Increase In Dye Concentration Research Articles

Response of soil fungi to textile dye contamination

This study examines the impact of textile dye contamination on the structure of soil fungal communities near a Shaoxing textile dye factory. We quantified the concentrations of various textile dyes, including anthraquinone azodye and phthalocyanine, which ranged from 20.20 to 140.62 mg kgˆ-1, 102.01 to 698.12 mg kgˆ-1, and 7.78 to 42.65 mg kgˆ-1, respectively, within a 1000 m radius of the factory. Our findings indicate that as dye concentration increases, the biodiversity of soil fungi, as measured by the Chao1 index, decreases significantly, highlighting the profound influence of dye contamination on fungal community structure. Additionally, microbial correlation network analysis revealed a reduction in fungal interactions correlating with increased dye concentrations. We also observed that textile dyes suppressed carbon and nitrogen metabolism in fungi while elevating the transcription levels of antioxidant-related genes. Enzymes such as lignin peroxidase (LiP), manganese peroxidase (MnP), laccase (Lac), dye-decolorizing peroxidases (DyPs), and versatile peroxidase (VP) were upregulated in contaminated soils, underscoring the critical role of fungi in dye degradation. These insights contribute to the foundational knowledge required for developing in situ bioremediation technologies for contaminated farmlands.

Exploring fungal-mediated solutions and its molecular mechanistic insights for textile dye decolorization

Decolorization of textile dyes and study of their intermediate compounds is necessary to comprehend the mechanism of dye degradation. In the present study, different fungal mediated solutions were explored to provide an alternative to treat the reactive dyes. Growing biomass of Pleurotus sajor caju showed 83% decolorization (249.99 mg L−1 removal) of Reactive Blue 13 (RB 13) and 63% decolorization (188.83 mg L−1) of Reactive Black 5 (RB 5) at 300 mg L−1 initial concentration on 8 d. Higher laccase activity was positively correlated with increase in decolorization. However, increasing dye concentration has inhibitory effect on fungal biomass due to increase in toxicity. In laccase mediated decolorization, laccase produced from P. sajor caju using carbon rich waste material as substrate showed 89% decolorization (276.36 mg L−1 removal) of RB 13 and 33% decolorization (105.37 mg L−1 removal) of RB 5 at 300 mg L−1 initial dye concentration in 100 min at 30 °C and pH 3.0’. Comparing the two methods, laccase-mediated decolorization shows better decolorization in less time and does not produce sludge. Further, the present work also attempted to study the dye degradation pathway for Reactive blue 13 via laccase mediated process. Fourier-transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), and gas chromatography–mass spectrometry (GC-MS) were utilized to identify the degraded products. The GC-MS analysis showed the formation of naphthalene, naphthalene 2-ol, benzene,1–2, dicarboxylic acid, 4, amino, 6,chloro, 1-3-5, triazin-2-ol as the final degraded products after enzymatic degradation of RB 13. These findings provide in-depth study of laccase-mediated textile dye degradation mechanism.

A hybrid electrocoagulation-biocomposite adsorption system for the decolourization of dye wastewater

Among the various methods for the removal of azo dye, electrocoagulation is recognized to be highly efficient. However, the process is associated with high operation and maintenance cost, which demands the need for reducing the electrolysis time without compromising the performance efficiency. This can be achieved by adopting hybrid electrocoagulation process with a low-cost but effective process, such as adsorption. The study investigated the performance of a hybrid electrocoagulation-biocomposite system (H-EC-BC) for removing methyl orange dye. Firstly, the operating parameters of electrocoagulation process were optimized and a removal efficiency of 99% has been attained using Fe-SS electrodes at a pH of 6 for a reaction time of 30 min. The performance of EC process was found to be decreasing with increase in dye concentration. Secondly, biocomposite was synthesized from Psidium guajava leaves and characterized using SEM, FTIR, EDAX, and XRD analyses. The results suggested that it is having a porous nature and cellulose crystal structure and confirmed the presence of chemical elements such as carbon (65.2%), oxygen (29.1%) as primary with Fe, Cl, Na and Ca as secondary elements. The performance of the biocomposite was evaluated for the dye adsorption using spectrophotometric methods. Various operating parameters were optimized using experimental methods and a maximum removal efficiency of 65% was achieved at a pH of 6, dosage of 5 g/L and an adsorption contact time of 120 min. The maximum efficiency (92.78%) was obtained with Fe-SS electrodes and KCl as a sustaining electrolyte under acidic circumstances (pH 6). The biocomposite was observed to be more efficient for higher dye concentration. Langmuir and Freundlich adsorption isotherms were fitted with the experimental results with R2 values as 0.926 and 0.980 respectively. The adsorption kinetics were described using Pseudo-first and Pseudo-second order models, wherein Pseudo-second order model fits the experimental results with R2 value of 0.999. The energy consumption of electrocoagulation (EC) process in the hybrid H-EC-BC system was compared to that of a standard EC process. The results demonstrated that the hybrid system is approximately 7 times more energy efficient than the conventional process, thereby implicating its adaptability for field application.

Synthesis, characterization of KAlPO4F and its application for methyl violet adsorption

KAlPO4F was prepared hydrothermally at 453 K, a time-saving method using cheap reagents. The white solid was characterized by different methods such as powder X-ray diffraction, thermal analysis, SEM and UV–Vis diffuse reflectance. The compound was successfully tested for the removal of methyl violet (MV), a hazardous dye. Experiments were carried out as a function of contact time, initial concentration, temperature and pH. The amount of dye uptake was found to vary with increasing initial solution pH and maximum adsorption was observed at pH 10; the equilibrium was attained in 270 min. The amount of dye uptake (mg/g) was found to increase with increase in dye concentration and contact time. The pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models were applied to fit the experimental data to elucidate the kinetic adsorption. The pseudo-second-order model was the best to describe the adsorption process. Different models analyzed the equilibrium isotherms; the applicability for the experimental data follows the order: Freundlich > Langmuir > Temkin. The thermodynamic parameters: ΔH° (39.034 kJ mol−1), ΔS° (134 J K−1 mol−1) and ΔG° (− 367.01 J mol−1) indicated that the adsorption process is endothermic and spontaneous with increasing disorder at the solid–solution interface.

Preparation and characterization of high flux cellulose acetate/hydroxyapatite composite ultrafiltration membranes for water treatment

In this study, we prepared cellulose acetate/hydroxyapatite (CA/HA) composite ultrafiltration membranes for water treatment. The organic-inorganic composite ultrafiltration membranes were prepared by doping different contents of HA nanoparticles into the CA by phase inversion method. The structure and morphology of the HA nanoparticles and membranes were characterized by X-ray diffraction, Fourier infrared spectroscopy and Scanning electron microscopy. Thermogravimetric analysis was used to describe thermal characteristics. The contact angle value and wettability test were used to determine the hydrophilicity of the polymer membrane. In addition, fluxes and rejection rates were tested at different pollutant concentrations and different pH values. The pore size and porosity gradually increased and the hydrophilicity and thermal stability of membrane were improved with the deposited HA content. With the addition of 5 wt% HA, the tensile strength of the membrane reached a maximum value of 2.80 MPa. The fluxes of pure water, CR, MB and BSA were 152.23, 111.25, 125.69 and 87.47 L/(m2·h), while the rejection rates of CR, MB and BSA were 99.99 %, 92.91 % and 99.99 %, respectively. In addition, the rejection decreased with increasing dye concentration and showed higher rejection under alkaline conditions. On the whole, the produced CA/HA composite membranes exhibited significantly higher permeability and rejection rates, offering them a lot of potential for water treatment applications.

Use of oak acorns adsorbent and response surface methodology for removal of crystal violet from aqueous solution

ABSTRACTThis study investigates the potential use of oak acorn pericarp powder as an effective adsorbent for removing crystal violet from aqueous solutions under citric acid activation. Various analytical techniques, including FTIR, EDS, and SEM, were used to examine the characteristics of the adsorbent obtained. Throughout the experiments, parameters such as adsorbent quantity, solution pH, and initial dye concentration were meticulously taken into account. To optimise this removal process, a customised experimental approach based on response surface methodology (RSM) was adopted, involving the performance of 20 series of experiments to assess the influence of key variables, including adsorbent dose (A), pH (B), and initial dye concentration (C), as well as their interactions. Statistical analysis reveals the high significance of the elimination model, supported by an extremely low probability value (p < 0.0001). Notably, increasing adsorbent mass and solution pH leads to higher rates of crystal violet removal. Conversely, as the initial dye concentration increases, the removal rate decreases. Furthermore, the interaction between these variables does not appear to have a significant influence. Under optimal conditions, a remarkable elimination rate of 99.96% was achieved. This involved a solution with an initial pH of 10.82, an adsorbent dose of 28.5 mg, and an initial dye concentration of 17.8 mg/L. The kinetics of crystal violet adsorption onto the adsorbent were effectively described by a pseudo-second-order equation. Additionally, the optimal multilayer uptake capacity of OA@CA for CV dye was determined to be 135.9 mg.g−1, and the Freundlich model demonstrated a significantly better fit to the experimental results when compared to the Langmuir model.

Granular titanium dioxide and silicon‐doped titanium dioxide as reusable photocatalysts for dye removal

AbstractIn this study, photocatalytic oxidation of methylene blue (MB) and malachite green (MG) dyes was investigated using granular pure titanium dioxide and silicon‐doped granular titanium dioxide as photocatalysts. Both catalysts were used repeatedly throughout the photocatalytic oxidation experiments. The effect of initial dye and catalyst concentration on photocatalytic oxidation was investigated. The photocatalytic oxidation followed first‐order kinetics for both catalysts. The efficiency of photocatalytic oxidation increased with the increasing catalyst concentration and decreased with the increasing dye concentration. In a 60‐min reaction using granular titanium dioxide, removal efficiencies of MB and MG at 20 g/100 mL catalyst loading and 10 mg/L initial concentration were 83% and 93.3%, respectively. In a 60‐min reaction using granular silicon‐doped titanium dioxide, the removal efficiencies of MB and MG at 5 g/100 mL catalyst loading and 10 mg/L initial concentration were 90.2% and 91.6%, respectively.

Examining Energy Storage Potential in Weakly Polar Nematic Liquid Crystals Infused with Anthraquinone Dye: A Comprehensive Approach

The applications of liquid crystals in the field of renewable, clean and sustainable technologies of energy storage are of utmost importance at present. This paper delves into dielectric spectroscopic studies of a weakly polar nematic liquid crystal (NLC) enriched with an anthraquinone dye. The primary objective is to assess the impact of increasing dye concentrations on various properties. Anthraquinone dye has been found to increase the dielectric permittivity of weakly polar NLC, leading to a 4.7-fold increase in dielectric anisotropy. Simultaneously, a reduction of around 11% in threshold and operating voltages of the NLC has also been recorded after using dye as the guest material. The added dipolar contributions provided by dye molecules have been attributed to this surplus permittivity. The NLC has been found to have an approximately 54% faster response to the applied field. The intrinsic polarization field of dye molecules accelerates nearby LC molecule reorientation, leading to a 56.5% faster fall time and a 29.8% faster rise time in a 3.0 wt% dye-doped LC cell. These experimental results have been validated via computational studies as well. The simulation results about dipole moment and polarizability provide robust support for our experimental results. Such composites evince their potential for energy storage and 5G communication technologies with adjustable impedance and permittivity.

Efficient separation of dyes using two-dimensional heterogeneous composite membranes

Two-dimensional materials are widely used in membrane separation, but the loose distribution and severe expansion between graphene oxide (GO) nanosheets limit its application. Here, we introduce a two-dimensional MOF material into the GO membrane to enhance its water permeance and separation performance. The MOF/GO composite membrane was prepared by vacuum filtration. The MOF and GO nanosheets were tightly stacked through the π-π effect, and the shortened transmission path and enhanced pore structure greatly improved the water permeance of the composite membrane. The MOF/GO membrane exhibited a high water permeance of 56.94 L m−2 h−1 bar−1. The rejection rates of methylene blue and was as methyl orange dyes were as high as 99.79% and 99.11%, respectively. At increased dye concentration, the rejection rate of methylene blue was still maintained greater than 99%. Dye rejection after 18 h of continuous operation remains above 90%. This work provides new ideas for improving membrane separation materials. The combination of two-dimensional heterogeneous materials can result in synergistic advantages for the development of composite membranes with high water permeance and high rejection rate.

Fundamental Understanding of Dye Coverage and Performance in Dye-Sensitized Solar Cells Using Copper Electrolyte

Dyes have played a pivotal role in the advancement of modern dye-sensitized solar cells (DSCs), as they not only facilitate light harvesting, but also serve as blocking layers to impede recombination. In this study, we conducted a systematic investigation to elucidate the influence of dye coverage on the photovoltaic parameters of copper-electrolyte-based DSCs by precisely controlling the dye coverage on the TiO2 substrate using D35 organic dye solutions with varying concentrations. The dye loading increased proportionally with the increase in dye concentrations until it reached saturation at a concentration of 0.2 mM. However, an optimal dye concentration of 0.1 mM was determined in terms of achieving the highest photovoltaic performance, under both outdoor and indoor light conditions. Notably, a maximum power conversion efficiency (PCE) of 6.50 ± 0.25% under outdoor illumination (100 mW/cm2) and 10.48 ± 0.30% under indoor light (1000 lux, WW CFL) was attained using a 0.1 mM D35 dye concentration. Additionally, the dark current and ideality factor (m) were found to be minimized at the 0.1 mM dye concentration. Furthermore, the ideality factor (m) exhibited disparities between indoor and outdoor light conditions. The lifetime obtained from electrochemical impedance spectroscopy (EIS) measurements correlated well with the ideality factor (m) and dark current. Notably, electron injection, dye regeneration, charge collection, and ion diffusion were observed to be independent of the dye coverage.

Raw sawdust utilization for the removal of acid red57 and basic fuchsin dyes from aqueous solution: equilibrium, kinetics, and thermodynamic investigation

The aim of work is the use of a cheap adsorbent; sawdust (SD), for the adsorption of anionic dye, acid red57 (AR57), and cationic dye, basic fuchsin (BF). The adsorption of AR57 and BF on SD increased by increasing contact time and adsorbent dosage, while decreased with the increase of temperature and initial dye concentration. The increase in pH decreased the adsorption of AR57 and increased the adsorption of BF. The effective pH, adsorbent dose, and contact time on the AR57 removal efficiency were found to be 3, 0.1 g and 50 min, respectively. While for BF it was found to be 6, 0.2 g and 50 min, respectively. Fitting equilibrium data to Langmuir, Freundlich and Temkin isotherms showed that Freundlich model is the most suitable to describe the acid red57 and basic fuchsin. The kinetic studies indicate that the adsorption of AR57 and BF follows a pseudo-second-order model. The adsorption of both AR57 and BF is spontaneous (ΔG = −3.97, −3.27 kJ/mol) and exothermic (ΔH = −22.9, −8.3 kJ/mol) with negative values of ΔG and ΔH. The negative values of ΔS of both AR57 and BF (ΔS = −64.6, −16.7 J/mol. K) showed that the randomness decreases through the adsorption process.

Experimental and Theoretical Evaluation of a Commercial Luminescent Dye for PVT Systems

Combining photovoltaic (PV) and photo-thermal (PT) energy collection strategies in a single system can enhance solar energy conversion efficiencies, leading to increased economic returns and wider adoption of renewable energy sources. This study focuses on incorporating a commercial luminescent organic dye (BASF Lumogen F Red 305) into ethylene glycol to explore its potential for PVT applications. The optical and electrical characteristics of the working fluid were evaluated at different temperatures under direct solar irradiance. Pristine ethylene glycol reduced the maximum PV cell temperature by 10 °C. The inclusion of luminescent dye at various concentrations further reduced the maximum temperature, with the lowest concentration achieving a 7 °C decrease compared to pristine ethylene glycol. The highest dye concentration (0.50 wt%) resulted in a significant temperature reduction of 12 °C. While electrical conversion efficiencies decreased with increasing dye concentration, all concentrations exhibited higher fill factors compared to the bare PV cell during the 100-min illumination period. A ray-tracing model was employed to analyze the behavior of the luminescent dye and quantify transmitted energy for electricity and thermal energy production. Different concentrations showed varying energy outputs, with lower concentrations favoring electrical energy and higher concentrations favoring thermal energy. Economic assessment revealed the viability of certain concentrations for specific countries, highlighting the trade-off between thermal and electrical energy generation. These findings provide valuable insights for PVT system applications in different geographical and economic contexts.

Enhanced Photocatalytic Degradation of Malachite Green Dye Using Silver-Manganese Oxide Nanoparticles.

Efficient and excellent nanoparticles are required for the degradation of organic dyes in photocatalysis. In this study, silver-manganese oxide nanoparticles (Ag-Mn-NPs) were synthesized through a wet chemical precipitation method and characterized as an advanced catalyst that has enhanced photocatalytic activity under sunlight irradiation. The nanoparticles were characterized using scanning electron microscopy (SEM), XRD, UV-vis light spectra, and energy-dispersive X-ray (EDX) spectroscopy, revealing their spherical and agglomerated form. The EDX spectra confirmed the composition of the nanoparticles, indicating their presence in oxide form. These bimetallic oxide nanoparticles were employed as photocatalysts for the degradation of malachite green (MG) dye under sunlight irradiation in an aqueous medium. The study investigated the effects of various parameters, such as irradiation time, catalyst dosage, recovered catalyst dosage, dye concentration, and pH, on the dye's photodegradation. The results showed that Ag-Mn oxide nanoparticles exhibited high photocatalytic activity, degrading 92% of the dye in 100 min. A longer irradiation time led to increased dye degradation. Moreover, a higher catalyst dosage resulted in a higher dye degradation percentage, with 91% degradation achieved using 0.0017 g of the photocatalyst in 60 min. Increasing the pH of the medium also enhanced the dye degradation, with 99% degradation achieved at pH 10 in 60 min. However, the photodegradation rate decreased with increasing dye concentration. The Ag-Mn oxide nanoparticles demonstrate excellent potential as a reliable visible-light-responsive photocatalyst for the efficient degradation of organic pollutants in wastewater treatment.

Structure, photoactivity, and antimicrobial properties of phloxine B / poly(caprolactone) nanocomposite thin films

Many applications of polymeric materials require chemical surface treatments. One possibility is the formation of a thin nanocomposite layer without changes in the polymer matrix. In this work, poly(caprolactone) was prepared with a thin nanocomposite layer composed of organoclay and photoactive dye, phloxine B (PhB). The principle of modification was the fusion of a thin layer of organoclay with a polymer matrix by the intercalation of polymer chains into the organoclay layer. The surface properties and composition of the thin layer of the nanocomposite were described using electron microscopy, measurements of water contact angles, X-ray diffraction, as well as X-ray photoelectron, UV–vis, and infrared spectroscopies. These methods revealed the effectiveness of polymer intercalation, confirmed the hydrophobic properties of the layer, the thickness of the composite at the level of several μm, the surface composition, and homogeneous distribution of PhB. The main outcomes were photoactive and antimicrobial properties of the films. The effects of various factors such as surfactant and dye concentrations and presence of polymer on photophysical properties were evaluated. PhB retained luminescence in all prepared materials to be highest at the lowest dye concentration and gradually decreased with increasing dye concentration. This trend was also confirmed by measurements of time-resolved fluorescence and quantum yields. In terms of antimicrobial activity, only the composite with the highest concentration of PhB exhibited a significant reduction in S. aureus biofilm growth. A more significant reduction was achieved using green light irradiation (about 3% of the growth in the control). The influence of other factors and potential applications will be the subjects of further studies.

Enhanced photocatalytic activity of Cu and Ni-doped ZnO nanostructures: A comparative study of methyl orange dye degradation in aqueous solution

Heterogeneous photocatalysis has been considered one of the most effective and efficient techniques to remove organic contaminants from wastewater. The present work was designed to examine the photocatalytic performance of metal (Cu and Ni) doped ZnO nanocomposites in methyl orange (MO) dye degradation under UV light illumination. The wurtzite hexagonal structure was observed for both undoped/doped ZnO and a crystalline size ranging between 8.84 ± 0.71 to 12.91 ± 0.84 nm by X-ray diffraction (XRD) analysis. The scanning electron microscope (SEM) and energy dispersive X-ray (EDX) revealed the irregular spherical shape with particle diameter (34.43 ± 6.03 to 26.43 ± 4.14 nm) and ensured the purity of the individual elemental composition respectively. The chemical bonds (O–H group) and binding energy (1021.8 eV) were identified by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results respectively. The bandgap energy was decreased from 3.44 to 3.16 eV when Ni dopant was added to the ZnO lattice. The comparative photocatalytic activity was observed in undoped and doped nanocomposites and found to be 76.31%, 81.95%, 89.30%, and 83.39% for ZnO, Cu/ZnO, Ni/ZnO, and Cu/Ni/ZnO photocatalysts, respectively, for a particular dose (0.210 g) and dye concentration (10 mg L−1) after 180 min illumination of UV light. The photocatalytic performance was increased up to 94.40% with the increase of pH (12.0) whereas reduced (35.12%) with an increase in initial dye concentration (40 mg L−1) using Ni/ZnO nanocomposite. The Ni/ZnO nanocomposite showed excellent reusability and was found 81% after four consecutive cycles. The best-fitted reaction kinetics was followed by pseudo-first-order and found reaction rate constant (0.0117 min−1) using Ni/ZnO nanocomposite. The enhanced photodegradation efficiency was observed due to decreases in bandgap energy and the crystalline size of the photocatalyst. Therefore, Ni/ZnO nanocomposite could be used as an emerging photocatalyst to degrade bio-persistent organic dye compounds from textile wastewater.

Soluble and supported hematin as a catalyst for decolourization of anthraquinone textile dyes: A kinetic modelling validation study

Hematin-catalysed decolourizations of alizarin red S solutions were carried out in order to validate a peroxidatic model in competition with pseudo-catalatic routes. Absorbance and dissolved oxygen were followed with time and hematin was used in solution or immobilized onto chitosan. Initial rates decreased with increasing dye concentration. Modelled dye concentration profiles properly reproduced experimental data. Optimized rate constants indicated that immobilization reduced hematin activity, emphasized dye inhibition and promoted the pseudo-catalatic pathway. The increase in H2O2 concentration increased oxygen evolution rates whereas the increase of dye concentration depleted them, which agree with the kinetic model proposal. These findings were also discussed considering some additional reactions which consume or evolve oxygen. UV–visible stack spectra of reacting systems allowed to propose some degradation products, whose molecular weights decreased with the increase of hydrogen peroxide to dye molar ratio. This is consistent with accumulation of inorganic radicalsproposed by the pseudo-catalatic mechanism.

Dominant role of organic dye on Mn: ZnS/PMMA polymer nanocomposites: Structural, thermal, linear, and nonlinear optical properties for optoelectronic and photonic applications

In this work, we investigated structural, thermal, linear, third order nonlinear (NLO), and optical limiting (OL) properties of an organic dye filled Mn: ZnS/PMMA polymer nanocomposite (PNCs). The structural properties were determined using fourier transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR) and X-ray diffraction (XRD) techniques. The surface morphology of samples studied using scanning and transmission electron microscope (SEM and TEM) photographs. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) helps to determine the thermal stability of prepared PNCs. The linear optical properties studied using UV-Visible spectroscopy. The samples better absorption spectra in the range 360 and 362 nm, and the optical energy band gap is reduced due to dye concentration increases. The samples exhibit strong fluorescence emission at 485 nm, confirming the blue emission. The fluorescence anisotropy (r) and polarisation (P) studies helps study molecular orientation of PNCs and energy transfer (ET) mechanism was explained using fluorescence lifetime decay curves. The third order nonlinear optical (NLO) properties were investigated using an open and closed aperture Z-scan technique with a DPSS continuous wave (CW) laser at 532 nm. The two-photon assisted nonlinear absorption (β), nonlinear refraction (n2) third-order nonlinear optical susceptibility (χ (3)) were investigated. The obtained β, n2 and χ (3) are found to be in the order ∼10−5 cmW−1, 10−8 cm2W−1 and 10−7 esu, respectively for all the samples. Further, they exhibited strong optical limiting behaviour with lower limiting thresholds (∼kW/cm2). The prepared PNCs exhibits strong linear and NLO properties showing that the PNCs could be suitable for optoelectronic and photonic applications.

Preparation, Characterization and Photocatalytic Degradation Studies of an Acrylic Acid-acryl Amide based TiO2 Hydrogel Nanocomposite: Real Samples of Pollutants Dyes

In this study, preparation of (AAc-AM)/TiO2 hydrogel nanocomposite. This hydrogel was prepared by copolymerization. Acryl amide (AM), acrylic acid (AAc) is an absorbent material of great use in the preparation of hydrogels, Where hydrogels based on acrylate are characterized by being hydrophilic and having the ability to retain water. The properties of nanocomposite were studied using several techniques (FESEM, XRD, and TEM). The photocatalytic degradation of Congo red (CR) under UV irradiation has been studied. The utilization of (AAc-AM)/TiO2 hydrogel nanocomposite as a catalyst in the photocatalysis process under several optimum conditions. The eff ect of the parameter contains the mass of the (AAc-AM)/TiO2 hydrogel nanocomposite catalyst and the concentration of Congo red (CR). Through the data, the photocatalytic activity increases by increasing the hydrogel nanocomposite mass from 0.1–0.3 g. Also, a decrease in photocatalytic effi ciency was observed with an increase in dye concentration. Observed that after re-use, (AAc-g-AM)/TiO2 hydrogel nanocomposite paper photocatalytic effi ciency from of the 1 cycle use 77.99 to 60.12% of 6 cycle use repeated to show that (AAc-g-AM)/TiO2 hydrogel nanocomposite surface appear good stability.

Decolourization and Detoxification of Azo Dye, Malachite Green by Pseudomonas monteilii Strain RZT1, a Bacterium Isolated from Textile Wastewater

Discharge of textile industrial effluent without proper treatment has become a severe hazard for the animal health and environment worldwide. Therefore, this study was designed to isolate azo dye-degrading bacteria from textile wastewater and evaluate their ability to biodegrade reactive dyes into non-toxic products. The potent bacterial strain which was isolated from textile wastewater was identified as Pseudomonas monteilii strain RZT1 on the basis of 16S rDNA sequence. The isolated bacterial strain exhibited good decolorization ability with yeast extract supplementation as cosubstrate in static conditions for Malachite Green dye. The optimal condition for the decolorization of Malachite Green dye by P. monteilii strain RZT1 were at pH 7.0 and 28°C. Decolorization rates of Malachite Green dye by P. monteilii strain RZT1 were varied with initial dye concentration as follow: 84.8%, 75.4%, 63.4% and 45.5% decolorization for 100ppm, 200ppm, 300ppm and 400ppm initial dye concentration respectively. We investigated the effects of dyes used in the textile industry on the seed germination of Five crops - Rice (Oryza sativa), Wheat (Triticum aestivum L.), Khesari (Lathyrus sativus), Mustard (Brassica nigra) and Bitter Melon (Momordica charantia). It was found that textile dye Malachite Green had negative effect on seed germination and seedling growth in test cultures. The harmful effects of dye on seed germination and early seedling growth parameters were augmented with increase of dye concentration. Interestingly, treatment of the Malachite Green dye with isolated bacteria reduced the adverse effects of that dye on seed germination and seedling growth. Thus, it indicated the potentiality of P. monteilii strain RZT1 for bioremediation of textile effluents into a non-toxic form for plants.

Synthesis of novel carbon-supported iron oxide sorbents for adsorption of dye from aqueous solutions: equilibrium and flow-through studies

Textile effluents contain dyes that negatively affect water bodies and inhibit photosynthesis by reducing sunlight penetration. This study investigated the adsorption capacity of an iron oxide sorbent immobilised on naturally derived carbon foam for the removal of organic methylene blue dye from water. In this study, the carbon precursor and iron oxide precursor were mixed and carbonised in a single vessel. Baking and carbonization of the natural grain combination produce a porous structure that can act as an effective support for the iron oxide particles. The carbon foam prepared had a self-assembled structure with flour as a basic element. Sorbents of 6 weight (wt)%, 15 wt% iron, and a 0 wt% iron control sample were prepared. Transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) techniques were used to examine the synthesised carbon foam physical properties and surface morphology. The adsorption capabilities were investigated in batch tests by determining the effects of an increase in iron content, sorbent dosage, contact time, and dye concentration. Breakthrough curves were obtained by varying the height of the sorbent bed and varying the flowrate of the dye solution. A higher bed height corresponds to a greater amount of adsorbent. The breakthrough and equilibrium adsorption capacities were found to increase with increasing bed height. When the flow rate is high, the dye solution leaves the column before equilibrium, resulting in shorter breakthrough and saturation times. Higher bed heights and lower flow rates resulted in optimal dye removal in the flow through the system. Breakthrough time increases with increasing iron content. The 15 wt% iron sample displayed superior adsorption capabilities than the 6 wt% sample, while the 0 wt% iron control sample displayed minimal adsorptive capabilities. The pseudo-first order kinetic model was the best fit model for this study (R2 > 0.96), and the adsorption equilibrium is best described by the Freundlich isotherm (R2 > 0.99). The results showed that an iron oxide sorbent immobilised on carbon foam made from natural sources is a good adsorbent for removing methylene dye.