Search Results (669)

Synthetic dyes from textile effluents represent a major environmental concern due to their persistence and toxicity. Reactive Black 5 (RB5) is widely used in the textile industry and is commonly applied as a model azo compound in sorption studies. This study comparatively evaluates the sorption performance of raw and carbonized sorbents derived from industrial hemp (Cannabis sativa L.) biowaste using an integrated experimental and theoretical approach. The sorbents were prepared through washing, drying, and phosphoric acid-assisted carbonization followed by pyrolysis. Structural and physicochemical properties were characterized using elemental analysis, FTIR spectroscopy, and SEM microscopy. Sorption performance toward RB5 was investigated through batch kinetic and equilibrium experiments, supported by kinetic (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models) and isotherm (Langmuir, Freundlich, and Temkin) modeling. Molecular docking simulations were performed to provide mechanistic insight into dye–sorbent interactions. Both materials exhibited rapid sorption kinetics, reaching equilibrium within approximately 45 min, with the pseudo-second-order model suggesting that surface-controlled interactions dominate the sorption rate. Molecular modeling, based on extensive conformational sampling, indicated a strong binding affinity between RB5 and cellulose-based structures, primarily associated with hydrogen bonding and other favorable noncovalent interactions. In contrast, graphene-based models revealed sorption governed by π–π interactions and confinement effects, supporting the experimentally observed differences between raw and carbonized sorbents. Full article

Aerobic ceramic membrane bioreactors (AeCeMBR) have shown great potential in treating wastewater (WW) from the textile industry; however, their operation faces challenges such as process variability, membrane contamination, and the need for accurate prediction of treated water quality under varying conditions. In this study, chemical oxygen demand (COD) and turbidity were selected as key indicators, as they directly reflect organic load removal and solids separation efficiency in MBR systems. The effect of four operational parameters: hydraulic retention time (HRT), organic loading rate (OLR), mixed liquor suspended solids (MLSS), and transmembrane pressure (TMP), was investigated using a response surface methodology (RSM) based on a Box–Behnken design. A random forest (RF) model coupled with Monte Carlo simulation (MC) was also developed using 174 experimental data points to enhance predictive power and quantify uncertainty. The RSM model showed strong agreement with experimental results (coefficient of determination (R²) > 0.95), achieving approximately 96% removal for both COD and turbidity, with validation errors of less than 2%. MC simulation (10,000 iterations) was applied to assess the effect of ±10% variance under operating conditions, providing a probabilistic view of system performance. The RF-MC framework demonstrated high predictive accuracy, with strong correlations between predicted and observed values (R² = 0.92 for COD and 0.97 for turbidity) and low uncertainty. Overall, this study proposes an integrated RSM, RF–MC approach for AeCeMBR systems, providing a robust and uncertainty-aware framework for process optimization and performance prediction under changing operating conditions. Full article

The release of microplastic fibers from synthetic textiles during domestic laundering is a major contributor to aquatic pollution. Nanomaterial-based surface treatments have recently emerged as a potential route for minimizing microfiber shedding. This study investigates the use, for the first time, of metal oxide nanoparticles (TiO₂, ZnO, MgO) functionalized with fatty acids (oleic acid (OA) and stearic acid (SA)) as microfiber-retaining agents. The nanoparticles were modified via a simple adsorption process at room temperature, monitored by zeta potential analysis, and confirmed by DSC-TG and FTIR-ATR analysis. When applied to polyester fabrics during simulated washing cycles, the hydrophobicity of the polyester surface coated with functionalized nanoparticles was assessed via contact angle measurements, and the effect on microfiber shedding was evaluated by the filtration of wastewater and by weighing the mass of fibers retained in the filters. ZnO and MgO nanoparticles treated with stearic and oleic acid demonstrated a significant reduction in fiber shedding compared to commercial laundry detergent (approximately 46–70%). In contrast, fatty acid adsorption onto TiO₂ was less efficient (reduction in microfiber release ~23%), and the TiO₂-based systems showed limited improvement in microfiber shedding, possibly due to insufficient hydrophobic interaction. These results demonstrate that fatty acid functionalization of low-cost inorganic nanoparticles is a promising strategy for mitigating microfiber pollution in laundry effluents. Full article

Textile dyes are considered emerging pollutants due to their recalcitrant and xenobiotic nature, making them toxic and mutagenic, leading to various environmental impacts. Aspergillus fungi, known for their metabolic diversity and high environmental adaptability, emerge as an alternative for remediating these contaminants. The evolution and trends in research on the application of Aspergillus in the bioremediation of textile dyes were assessed through a scientometric analysis of articles indexed in Web of Science, PubMed, and Scopus, using the Bibliometrix tool. A total of 283 documents were identified over 28 years since the first publication, indicating that although the topic is established, research output remains limited. Publications originated from 43 countries, with India as the leading contributor; however, the low rate of international collaboration (12.37%) highlights the need for stronger global partnerships. Research primarily focused on dye decolorization via biosorption and biodegradation, with Aspergillus niger and Aspergillus flavus as the most frequently studied species. Recent trends emphasize lignolytic enzymes, especially laccase, and integrative approaches combining biological and physicochemical processes. The results also reveal the urgent need for comprehensive toxicological assessments beyond phytotoxicity, considering increasing concerns about textile effluent impacts on ecosystems and human health. Full article

The removal of recalcitrant industrial dyes from wastewater has emerged as a critical environmental challenge, particularly in the context of the accelerating decline of global freshwater reserves. Given that these contaminants originate predominantly from the effluents of textile, chemical, and related manufacturing sectors, the deployment of advanced treatment technologies prior to discharge is imperative to mitigate their ecological impact. This study investigates the photocatalytic degradation of indigo carmine using a synthesized MgAl–LDH material. LDH is shown to act as an active photocatalytic component rather than a support, with its remarkably simple synthesis offering a practical alternative to the complex catalysts dominating the current literature. The catalyst’s structural, morphological, and surface characteristics were comprehensively validated through XRD, SEM, EDX, and BET analyses. The catalyst was evaluated under varying hydrogen peroxide doses and across an initial dye concentration range of 5 × 10⁻⁵ to 5 × 10⁻⁴ M. Increasing the H₂O₂ volume (3.5–20 mL, corresponding to H₂O₂ excess ratios of 17.5–100) significantly enhanced the oxidation rate, whereas higher dye concentrations reduced efficiency due to photon competition and partial saturation of catalytic sites. These experiments provided the basis for extracting kinetic parameters and assessing the mechanistic pathways governing the photocatalytic process. The kinetic behavior of indigo carmine degradation was evaluated by fitting the experimental data to zero-order, first-order, and second-order empirical models to identify the rate law that best describes the reaction. Reusability tests showed that MgAl–LDH maintains high activity over multiple cycles, with only a moderate decline, demonstrating its stability and suitability for practical wastewater treatment applications. Full article

Synthetic textile dye solutions are commonly used as controlled model systems to evaluate adsorbent performance before application to real textile wastewater matrices. In this study, a magnetic adsorbent was developed by functionalizing pomegranate peel-derived biochar with iron oxide (Fe₃O₄) nanoparticles and was applied for chemical oxygen demand (COD) removal from synthetic aqueous solutions containing three individual acid dyes: Buracid Yellow BGL, Buracid Navy Blue RL, and Buracid Red FN. The effects of adsorbent loading, pH, contact time, and dye type on COD removal were systematically evaluated and optimized using Response Surface Methodology (RSM). The experimental results showed that adsorbent loading, pH, and contact time significantly influenced COD removal efficiency. The developed quadratic model showed good explanatory performance, with R² = 83.42% and adjusted R² = 79.28%, while the predicted R² value of 72.65% indicated moderate predictive capability. Under the identified optimum operating region (pH 7.4, contact time 35 min, and adsorbent loading 80 g/L), COD removal efficiency reached up to 84%, depending on dye type. These findings indicate that Fe₃O₄-modified pomegranate peel biochar is a promising adsorbent for COD reduction from synthetic textile dye solutions. However, further validation using real textile wastewater is required to evaluate matrix effects caused by salts, surfactants, suspended solids, mixed dyes, and other textile auxiliaries. Full article

The discharge of dye-loaded textile effluents poses serious environmental concerns due to their high stability. In this study, a magnetic Fe₂O₃/TiO₂/NBC (FNT) heterostructure, derived from Cannabis sativa-based nanobiochar (NBC), was developed for crystal violet (CrV) degradation via peroxymonosulfate (PMS) activation. The crystalline structure, surface functional groups, morphology, and elemental composition were analyzed using advanced characterized of the synthesized catalyst. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of Fe³⁺, Ti⁴⁺, and abundant surface oxygen species. Under UV light, efficient electron transfer across the FNT interface promoted PMS decomposition into hydroxyl and sulphate radicals. Electrochemical results indicated reduced charge recombination and enhanced electron mobility. Under optimal conditions (PMS = 75 mg/L, FNT = 30 mg/L, pH 7), 98.9% CrV degradation was achieved within 120 min. The catalyst maintained over 97% efficiency after five cycles, demonstrating excellent stability and reusability. Overall, this research demonstrates a robust and sustainable catalytic system for efficient dye degradation, offering strong potential for practical wastewater treatment applications. Full article

Copper cobalt sulfide (Cu-CoS₂) nanoparticles (NPs) were synthesized via the co-precipitation method in the present study. The synthesized nanoparticles were employed as photocatalysts for the degradation of two hazardous dyes, Eosin B (EB) and Rhodamine B (RB), under sunlight irradiation. The synthesized nanoparticles were characterized using Energy Dispersive X-ray spectroscopy, Scanning Electron Microscopy, UV-Visible spectroscopy, Fourier Transform Infrared spectroscopy, and X-ray Diffraction analysis. The calculated optical band gap of Cu-CoS₂ was 2.06 eV, while the point of zero charge (PZC) was determined to be 7. The XRD results confirmed the crystalline nature of the Cu-CoS₂ nanoparticles with an average crystallite size of 28.23 nm. The catalyst exhibited higher photocatalytic degradation efficiency for EB than for RB in single-dye solutions. In contrast, the presence of EB in the binary dye mixture did not significantly influence the degradation of RB. The effects of various operational parameters, including dye concentration, pH, temperature, and catalyst dosage, were systematically investigated. The photocatalytic degradation efficiency of both dyes decreased with increasing initial dye concentration. Optimum degradation conditions for both single and binary dye systems were obtained at dye concentrations of 40:20 μM, pH 5 for EB, pH 9 for RB, and a temperature of 50 °C. The maximum degradation efficiencies achieved in single-dye solutions were 97% for RB and 92% for EB, whereas degradation efficiencies of 98% for RB and 82% for EB were observed in binary dye systems. Furthermore, first-order and second-order kinetic models were applied to evaluate the photodegradation process, and the experimental data showed better agreement with the second-order kinetic model. Full article

Industrial and domestic wastewaters, nonpoint pollution sources, and climate change affect stream ecosystems, water quantity, and quality. Within the scope of this study, the water quality of Nilüfer Stream was evaluated using the Water Quality Index (WQI), One-Way ANOVA, the Kruskal–Wallis Test, and Principal Component Analysis (PCA). In the study, 4686 water quality data from seven sampling stations between 2008 and 2024 were used. WQI results showed a distinct decrease in water quality from the upstream to the downstream of the Stream. Average WQI values for the stations were found to be between 140.83 and 487.83. The lowest WQI value was found at Station 1 and the highest WQI value was found at Station 7. According to WQI, the ranking of the stations by magnitude was St7 > St4 > St5 > St6 > St2 > St3 > St1. A statistically significant difference was observed between the stations in terms of WQI, ANOVA, and Kruskal–Wallis Test (p < 0.05), and water quality was found to be seasonally diverse. Generally, at stations (except for two stations), the seasonal WQI values ranked by magnitude were autumn > summer > winter > spring. The PCA showed that relationships among parameters originating from industrial wastewater associated with the textile, automotive, and metal industries were stronger (component loadings > 0.75), whereas the groups identified in the upstream basin indicated domestic pollution and agricultural pollution from fertilizers and pesticides. PCA conducted between meteorological parameters and the WQI values of the stations showed that climate change could be effective at only two stations. It was determined that the region located before the wastewater treatment plant (St4) was associated with precipitation, humidity, and evaporation, while the downstream region (St7) was related to wind speed. It was observed that water quality was more influenced by industrial, urban, and agricultural pollution sources than by climate change. Full article

Green synthesis of KGM-capped CeO₂ nanoparticles was successfully achieved through a simple coprecipitation method using Konjac Glucomannan (KGM) as a biopolymeric capping and stabilizing agent. The reaction conditions were optimized by varying pH (9–11) and temperature (30–70 °C) to evaluate their influence on nanoparticle formation and photocatalytic performance. The synthesized KGM–CeO₂ nanoparticles were comprehensively characterized using FTIR, UV–Vis spectroscopy, XRD, SEM–EDS, TEM, DLS, and ZP analysis to investigate their structural, optical, morphological, and surface properties. The characterization results confirmed the successful formation of porous sponge-like branched CeO₂ nanostructures with irregular morphology. XRD analysis revealed the crystalline nature of the nanoparticles with an average crystallite size of approximately 7.7 nm, while DLS analysis showed an average hydrodynamic particle size of 29.7 nm with a biomodal particle size distribution. The positive zeta potential value (+16.75 mV) confirmed good colloidal stability and reduced agglomeration due to effective capping by KGM. The synthesized nanoparticles also exhibited favorable optical properties with band gap values suitable for photocatalytic applications. The adsorption and photocatalytic degradation performance of the KGM–CeO₂ nanoparticles was investigated against synthetic textile dyes, including Naphthol Blue Black (NBB), Methyl Orange (MO), and a mixed NBB–MO dye system under acidic conditions. Using an adsorbent dosage of 50 mg and dye concentrations of 100 mg/L, the material achieved degradation efficiencies of approximately 99% for NBB, 91% for MO, and 52% for the mixed dye system under UV irradiation for 120 min. Adsorption kinetic studies indicated that the pseudo-second-order model provided the best fit, suggesting that chemisorption is the dominant adsorption mechanism involving multifunctional surface interactions. These findings are particularly relevant for industrial wastewater treatment, since actual textile effluents typically contain complex mixtures of dyes and organic contaminants rather than single dye pollutants. The mixed dye experiments, therefore, provide a more realistic simulation of industrial wastewater conditions. Overall, the synthesized KGM–CeO₂ nanoparticles demonstrate excellent potential as an eco-friendly, cost-effective, and sustainable multifunctional material for adsorption-assisted photocatalytic treatment of dye-contaminated wastewater. Further optimization of operational conditions and catalyst surface properties may enhance its efficiency in multicomponent wastewater systems. Full article

The textile industry contributes significantly to environmental pollution through massive water usage and toxic synthetic dye effluents. Bioremediation offers a sustainable solution by using microorganisms, such as bacteria, to transform complex contaminants into simpler substances. This study evaluated the bioremediation potential of fifteen halotolerant endophytic bacteria isolated from black beans (Phaseolus vulgaris L.) against various textile dyes. The strains included Bacillus cereus, Bacillus amyloliquefaciens, Priestia megaterium, and Staphylococcus warneri. Initial screenings across different TSA (Tryptic Soy Agar) medium concentrations (10%, 50%, 100%) revealed that bacterial growth and discoloration—assessed via halo formation—were most pronounced in 50% medium. While several dyes showed no reaction, Malachite Green and Congo Red were successfully decolorized. In liquid medium assays TSB (Tryptic Soy Broth) (50%) quantitative analysis via spectrophotometry showed that strains PV57, PV107, and PV112 achieved approximately 45% discoloration for Congo Red. Most notably, PV18 and PV114 achieved discoloration efficiencies of 91.69% and 88.72%, respectively, for Malachite Green after 72 h. These findings indicate that salt-tolerant endophytic bacteria are promising candidates for the decolorization of textile dyes. However, further studies are required to determine whether the observed discoloration results from biodegradation, biotransformation, or biosorption. This study underscores the potential of agricultural endophytes in managing industrial waste effectively. Full article

Valorization of agro-industrial waste into functional materials is fundamental to the circular economy, especially for addressing the persistent contamination by anionic azo dyes in textile wastewater. This study evaluates guava seeds modified with hexadecyltrimethylammonium bromide (GS-M) as low-cost biosorbents for the removal of Direct Blue 71 (DB71), comparing their performance with that of natural seeds (GS-N) in batch systems and fixed-bed columns. Characterization by infrared spectroscopy (FTIR) and electron microscopy (SEM-EDS) confirmed successful surfactant immobilization, thereby creating a cationic surface with strong electrostatic affinity for anionic dye molecules. Batch experiments showed that GS-M achieved 98% DB71 removal within 120 min, whereas GS-N reached only 58% after 300 min. For GS-M, both pseudo-first-order and pseudo-second-order models fit the kinetic data well, consistent with concurrent electrostatic and hydrophobic interactions; GS-N was best described by the Elovich model, indicating rate limitation by electrostatic repulsion. GS-M maintained removal efficiency above 84% across pH 3–9, whereas GS-N was effective under acidic conditions. Langmuir maximum adsorption capacity (Q_o) values for GS-M were 6.02 mg/g at pH 4 and 7.87 mg/g at pH 8, a 1.5- to 2.2-fold increase over GS-N under matched conditions. Three adsorption–desorption cycles retained ~49% of the initial GS-M capacity, supporting a short-cycle reuse profile rather than indefinite multi-cycle operation. Fixed-bed column performance was highly sensitive to the hydraulic loading rate (v_c), with breakthrough times increasing nearly eightfold as v_c decreased. The Bed Depth Service Time (BDST), Thomas, and Yoon–Nelson models described the dynamic data consistently, yielding a maximum dynamic capacity of 165.6 mg/L under optimal conditions and providing a quantitative basis for scale-up. These results establish surfactant-modified guava seeds as a low-cost, pH-resilient biosorbent system aligned with circular-economy principles for the sustainable remediation of textile wastewater. Full article

This work introduces a textile-based platform for biocatalysis by integrating a copper-based hybrid domain onto aminated/amidine-functionalized acrylic textile (TAC–Cu), producing a functional bio-textile capable of high-performance enzyme immobilization. The textile substrate was chemically modified with ethylenediamine to generate amine/amidine-type functional groups, enabling in situ formation of copper-based hybrid structures through either a conventional solvothermal approach or a plant-mediated route employing Costus speciosus extract. The green-synthesized TAC–Cu composite exhibited superior structural uniformity, improved porosity, and enhanced surface chemistry, resulting in a higher horseradish peroxidase (HRP) immobilization yield (92%) compared with the chemically synthesized analogue. The resulting HRP-functionalized bio-textile demonstrated markedly improved catalytic behavior, including a reaction rate constant nearly twice that of the free enzyme, and strong operational robustness. As a technical textile engineered for environmental applications, the composite achieved 90% bisphenol A (BPA) removal within 90 min and retained substantial enzymatic activity even at 80 °C, whereas free HRP was almost fully deactivated. Overall, this study highlights the potential of eco-engineered TAC–Cu materials as a new class of functional and sustainable bio-textiles, combining enzyme stabilization, high catalytic efficiency, and suitability for wastewater treatment and other technical textile applications. Full article

Increasing volumes of dye-containing wastewater generated by the textile industry have become a serious environmental issue, particularly in Indonesia, where textile production contributes substantially to industrial activity. Among synthetic dyes, methylene blue (MB) is widely used because of its low cost and high solubility in water; however, its persistence, toxicity, and potential carcinogenicity make its removal from wastewater highly important. Conventional treatment methods are often limited by incomplete degradation and secondary waste generation. In this study, iron oxide nanoparticles (IONPs) were synthesized through a green route using Psidium guajava leaf extract as both a reducing and stabilizing agent. Characterization by PSA, UV-Vis, SEM-EDX, and XRD confirmed the formation of magnetite-like iron oxide particles with sizes ranging from 209.2 to 291.4 nm. Photocatalytic experiments showed high MB degradation efficiency (94.7–99.0%) under UV irradiation, highlighting the potential of guava leaf-mediated IONPs as low-cost, sustainable photocatalysts for wastewater treatment. Full article

With the growing severity of water pollution, conventional treatment technologies are increasingly unable to satisfy the demand for deep purification. Catalytic wastewater treatment has emerged as an effective strategy for degrading refractory pollutants because of its high efficiency, mild operating conditions, and environmentally friendly nature. This review systematically summarizes recent progress in catalytic materials for wastewater treatment, covering four major categories: metal-based materials, carbon-based materials, multicomponent composites, and photo/electrocatalytic systems. Particular attention is given to their design strategies, structural characteristics, and performance advantages. On this basis, the full mechanistic chain is discussed, from interfacial adsorption and activation to reactive-species generation, including both radical and non-radical pathways, intermediate transformation, and macroscopic reaction kinetics. The review also highlights representative applications in practical wastewater streams, including textile dyeing and pharmaceutical, chemical, landfill leachate, and municipal tailwater treatment, thereby demonstrating the engineering potential of catalytic technologies. At the same time, several critical challenges remain, including insufficient long-term material stability, incomplete mechanistic understanding in complex water matrices, limited adaptability to real wastewater, and the high cost of large-scale preparation. Future research should therefore focus on the development of highly stable, low-cost, and interference-resistant catalytic materials, deeper mechanistic elucidation through in situ characterization and theoretical calculations, stronger integration with membrane separation, biological treatment, photovoltaic or electrochemical processes, and the establishment of standardized evaluation protocols and life-cycle assessment frameworks. These efforts will accelerate the transition of catalytic wastewater treatment toward greener, smarter, and more practical engineering applications. Full article