysterophorus weed into biochar for adsorptive removal of industrial dyes from multi-pollutant aqueous systems

Commercial Versus Natural Activated Carbon Fabricated Sheets: Applied to Dyes Removal Application

AbstractIndustrial dyes are considered one of the main causes of increased water pollution of water. Many businesses, such as steel and paper, are located along riverbanks because they require large amounts of water in their manufacturing processes, and their wastes, which contain acids, alkalis, dyes, and other chemicals, are dumped and poured into rivers as effluents. For example, chemical enterprises producing aluminum emit a significant quantity of fluoride into the air and effluents into water bodies. Fertilizer facilities produce a lot of ammonia, whereas steel plants produce cyanide. Many nations consider employing wastewater treatment plants using physical, biological, and chemical methods to clean the wastewater to address environmental crises. The treated water can be used for targeting the irrigation systems in its majority, as it is biologically acceptable for that specific use, industrial dyes are considered one of the leading causes of increased water pollution of water. Many businesses, such as steel and paper, are located along riverbanks because they require large amounts of water in their manufacturing processes, and their wastes, which contain acids, alkalis, dyes, and other chemicals, are dumped and poured into rivers as effluents. For example, chemical enterprises producing aluminum emit a significant quantity of fluoride into the air and effluents into water bodies. Fertilizer facilities produce much ammonia, whereas steel plants produce cyanide. Chromium salts are used in. Many nations consider employing wastewater treatment plants using physical, biological, and chemical methods to clean the wastewater to address environmental crises. The treated water can target the majority of irrigation systems, as it is biologically acceptable for that specific use, which economizes the use of freshwater sources for municipal use. This study presents a novel method for fabricating an efficient adsorbent sheet for wastewater treatment. The sheets are fabricated by combining sugarcane bagasse pulp as a scaffold with commercial, naturally activated carbon, and bimetallic‐prepared adsorbents. Sugarcane bagasse is utilized in producing activated carbon because of its high carbon contents, availability, and low cost. The prepared composite sheets are synthesized and investigated for pollutants removal of crystal violet (CV), methyl orange (MO), and Chromium (CI) dyes. Different weight ratios of activated carbon are used to form a bio‐composite mixed sheet. The formed sheets’ morphology is performed via a high scanning electron microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). To determine the adsorption mechanism, the intra‐particle diffuse screening experiment is used to test the experimental data. All the prepared sheets can retain the pollutants, with the best removal efficiency of 98% for methyl orange adsorption onto the bio‐composite mixed sheet. The results of the parameter (time, concentration, and dose) sets provided valuable proof that the adsorption of methyl orange onto the bio‐composite sheet mixed with naturally activated carbon is an endothermic phenomenon involving physical adsorption.

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.

Sustainable Bio-Based Adsorbents for Simultaneous and Efficient Removal of Hazardous Dyes from Aqueous Solutions.

Dyes provide a notable environmental issue as a result of their intrinsic poisonous and carcinogenic characteristics. An estimated 60,000 metric tons of dyes has been discharged into the environment, leading to a substantial increase in water pollution. The mitigation of these dyes is a substantial and intricate challenge. The primary objective of this research is to conduct a comprehensive analysis of the adsorption of cationic dyes containing positively charged groups such as sulphonates, amines, and triphenylmethanes. The adsorption study was carried out using four different low-cost adsorbents derived from biowaste, specifically Groundnut Shell (GS), Mosambi Peel (MP), Mango Bark (MBARK), and Mango Leaves (ML). The adsorbent materials were characterized using FTIR, UV-Vis spectroscopy, scanning electron microscopy (SEM), point-of-zero charge (PZC), and BET techniques. The adsorption capacity was found to be between 1.5 and 2.2 mg/gm for Groundnut Shell, Mosambi Peel, Mango Bark, and Mango Leaves for individual dye removal (Crystal violet, Methylene blue, Rhodamine B, and Malachite green). It was observed that adsorbent derived from mango bark showed excellent adsorption (%) in a mono-component dye system and, thus, was explored for the simultaneous removal of a mixture of the same dyes. MBARK exhibited an excellent overall dye removal efficiency of 94.44% (Qe = 2.7 mg/g) for the dye mixture in 60 min. From a detailed kinetic investigation, it was concluded that the adsorption followed the pseudo-second-order model (R2= 0.99963 to 1 for different dyes and adsorbents) hinting at chemisorption. The effect of the pH of the analyte solution and the dosage of adsorbent was also studied for simultaneous removal. The isothermal studies demonstrated that the Langmuir adsorption model (R2 = 0.99416) was the best-fitted model, suggesting monolayer adsorption. The adsorption process was predicted to be governed by ion exchange, electrostatic interaction, hydrogen bonding, pi-pi interaction, etc., based on charge, functional groups, and pH of dyes and adsorbent. Thus, this study highlights the application of low-cost biowaste as a potential adsorbent for the mitigation of toxic industrial dyes present in wastewater.

Green synthesis of gold nanoparticles using macroalgae Halimeda macroloba extract and their photocatalytic degradation of methylene blue and methyl orange

AbstractGreen synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical and environmental applications. This study reported the novel eco‐friendly synthesis of AuNPs using green macroalgae Halimeda macroloba (HM) extract and evaluate their photocatalytic potential. The green synthesized H. macroloba mediated gold nanoparticles (HM‐AuNPs) was characterized using UV–visible spectrophotometry, Fourier‐transform infrared (FT‐IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscope‐energy dispersive spectroscopy, x‐ray photoelectron spectroscopy (XPS), and particle size distribution (PSD) anlaysis. The UV–visible spectrum shows a sharp intense plasmonic resonance peak at 543 nm. The bioactive compounds present in HM were primarily responsible for the biological reduction of gold ions validated by FT‐IR analysis. XRD analysis proved the crystalline face centered cubic structure of the HM‐AuNPs. The average particle size of 18.72 nm and morphological evidences were obtained from the images from TEM. The metallic form of biosynthesised HM‐AuNPs was confirmed by XPS results with a distinctive binding energy. The photocatalytic degradation ability of the green synthesized HM‐AuNPs was investigated against the methylene blue (MB) and methylene orange (MO) dyes under sunlight irradiation. The HM‐AuNPs exhibited 97.23% and 89.91% photocatalytic activity against MB and MO after 90 min of exposure to sunlight, respectively. The overall results of this research indicate that H. macroloba mediated HM‐AuNPs can be used as an effective option for the degradation of industrial dyes.

Modern ecofriendly approach for extraction of luteolin natural dye from weld for silk fabric and wool yarn dyeing

The increasing apprehension regarding the ecological effects of synthetic dyes has prompted a transition towards sustainable and environmentally friendly substitutes in the textile sector. This research examines the eco-friendly use of a natural pigment obtained from the weld flower for dyeing of silk fabric and wool yarn. The study investigates the use of microwave-assisted extraction to acquire the luteolin based pigment found in the weld flower. An assessment is conducted to evaluate the effectiveness of microwave radiation in improving the extraction process, emphasizing its capacity to accelerate and enhance the production of the natural colorant. Moreover, the process of optimizing dyeing conditions is carried out utilizing a response surface approach, with a specific focus on parameters including temperature, time, pH, and salt content. The study also investigates the influence of mordants, such as iron salt, and aluminum salt, on improving color fastness and attaining bright and enduring hues. The study expands its research to examine the impacts of plant-based extracts, such as madder root, and oak, as bio-mordants for producing a wide array of colors. The study additionally highlights the favorable influence on color fastness, exhibiting significant enhancements in light fastness, wash fastness, and rubbing fastness for both silk and wool. The measurable results validate the effectiveness of the suggested environmentally friendly dyeing techniques, provide numerical evidence of their suitability for sustainable textile manufacturing.

Indigo dyes: Toxicity, teratogenicity, and genotoxicity studies in zebrafish embryos

Wastewater released by textile dyeing industries is a major source of pollution. Untreated wastewater released from indigo dyeing operations affects aquatic ecosystems and threatens their biodiversity. We have assessed the toxicity of natural and synthetic indigo dye in zebrafish embryos, using the endpoints of teratogenicity, genotoxicity, and histopathology. The zebrafish embryo toxicity test (ZFET) was conducted, exposing embryos to ten concentrations of natural and synthetic indigo dyes; the 96-hour LC50 values were approximately 350 and 300 mg/L, respectively. Both dyes were teratogenic, causing egg coagulation, tail detachment, yolk sac edema, pericardial edema, and tail bend, with no significant difference in effects between the natural and synthetic dyes. Both dyes were genotoxic (using comet assay for DNA damage). Real-time RT-PCR studies showed upregulation of the DNA-repair genes FEN1 and ERCC1. Severe histological changes were seen in zebrafish larvae following exposure to the dyes. Our results show that indigo dyes may be teratogenic and genotoxic to aquatic organisms, underscoring the need for development of sustainable practices and policies for mitigating the environmental impacts of textile dyeing.

α-Fe2O3/g-C3N4 nanocomposite with type II heterojunction for methylene blue photodegradation

Recently, the widespread use of industrial dyes, such as methylene blue, is raising concerns about organic pollutants. These compounds can persist in the environment, contaminating water sources and harming aquatic ecosystems. The aim of the current study is to develop a nano-composite by mechanically grinding graphitic carbon nitride g-C3N4 and hematite α-Fe2O3, which cloud potentially be used for degradation of Methylene bleu organic pollutant. The obtained heterojunction nanocomposite, named 1 % α-Fe2O3/g-C3N4 (Fe/gCN), was characterized using XRD, ATR-FTIR, and SEM-EDS analysis. The industrial methylene blue (MB) dye was used to assess the visible light photodegradation efficiency of the Fe/gCN nanocomposite. The findings revealed a notable improvement in the photocatalytic degradation performance of the Fe/gCN nanocomposite. Furthermore, the band gap of Fe/gCN nanocomposite was narrowed from 2,78 to 2,54 eV Comparing to gCN alone. Compared with pure α-Fe2O3 and gCN, the Fe/gCN nanoparticles showed enhanced visible-light-induced photocatalytic performance which degrade efficiently 99,64 % of MB dye. The optimal conditions were determined as: pH =10,3, photocatalyst mass of 0,6 g/l and contact time t = 120 min for the Fe/gCN composite. •OH and •O2− radicals were identified as the dominant active species responsible for MB degradation and played the most crucial roles, while h+ and e− radicals were less contributing in MB photocatalytic elimination. Kinetic studies indicated that the MB photocatalytic decomposition of by Fe/gCN followed a pseudo second-order (PSO) model. These findings underscore the great potential of Fe/gCN nanocomposite for the visible light-induced MB dye photodecomposition.

Efficient zero wastewater and salt-free of cotton fiber dyeing via hydrophobic organic chemical/water two-phase dyeing system

For cotton fabric dyeing, a significant quantity of salt and water are typically consumed in the conventional water dyeing bath. In this study, an environmentally friendly alternative was investigated that could eliminate water waste and salt usage, as well as reducing chemical consumption. This method, which employs a hydrophobic organic chemical/water two-phase dyeing system, solely involves fiber swelling, dye dissolution, and the use of alkaline agents. By substituting the water required for heat and mass with an organic chemical, 71.43% dye reduction can be achieved in dye consumption compared to traditional water-based dyeing method. Benefiting from the natural affinity between dyes and cotton fibers, without any interaction with hydrophobic organic chemicals, reactive dye can diffuse into the fiber surface, which can achieve above 98% dye uptake and 90% fixation rate. The K/S value of the dyed cotton fabric is much higher than that of conventional water bath at the same dye concentration, and it is the highest when the water content is 120 %. Moreover, the uniform distribution of dye and the color fastness of the dyed fabric are comparable to traditional water-based dyeing. Due to the influence of intermolecular forces, the aggregation of dye is changed to varying degrees in different hydrophilic and hydrophobic cotton fiber dyeing systems, which further influences the dyeing quality. This study not only improves the utilization of dye but achieves salt-free, no wastewater emission and reduces the dyeing cost, providing an economical and sustainable dyeing method for the industrial dyeing of cotton fabric.

A loose polyethersulfone hybrid nanofiltration membrane incorporated with polyethyleneimine-decorated silica nanoparticles for highly-efficient dye/salt separation

Loose nanofiltration (LNF) is a newly-developing technology for desalting dye-containing saline effluents, but suffers from membrane materials with low permeance and poor dye/salt separation selectivity. Herein, a hybrid polyethersulfone (PES) LNF membrane for dye/salt separation was prepared via a nonsolvent-induced phase inversion method, which was carried out using polyethyleneimine (PEI)-modified silica nanoparticles as a dopant. This design not only featured a hybrid PES LNF membrane with high porosity and small mean pore size, but also partially neutralized its charge and enhanced its hydrophilicity. Hybrid PES LNF membrane from a 21-wt% PES solution with 3-wt% PEI-decorated silica nanoparticles addition was demonstrated to achieve high water permeance (92.0 L m−2 h−1 bar−1) and dyes retention ratio (98.4 % for Congo Red, 98.8 % for Nile Blue A, and 95.1 % for Methyl Blue) accompanied with fully-pass for various salts (Na2SO4, NaCl, MgCl2 and CaCl2). In addition, the hybrid membrane exerted excellent resistances to strong acidic, oxidative and hot water (90 °C) environments and exhibited a pH-sensitive permeability. Multicycle test revealed that the hybrid membrane had high permeance recovery ratio (>92.8 %) and maintained its high dye retention and complete salt permeation even after 10 cycles, manifesting its outstanding fouling resistance and recyclability. Besides, the hybrid membrane repelled 92.6 % of dyes from a simulated wastewater consisting of multiple industry-applied direct dyes and salts after 12 h consecutive test, but allow 100 % of mixed salts passing through the membrane, proving its practical applicability to industrial dyeing wastewater. This study provided a simple and economically feasible route to high-performance LNF membrane production for dye/salt separation, thus popularizing LNF process in dyeing wastewater treatment, organic products purification, and resource recovery.

Electrocatalytic recycling of indigo dye from waste denim fabric: an engineering approach toward efficient denim dye reuse

The denim fabric industry has experienced exponential growth and escalating concerns regarding sustainable production and recycling practices. The wide utilization of indigo dye in denim manufacturing presents significant challenges owing to its intricate chemical structure and inherent resistance to degradation. Improper disposal of waste denim fabric and the release of indigo dye impose severe ecological ramifications. In this study, we explore the productive application of electrochemistry to recycle indigo dye from waste denim fabric while repurposing the electrolyte for denim dyeing. Notably, the separation of indigo from waste denim textiles reaches 82.34%. It is calculated that 21.59 g of indigo can be recovered from 1 kg of denim waste. Recovered indigo can be reused for cotton yarn dyeing. In the experiment, indigo was recovered from 0.03 square meters of denim waste, and the K/ S value of the yarn was up to 2.997 after five dyeing cycles. The loss of fabric strength after recycling is as low as 13.32%, which has little effect on secondary fabric recycling. Our recycling method reduces the waste of 978.41 g of waste fabric and 21.59 g of indigo per kilo compared to conventional treatment. This research provides compelling scientific evidence supporting adopting a closed-loop system within denim production, underlining the potential for environmentally conscious and economically viable practices in the industry.

Rapid quantitative analysis of natural indigo dye content using near-infrared spectroscopy

Natural indigo, the most widely produced and utilized natural dye, encounters quality challenges due to the lack of standardization in the natural dye industry. Rapid determination of natural indigo dye contents before the dyeing process appears extremely important. In this study, two prediction models for different concentrations were established using partial least squares in conjunction with near-infrared analysis quantitatively to analyze the natural indigo dye content. A total of 228 indigo samples were collected from 14 different dyestuffs across various regions, with concentrations ranging from 100 to 1000 mg/L and 10 to 100 mg/L, respectively. The spectral pre-processing methods of multiplicative scatter correction plus first-order derivative and Savitzky–Golay smoothing plus band normalization plus first-order derivative were selected to enhance the model prediction accuracy. The optimized model exhibited excellent prediction accuracy. Within the concentration range of 100–1000 mg/L, the model has an R2 value of 0.9994, and a root mean square error of prediction value of 6.36 mg/L. In the concentration range of 10–100 mg/L, the model returned an R2 value of 0.9907, and a root mean square error of prediction value of 2.80 mg/L. The model's detection limit stands at 49.2 mg/L. The results demonstrated that the near-infrared models developed in this study can be used rapidly and accurately for the quantitative determination of natural indigo dyes.

Industrial dye effluent degradation and in-vitro biological characteristics of MgO NPs anchored few layered g-C3N4 nanoribbons

In recent years, contaminated water consumption by humans and animals are lead to various types of diseases and environmental pollutant. Especially textile dye effluents are the highest contaminants in water bodies than any other industries. This article reports a green process for synthesizing MgO nanoparticles supported by the exfoliated g-C3N4 nano composites for dye effluent treatment. The cubic and hexagonal phase structure was achieved for synthesized MgO NPs and E-GCN, respectively, with spherical and curled ribbon-like morphology. The specific surface area was measured as 70.48, 54.22, and 79.11 m2/g, respectively, for MgO NPs, E-GCN, and MgO/E-GCN nanocomposite. Similarly, corresponding optical properties were achieved with an energy gap of 3.42, 2.48, and 2.78 eV. XPS analysis confirms the formation of MgO/E-GCN nanocomposite by detecting their characteristic elemental peaks. The bioactivities including antibacterial, turbidimetric, and antioxidant efficacy, were also investigated. Thus, the MgO/E-GCN nanocomposites was exhibitd greater susceptibility against pathogenic bacteria due to its production of high reactive oxygen species. Further, the catalysts were used to degrade cationic dye (Crystal Violet) and anionic dye (Eosin Yellow) under sunlight exposure. The photocatalytic efficiency of MgO/E-GCN nanocomposite was highly influenced towards CV (98.9 %) and EY (97.33 %) dye degradation, because of its high surface area with active UV–Visible region. Therefore, the combination of naturally inspired MgO NPs and morphologically modified E-GCN nanocomposites are being a sustainable material development for environmental remediation and biological applications.

Multi-azobenzene moieties on rigid cyclotriphosphazene core: Synthesis, structural characterization, electrochemistry, and photoisomerization study

Multi-azobenzene derivatives capable of showing multi-stimuli responsive material can exhibit superior performance in biomedicine, the dye industry, cosmetics, and photonics. Here, a nucleophilic substitution reaction was employed to assemble two (Az2CPZ(biph)2) or four (Az4CPZ(biph)) or six (Az6CPZ) units of azobenzene moieties on the cyclotriphosphazene (CPZ) core. We have observed that the color of each compound varied by changing the number of azobenzene moieties on the CPZ core. These compounds were characterized by elemental analysis, 1H, 13C{1H}, and 31P{1H} NMR techniques. Single crystal X-ray diffraction techniques ensure the trans conformation in the azobenzene for Az2CPZ(biph)2 and Az4CPZ(biph). Electronic spectroscopy forAz2CPZ(biph)2,Az4CPZ(biph), andAz6CPZhaving π-π* transition around 325 nm show a hypsochromic shift with ∼25 nm compared to the parent molecule, 4-hydroxyazobenzene AzH. As a result of the electronic spectroscopy, the cis isomer formation enhanced upon increasing the concentration ofAz2CPZ(biph)2/Az4CPZ(biph)/Az6CPZ in DCM/DMF. The photoisomerization study confirms that these molecules having at least one azo moiety can switch from trans to cis conformation upon exposure to 365 nm light. Interestingly, the thin-layer chromatography (TLC) corroborated the switch of trans to cis conformation occurs at room temperature in a solution state even without UV irradiation. The proton NMR integration providesthe generationofthe cis-azobenzene moiety is about 12–20 % inAz2CPZ(biph)2upon exposure to 365 nm light for 15 to 60 mins. Additionally, TLC verifies the generation of multiple isomers that confirm multi-functional switch behavior when the sample with UV exposure time increases. Owing to these molecules undergoing a isomerization process (trans-azo⇌cis-azo) even without UV, their fluorescence gets quenched in the solution state. Cyclic voltammetry confirms the quasi-reversible type redox behavior of all compounds in dry dichloromethane. We believe the results presented in this work will be significant for dye and biomedical applications.

Multifunctional Ce+3 doped nickel-cobalt mixed ferrites via co-precipitation method for photocatalytic and antibacterial activity

The overuse of industrial dyes and anti-bacterial drugs are destroying fresh water reservoirs and making bacteria more resistant, respectively. To sort out these problems, we have synthesized Cerium doped Nickel-Cobalt mixed ferrites (Ce-@NCMF) with chemical composition [Ni0.4Co0.6CexFe2-xO4 (where x = 0.00, 0.10, 0.15, 0.20 and 0.25)] via co-precipitation method. Influence of cerium doping on the structural, optical, electrical, magnetic, photocatalytic and anti-bacterial properties of Ce-@NCMF studied. Powder x-ray diffraction analysis (PXRD) confirmed the synthesis of Ce-@NCMF. Decrease of crystallite size from 29.71 to 24.95 nm was observed with increase in dopant concentration. Tauc’s plot indicated the decrease of energy bandgap from 2.10 to 1.89 eV with increase in dopant concentration, which revealed the absorption of light in visible region to generate electron–hole pairs for photocatalytic applications. FTIR spectra indicated the presence of M-O bonds as major functional group present in Ce-@NCMF. Electrical properties demonstrated the prominent increase of electrical conductivity with increase of Ce-doping. VSM analysis was performed to analyse the magnetic properties of materials and showed prominent decrease in saturation magnetization value from 84.66 to 19.85 emu g−1. Owing to optical bandgap in the visible region, all the synthesized samples were evaluated for their photocatalytic potential for the degradation of methylene blue. Ce-@NCMF at x = 25% dopant value showed maximum degradation efficiency (95%) under sunlight irradiation of 90 min. Kinetic studies of dye degradation followed pseudo-1st order kinetics with maximum rate constant (k) value of 2.78×10−2 min−1. Antibacterial activity results showed the bioactive nature of Ce-@NCMF against all strains of bacteria in consistent with the crystallite size of samples. Smallest crystallite size Ce-@NCMF were found most active against gram-negative bacterial strains.

Design, Synthesis, Characterization, and Antimicrobial Properties of New Azo Disperse Dyes Incorporating Quinazolinone-Pyrazolone Moieties and Their Applications for Dyeing of Polyester Fabrics

The current study outlines a straightforward and efficient method for creating new quinazolinone disperse dyes based on pyrazolone moieties, starting with quinazolinone and a variety of substituted pyrazolone as couplers. The synthesized dyes were characterized using a variety of spectroscopic and analytical methods. The synthesized dyes' ultraviolet–visible spectra showed bands brought on by several molecular transitions. We investigated in detail the multifunctional characteristics such color representation, dyeing duration, concentration, pH, buildup, and fastness properties of the dyed samples. Fastness properties and colorimetric data showed satisfactory results, demonstrating the effectiveness of these dyes in dyeing polyester fabrics. A pH of 5 and a dyeing temperature of 130 °C were the ideal conditions for dyeing polyester fabrics. Additionally, an ultraviolet protection factor test was performed on the dyed fabrics, and the results showed that these dyes provide the best UV protection. These dyes are suitable for industrial dyeing applications since they are easy to manufacture and scale up. Additionally, in-vitro testing was done to determine the dyes' antibacterial effectiveness against various bacteria and fungi. The antibacterial activity of the dyes was moderate to very good against both Gram-positive and Gram-negative bacteria, as well as fungi.

The Potential of Electrospun Membranes in the Treatment of Textile Wastewater: A Review.

Water security and industrial wastewater treatment are significant global concerns. One of the main issues with environmental contamination has been the discharge of dye wastewater from the textile and dye industries, contributing to an ever-growing problem with water pollution, poisoning water supplies, and harming the ecosystem. The traditional approach to wastewater treatment has been found to be inefficient, and biosorption techniques and mechanisms have been proven to be a successful replacement for conventional methods. Recent developments have led to the recognition of fibrous materials as an environmentally friendly option with broad application in several industries, including wastewater treatment. This review explores the potential of fibrous materials produced by the electrospinning technique as adsorbents for wastewater treatment, while at the same time, for the removal of adsorbates such as oil, dyes, heavy metals, and other substances, as reported in the literature. Textile wastewater filtering structures, produced by electrospinning, are summarized and the use of synthetic and natural polymers for this purpose is discussed. The limitations of electrospun textile wastewater filtering structures are also mentioned. Electrospun nanofibrous membranes appear to be a very promising route to filter textile wastewater and therefore contribute to water reuse and to reducing the contamination of water courses.

Decolorization and detoxication of malachite green by engineered Saccharomyces cerevisiae expressing novel thermostable laccase from Trametes trogii

Malachite Green (MG) is a widely used industrial dye that is hazardous to health. Herein, the decolourisation and detoxification of MG were achieved using the engineered Saccharomyces cerevisiae expressing novel thermostable laccase lcc1 from Trametes trogii. The engineered strain RCL produced a high laccase activity of 121.83 U L-1. Lcc1 was stable at temperatures ranging from 20 ℃ to 60 ℃ and showed a high tolerance to organic solvents. Moreover, Lcc1 could decolorize different kinds of dyes (azo, anthraquinone and triphenylmethane), among which, the decolorization ability of MG is the highest, reaching 95.10 %, and the decolorization rate of other triphenylmethane dyes also over 50 %. The RCL decolorized about 95 % of 50 mg L-1 of MG dye in 10 h at 30 ℃. The MG degradation products were analyzed. The industrial application potential of the RCL was evaluated by treating industrial wastewater and the decolourisation rates were over 90 %.

KOH-activated biochar and chitosan composites for efficient adsorption of industrial dye pollutants

The treatment of dye pollutants remains a challenge in the current management of the water environment. In this study, an innovative biochar material co-modified with KOH and chitosan was synthesized. The morphology and physicochemical properties of the modified biochar material were assessed by SEM, FTIR, XPS, XRD, and thermogravimetric analyses. The results revealed a significant enhancement in chitosan loading due to the pretreatment of biochar with KOH. The co-modified biochar with KOH and chitosan (CHKBC) exhibited an enriched composition of functional groups such as − COOH, −NH2, and − OH, leading to a substantial increase in the maximum adsorption of MB by the biochar from 8.83 mg g−1 to 62.04 mg g−1, a 7.03-fold increase. The excellent adsorption performance of CHKBC for MB was maintained at different solution temperature (288–––318 K) and pH (5–––11) conditions. The main adsorption mechanisms of MB removal by CHKBC involved ion exchange, pore filling, electrostatic attraction, π - π interactions, and hydrogen bonding. Overall, CHKBC has higher chitosan loading, more uniform chitosan distribution, and better adsorption efficiency of MB. It is a promising adsorption material with low cost and a simple production process.

In-situ one-pot synthesis, characterization of magnetic hydrochar and its application as Fenton-like catalyst for the degradation of methylene blue dye

The widespread use of dyes in various industries has led to alarming levels of water pollution, posing significant environmental and health risks. This study presents biochar being a carbon-rich source, produced from Acacia koa pod covers has been used as a sustainable source to prepare Ak/BC-Fe3O4 magnetic nanocomposite, subsequently employed for Fenton-like degradation of methylene blue (MB) dye. FESEM-EDS revealed that the synthesized nanocomposite has a morphology of spherical magnetic nanoparticles being embedded on the biochar base and EDS further confirmed the synthesis of magnetic biochar by detecting only C, O, and Fe. The nanocomposite is mesoporous with a pore volume of 0.03204 cm3/g and a surface area of 7.11 m2/g as shown by the BET results. XRD substantiated the presence of an amorphous structure of biochar and the presence of ultra-small crystallites of Fe3O4 nanoparticles. FTIR signified the presence of specific functional groups for Fe–O and biochar whereas, XPS showed the peaks at 712.39 and 725.78 eV indicated the coexistence of Fe2+ and Fe3+. The nanocomposite is superparamagnetic with a saturation magnetization of 8.64 emu/g having remarkable magnetic separation capacity. Fenton-like degradation of MB dye in the presence of H2O2 revealed a first-order reaction with removal efficiency ranging between 82 and 96% in 120 min with convenient recycling ability for 7 cycles. Hence, this study underscores the outstanding characteristics and MB degradation efficiency of Ak/BC–Fe3O4, emphasizing its synthesis from sustainable plant biomass as a promising solution to address water pollution challenges associated with dye contamination.