Dye Effluent Research Articles

Modeling and optimization of photocatalytic dye degradation using tungstophosphoric acid on h-BN: RSM, ANN and ANFIS comparative approaches

Effluent dyes are a significant threat to aquatic environments, causing water pollution that endangers human health and ecosystems. This study addresses the urgent need for effective dye degradation technologies by synthesizing tungstophosphoric acid (TPA) and porous hexagonal boron nitride (h-BN) nanocomposites (TPA@h-BN). TPA was immobilized on h-BN nanosheets in varying amounts (10–40 %), with the 30 %TPA@h-BN composite showing superior photocatalytic performance in methylene blue (MB) dye degradation. The photocatalytic process was investigated using batch experiments designed by central composite design (CCD). Subsequently, response surface methodology (RSM), artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) were employed to model the effects of reaction time, catalyst dosage, dye concentration and stirring speed. Statistical parameters were calculated for all three models, with the regression coefficients (R2) for RSM, ANN and ANFIS found to be 0.981, 0.977 and 0.928, respectively. These results indicate that the RSM and ANN models possess higher predictive capability and accuracy compared to the ANFIS model. Optimal dye degradation of 95.40 % was achieved in 240 min using 60 mg of 30 %TPA@h-BN, 15 ppm dye concentration and 550 rpm stirring. The process followed pseudo-first-order kinetics with a rate constant of 0.01303 min−1.

Biological treatment of methyl orange dye and textile wastewater using halo-alkaliphilic bacteria under highly alkaline conditions.

As the textile wastewater is highly saline and has high pH it is important to employ extremophilic microbes to survive in harsh conditions and provide effective bioremediation of textile dyes. This study aims to find a sustainable solution for dye removal by investigating the potential of an indigenously isolated bacterium, Nesterenkonia lacusekhoensis EMLA3 (halo-alkaliphilic) for treatment of an azo dye, methyl orange (MO) and textile effluent. MO dye decolorization studies were conducted using mineral salt media (MSM) by varying incubation time (0-120h), initial dye concentration (50-350mg/L), pH (7.0-12.0), inoculum dose (3-10%), agitation (stationary, 100rpm and 200rpm), and temperature (20-55°C). Dye removal by the bacterium for 50mg/L of dye was > 97.0% within 72h of incubation at pH 11.0 in stationary condition. Bacterium had excellent reusability i.e. > 97% dye removal for up to 5 cycles. Moreover, bacterium has the potential for co-removal of chromium (VI) (3.5-28mg/L), and also almost complete dye removal in presence of high amount of NaCl. Liquid chromatography-mass spectrometry showed degradation as the mechanism of dye removal. Application of the bacterium to MO dye spiked real textile wastewater showed excellent dye removal. Phyto-toxicity assessment conducted on Vigna radiata and Triticum aestivum seeds, showed 100% germination of biotreated textile wastewater indicating its reuse potential.

Development of ternary PANI/GO-Fe3O4@AgNps nanocomposites for photocatalytic remediation of toxic dye effluent under energy-efficient system

The environmental toxicity of effluents contaminated with synthetic industrial dyes and their resistance to conventional treatments drive the need for developing innovative treatment technologies such as visible photoactive catalysts in a photocatalytic system. In this study, novel nanocomposite photocatalysts were synthesized for photocatalytic remediation of toxic dye effluent under energy-efficient Light Emitting Diode (LED) irradiation. Concise instrumental analysis was used to investigate the morphological, functional, particle size, thermal and optoelectronic features of the developed photocatalytic nanocomposites. Their performance was tested with cationic (methylene blue) and anionic (methyl orange) model dyes. The instrumental elucidation reveals the coating of amorphous polyaniline with other composites, giving the blend rapid reactivity, which promotes photocatalyst-dye interaction. The composites exhibit lowered bandgap (2.66 eV, 2.85 eV and 2.27 eV) when compared to polyaniline (3.34 eV) used as macromolecular support via in situ coupling. This accounts for the efficiency of 95 % and 98 % reported for methylene blue and methylene orange, respectively, at optimal experimental conditions of 90 min irradiation time, pH of 5 and dosage of 20 mg/100 mL dye effluent. The study also proposed a Z-scheme mechanism with the vital role of •O2 –, •OH and h+ reactive species in the photodegradation of the dye molecules.

Process modeling and optimization of photocatalytic treatment of dye-polluted effluent using novel polyaniline/graphene oxide-Fe3O4-Ag nanocomposites

This study developed a novel photocatalytic nanocomposite via in situ polymerization with 3 % blend of graphene oxide (GO), magnetite (Fe3O4) and silver nanoparticle (Ag-Nps) from AgNO3. Also, the process applied a new Fenton mediative approach for efficient abatement of toxic dye molecules in textile effluent under an energy-efficient source. The research focused on modeling and optimizing photocatalytic degradation of methylene blue dye (10 mg/L), using the most influencing variables such as pH (3–7), photocatalyst dosage (10–30 mg/100 mL) and irradiation time (20–90 min). The study demonstrated high photocatalytic efficiency for a 2.27 eV bandgap photocatalyst under 18 W visible LED light irradiation. The selected statistical model at optimized conditions allowed effective treatment of heavily polluted dye effluent from the flax textile industry, assessing efficiency via physicochemical property changes. The result suggested the selected quadratic model whose value of R2Adjusted was close to R2predicted with good correlation and reliability. All experimental variables via the analysis of variance were statistically significant (p-values <0.0001), with irradiation time and photocatalyst dosage having the greatest interactive influence on dye-effluent photocatalysis. Also, the optimization of the response gave an efficiency of 96.10 % which was validated by 5 repetitive experimental runs having an efficiency of 95.8 % ± 0.05 at selected optimized conditions of 79.24 min, 5.25 pH and dose of 21.76 mg/ 100 mL effluent. Thereafter, at the optimized conditions and 360 min of irradiation, 95.99 % dye effluent treatment were achieved. Thus, the study presents versatile industrial photocatalysts for treating heavily polluted dye effluent.

A review of the effectiveness of metal–organic frameworks in removing dye effluents

ABSTRACT This review evaluates the effectiveness of metal–organic frameworks (MOFs) in treating dye wastewater. MOFs are highly effective in dye effluent removal due to their multifunctionality, water stability, and recyclability. They offer exceptional dye removal and degradation capabilities, with significant surface area and adjustable pore size. Among various dye removal techniques (chemical, physical, and biological), adsorption has emerged as a cost-effective and highly efficient method. Researchers analyse adsorption isotherms and kinetics to understand the efficiency of MOFs in dye absorption from wastewater. Characterization studies confirm the effectiveness of MOFs. Conventional adsorbents fall short of industrial dye removal, thus making MOFs a promising alternative. This review assesses MOFs’ efficacy in treating dye wastewater, highlighting their superior adsorption capacity over conventional materials. Various MOF types, including modified and gel-based variants, show promise. Research into inexpensive and efficient adsorbents from available resources for colour removal is increasingly vital. Studies demonstrate the efficacy of numerous affordable adsorbents in wastewater colour removal.

Rapid Degradation of Dye Effluents with A SnS Catalyst: A Sustainable Approach Using Natural Light Under Ambient Conditions.

Dye degradation presents a persistent challenge in addressing water pollution. While several methods, including adsorption, biodegradation, and advanced oxidation processes, have been extensively explored, photocatalysis remains one of the most effective techniques. Conventional photocatalytic dye degradation processes often rely on expensive light sources and are time-intensive. Herein, we synthesized a SnS catalyst by the solvated metal atom dispersion (SMAD) method, using Sn foil and sulfur powder. The catalyst exhibited remarkable performance, achieving complete degradation of methylene blue within 2 minutes under ambient room light, without the need for any external light source. Similar degradation efficiency was achieved for methyl orange. To evaluate the role of light for the degradation, control experiments were conducted in the dark using methylene blue as a model dye. Although the degradation rate was slightly reduced, the catalyst still facilitated dye degradation in the absence of light. Additionally, the catalytic performance was tested with four other dyes under natural light, all of which yielded promising results, demonstrating the versatility and effectiveness of the SnS catalyst in dye degradation. This work highlights the potential of the SnS catalyst for efficient and rapid dye degradation under both light and dark conditions, offering an energy-efficient solution for wastewater treatment.

Preparation and characterisation of chitosan/bacterial Escherichia coli biocomposite for malachite green dye removal: modeling and optimisation of the adsorption process

ABSTRACT Herein, a new biocomposite was obtained by loading a bacterial suspension of Escherichia coli onto a chitosan matrix to produce a unique biocomposite (chitosan – E. coli) with effective properties for biosorption of malachite green dye from water. The physicochemical characteristics of the chitosan – E. coli biocomposite were studied by employing XRD, FTIR, FESEM-EDX and pHpzc. The optimisation of biosorption conditions was achieved using a Box-Behnken Design (RSM-BBD) to assess the effect of variables on the dye removal: biocomposite dose (0.02–0.1 g/100 mL), pH (4–8) and contact time (10–300 min). The optimal conditions for dye removal (84.3%) were achieved with a chitosan – E. coli dose of 0.1 g/100 mL, and a contact time of 160 minutes with a pH of 8. The equilibrium and kinetic experimental findings show the biosorption of malachite green dye by chitosan – E. coli follows the Langmuir and pseudo-second-order models, respectively. The maximum dye adsorption capacity (q max ) of malachite green for the chitosan – E. coli biocomposite was 164.7 mg/g, where the dye adsorption mechanism was attributed to several effects such as hydrogen bonding, n-π interactions, and electrostatic attraction. Thermodynamic analysis indicated that the biosorption process was spontaneous and endothermic, with a positive enthalpy change (ΔH° = 40.9 kJ/mol) and a negative Gibbs free energy (ΔG°) at all tested temperatures. The biocomposite chitosan – E. coli adsorbent exhibits favourable cationic dye adsorption that is anticipated to have utility for remediation of dye effluent in industrial wastewater.

Mitigating pollutants in textile dye wastewater with Aloe vera (L.) Burm. f. and Abelmoschus esculentus (L.) Moench: A study on treatment efficacy

Textile wastewater, particularly those containing dyes, presents significant threats to environmental quality and human health. This study assessed the efficacy of Aloe vera (L.) Burm. f. and Abelmoschus esculentus (L.) Moench (Okra) in removing pollutants from textile dye effluent collected in Dindigul, Tamil Nadu. The effluent samples were treated with varying doses of phyto-coagulants (0.02 g, 0.04 g, 0.06 g, 0.08 g, 0.10 g, and 0.12 g), as well as isolated polysaccharides from Aloe vera and Okra, to identify optimal strategies for reducing color, Total Dissolved Solids (TDS), and Chemical Oxygen Demand (COD). The findings revealed that the phyto-coagulants, particularly Okra polysaccharides, significantly reduced pollution levels, achieving a 90 % reduction in color, 96 % reduction in TDS, and 82 % reduction in COD. To further understand the mechanism of pollutant removal, GC–MS, FTIR, and Zeta potential analyses were conducted. This study highlights the effectiveness of natural coagulants in mitigating environmental pollution and preventing the entry of harmful chemical contaminants into the food chain. The study supports the potential of Aloe vera and Okra as sustainable and eco-friendly solutions for addressing the environmental challenges posed by textile wastewater pollution.

Deposition of Titanium Dioxide Particles on Kanthal Coils by Direct Heating Technique for Photodegradation of Methylene Blue Solution

Organic dyes are extensively used in textile and batik industry. Dispose of untreated dye effluent into water system is hazardous to human and environment. Advanced oxidation process (AOPs) based on heterogeneous TiO2 photocatalyst is proven for effluent treatment. Immobilization of TiO2 photocatalyst on supporting substrate is one of the research focuses to realize its application in industry to minimize the loss of TiO2 photocatalyst over time during effluent treatment. Many synthesis techniques have been used to grow TiO2 photocatalyst on supporting substrates. However, these synthesis techniques are either time- or cost-consuming. In this work, a novel direct heating (DH) technique has been developed for the first time to deposit TiO2 particles on kanthal coils. The optimum deposition of TiO2 particles was achieved in 15 min using 60 W. The TiO2 particles contained mixture of anatase (82.7%) and brookite (17.3%), with an average particle size of 167.36±15.37 nm. The surface coverage of TiO2 particles on kanthal wire was good, with minimum agglomeration. The TiO2 particles deposited on kanthal coils recorded 43.7% of photodegradation efficiency in methylene blue removal under UV light.

Utilization of waste citrus limetta peel for the green synthesis of iron catalyst and its subsequent application in fluidized-bed Fenton-like process for environmental sustainable treatment of organic pollutant

This work focuses on the environmental friendly synthesis of an iron-based catalyst utilizing extract from waste citrus limetta peels. The main objective is to encourage the sustainable use of bio-waste materials in catalytic processes. This innovative method demonstrates the efficacy of bio-derived materials in catalysis by removing the need for hazardous chemicals. The green-synthesized catalyst was analyzed using many characterization methods, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). These analyzed results give insightful information on the physicochemical properties of green-synthesized catalysts. Furthermore, the prepared catalyst was utilized in a fluidized-bed reactor to facilitate the Fenton degradation of dye effluent, with a specific focus on the commonly used Eosin yellow (EY) dye. The iron catalyst derived from plant-based waste material accomplished an impressive 98% degradation of EY within a 90-minute time frame under optimized working conditions, using a minimal quantity of catalyst. An in-depth analysis was conducted to study the kinetics and process mass transfer in order to improve the comprehension of catalytic processes occurring in the fluidized-bed reactor. The Fenton decomposition of dye effluent is likely to be explained by first-order reaction kinetics. Additionally, confirmed enhanced catalytic durability and decreased deactivation of surface sites of the prepared catalyst after three consecutive oxidation cycles. These findings underscore the potential of this approach in sustainable wastewater treatment, highlighting both its efficiency and cost-effectiveness.

Adsorption of Carotenoids, Chloride, and Sulfate from Annatto Dye Agro-Industrial Effluent

&lt;p&gt;Natural dyes, such as annatto, are widely used in the food and pharmaceutical industries. However, the effluents from annatto dye production pose environmental challenges due to the presence of residual dye components, organic matter, and dissolved inorganic species (chloride and sulfate). This study, the first attempt in the literature to deal with real annatto dye effluent, aimed to evaluate the use of activated carbon for the removal of carotenoids (norbixin), chloride, and sulfate. A 2³ full-factorial design was employed to optimize the adsorption process parameters (temperature, pH, and adsorbent mass). The results showed that up to 90% of carotenoids and chloride could be removed under optimized conditions (low temperature and pH). Sulfate removal was more strongly influenced by the pH of the medium, with a maximum removal of 53%. The adsorption process was well-described by empirical models, though traditional isotherm models did not adequately represent the experimental data. Hypotheses that support isotherm models such as pore homogeneity, monolayer formation, constant internal diffusion were not satisfied. This study demonstrates the potential of activated carbon adsorption as a feasible method for treating food industry effluents containing high loads of carotenoids and inorganic salts.&lt;/p&gt;

Recycling and breakdown photodegradation processes cost of BEN-TiQD via different photodegradation processes of Brilliant Green S dye and industrial effluents

The development of efficient photocatalytic materials for environmental remediation is of paramount importance. This study reports the synthesis and characterization of novel bentonite-titanium dioxide quantum dot (BEN-TiQD) nanocomposites for the photodegradation of Brilliant Green S, a prominent industrial pollutant. The nanocomposites were prepared via a co-precipitation method, ensuring uniform dispersion of TiO2 nanoparticles on the bentonite (BEN) surface, followed by heat treatment to achieve optimal crystallinity and surface properties. Comprehensive characterization techniques, including FTIR, XRD, SEM, BET surface area analysis, and optical spectroscopy, were employed to elucidate the structural, morphological, and photophysical characteristics of the composites. The BEN-TiQD nanocomposites exhibited an augmented surface area of 277.75 m2/g, surpassing BEN alone by more than threefold, and an intermediate bandgap of 3.17 eV, rendering them suitable for visible light absorption and photocatalytic applications. The photocatalytic efficacy of BEN-TiQD was evaluated by monitoring the degradation of Brilliant Green S under various operational parameters. The nanocomposites demonstrated superior photocatalytic performance, with a rate constant of 22.24 × 10−3 s−1, significantly only lower than TiQD (28.32 × 10−3 s−1) by nearly about 21.5 %. The enhanced activity was attributed to the quantum size effect of the incorporated TiO2 quantum dots, optimizing light absorption and charge separation. Mechanistic studies revealed the generation of reactive oxygen species, particularly hydroxyl radicals, as the primary drivers of dye degradation. The reusability of BEN-TiQD was evaluated through multiple photocatalytic cycles, exhibiting remarkable stability for up to six consecutive cycles. However, a gradual decline in photodegradation efficiency was observed after prolonged sunlight exposure, likely due to particle agglomeration and reduced surface area. This research contributes to the field of environmental remediation by developing a novel composite material that synergistically combines the adsorptive properties of BEN with the photocatalytic capabilities of titanium dioxide quantum dots. The findings pave the way for further exploration and optimization of these composites for sustainable and efficient treatment of industrial dyes and effluents, addressing critical environmental challenges.

Efficient biodecolorization of direct black 22 Azo Dye by Aspergillus tamarii Kita UCP1279 isolated from caatinga soil

The textile industry is a major consumer of water, generating large volumes of wastewater contaminated with harmful substances, particularly azo dyes, which contain aromatic rings, amines, and sulfonic groups that contribute to their environmental toxicity. The use of microbial agents for wastewater treatment offers a cost-effective and sustainable solution, minimizing sludge production. Fungi from the Caatinga biome have demonstrated potential for bioremediation, especially under extreme environmental conditions. This study explores the ability of Aspergillus tamarii Kita to decolorize the azo dye Direct Black 22 (DB22) under varying conditions, including the use of both active and inactive fungal biomass, in static and agitated systems (120 rpm), at a controlled temperature of 30°C. Dye concentrations of 50, 125, and 250 mg/L were evaluated over time intervals of 75, 180, and 180 minutes, respectively. The influence of dissolved oxygen concentration and redox potential on the decolorization process was also investigated to identify optimal treatment conditions. Decolorization efficiency was quantified via spectrophotometric analysis. Results revealed decolorization rates of 100%, 97%, and 63% for the respective dye concentrations, with active biomass in agitated conditions achieving the highest removal rates. The study further demonstrated that dissolved oxygen levels and redox potential are critical factors in enhancing dye decolorization. These findings underscore the bioremediation potential of Aspergillus tamarii Kita in treating textile dye effluents, offering a promising approach to sustainable industrial wastewater management.

Enhancing Azo Dye Mineralization and Bioelectricity Generation through Biocathode-Microbial Fuel Cell Integration with Aerobic Bioreactor

This study explores the efficient decolorization and complete mineralization of the diazo dye Evans blue, using an integrated aerobic bioreactor system coupled with a double-chamber microbial fuel cell (DCMFC) including a bio-cathode and acetate as a cosubstrate. The research addresses the environmental challenges posed by dye-laden industrial effluents, focusing on achieving high decolorization efficiency and understanding the microbial communities involved. The study utilized mixed strains of actinomycetes, isolated from garden compost, to treat initial dye concentrations of 100 mg/L and 200 mg/L. Decolorization efficiency and microbial community composition were evaluated using 16S rRNA sequencing, and electrochemical impedance spectroscopy (EIS) was used to assess anode and DCMFC resistance. The results demonstrated decolorization efficiencies ranging from 90 ± 2% to 98 ± 1.9% for 100 mg/L and from 79 ± 2% to 87% ± 1% for 200 mg/L. An anode resistance of 12.48 Ω indicated a well-developed biofilm and enhanced electron transfer. The microbial community analysis revealed a significant presence of Pseudomonadota (45.5% in dye-acclimated cultures and 32% in inoculum cultures), with key genera including Actinomarinicola (13.75%), Thermochromatium (4.82%), and Geobacter (4.52%). This study highlights the potential of the integrated DCMFC–aerobic system, utilizing mixed actinomycetes strains, for the effective treatment of industrial dye effluents, offering both environmental and bioenergy benefits.

Fabrication of nanocomposite membranes containing Ag/GO nanohybrid for phycocyanin concentration

In this research, silver/graphene oxide (Ag/GO) nanohybrid was first synthesized and used in production of polysulfone (PSF) ultrafiltration (UF) membranes via phase inversion method for concentrating phycocyanin (PC) and treating methylene blue (MB) dye effluent. Designing the experiment (DOE) using Box-Behnken method by Design Expert software helped to calculate the optimal values of the variables under study. The studied variables included PSF polymer concentration, polyvinyl pyrrolidone (PVP) pore-former concentration and Ag/GO nanohybrid content, which were investigated for their effects on pure water flux (PWF) and MB pigment rejection. According to the results of the DOE, the membrane containing 19.485 wt% PSF, 0.043 wt% PVP and 0.987 wt% Ag/GO was selected as the optimal membrane. Due to the high price of PC as drug, and the importance of removing MB pigment from the effluent of dyeing and textile industries, the membranes were first optimized with MB pigment and then the optimal membrane was used for concentrating PC. The results showed that PWF reaches from 40.05 L.m− 2.h− 1 (LMH) for the neat membrane to 156.73 LMH for the optimized membrane, which shows about 4 times improvement. Compared to the neat membrane, flux recovery ratio (FRR) of the optimized membrane increased by about 20% and its total fouling (Rt) decreased by about 10%. Also, the results showed that the optimized membrane can remove 81.6% of MB, as well as to reject 93.8% of PC.

Dye degradation and antimicrobial efficacy of cesium-doped Y2O3 nanostructures: in silico docking study.

Developing multifunctional nanomaterials is crucial to rising global concerns over environmental contamination caused by dye effluents and antibiotic resistance. This work presents cesium (Cs)-doped Y2O3 nanostructures (NSs) as viable options for catalytic dye degradation and antibacterial action. This study prepared yttrium oxide (Y2O3) and various (2, 4, and 6 wt%) concentrations of Cs-doped Y2O3 NSs via co-precipitation technique. The pure and Cs-doped Y2O3 NSs were used to degrade methylene blue (MB) at different pH levels and assess the antibacterial properties against multidrug-resistant (MDR) Escherichia coli (E. coli). The X-ray diffraction spectra of the pure and Cs-doped Y2O3 revealed the presence of cubic and monoclinic structures. The UV-vis absorption spectra displayed distinct peaks at 274 nm and a reduction in band gap energy (from 4.94 eV to 4.41 eV) upon incorporation of Cs. Maximum degradation efficiency of up to 99% attributed to 6% Cs-doped Y2O3. The bactericidal activity against MDR E. coli exhibited 4.15 mm inhibition zones at higher concentrations of Cs-doped Y2O3. The bactericidal mechanism of Cs-Y2O3 NSs was further investigated by molecular docking studies for β-lactamase and DNA gyrase enzymes.

Adsorption Behavior and Mechanism of Brilliant Green Dye onto Acid-modified Mesoporous Volcanic Pumice

Water pollution is a major problem in the environment. The important one is the dying effluent from the textile industry. Dye effluent has affected human health and aquatic life. Recently, natural adsorbents have been most commonly used for dye treatment wastewater. This study explores the adsorption mechanism of brilliant green onto HCl-modified pumice. It involves a comparative analysis of the raw and HCl-modified pumice's characterization and adsorption properties. The adsorption experiments were carried out by considering several parameters, such as pH, contact time, initial dye concentrations, and temperatures. The research indicated that the raw and acid-treated pumice possess Si-OH and Si-O-Si groups. These pumice adsorbents are classified as mesoporous, exhibiting BJH pore diameters of 3.23 nm for the raw form and 3.69 nm for the acid-modified variant. The adsorption data revealed that the uptake of brilliant green dye was maximal at a pH of 8. The equilibrium results closely matched the Langmuir isotherm model. The maximum adsorption capacities were 37.13, 40.17, and 42.73 mg g-1 for the raw pumice, and 46.72, 51.81, and 56.17 mg g-1 for the modified pumice at 20, 30, and 40 °C, respectively. Furthermore, the removal efficiency of brilliant green dye with modified pumice was 91.93%, 95.29%, and 96.27% at 20°C, 30°C, and 40°C, respectively. The pseudo-second-order model was the most suitable for elucidating the kinetic adsorption data. The thermodynamic analysis revealed that the adsorption process was endothermic, spontaneous, and physical. Dipole-dipole H-bonding interaction, Yoshida H-bonding, electrostatic interaction, n-𝝅 interaction, cation exchange, and pore filling were all engaged in its process. Consequently, the local pumice volcanic rock became a great, cheap, abundant, and environmentally friendly adsorbent for removing dyes from effluents.

Synergistic effects of Fe2O3 supported on dendritic fibrous SBA-15 for superior photocatalytic degradation of methylene blue

Environmental pollution caused by dye effluent has attracted much attention, and thus developing photocatalysts with superior photodegradation performance is an imperative task. A series of Fe supported on dendritic fibrous SBA-15 (Fe/DFSBA-15) catalysts with various Fe contents were prepared using a microemulsion coupled with ultrasonic-assisted impregnation methods. The findings revealed that the structural stability of DFSBA-15 was unaffected by the amount of Fe loaded. As the Fe loading increased, the size of Fe2O3 nanocrystals increased while the catalysts’ surface area decreased. The bandgap energy of the catalyst decreased with increasing Fe loading and became constant after reaching an optimal Fe loading of 10 wt%. The one-factor-at-a-time study revealed that 10Fe/DFSBA-15 degraded 94.72 % of methylene blue (MB) within 180 min at 1.5 g/L catalyst dosage, pH 8, and 10 mg/L of concentration, owing to Si-O-Fe coordination, modest Fe2O3 crystallite size, homogeneous metal distribution, slower recombination rate, and low bandgap energy. The advantageous features of 10Fe/DFSBA-15 resulted in accelerating the photodegradation rate, where 10Fe/DFSBA-15 is found as the optimal catalyst. The addition of Fe particles to the DFSBA-15 largely improved their photocatalytic activity toward MB degradation, making it a potential candidate for removing pollutants from aqueous solutions.

Reuse and Recovery of Water from Industrial Textile Dyeing Effluent Using High-Performance Electrodes Continuous Flow Electrocoagulation Reactor

The dye effluents released from the textile and printing industries contain strong colorants, inorganic salts, and other toxic compounds. The conventional coagulation technique of dye effluent treatment is plagued with issues of low removal rate of color, generation of large quantities of sludge, and toxic end-products. Recently electrocoagulation technique gained immense attention due to its high efficiency. This technique involves the dissolution of the sacrificial anodes to provide an active metal hydroxide as a strong coagulant that destabilizes the pollutants and removes them by precipitation or flocculation. This study is about the efficiency of the electrocoagulation process using titanium coated - aluminum and mild steel electrodes to treat industrial dye wastewater. Effects of parameters such as current density &amp; initial dye concentration were investigated. It was observed that, for the same current density, electrode consumption was higher with TiO2/Al electrode than with mild steel electrode, resulting in more color removal efficiency (CRE) using TiO2/Al electrode. The settling rate of the flocs was higher in the rector having TiO2/Al electrode at the 100 mL with current density (2.5 mL.min-1 to 5.3 mL.min-1), while in the reactor with mild steel electrode, the settling rate was very less. The results showed that dye removal was 95.11% and 92.1% for mild steel and titanium-coated electrodes, respectively. It was observed that 50 % of Aluminum was removed from the treated effluent after the final stage of filtration. Based on the multicriteria analysis to identify the optimum operational parameters to be applied at the field level, it was observed that maximum CRE may be obtained with TiO2/Al electrode and the applied current of 1 Amps with a flow rate of 100 mL.min-1. It can be concluded that electrocoagulation is a highly efficient and the fastest method to treat dye effluents from industries.

Evaluation of physiochemical and in-vitro characteristics of Ixora Coccinea mediated Co3O4 nanoparticles for photocatalytic degradation of toxic textile dye effluents

Discharging colored wastewater from the textile industry into water bodies disrupts the natural ecosystem and reduces the productivity of aquatic life. It is challenging to degrade complex dye molecules, including pathogens and bacteria. This research article deals with the photocatalytic activity of cobalt oxide nanoparticles mediated Ixora coccinea plant extract for industry effluent treatment applications. The green synthesized nanoparticles were found to have high crystallinity and purity, cubic crystal structure, and spherical morphology with 21.5 nm crystallite size. Further, the biological properties, such as antibacterial, antioxidant, and bacterial growth inhibition activity, were evaluated. With 88 % and 83 % bacterial growth inhibition, the antibacterial activity showed a maximum bacterial zone inhibition of 31 ± 0.4 mm for positive and 29 ± 0.3 mm for harmful bacterial strains. Then, the level of scavenging free radicals measured about 93.87 %. The photocatalytic activity was evaluated against the textile dyes under direct sunlight irradiation. The maximum dye degradation was achieved for Alizarin red (85.2 %), Crystal violet (90.7 %), Reactive black (94.5 %), and Rhodamine B (96.4 %) dyes at the end of 90 min of irradiation. Moreover, this research paper introduces a method for creating cobalt nanoparticles using natural and sustainable approaches. These nanoparticles have potential in several fields, such as medicine, catalysis, and water remediation.