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The present study is focused on the synthesis of zero-valent iron/cellulose acetate (Fe0-x/CA) membranes by phase inversion route for the activation of peroxymonosulfate (PMS). The generated •OH and SO4•− effectively degraded methylene blue (MB) dye in water to give comparatively non-toxic byproducts. The SEM investigations revealed that Fe0 nanoparticles are evenly dispersed into the CA membrane resulting in decline of agglomeration and enhancing the roughness of the composite surface. Moreover, the catalytic degradation of MB demonstrated that M5-alone showed 85% and was further boosted to 97% when coupled with PMS (M5/HSO5−). The catalytic degradation of degradation of MB by M5/HSO5− membrane system in acidic, neutral, and basic media indicated that the degradation was 99.5%, 98.0%, 97.0%, 86.0% and 70.0% when the pH of the medium was 3, 5, 7, and 11, respectively. Furthermore, the degradation performance of M5/HSO5− membrane system was evaluated in de-ionized water (DIW), tape water (TPW) and industrial wastewater (IWW) and the results indicated that MB catalytic degradation was in the order of DIW (97%) > TPW (84%) > IWW (68%). Besides, various parameters like water flux permeability, contact angle, porosity, and fouling performance were also investigated. In addition, the degradation products were evaluated, and the degradation pathways were proposed accordingly. [ABSTRACT FROM AUTHOR]

The present study evaluates the color wastewater treatment in the textile industry by the persulfate/ dithionite (PS/DTN) process. This study was performed on a laboratory scale in a reactor with a batch system. The wastewater was taken from the textile industry, and the efficiency of the PS/DTN process in the treatment and removal of COD of this wastewater was optimized by the operational parameters of pH, PS, DTN, and reaction time. Optimal values of these parameters were obtained at pH = 3, PS = DTN = 1.5 g/L, and reaction time = 90 min. Although in optimal condition, the removal efficiency of COD and TOC reached 64.9 and 54.5%; it does not meet the required discharge conditions and standards. On the other hand, it was observed that this process has a good ability to improve the biodegradability properties of textile wastewater, and the results showed a good increase in BOD5/COD and average oxidation state (AOS) and carbon oxidation state (COS) indexes to 0.47, 0.7, and by 2.4. Dominant radical contributed to the system for oxidation was found to be SO 4 ∙ - based on the scavenger radical test. According to the findings, it can be suggested that this system can be proposed as a pre-treatment step to reduce the toxicity of wastewater and reduce the input COD load to the biological system. [ABSTRACT FROM AUTHOR]

The color of textile wastewater is still a main problem in wastewater treatment by biological processes. The colored effluents from textile factories usually exceed effluent standards. Therefore, various innovations were developed to treat textile wastewater for decolorization in the effluents. This research aims to decolorize textile wastewater by immobilizing white rot fungi degradation. At first, the 11 fungal stains were tested to find the decolorized efficiency then the high decolorized efficiency fungal stains were immobilized on four material media, namely water hyacinth stalks, coconut husk, corn cob, and loofah. After that, the immobilized fungi were cultivated in the culture media at 30, 60, and 120 C/N ratios, respectively. The results showed that Trametes sanguinea and Perenniporia tephropora were two stains with a high decolorized efficiency of 68.8% and 67.5% respectively, and the decolorized efficiency was increased when immobilized on loofahs and fed with 120 C/N ratio medium. In a comparison of two fungal stains, P. tephropora was found more suitable for the decolorization of textile wastewater than T. sanguinea because T. sanguinea could produce red-orange pigments that induced the colored enhancement in wastewater over time. Finally, immobilized P. tephropora was cultivated in a 120 C/N ratio medium within a 10 L continuous stirred tank reactor (8 L working volume) to investigate the decolorized efficiency, enzymatic activity, and repeated batch. It was found that three repeated cycles were carried out by reusing the immobilized P. tephropora and the highest decolorized efficiency was 63.4%. The enzymatic activity of laccase, manganese peroxidase, and lignin peroxidase was 15.5 U/L, 85.9 U/L, and 0 U/L, respectively [ABSTRACT FROM AUTHOR]

This work focused on the decolorization of methyl red (MR) from an aqueous solution utilizing Rumex abyssinicus-derived biochar (RAB). RAB was prepared to involve unit operations such as size reduction, drying, and carbonization. The pyrolysis of the precursor material was carried out at a temperature of 500 °C for two hours. After that, the prepared RAB was characterized by the pH point of zero charge (pHpzc), the Brunauer–Emmett–Teller (BET) method, Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared (FTIR) spectroscopy. On the other hand, a batch adsorption experiment of MR removal onto RAB was conducted, considering four operating parameters: pH, contact time, adsorbent dose, and initial dye concentration. The characterization of the adsorbent material revealed a porous and heterogeneous surface morphology during SEM, a specific surface area of 45.8 m2/g during the BET method, the presence of various functional groups during FTIR, and a pHpzc of 6.2. The batch adsorption experiment analysis results revealed that a maximum removal efficiency of 99.2% was attained at an optimum working condition of pH 6, contact time of 40 min, initial dye concentration of 70 mg/L and adsorbent dosage of 0.2 g/100 mL. Furthermore, Freundlich isotherm (R2 = 0.99) and pseudo-second-order kinetics (R2 = 0.99) models confirmed the heterogeneous surface interaction and chemisorption nature. Generally, this study highlighted that RAB could be a potential adsorbent for the detoxification of MR-containing industrial effluents. [ABSTRACT FROM AUTHOR]

The textile industry is discharging high concentrations of anionic and cationic azo dyes into the nearby environment, which can cause adverse effects on public health, and the aquatic environment. Therefore, this study aimed to develop giant reed biochar and apply for the removal of Basic blue 41 (BB41) and Eriochrome black T (EBT) azo dyes from water. Characterization techniques such as BET surface area analyzer, Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermal gravimetric analyzer (TGA) were applied for biochar description. The biochar exhibits a high fixed carbon content (80.4%), a low ash content (3.8%), a large surface area (429.0 m2/g), and good thermal stability. High removal efficiencies of BB41 98.6% and EBT 82.5% were recorded at the specific experimental condition. The experimental data were fitted with the Langmuir isotherm model at R2 0.99 for both dyes whereas the adsorption kinetics revealed the pseudo-second-order kinetics at R2 ∼ 1 and 0.99 for BB41 and EBT, respectively. Furthermore, four regenerations of biochar with adsorption performances of BB41 and EBT dyes were found to be 94.7% and 79.1%, respectively. Finally, this adsorbent can be considered an economically viable material for the removal of synthetic dyes from wastewater systems. In conclusion, the study findings showed that the adsorbent material is promising to apply for water and wastewater treatment but still, the study of adsorption interaction and modifications of the surface functionalities are essential to accommodate multipollutant removal from real water systems. [ABSTRACT FROM AUTHOR]

In the photo-oxidation processes, the oxidants play a vital role in removing color. However, a comprehensive comparison of the three common oxidants' performance for color removal from textile wastewater has not been conducted. Also, the effect of periodate in the presence of ferrous for color removal has not been investigated extensively. The object of this study was to evaluate and compare the effect of three common oxidants on the removal of color. Central composite design was employed to design the experiments and evaluate the interaction between parameters and their impact on color removal. The photo-oxidation processes were carried out under UV light irradiation (60 W) in the presence of ferrous (Fe2+) and three oxidants, namely hydrogen peroxide (H2O2), sodium persulfate (SPS), and sodium periodate (SPI). The four main variables were the reaction time, the pH value, the concentration of oxidants, and the concentration of ferrous. Finally, the optimal values for all parameters were shown and these three processes were compared with each other. Although the UV/SPI/Fe2+ process had the highest color removal (96%), by considering all parameters, the UV/SPS/Fe2+ was a better choice because of its high efficiency, low reaction time, and low oxidant concentration. The results suggested that the photo-Fenton process could not be a good option among these processes, as it required the longest reaction time and highest oxidant concentration while achieving the lowest removal efficiency (82%). The results of this study can help with the decision-making process to select a better process for textile wastewater treatment. [ABSTRACT FROM AUTHOR]

This paper examined the performance of an integrated wastewater treatment system, namely an Electro-Fenton (EF) with Anaerobic Sequencing Batch Reactor (ASBR), for textile dyeing wastewater. Laboratory-scale feasibility studies on electro-Fenton processes using a novel steel flake used as a catalyst were carried out to investigate the color and chemical oxygen demand (COD) by effects of optimum variables such as pH, catalyst dose, and H2O2 dose by varying one variable at a time. A novel steel flakes, which were used as a catalyst in this research, had particle dimensions ranging from 0.25 to 1.75 mm. To characterize the steel flakes, Scanning Electron Microscopy (SEM), EDAX, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and Thermo Gravimetric Analysis (TGA) were used. Performance of novel electro-Fenton and anaerobic sequencing batch reactor treating textile dyeing wastewater was evaluated. Electro-Fenton with steel flakes catalyst treatment was able to remove 97.5% color and59% COD and the pre-treated effluent was transferred to anerobic sequencing batch reactor biological treatment. The maximum color and COD removal of 100% and 94% respectively in the coupled process. The use of steel flakes catalyst in the combined electro-Fenton with ASBR reaction greatly improves COD removal without formation of sludge. Thus, the developed system is economically feasible and superior to other conventional treatment systems. [ABSTRACT FROM AUTHOR]

Membrane bioreactor (MBR) is a promising technology for the treatment of municipal and industrial wastewater, including highly contaminated textile wastewater. However, membrane fouling remains a critical challenge due to reduced flux. This study investigates the efficacy of a moving bed MBR (MB‐MBR) technology for textile wastewater treatment, focusing on chemical oxygen demand (COD) removal, and its impact on mitigating membrane fouling. In a 50‐day study, a conventional MBR (R1) was compared with an MB‐MBR (R2) augmented with free‐floating biocarriers (accounting for 20% of the reactor volume). Both systems used flat sheet ceramic membrane modules. The results indicate that the MB‐MBR achieved superior performance, with COD and colour removal of 89% and 81%, respectively, compared with 87% and 73% in the conventional MBR. Importantly, the introduction of biocarriers eliminated the need for offline physical membrane cleaning in the MB‐MBR. The free‐floating biocarriers lowered transmembrane pressure, reduced capillary suction time and reduced fouling through their scouring action. Highlights: A conventional MBR and moving bed‐MBR were compared in textile wastewater treatment.Almost equal COD removal efficiencies were found in both operations.Higher color removals were obtained by moving bed‐MBR process.The moving bed‐MBR reduced the TMP, CST of sludge and membrane fouling propensity. [ABSTRACT FROM AUTHOR]

Real textile wastewater (RTWW) poses significant environmental challenges. RTWW typically contains high levels of organic compounds, such as dyes, as well as inorganic substances like salts. These contaminants can harm aquatic life when released into water bodies without appropriate treatment. RTWW was subjected to a series of sequential treatments: exchange resins for removing ions, advanced oxidation with bicarbonate-activated peroxide to degrade organic matter, and a biological treatment based on the Zahn–Wellens test to remove remaining chemical oxygen demand (COD) The advanced oxidation process based on the activation of H2O2 with NaHCO3 (catalyzed with cobalt impregnated on a pillared clay, Co/Al–PILC)) was optimized using central composite design (CCD) and response surface methodology (RSM). After the process integration, reductions in ion concentrations, chemical oxygen demand (COD), and total organic carbon content (TOC) were achieved. Reduced hardness (99.94%) and ions (SO42− and acid black 194 dye of 99.88 and 99.46%, respectively), COD (96.64%), and TOC (96.89%), guaranteeing complete treatment of RTWW, were achieved. Additionally, the biodegradability index of RTWW increased from 0.28 ± 0.01 to 0.90 ± 0.01, and phytotoxicity was reduced, going from a phytotoxic that inhibited the germination of lettuce seeds to a phytostimulant after biological treatment with activated sludge. [ABSTRACT FROM AUTHOR]

Microalgae technology is a viable solution for environmental conservation (carbon capture and wastewater treatment) and energy production. However, the nutrient cost, slow-kinetics, and low biosorption capacity of microalgae hindered its application. To overcome them, algal-biochar (BC) can be integrated with microalgae to treat textile wastewater (TWW) due to its low cost, its ability to rapidly adsorb pollutants, and its ability to serve as a nutrient source for microalgal-growth to capture CO2 and biodiesel production. Chlorella vulgaris (CV) and algal-BC were combined in this work to assess microalgal growth, carbon capture, TWW bioremediation, and biodiesel production. Results showed the highest optical density (3.70 ± 0.07 OD680), biomass productivity (42.31 ± 0.50 mg L−1 d−1), and dry weight biomass production (255.11 ± 6.01 mg L−1) in an integrated system of CV-BC-TWW by capturing atmospheric CO2 (77.57 ± 2.52 mg L−1 d−1). More than 99% bioremediation (removal of MB-pollutant, COD, nitrates, and phosphates) of TWW was achieved in CV-BC-TWW system due to biosorption and biodegradation processes. The addition of algal-BC and CV microalgae to TWW not only enhanced the algal growth but also increased the bioremediation of TWW and biodiesel content. The highest fatty acid methylesters (biodiesel) were also produced, up to 76.79 ± 2.01 mg g−1 from CV-BC-TWW cultivated-biomass. Biodiesel's oxidative stability and low-temperature characteristics are enhanced by the presence of palmitoleic (C16:1) and linolenic (C18:3) acids. Hence, this study revealed that the integration of algal-biochar, as a biosorbent and source of nutrients, with living-microalgae offers an efficient, economical, and sustainable approach for microalgae growth, CO2 fixation, TWW treatment, and biodiesel production. [ABSTRACT FROM AUTHOR]

This study reported the synthesis and assessment of zinc oxide/iron oxide (ZnO/Fe2O3) nanocomposite as photocatalysts for the degradation of a mixture of methylene red and methylene blue dyes. X-ray diffraction analysis confirms that the crystallite of zinc oxide (ZnO) has a hexagonal wurtzite phase and iron oxide (Fe2O3) has a rhombohedral phase. Fourier Transform Infra-Red spectrum confirms the presence of Zn–O vibration stretching at 428, 480 and 543 cm−1 stretching confirming Fe–O bond formation. Scanning Electron Microscope images exhibited a diverse size and shape of the nanocomposites. The ZnO-90%/Fe2O3-10% and ZnO-10%/Fe2O3-90% nanocomposites reveal good photocatalytic activity with reaction rate constants of 1.5 × 10−2 and 0.66 × 10−2; and 1.3 × 10−2 and 0.60 × 10−2 for methylene blue and methyl red dye respectively. The results revealed that the synthesized ZnO/Fe2O3 nanocomposite is the best catalyst for dye degradation and can be used for industrial applications in future. [ABSTRACT FROM AUTHOR]

In the current study, bioelectricity and polyhydroxyalkanoate (PHA) production were integrated by a dual chamber microbial fuel cell (MFC) using Enterobacter sp. TS1L and textile wastewater (TW), and the method was evaluated. The highest open circuit voltage (OCV, 986.50 mV), current density (CD, 6.04 W/m3) and power density (PD, 0.32 W/m3) were observed when sterile TW was used as the substrate. Sterilization had no effect on electricity generation, while the OCV, CD and PD were not significantly different. The prolong MFC was operated by Enterobacter sp. TS1L using non-sterile TW for a period of 7 days. Throughout the 7-day operation, the experiment yielded a consistent CD output, ranging from 1.56 A/m3 to 2.31 A/m3. After MFC treatment, the quality of the effluent surpassed the Thailand water quality standard. A high percentage of decolorization (72.9%) was observed by Enterobacter sp. under TW-fed MFC. Thereafter, biomass was collected, then, PHA was extracted and characterized. The highest biomass (3.5 ± 0.6 g/L) and PHA (56.1 ± 1.5% cell dry mass, CDM) level were observed at 6 days of MFC operation. The isolated polymer from Enterobacter sp. TS1L was confirmed to be medium chain length-co-long chain length PHA (mcl-co-lcl PHA) containing 3-hydroxyhexadecanoate (3HD, C14) and 3-hydroxyoctadecanoate (3HOD, C18). [ABSTRACT FROM AUTHOR]

Cassia fistula (C. fistula) seed-derived coagulants have demonstrated substantial potential for treating dye-based wastewater. Such coagulants exhibit notable coagulating-flocculating activity and are environmentally friendly. However, recovering these natural coagulants from aqueous media poses challenges. In this study, we introduce a novel plant-derived magnetic coagulant that is a combination of C. fistula seed gum with magnetic spinel ferrite. This research includes a pilot-scale study to simulate full-scale textile wastewater treatment using this composite. Material characterisations revealed that spherical CoFe2O4 particles could be effectively coated with the active coagulant, C. fistula gum. The saturation magnetisation of the composite, measured at 54.11 emu/g, facilitates its convenient separation from aqueous solutions using an external magnetic field. Bench-scale studies showed that initial pH and coagulant dosage substantially affect the removal efficiency of colour and chemical oxygen demand (COD). In the pilot-scale study, the C. fistula-CoFe2O4 composite demonstrated promising coagulant properties. It achieved a colour removal percentage of 94.0 % with a volume of 30 L and a coagulant dosage of 12.3 g L-1 . Using this coagulation-flocculation process as a primary treatment step, possibly followed by biological or membrane methods, can help meet Vietnamese environmental standards. [ABSTRACT FROM AUTHOR]

Abstract The textile industry is discharging high concentrations of anionic and cationic azo dyes into the nearby environment, which can cause adverse effects on public health, and the aquatic environment. Therefore, this study aimed to develop giant reed biochar and apply for the removal of Basic blue 41 (BB41) and Eriochrome black T (EBT) azo dyes from water. Characterization techniques such as BET surface area analyzer, Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermal gravimetric analyzer (TGA) were applied for biochar description. The biochar exhibits a high fixed carbon content (80.4%), a low ash content (3.8%), a large surface area (429.0 m2/g), and good thermal stability. High removal efficiencies of BB41 98.6% and EBT 82.5% were recorded at the specific experimental condition. The experimental data were fitted with the Langmuir isotherm model at R2 0.99 for both dyes whereas the adsorption kinetics revealed the pseudo-second-order kinetics at R2 $$\sim$$ ∼ 1 and 0.99 for BB41 and EBT, respectively. Furthermore, four regenerations of biochar with adsorption performances of BB41 and EBT dyes were found to be 94.7% and 79.1%, respectively. Finally, this adsorbent can be considered an economically viable material for the removal of synthetic dyes from wastewater systems. In conclusion, the study findings showed that the adsorbent material is promising to apply for water and wastewater treatment but still, the study of adsorption interaction and modifications of the surface functionalities are essential to accommodate multipollutant removal from real water systems.

Abstract Microalgae technology is a viable solution for environmental conservation (carbon capture and wastewater treatment) and energy production. However, the nutrient cost, slow-kinetics, and low biosorption capacity of microalgae hindered its application. To overcome them, algal-biochar (BC) can be integrated with microalgae to treat textile wastewater (TWW) due to its low cost, its ability to rapidly adsorb pollutants, and its ability to serve as a nutrient source for microalgal-growth to capture CO2 and biodiesel production. Chlorella vulgaris (CV) and algal-BC were combined in this work to assess microalgal growth, carbon capture, TWW bioremediation, and biodiesel production. Results showed the highest optical density (3.70 ± 0.07 OD680), biomass productivity (42.31 ± 0.50 mg L−1 d−1), and dry weight biomass production (255.11 ± 6.01 mg L−1) in an integrated system of CV-BC-TWW by capturing atmospheric CO2 (77.57 ± 2.52 mg L−1 d−1). More than 99% bioremediation (removal of MB-pollutant, COD, nitrates, and phosphates) of TWW was achieved in CV-BC-TWW system due to biosorption and biodegradation processes. The addition of algal-BC and CV microalgae to TWW not only enhanced the algal growth but also increased the bioremediation of TWW and biodiesel content. The highest fatty acid methylesters (biodiesel) were also produced, up to 76.79 ± 2.01 mg g−1 from CV-BC-TWW cultivated-biomass. Biodiesel’s oxidative stability and low-temperature characteristics are enhanced by the presence of palmitoleic (C16:1) and linolenic (C18:3) acids. Hence, this study revealed that the integration of algal-biochar, as a biosorbent and source of nutrients, with living-microalgae offers an efficient, economical, and sustainable approach for microalgae growth, CO2 fixation, TWW treatment, and biodiesel production. Graphical Abstract

Background and purpose: Azo dyes are present in the wastewater of most textile factories, and if they enter water resources, they pose risks to the health of humans and the living environment due to the effects of toxicity, biological accumulation, and mutagenicity. This study aimed to determine the removal of azo dye by a biological method using wastewater treatment plant sludge in aerobic and anaerobic conditions and isolation and identification of bacteria. Materials and methods: This experimental study, was conducted in the faculty of health, at Mazandaran University of Medical Sciences. In this study, the removal of reactive red azo dye 195 in the wastewater of textile factories was investigated using the activated sludge of the wastewater treatment plant. Experiments were carried out in batch mode in both aerobic and anaerobic conditions with 192 samples. The concentrations of azo dye in the range available in the wastewater of textile factories were 50, 65, and 80 mg/liter. The culture medium used in this study was a mineral medium containing glucose. Bottles containing culture medium, sludge, and azo dye were kept at 30°C in an incubator in aerobic and anaerobic conditions for 8 days. The effect of factors including contact time, amount of sludge, and concentration of color was investigated. Sampling was done at the contact times of 1, 2, 4, and 8 days and after centrifuge, the color concentration was measured by spectrophotometric method at a wavelength of 545 nm. The total organic carbon (TOC) concentration of the samples was measured by a TOC analyzer. After removing the color, the bacteria in the bottles were identified by the differential diagnosis method and using special culture media, gram staining techniques, and biochemical tests. Results: In anaerobic conditions and contact time of 8 days, the removal of azo dye in concentrations of 50 and 80 mg/liter by using 5 ml of biomass was obtained by 93 and 82%, respectively. In the aerobic condition, the removal of the dye was achieved to more than 90% within two days, and after that, the removal efficiency reached 100% with a gently increasing slope up to 8 days. By increasing the concentration of dye from 50 to 80 mg/liter, the removal efficiency decreased by about 10%. Increasing the volume of sludge from 5 to 10 ml in both cases did not have a significant effect on increasing the amount of dye removal. The amount of azo dye removal was higher in aerobic than in anaerobic conditions. In aerobic conditions, for all dye concentrations, the TOC removal rate was about 85-90%. There was no significant difference in the amount of TOC removal for 5 and 10 ml of sludge. The average TOC removal in aerobic was about 10% higher than in anaerobic conditions. In the aerobic condition, the identified bacteria included Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aerogenosa, and in the anaerobic condition, the identified bacterial species were Lactobacillus, Enterococcus faecalis, and Bacillus cereus. Conclusion: Complete removal of azo dye from textile wastewater by sludge biomass under microaerophilic culture conditions is possible with a contact time of 8 days or more. The dye removal efficiency was higher in partial aerobic than in absolute anaerobic conditions. The identified azo dye-removing bacteria were mainly facultative anaerobic and microaerophilic.

Abstract The textile dyeing and manufacturing industry is the major producer of significant amounts of wastewater that contain persistent substances such as azo dyes that require adequate remediation measures. Far ultraviolet at 222 nm light may provide an advantage for contaminants degradation as compared to conventional UV sources (254 nm). In this paper, the degradation of reactive black 5 (RB5) in artificial wastewater has been performed using a 222 nm Kr/Cl2 excimer source under direct photolysis and an advanced oxidation process using TiO2/H2O2. The solution pH, catalyst concentration, 222 nm intensity, initial concentration of dye, and addition of H2O2 influence the degradation rate constant. The molar absorption coefficient, quantum yield of RB5 at 222 nm and the electrical energy per order (EEO) from different treatment methods have been reported. RB5 shows 1.26 times higher molar absorption at 222 nm than at 254 nm. The EEO for excimer-222/H2O2 ( $$\sim$$ ∼ 13 kWh/m3) is five times lower than that of the excimer-222/TiO2 process, which makes the process energy efficient. The degradation of wastewater has been carried out at three distinct pH values (2, 6, and 10), and the pH level of 10 exhibited the highest degree of degradation. The degradation rate in the alkaline medium is 8.27 and 2.05 times higher than in the acidic or ambient medium. Since textile effluent is highly alkaline, this result is significant, as no neutralization of the wastewater is required, and direct treatment is possible. A possible degradation pathway has been established based on Fourier transform infrared spectroscopy (FTIR) and high resolution mass spectroscopy (HRMS) analysis. The phytotoxicity of the treated wastewater has also been evaluated for its suitability for reuse in agriculture. The study reveals that the excimer-222/H2O2 treated wastewater significantly enhanced the germination percentage of Raphanus sativus seed (97%) compared to dye wastewater-grown seeds (75%). This work offers crucial information for future studies on the direct and indirect photolysis of azo dyes, as well as insight into the process of RB5 degradation under Kr/Cl2 excimer radiation.

Abstract Textile wastewater is among the most polluted types of industrial waste. Wastewater treatment in the textile industry is notoriously difficult because of the use of complex chemicals and dyes in the textile production steps, and conventional methods are not enough to treat these. Textile wastewater, known for its high pollution levels, poses challenges for treatment due to complex chemicals and dyes. A comparative study was conducted on simple ozonation and catalytic ozonation (CO) using alum to degrade methylene blue (MB). The authors analyzed various factors like time, pH, catalyst loading and ozone dosages during the study. Results showed that catalytic activity in ozonation depends on pH and ozone flow. The maximum MB elimination was achieved at pH 6.6 and 200 V ozone flow. Scanning electron microscopy (SEM) was used to characterize the surface morphology of the catalyst, Fourier transform infrared spectroscopy (FTIR) was used to identify the important functional groups, and energy dispersive X-ray spectroscopy (EDS) was used to characterize the catalyst's elemental composition. Compared to simple ozonation, CO showed higher removal in the initial phase. Real textile wastewater analysis confirmed the effectiveness of alum catalysts in achieving significant removal of MB (87%) through this novel cost-efficient process. Graphical Abstract

Abstract Recent textile industry expansion has a major environmental impact if not addressed. Being a water intensive industry, textile manufacturing is usually associated with wastewater management challenges. Electrocoagulation (EC) is recognized as one of the effective solutions to address these challenges. This study aims to investigate the potential of integrating seawater into the EC process for textile wastewater treatment, targeting optimal pollutant removal efficiencies. A simple electrolytic reactor was designed to investigate the removal efficiency of these treatments for chemical oxygen demand (COD), total suspended solids (TSS), turbidity, and color from textile wastewater at different seawater percentages and retention times. Notably, the addition of seawater not only improves the EC process efficiency but also significantly dilutes pollutants, reducing their concentrations. This dual effect enhances removal efficiency and dilution optimizes the treatment outcome. The highest removal efficiencies were achieved for COD (47.26%), TSS (99.52%), turbidity (99.30%), and color (98.19%). However, pH, dissolved oxygen (DO), and electrical conductivity increased with increasing retention times and seawater percentages in the EC process. Moreover, Seawater − EC integration reduces power usage to 15.769 Am−2 and costs approximately 0.20 USD/m3. To assess the effects of the retention times and seawater percentages on pollutant removal from textile wastewater, an analysis of variance (ANOVA) was conducted utilizing the Design-Expert 11 software. The best model obtained using Central Composite Design (CCD) was quadratic for COD (R 2 = 0.9121), color (R 2 = 0.9535), turbidity (R 2 = 0.9525), and TSS (R 2 = 0.9433). This study suggests that higher seawater percentages and longer retention times effectively eliminate contaminants but increase ion concentrations.

Sustainable water management is very important for industries with high water consumption and wastewater generation, such as the textile industry. This study aims to investigate the treatment of textile wastewater with ultraviolet (UV) assisted and Fe2+ catalyzed sodium percarbonate (SPC) oxidation, which is an eco-friendly treatment method in terms of both added oxidant and activation methods. Based on the removal efficiencies and reaction rates, a sorting was made as UV/SPC/Fe2+ > SPC/Fe2+ > UV/Fe2+ > UV/SPC > SPC > UV. It was observed that the removal efficiencies increased as the SPC dose increased, and decreased due to the scavenging effect with the 5 g/L oxidant dose, and the optimum SPC dose was determined as 2.5 g/L. It was determined that the removal efficiencies were higher in acidic conditions and high UV power applications. Under optimum operating conditions (pH:3, SPC dose: 2.5 g/L, Fe2+ dose: 1 g/L, UV lamps: 4), 68% COD, 80.9% UV254, and 92% color removal were achieved. Under optimum conditions energy cost, chemical cost, and operational cost were calculated as 11.9 $/m3, 0.20 $/m3, and 12.1 $/m3, respectively. By reducing the process COD concentration to 236.2 mg/L, discharge standards have been achieved, and the applicability of the UV/SPC/Fe2+ process was proven. [ABSTRACT FROM AUTHOR]

Membrane distillation (MD) is a promising technology for desalination of different water streams. However, treating wastewater with complex compositions remains a challenge. In this study, we adopted the MD process to treat complex and harmful methylene blue (MB) dye-containing textile wastewater. The effect of relevant operating parameters on the MD process performance was investigated. Additionally, the membrane wettability during the MD process was evaluated. The results showed that increasing the temperature difference and feed flow velocity led to an increase in permeate flux (Jp) and a decrease in specific energy consumption (SEC). The Jp and SEC models exhibited good agreement between predicted and experimental values, with an R2 of 98.50% and 86.18%, respectively. During the 22 h of operation, the MD process applied for the treatment of dye wastewater demonstrated a decline of Jp by 71.8% and a slight decrease in dye rejection to attain 95.9%. The decline of the surface contact angle and the liquid entry pressure values and an increase in the permeate water conductivity detected the membrane wettability. The obtained results suggest that the MD process could present an efficient solution for the treatment of MB-dye wastewater. However, upscaling the MD technology requires further improvements on real wastewater treatment for a longer run time. [ABSTRACT FROM AUTHOR]

Background and purpose: Azo dyes are present in the wastewater of most textile factories, and if they enter water resources, they pose risks to the health of humans and the living environment due to the effects of toxicity, biological accumulation, and mutagenicity. This study aimed to determine the removal of azo dye by a biological method using wastewater treatment plant sludge in aerobic and anaerobic conditions and isolation and identification of bacteria. Materials and methods: This experimental study, was conducted in the faculty of health, at Mazandaran University of Medical Sciences. In this study, the removal of reactive red azo dye 195 in the wastewater of textile factories was investigated using the activated sludge of the wastewater treatment plant. Experiments were carried out in batch mode in both aerobic and anaerobic conditions with 192 samples. The concentrations of azo dye in the range available in the wastewater of textile factories were 50, 65, and 80 mg/liter. The culture medium used in this study was a mineral medium containing glucose. Bottles containing culture medium, sludge, and azo dye were kept at 30°C in an incubator in aerobic and anaerobic conditions for 8 days. The effect of factors including contact time, amount of sludge, and concentration of color was investigated. Sampling was done at the contact times of 1, 2, 4, and 8 days and after centrifuge, the color concentration was measured by spectrophotometric method at a wavelength of 545 nm. The total organic carbon (TOC) concentration of the samples was measured by a TOC analyzer. After removing the color, the bacteria in the bottles were identified by the differential diagnosis method and using special culture media, gram staining techniques, and biochemical tests. Results: In anaerobic conditions and contact time of 8 days, the removal of azo dye in concentrations of 50 and 80 mg/liter by using 5 ml of biomass was obtained by 93 and 82%, respectively. In the aerobic condition, the removal of the dye was achieved to more than 90% within two days, and after that, the removal efficiency reached 100% with a gently increasing slope up to 8 days. By increasing the concentration of dye from 50 to 80 mg/liter, the removal efficiency decreased by about 10%. Increasing the volume of sludge from 5 to 10 ml in both cases did not have a significant effect on increasing the amount of dye removal. The amount of azo dye removal was higher in aerobic than in anaerobic conditions. In aerobic conditions, for all dye concentrations, the TOC removal rate was about 85-90%. There was no significant difference in the amount of TOC removal for 5 and 10 ml of sludge. The average TOC removal in aerobic was about 10% higher than in anaerobic conditions. In the aerobic condition, the identified bacteria included Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aerogenosa, and in the anaerobic condition, the identified bacterial species were Lactobacillus, Enterococcus faecalis, and Bacillus cereus. Conclusion: Complete removal of azo dye from textile wastewater by sludge biomass under microaerophilic culture conditions is possible with a contact time of 8 days or more. The dye removal efficiency was higher in partial aerobic than in absolute anaerobic conditions. The identified azo dye-removing bacteria were mainly facultative anaerobic and microaerophilic. [ABSTRACT FROM AUTHOR]

Аbstract: With the rapid growth of industrialization/urbanization, the discharge of industrial effluent into the environment is increasing day by day. Conventional technologies for wastewater treatment possess difficulties in meeting all the requirements of wastewater discharge standards, and therefore, the exploration and establishment of new procedures to treat wastewater is a need of hour. Advanced oxidation processes (AOPs) possess an ability of strong oxidation, complete destruction and mineralisation, and no secondary pollutants. It has been proved in the literature that the addition of the catalyst in AOPs can largely enhance the treatment efficiency. The current study mainly emphasizes the practical applications of AOPS towards textile wastewater treatment. The study includes the pros and cons of individual AOPs, fixed photocatalysis, the dual process of photocatalysis and photo-Fenton coupled photocatalysis/photo-Fenton and biological treatment process. This article summarizes the useful theoretical foundation of the scientists and discusses the key areas that need more investigation in the fields of AOPs for industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

The textile dyeing and manufacturing industry is the major producer of significant amounts of wastewater that contain persistent substances such as azo dyes that require adequate remediation measures. Far ultraviolet at 222 nm light may provide an advantage for contaminants degradation as compared to conventional UV sources (254 nm). In this paper, the degradation of reactive black 5 (RB5) in artificial wastewater has been performed using a 222 nm Kr/Cl2 excimer source under direct photolysis and an advanced oxidation process using TiO2/H2O2. The solution pH, catalyst concentration, 222 nm intensity, initial concentration of dye, and addition of H2O2 influence the degradation rate constant. The molar absorption coefficient, quantum yield of RB5 at 222 nm and the electrical energy per order (EEO) from different treatment methods have been reported. RB5 shows 1.26 times higher molar absorption at 222 nm than at 254 nm. The EEO for excimer-222/H2O2 (∼ 13 kWh/m3) is five times lower than that of the excimer-222/TiO2 process, which makes the process energy efficient. The degradation of wastewater has been carried out at three distinct pH values (2, 6, and 10), and the pH level of 10 exhibited the highest degree of degradation. The degradation rate in the alkaline medium is 8.27 and 2.05 times higher than in the acidic or ambient medium. Since textile effluent is highly alkaline, this result is significant, as no neutralization of the wastewater is required, and direct treatment is possible. A possible degradation pathway has been established based on Fourier transform infrared spectroscopy (FTIR) and high resolution mass spectroscopy (HRMS) analysis. The phytotoxicity of the treated wastewater has also been evaluated for its suitability for reuse in agriculture. The study reveals that the excimer-222/H2O2 treated wastewater significantly enhanced the germination percentage of Raphanus sativus seed (97%) compared to dye wastewater-grown seeds (75%). This work offers crucial information for future studies on the direct and indirect photolysis of azo dyes, as well as insight into the process of RB5 degradation under Kr/Cl2 excimer radiation. [ABSTRACT FROM AUTHOR]

Adsorption has proven to be a cost-effective option for treating wastewater containing dyes and other pollutants, as it is a simple and low-cost technique. In this work, cellulose nanocrystals (CNCs) were extracted from sugarcane bagasse using the acid hydrolysis technique and used as an effective adsorbent for removing methylene blue dye. The chemistry behind the segregation of cellulose nanocrystals from sugarcane bagasse and its adsorption of methylene blue dye from textile wastewater has been discussed. The obtained nanocrystals were characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy, X-ray diffraction (XRD), and thermos gravimetric analysis (TGA). The dye solution was subjected to extracted CNC, observed the dye absorption capacity, and found that the absorbance of the dye solution after treatment was decreased compared to the stock solution. With an increase in treatment time from 30 to 90 min, there was a rapid decrease in absorbency values obtained through UV spectroscopy. [ABSTRACT FROM AUTHOR]

Moringa oleifera biochar (MOB) was used to extract dyes from textile wastewater and methylene blue (MB)-infused synthetic aqueous solution. Different process parameters, such as pH, agitation speed, the dosage of adsorption, and time of interaction, have been investigated by batch experiments. Up to 99% of dye removal was achieved for textile wastewater and 98% for MB-infused aqueous solution under optimum operating conditions. The optimum dosage, contact period, and agitation speed were 6 g/L, 15 min, and 200 rpm, respectively. An improvement in adsorption rates at higher pH was observed. The dye removal rate for pH less than 6 was insignificant, and the maximum removal was observed at a pH range of 10 to 12. Batch experiments showed that the Freundlich isotherm model better described the adsorption process for textile wastewater and MB dye solution. Lagergren's pseudo-second-order kinetic model fitted relatively well (R2 = 0.99) over the observed contact period (5–60 min) compared to the pseudo-first-order kinetic model. Besides dye removal, MOB showed a significant reduction capacity of BOD5, COD, and EC values for textile wastewater treatment. The results indicate that MOB adsorbent has a high potential for being used as a low-cost adsorbent to treat textile wastewater in south-Asian countries since it is abundantly available in the subcontinent. [ABSTRACT FROM AUTHOR]

Textile wastewater is among the most polluted types of industrial waste. Wastewater treatment in the textile industry is notoriously difficult because of the use of complex chemicals and dyes in the textile production steps, and conventional methods are not enough to treat these. Textile wastewater, known for its high pollution levels, poses challenges for treatment due to complex chemicals and dyes. A comparative study was conducted on simple ozonation and catalytic ozonation (CO) using alum to degrade methylene blue (MB). The authors analyzed various factors like time, pH, catalyst loading and ozone dosages during the study. Results showed that catalytic activity in ozonation depends on pH and ozone flow. The maximum MB elimination was achieved at pH 6.6 and 200 V ozone flow. Scanning electron microscopy (SEM) was used to characterize the surface morphology of the catalyst, Fourier transform infrared spectroscopy (FTIR) was used to identify the important functional groups, and energy dispersive X-ray spectroscopy (EDS) was used to characterize the catalyst's elemental composition. Compared to simple ozonation, CO showed higher removal in the initial phase. Real textile wastewater analysis confirmed the effectiveness of alum catalysts in achieving significant removal of MB (87%) through this novel cost-efficient process. Highlights: Methylene Blue was treated with the catalytic ozonation method, with first ever use of alum as a novel ozonation catalyst. Both simple ozonation and catalytic ozonation were efficient treatment processes; however, maximum removal efficiency for Methylene Blue of 86% was achieved by alum based catalytic ozonation process. On optimizing pH to 6.6, maximum removal efficiencies for Methylene Blue improve to 85% and 99% for simple ozonation and catalytic ozonation processes, respectively. The improved results for catalytic ozonation are owed to predominant hydroxyl radical mechanism. [ABSTRACT FROM AUTHOR]

Applicable and low‐cost ultrafiltration membranes based on waste polystyrene (WPS) blend and poly vinylidene fluoride (PVDF) were effectively cast on nonwoven support using phase inversion method. Analysis was done into how the WPS ratio affected the morphology and antifouling performance of the fabricated membranes. Cross flow filtration of pure water and various types of polluted aqueous solutions as the feed was used to assess the performance of the membranes. The morphology analysis shows that the WPS/PVDF membrane layer has completely changed from a spongy structure to a finger‐like structure. In addition, the modified membrane with 50% WPS demonstrated that the trade‐off between selectivity and permeability is met by a significant improvement in the rejection of the membrane with a reduction in permeate flux due to the addition of PVDF. With a water permeability of 50 LMH and 44 LMH, respectively, the optimized WPS‐PVDF membrane with 50% WPS could reject 81% and 74% of Congo red dye (CR) and methylene blue dye (MB), respectively. The flux recovery ratio (FRR) reached to 88.2% by increasing PVDF concentration with 50% wt. Also, this membrane has the lowest irreversible fouling (Rir) value of 11.7% and lowest reversible fouling (Rr) value of 27.9%. The percent of cleaning efficiency reach to 71%, 90%, and 85% after eight cycles of humic acid (HA), CR, and MB filtration, respectively, for the modified PS‐PVDF (50%–50%). However, higher PVDF values cause the membrane's pores to become clogged, increase the irreversible fouling, and decrease the cleaning efficiency. In addition to providing promising filtration results, the modified membrane is inexpensive because it was made from waste polystyrene, and as a result, it could be scaled up to treat colored wastewater produced by textile industries. Practitioner Points: Recycling of plastic waste as an UF membrane for water/wastewater treatment was successfully prepared and investigated.Mechanical properties showed reasonable response with adding PVDF.The modified membrane with 50% PS demonstrated that the trade‐off between selectivity and permeability is met by a significant improvement in the rejection. [ABSTRACT FROM AUTHOR]

The continuous growth in the production, unsustainable use, and disposal of plastics in recent decades has led to the emergence of a new type of pollutant, microplastics (MPs). In this article, the focus is on the form of MPs, which are produced by the fragmentation of textile fibres during washing processes. The problems associated with the characterisation and quantification of MPs in this type of sample are related to the wide range of concentrations, forms, and degree of degradation as well as physico-chemical and biological properties. Although the basic principles for the analysis of microplastics present in the environmental samples are known, there is the lack of standardised methods for the analysis of MPs in laundry effluents and domestic washing. Therefore, the continuous development of sophisticated analytical techniques and methodologies is required for the reliable collection and isolation, quantification, and characterisation of one of the most challenging analytes. The aim of this review is to outline the key steps of MPs analysis in laundry effluents and domestic washing, focusing on those steps that are underestimated in the current literature: sampling and sample preparation for analysis. Precisely these analytical steps, which can become the main source of analytical measurement system errors, ensure the quality of the analysis. This paper emphasises the importance of monitoring background contamination and presents guidelines to ensure quality control specifically for this type of analyte. [ABSTRACT FROM AUTHOR]

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

The textile industry has significant environmental impacts, and employing physical, chemical, and biological technologies is crucial for sustainable treatment strategies. Photocatalytic degradation is a straightforward and important technique. This study investigated the photodegradation of textile wastewater, Reactive Red 198 and Blue 133 dyes using magnetic graphene oxide embedded on a chitosan matrix under UV and visible light. Magnetite nanoparticles were prepared via the co-precipitation method of a solution containing Fe2+ and Fe3+ ions under alkaline conditions. Then, magnetic nanoparticles were modified with graphene oxide and chitosan under ultrasound to enhance photoresponse. Characterization included FT-IR, Raman spectroscopy, XRD, zeta potential, DRS, VSM, TGA, DTA, BET, SEM, EDS, and TEM. Optimization of parameters such as pH, photocatalyst quantity, dye concentration, and irradiation time was performed. Under optimal conditions, Reactive Red 198 removal efficiencies were 77.91%, 90.95%, and 95.01% for magnetite, magnetic graphene oxide, and magnetic graphene oxide/chitosan, respectively. Blue 133 removal efficiencies were 48.15%, 66.6%, and 82.1% for the same compounds. After three days of visible light exposure, Reactive Red 198 removal percentages were 79.46%, 90.36%, and 94.75%, and Blue 133 removal percentages were 70.15%, 72.6%, and 90.85% for magnetite, magnetic graphene oxide, and magnetic graphene oxide/chitosan, respectively. The second-order kinetic model demonstrated high accuracy with R2 values of 0.997 and 0.998 for Red 198 and B133 removal, respectively, when applied to magnetic graphene oxide/chitosan. The nanocomposite's reusability was assessed over three cycles, and after two cycles, the removal percentage remained high at approximately 83.96% and 77.66%. [ABSTRACT FROM AUTHOR]

Developing low-cost and stable adsorbent is urgent and attractive to remove hazardous dye from water. In this study, zirconium based metal-organic framework (NH2-UiO-66) was grown on waste wool fibers and the fabricated composite adsorbent (NH2-UiO-66/wool) was used to remove anionic dye methyl orange (MO). After characterizing the adsorbents, we determined the effect of pH and initial concentration of MO on adsorption performance. Moreover, adsorption kinetics and isotherms were conducted to reveal the adsorption mechanism. The results showed that NH2-UiO-66/wool achieved the highest adsorption capacity at natural pH with the maximum adsorption of 61.0 mg/g adsorbent, which is higher than most biomass based adsorbents. Moreover, NH2-UiO-66/wool enabled a broad range of pH (3-11) and initial concentration of MO (10-50 mg/L). Adsorption kinetics and isotherms of NH2-UiO-66/wool fitted well with pseudo-second-order model and Langmuir mode, respectively. NH2-UiO-66/wool presented 40.3 times higher of kinetics constant than that of original wool in the presence of initial MO concentration of 10 mg/L due to the positive nature of NH2-UiO-66. Ultimately, NH2-UiO-66/wool presented excellent regeneration ability with 500 mg/L NaCl solution and regeneration efficiency remained 98% after 10 cycles. Overall, this work may provide new insights into the development of MOFs/wool adsorbents for enhanced dye removal. [ABSTRACT FROM AUTHOR]

Various industries polluting the water bodies by discharging untreated wastewater directly into the environment and conventional wastewater treatments are often insufficient for effectively treating the pollutants. However, membrane bioreactors (MBRs) offer a promising solution for wastewater treatment where membrane serving as the heart of the system. In this study, polyethersulfone (PES) was used as the membrane material and hydrophilicity of the membranes were tuned up by mixing with hydrophilic additives such as polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) and the membranes have shown promising results in treating wastewater, particularly in terms of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and color removal. For example, PES-PEG membrane demonstrated COD, BOD, and color removal of 96 %, 94 %, and 92 %, respectively while those were 95 %, 94 %, and 92 %, respectively for PES-based commercial membrane. Although the performances of fabricated membranes were comparable to that of commercial membrane in COD, BOD, and color removal efficiencies, there is room for improvement in permeate yields. Notably, the average permeate efficiency for MBR modules produced with PES-3PEG and PES-5PVP membranes was recorded as 47 % (18 L/m2h) and 13 % (5 L/m2h) respectively of the commercial membrane (38 L/m2h). Despite the variance in permeate yields, the fabricated membranes also showcased significant efficacy in removing microorganisms, a crucial aspect of wastewater treatment. Their performance in this regard proved highly comparable to that of the commercial membrane, emphasizing the potential of these fabricated membranes in enhancing the wastewater treatment.

Abstract The existence of artificial dyes in water is a significant environmental concern, as it can lead to poor water quality. Photodegradation is becoming an increasingly popular method for treating water contaminated with dyes. In this study, the photodegradation of Reactive Red 66 and Reactive Red 120 dyes, as well as textile wastewater, was investigated under UV and visible light irradiation. To enhance the photoresponse of the MFe2O4 (M = Co, Ni) nanoparticles, modifications were made by incorporating graphene oxide. The MFe2O4 nanoparticles and MFe2O4/GO nanocomposite photocatalysts were subjected to several characterization techniques, including FT-IR, Raman spectroscopy, XRD, DRS, zeta potential, VSM, TGA, DSC, BET, SEM, and EDAX analysis. Experiments were conducted to optimize several key parameters involved in the photodegradation process, including pH, photocatalyst dosage, initial dye concentration, and irradiation time. The removal efficiency of Reactive Red 66 and Reactive Red 120 dyes using CoFe2O4 nanoparticles was found to be 86.97 and 82.63%, respectively. Also, the removal percentage of these dyes using CoFe2O4/GO nanocomposite photocatalyst was 95.57 and 90.9% for Reactive Red 66 and Reactive Red 120, respectively. Experiments found that NiFe2O4 nanoparticles removed 90.92% of Reactive Red 66 dye and 84.7% of Reactive Red 120 dye. The NiFe2O4/GO nanocomposite photocatalyst showed even higher removal efficiencies, degrading 97.96% of Reactive Red 66 and 93.44% of Reactive Red 120. After three days of exposure to visible light irradiation, the removal percentage of Reactive Red 66 using MFe2O4 and MFe2O4/GO nanocomposite was investigated.

The research aims to find out the reusability of jute stick charcoal (JSC) to remove Remazol Red (RR) from textile effluents. The JSC was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy to analyze the morphology, functional groups, and chemical composition, respectively. The batch adsorption method was applied in this study, and it disclosed that dye uptake depends on various factors, namely, pH, contact time, adsorbent dose, and dye concentration. Notably, 93.12% of the dye was removed with the best removal efficiency at a pH of 1, an adsorbent dose of 0.6 g, and an equilibrium time of 120 min, where the adsorption occurred rapidly in the first 20 min. The Langmuir isotherm model successfully defined the adsorption phenomena, yielding an R2 value of 0.995. The kinetic experimental data followed the pseudo-second-order model (R2 = 0.999). The optimum adsorption parameters were implemented for the effluent obtained from a dye bath where a fabric sample (5 g) was dyed with RR, and 62.4% dye was removed. For the scaled application of JSC to a wastewater stream, the raw textile effluent was also treated, which resulted in 52.6% of dye removal. These results show that JSC is a promising adsorbent for treating textile wastewater. HIGHLIGHTS Adsorption of RR dye on JSC and characterization of JSC were studied.; The adsorption process is highly pH-specific (pH = 1).; Nearly 93.12% of the dye removal was observed at optimized conditions.; The experimental findings fit well with pseudo-second-order and Langmuir models.; The optimum conditions have been implemented on both the dyed sample fabric bath (62.4% removal) and actual raw textile effluent (52.6%).;

Nanotechnology advances wastewater treatment through the application of Nano entities that optimize contaminant removal and enhance water purification efficacy. In this study, ZnO nanoparticles (ZnO NPs) were synthesized using Klebsiella pneumoniae, subsequently, a chitosan/ZnO nanocomposite (CS/ZnO NC) was prepared for removing reactive black 5 (RB-5) dye from synthetic wastewater. The biosynthesized nanomaterials were characterized using UV–VIS, FTIR, XRD, SEM and TEM techniques. The UV–Vis absorbance peaks at 370 nm and 350 nm corresponded to the characteristic surface plasmon resonance of ZnO NPs and the CS/ZnO NC, respectively. Additionally, FTIR analysis identified the various functional groups associated with ZnO NPs and the CS/ZnO NC. XRD analysis revealed their crystallinity to be approximately 22.44 and 25.76, respectively. The SEM images of ZnO NPs and the CS/ZnO NC show hexagonal plate-like particles with sizes of 33.66 nm and 38.64 nm, respectively. Four concentrations of ZnO NPs and CS/ZnO NC (0.25, 0.5, 1, and 2 mg/mL) were evaluated for RB-5 degradation at three different levels (25, 50, and 100 mg/L). Statistical analysis showed that chitosan/ZnO NC achieved 95 % dye degradation, compared to 81 % degradation with the same amount of ZnO nanoparticles. Furthermore, a pot experiment was carried out to evaluate the phytotoxicity effects of treated wastewater on wheat (Triticum aestivum L.). Both ZnO NPs and CS/ZnO NC did not significantly affect the viability of epithelial retinal cell lines at concentrations up to 100 µg/mL, suggesting a safe cytotoxic profile within this dosage range. Overall, CS/ZnO NC proved effective for treating industrial wastewater, making it suitable for recycling in agricultural applications

Water scarcity is an unavoidable challenge due to the rapid depletion of natural resources and environmental degradation. The main aim of the present study is to investigate the removal performance of native microalgae with bacteria as co-culture under varied conditions and to check the growth patterns of microalgae in real wastewater. This research evaluates the feasibility of utilizing real textile wastewater as a growth medium for microalgal production and wastewater treatment. Textile wastewater combines various organic and inorganic chemicals, typically consisting of dyes and nutrients. The microalgal-bacterial consortium appeared to be a promising tool for the bioremediation of real textile wastewater. In this study, a fed-batch reactor was used to treat real textile wastewaters in a 24-h cycle duration of a week. The experiment was conducted in three different stages which are single stage, two stage, and consortium to remove nutrients. The results indicated that a consortium of microalgae-bacteria provides maximum removal efficiency, i.e., 58.57% nitrate (NO3−), 86.42% phosphate PO43- PO 4 3 - , and 91.5% chemical oxygen demand (COD) with a maximum 12.88 mg/L and 1.7 g/L of chlorophyll and bacterial dry cell weight, respectively. At the same time, maximum color removal was achieved in a single stage (only algae), i.e., 41.54%. Hence, results indicated that this method treats real textile wastewater cost-effectively and produces biomass that could be utilized as a biofertilizer and energy-efficient projects. The release of textile wastewater containing excessive contaminants is responsible for pollution in aquatic bodies. The best removal efficiencies of nitrogen, phosphorus, chemical oxygen demand (COD), and color were obtained through the microalgal-bacterial consortium in batch-scale treatment. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are used in several industrial applications, such as in textile manufacturing, and are known as "forever chemicals" due to their spread, stability and (eco-)toxicity, gaining increasing concern. To avoid PFAS spread in the environment, reducing the environmental risk on receiving surface water, prevention and removal strategies should be implemented at multiple levels, comprising both textile factories and municipal wastewater treatment plants (WWTP). This study presents an integrated scenario analysis to compare and prioritize prevention and removal strategies based on their potential in risk minimization. Field monitoring campaigns, lab- and pilot-scale experiments on two established removal processes (pressure-driven membrane separation, adsorption on activated carbon) were combined, and environmental risk was assessed due to a mixture of 15 PFAS. About prevention, substitution of long-chain PFAS with short-chain PFAS were considered, as well as the reduction of PFAS used in textile processing. The proposed approach was applied in a textile district in northern Italy without PFAS spikes in the tested wastewaters. This approach has proven to be beneficial in determining the optimal combination of actions to be implemented across different levels of the industrial district (including textile factories and/or municipal WWTP). This methodology provides a clear indication of the environmental advantages, specifically in minimizing risks, resulting from the implementation of diverse PFAS reduction strategies. Compared to the current scenario, resulting in an unacceptable risk (risk quotient, RQ=2.2), the risk can be reduced below the acceptable threshold (RQ=0.9) by the combination of (i) PFAS reduction/replacement in textile processing, (ii) treatment of wastewater discharged by textile factories through membrane separation prior to the discharge in the sewer, and (ii) WWTP upgrade through an activated carbon adsorption downstream the ozonation step. [Display omitted] [ABSTRACT FROM AUTHOR]

The existence of artificial dyes in water is a significant environmental concern, as it can lead to poor water quality. The use of photodegradation becomes an increasingly popular method for treating water. In this study, the photodegradation of Reactive Red 66, Reactive Red 120 dyes and textile wastewater was studied under UV and visible light. To enhance the photoresponse of the Iron (II, III) oxide, modifications were made to the graphene oxide. Iron (II, III) oxide and its nanocomposite photocatalysts were subject to characterization techniques; including FT-IR, Raman, XRD, DRS, zeta potential VSM, SEM, EDAX, and AFM. A series of experiments were conducted to optimize several parameters in the photodegradation process. Under optimal conditions, the removal efficiency of Reactive Red 66 and Reactive Red 120 dyes using Iron (II, III) oxide was found to be 94.8, and 88.5%, respectively. Also, removal percentage of these dyes using Iron (II, III) oxide/GO nanocomposite has been 95.2, and 91.3%. After three days of exposure to visible light, the removal percentage of Reactive Red 66 using Iron (II, III) oxide and Iron (II, III) oxide/GO was 85.7 and 92.1%, respectively. Similarly, the percentage of Reactive Red 120 removal using Iron (II, III) oxide and Iron (II, III) oxide/GO under visible light after three days were 81.9 and 85.0%, respectively. The dye removal efficiency was determined in textile wastewater by measuring BOD and COD. Kinetic studies demonstrated that the photocatalytic reactions followed the pseudo-second-order. Additionally, the reusability of the prepared photocatalyst was also evaluated. [ABSTRACT FROM AUTHOR]

The existence of artificial dyes in water is a significant environmental concern, as it can lead to poor water quality. Photodegradation is becoming an increasingly popular method for treating water contaminated with dyes. In this study, the photodegradation of Reactive Red 66 and Reactive Red 120 dyes, as well as textile wastewater, was investigated under UV and visible light irradiation. To enhance the photoresponse of the MFe2O4 (M = Co, Ni) nanoparticles, modifications were made by incorporating graphene oxide. The MFe2O4 nanoparticles and MFe2O4/GO nanocomposite photocatalysts were subjected to several characterization techniques, including FT-IR, Raman spectroscopy, XRD, DRS, zeta potential, VSM, TGA, DSC, BET, SEM, and EDAX analysis. Experiments were conducted to optimize several key parameters involved in the photodegradation process, including pH, photocatalyst dosage, initial dye concentration, and irradiation time. The removal efficiency of Reactive Red 66 and Reactive Red 120 dyes using CoFe2O4 nanoparticles was found to be 86.97 and 82.63%, respectively. Also, the removal percentage of these dyes using CoFe2O4/GO nanocomposite photocatalyst was 95.57 and 90.9% for Reactive Red 66 and Reactive Red 120, respectively. Experiments found that NiFe2O4 nanoparticles removed 90.92% of Reactive Red 66 dye and 84.7% of Reactive Red 120 dye. The NiFe2O4/GO nanocomposite photocatalyst showed even higher removal efficiencies, degrading 97.96% of Reactive Red 66 and 93.44% of Reactive Red 120. After three days of exposure to visible light irradiation, the removal percentage of Reactive Red 66 using MFe2O4 and MFe2O4/GO nanocomposite was investigated. [ABSTRACT FROM AUTHOR]

Water makes up most of the Earth, although just 0.3% is usable for people and animals. The huge oceans, icecaps, and other non-potable water resources make up the remaining 99.7%. Water quality has declined in recent decades due to pollution from population growth, industry, unplanned urbanization, and poor water management. The textile industry has significant global importance, although it also stands as a major contributor to wastewater generation, leading to water depletion and ecotoxicity. This issue arises from the extensive utilization of harmful chemicals, notably dyes. The main aim of this review article is to combine and assess the impacts of textile wastewater that contains dyes and chemicals, and to examine their potential consequences on human health, aquatic health, and the environment. Moreover, the dedicated section presents an in-depth review of various environmentally sustainable approaches for the management and treatment of wastewater in the textile industry. These approaches encompass bio adsorbents, biological methods, membrane technology, ion exchange, advanced oxidation processes, as well as physicochemical and biochemical processes. Furthermore, this study also evaluates the contemporary progressions in this particular domain, taking into account the corresponding advantages and disadvantages. Finally, this article highlights the significance of recovering and reusing dyes, alkalis, and electrolytes in wastewater treatment. Additionally, it emphasizes the necessity of performing technoeconomic analyses and life cycle assessments (LCA) on wastewater treatment plants. [ABSTRACT FROM AUTHOR]