Textile Industry Effluent Research Articles

Treatment of carpet and textile industry effluents using Diplosphaera mucosa VSPA: A multiple input optimisation study using artificial neural network-genetic algorithms

The wastewater treatment efficiency of Diplosphaera mucosa VSPA was enhanced by optimising five input parameters and increasing the biomass yield. pH, temperature, light intensity, wastewater percentage (pollutant concentration), and N/P ratio were optimised, and their effects were studied. Two competitive techniques, response surface methodology (RSM) and artificial neural network (ANN), were applied for constructing predictive models using experimental data generated according to central composite design. Both MATLAB and Python were used for constructing ANN models. ANN models predicted the experimental data with high accuracy and less error than RSM models. Generated models were hybridised with a genetic algorithm (GA) to determine the optimised values of input parameters leading to high biomass productivity. ANN-GA hybridisation approach performed in Python presented optimisation results with less error (0.45%), which were 7.8 pH, 28.8 °C temperature, 105.20 μmol m−2 s−1 light intensity, 93.10 wastewater % (COD) and 23.5 N/P ratio.

A study of basic and reactive dyes removal from synthetic and industrial wastewater by electrocoagulation process

Large-scale textile industries used large amounts of toxic chemicals which are very hazardous to human health and environmental sustainability. In this study, the removal of various dyes from effluents of textile industries using the electrocoagulation process was investigated. The studied dyes were Reactive Red 120 (RR-120), Basic Blue 3 (BB-3), and Basic Red 46 (BR-46), which were found in samples collected from effluents of three major textile factories in the Amhara region, Ethiopia. For maximum removal, the dye BB-3 required acidic pH 3, RR-120 basic pH 11, while BR-46 neutral pH 7 conditions. BB-3 required a longer treatment time of 80 min than BR-46 and RR-120, which required 30 and 40 min, respectively. The best removal efficiency of 99.5%, 93.5%, and 96.3% was achieved for BR-46, BB-3, and RR-120, respectively, from synthetic wastewater containing 10 mg l-1of each dye at an applied potential of 10 V. The method was applied to real textile wastewaters and 73.0 to 99.5% removal of the dyes was achieved, Indicating Electrocoagulation can be used as a simple, and reliable method for the treatment of real wastewater from textile industries. It is used as a potentially viable and inexpensive tool for the treatment of textile dyes Analysis of the electrochemically generated sludge by X-ray Diffraction, Scanning Electron Microscope, and Fourier Transform Infrared Spectroscopy revealed the expected crystalline aluminum oxides (bayerite (Al(OH)3 diaspore (AlO(OH)) found in the sludge. The amorphous phase was also found in the floc. Textile industry owners should be aware of the impact of the discharge of effluents on the Ecosystem and should use the investigated electrocoagulation method for effluent treatment before discharging into the environment.

Effect of the Standardized ZnO/ZnO-GO Filter Element Substrate driven Advanced Oxidation Process on Textile Industry Effluent Stream: Detailed Analysis of Photocatalytic Degradation Kinetics.

A simple process of synthesizing coated filter element substrates (FES) containing zinc oxide (ZnO) nanorods and ZnO graphene-oxide nanocomposite for a pilot-scale industrial dye-effluent treatment plant is proposed. This work reports a detailed analysis of the photocatalysis mechanism on real industrial effluent streams containing a mixture of dyes. The analysis is very relevant for conducting advanced oxidation process-assisted effluent remediation at a field-level treatment operation. Estimation of the dye concentration shows nearly complete (≥98%) degradation from an initial dye sample concentration. A detailed study for the analysis of the initial reactive dyes and their degradation products was performed for quantification and identification of the degradation products through various spectral techniques. A design of the remediation mechanism through degradation pathways is proposed for characterizing the organic compounds in the degraded dye products. A regeneration and reusability study was performed on the FES presenting the durability of the FES-designed synthesis process originally for 11 cycles and regenerated FES for six cycles for achieving a threshold of 60% degradation efficiency. The experimental results demonstrate the efficacy of FES through the designed immobilized approach for the complete remediation of textile dye effluents for a 4 h treatment plant process and the consistent operability of the FES for the combined dye wastewater treatment operations.

Isolation, Identification and Molecular Characterization of Indigenous Bacterial Isolates from Textile Effluent and Contaminated Soil using 16s rRNA Sequencing

Textile industry effluent poses a serious environmental threat. Many physical and chemical methods for treating wastewater have been used, but due to high operating costs, a suitable alternative is required. As a result, the study focuses on the use of biological organisms with bioremediation potential which leads to the development of cost-effective and nontoxic methods. The present study focuses on the isolation of possible bacterial isolates from textile effluent contaminated soil and effluent. A total of four bacterial isolates were successfully isolated, three from textile industry effluent contaminated soil and one from textile industry effluent. Based on the results of morphological, biochemical and molecular datasets, the current study identified bacterial isolates belonging to three genera: Brevibacillus, Achromobacter and Pseudomonas. The 16S rRNA sequence technique was used to characterize and identify the bacterial isolates. The isolates were submitted to GenBank like Achromobacter xylosoxidans KUESCCHK-6, Pseudomonas aeruginosa KUESCCHK-5, Achromobacter insuavis KUESCCHK-7 and Brevibacillus panacihumi KUESCCHK-8 with accession numbers OM475749, OM475764, OL797980 and OM475766 respectively. Bacteria can survive in contaminated environments because of their metabolic ability to use available resources and ability to find a suitable niche.

Fabrication of engineered biochar-iron oxide from date palm frond for the effective removal of cationic dye from wastewater

Wastewater containing dye is harmful to the environment. Methylene blue (MB) dye can be removed from wastewater using low-cost, renewable adsorbents. In this study, modified biochar (Biochar-FexOy), pristine biochar and FexOy were fabricated, characterized, and investigated for their performance to remove MB dye from wastewater. The Biochar-FexOy (85.1 mg/g) showed increased adsorption capacity in comparison to biochar (60.1 mg/g) and FexOy (50 mg/g) at an optimum pH of 8 due to the increase in surface area, porosity, and deposition of metal ions on its surface for adsorption. The enhanced MB adsorption by the Biochar-FexOy can be attributed to electrostatic attraction, hydrogen bonding, π-π interactions, and possible cationic exchange as evidenced by the result of the FTIR, EDX, and XRD analysis. Moreover, the adsorption of MB dye by the Biochar-FexOy showed an antagonistic effect in the presence of NaHCO3− and NaCl salt but showed a synergistic effect in the presence of Cu (II) ions. The Langmuir and pseudo-second-order isotherm model best describe the adsorption process of MB dye over the Biochar-FexOy. The adsorption capacity was still high after 4 regeneration cycles for the Biochar-FexOy which concludes that modified biochar can be effectively utilized for dye wastewater treatment. Finally, the fixed-bed column adsorption performance demonstrated that Biochar-FexOy could be used to polish real secondary textile industry effluents prior to treatment.

Eco-friendly biological degradation and detoxification of congo red dye indigoes monospecies and mixed culture of bacterial strains isolated from textile industrial effluents

Eco-friendly biological degradation and detoxification of congo red dye indigoes monospecies and mixed culture of bacterial strains isolated from textile industrial effluents

Determination of the Optimum Conditions for Removal of Congo Red Dye by Peroxidase Enzyme Plant

The pollution producing from textile industries effluents is growing since the years, due to at discharged lots of it in water without treatment. The resulting effluent is colourful, highly toxic, and poses a significant environmental hazard. This problem can be solved by using enzymic biological treatment, where the Congo red dye was used with concentrations (100,200,300,500) mg /L, pH values (3,4,5,6,7,8), and variable temperatures (25,35,45)°C, the best removal of Congo red (CR) dye under optimum conditions for degradation was at concentration of 100 mg/L, at (pH 6, 25 °C) with efficiency of 99.85 % using the peroxidase enzyme extracted from red radish plant, while the removal percentage decreased when increase dye concentration .

Bio-mediated synthesis of CuO nano bundles from Gomutra (cow urine): Synthesis, characterization, photodegradation of the malachite green dye and SBH mediated reduction of 4-nitrophenol

We synthesized CuO nano bundles-like structures from Gomutra (cow urine). Urea and uric acid, which are present in the gomutra, act as reducing and capping agents, resulting in unique CuO nano bundles-like structure formation. No such morphological formation was observed from synthetic urea. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDAX), UV–Visible, Fourier transforms infrared (FT-IR), Brunauer -Emmett-Teller (BET), and (photoluminescence) PL-Spectrofluorometer were used to analyze bio-mediated synthesized CuO nano bundle-like structures. From XRD analysis, the CuO nano bundle exhibits a monoclinic system with an average crystalline size of 15.76 nm. SEM results signified nano bacillus-like structures, resembling nano bundle-like designs in aggregate. EDAX anticipated the presence of only Cu and O atoms. FT-IR validates the existence of Cu and O bonds. The band gap was calculated using the DRS [Diffused reflectance mode] technique, and the value was found to be 1.29 eV. The BET and BJH [Barret-Joyner-Halenda] analysis estimated the surface area and pore size to be 28.24 Cm3/g and 11.5 nm. Intense emission peaks are seen at 465 nm from the PL spectrometer. Electron-hole transfer behavior in CuO nano bundles stemmed from Electrochemical impedance spectroscopy (EIS technique). The photocatalytic performance of malachite Green was examined in an aqueous medium, and degradation efficiency was found to be 98.2% in 70 min [min] with a rate constant of 0.0303 min−1. The catalyst ensured good activity for up to five cycles and was also found to be stable from SEM and XRD results. In addition, intermediated products were analyzed by the LC-MS, Electron Spin Resonance (ESR), and TOC [Total organic carbon] techniques. Required supporting evidence was elucidated in the Schematic pathway. CuO nano bundles also exhibited good catalytic behavior for reducing 4-nitrophenol in the ultrasonication method at room temperature with the whole reduction of nitro groups was proven by UV– Visible, FT-IR, and LC-MS technique, and the rate constant was found to be 0.3142 min−1. The present result clearly highlights that CuO nano bundles synthesized using gomutra can play a critical role in removing hazardous dyes from effluents of textile and dye industries. Further expanding the application of these nano bundles will promote an effective complementary and alternative strategy for treating refractory pollutants from wastewater.

Adsorption linked fungal degradation process for complete removal of Lanasyn olive dye using chemically valorized sugarcane bagasse

Textile dye effluents have been reported for many deleterious effects; therefore, it is essential to remove before releasing into waterbodies. A two-step agro-waste-based technology for the remediation of a textile dye Lanasyn olive was developed in this study. The first step involved the chemical modification of agro-waste sugarcane bagasse (SCB) with a natural acid (alginic acid). The modified SCB was used for the column bed preparation and adsorptive removal of the dye. In the second step, SCB used for dye removal was decolorized through a fungus Pleurotus sp. to produce a dye-free SCB with a potential for application as manure. To evaluate the efficacy of the column device, parameters like removal percentage, and adsorption capacity were determined. There was 90% removal of dye in aqueous dye solution and 83% removal in dye spiked textile industry effluent. To comprehend the column properties, three non-equilibrium models—Thomas, Yoon-Nelson, and Adams-Bohart—were used. Among the models applied, Adams-Bohart fitted well with the obtained data. Dye bioremediation efficiency by Pleurotus sp. was assessed by studying the deviation in absorption maxima, dye decolorization on the agar plate, Fourier-transform infrared spectroscopy (FTIR). The fungus-treated SCB showed no signs of residual toxicity towards alga Chlorella vulgaris. The carbon, hydrogen, nitrogen, sulfur (CHNS) profile examination of spent SCB revealed significantly improved nitrogen content after the treatment (from 0.35% to 0.69%). The prototype of the column, chemical valorization of SCB, and degradation of dye-adsorbed SCB through Pleurotus sp. provides a green solution for the safe disposal of textile dye through a novel agro waste-based treatment process.

Facile synthesis and physicochemical characterization of κ-Carrageenan-silver-bentonite based nanocatalytic platform for efficient degradation of anionic azo dyes

Water pollution due to textile industry effluents is a global concern that warrants versatile research solutions for degrading them, and for a sustainable environment. In the present work, by using the imperative role of nanotechnology, a facile one-pot synthesis has been devised to generate κ-carrageenan capped silver nanocatalyst (CSNC), and was immobilized on 2D bentonite (BT) sheets to generate nanocatalytic platform (BTCSNC) for the degradation of anionic azo dyes. The nanocomposite(s) were physicochemically characterized using UV–Vis, DLS, TEM, FESEM, PXRD, ATR-FTIR, TGA, BET and XPS etc., to obtain insights into the nanocomposite composition, structure, stability, morphology and mechanism of interaction. The obtained CNSC are monodispersed, spherical with a size of 4 ± 2 nm, and were stabilized by the functional groups (-OH, COO‾, and SO3‾) of κ-Crg. The broadening of peak corresponding to basal plane (001) of BT montmorillonite in PXRD spectra established its exfoliation upon addition of CSNC. XPS and ATR-FTIR data evidenced the absence of covalent interactions between CSNC and BT. The catalytic efficiency of CSNC and BTCSNC composites were compared for the degradation of methyl orange (MO) and congo red (CR). The reaction followed a pseudo first order kinetics, and immobilization of CSNC on BT resulted in a 3–4 fold enhancement in degradation rates. The rates achieved for the degradation kinetics are: MO degradation within 14 s (Ka 9.86 ± 2.00 min−1), and CR degradation within 120 s (Ka of 1.24 ± 0.13 min−1). Further, a degradation mechanism has been proposed by analyzing the products identified through LC-MS. The reusability studies of the BTCSNC evidenced the complete activity of the nanocatalytic platform for six cycles, and gravitational separation method for catalyst recycling. In a nutshell, the current study provided an environmentally friendly, sizable, and sustainable nano catalytic platform” for the remediation of industrial wastewater contaminated with hazardous azo dyes”.

Sustainable and efficient removal of cationic, anionic and neutral dyes from water by pre-deposited vinasse biochar membrane

This study demonstrated a simple and sustainable approach for removing dyes from water through a new pre-deposited vinasse biochar (PDVB) membrane, which was developed by single-step deposition of vinasse biochar powder on a filter paper support via vacuum pumping. The PDVB membrane combined advantages of adsorption and membrane filtration processes in one-stage. Performance of the PDVB membranes with water-wettable surface was examined on methylene blue (as a model dye) solution as functions of pyrolysis temperature, amount of biochar on the membrane unit area, solution pH, initial concentration and temperature of dye solution in a dead-end filtration mode. The best performance (removal efficiency >99%, flux: 8017 L/(m2.h)) was obtained at a wide pH range (2−11) by using membrane (7.95 mg biochar/cm2, derived from pyrolysis of vinasse at 900 °C). Moreover, initial dye concentration and solution temperature had no considerable effect on membrane performance, which was stable even after ten cycles of filtration-regeneration by ethanol-washing. At pH 2, the membrane was also quite good at removing Congo red (anionic dye) with efficiency of 98%, which decreased when increasing pH from 2 to 11. Behavior of membrane towards dyes with different characteristics was explained by considering high surface area (756 m2/g) of the biochar and phenomenon, including aromatic stacking and electrostatic-attraction between dye molecule and biochar surface. All findings and application to a real textile industry effluent demonstrated that developed membrane was easy-to-use and sustainable material for effective treatment of water and wastewater containing dyes with different molecular weights and ionic characteristics.

Sonochemical synthesis of Ce-TiO2 nanocatalyst and subsequent application for treatment of real textile industry effluent

Treatment of real textile industry effluent using photocatalysis, sonocatalysis, sonophotocatalysis and H2O2 assisted sonophotocatalysis have been studied based on the use of Ce-TiO2 nanocatalyst synthesized using sonochemical co-precipitation method. Characterization studies of the obtained catalyst revealed crystallite size as 1.44 nm with particles having spherical morphology. A shift of the absorption edge to the visible light range was also observed in UV–Vis diffuse reflectance spectra (UV-DRS) analysis. The effects of different operational parameters viz catalyst dose (0.5 g/L-2 g/L), temperature (30 °C-55 °C) and pH (3–12) on the COD reduction were studied. The reduction in the COD was higher at lower pH and the optimum temperature established was 45 °C. It was also elucidated that the required catalyst dose was lesser in combined sonophotocatalysis when compared with individual photocatalysis and sonocatalysis. Combination of processes and addition of oxidants increased the COD reduction with the sonophotocatalytic oxidation combined with H2O2 treatment showing the best results for COD reduction (84.75%). The highest reduction in COD for photocatalysis was only 45.09% and for sonocatalysis, it was marginally higher at 58.62%. The highest reduction in COD achieved by sonophotocatalysis was 64.41%. Toxicity tests coupled with Liquid Chromatography Mass Spectrometry (LC-MS) analysis revealed that there were no additional toxic intermediates added to the system during the treatment. Kinetic study allowed establishing that generalized kinetic model fits the experimental results well. Overall, the combined advanced oxidation processes showed better results than the individual processes with higher COD reduction and lower requirement of the catalyst.

Sunlight-driven photocatalytic degradation of ciprofloxacin and organic dyes by biosynthesized rGO–ZrO2 nanocomposites

Aquatic ecology has been greatly threatened by the discharge of effluents of textile and antibiotic industries into natural waters. Herein, an efficient and easily recycled reduced graphene oxide/zirconium oxide nanocomposite has been synthesized using banana peel extract (abbreviated as rGO-ZrO2 in this work). The X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), UV-visible diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy were used to analyze the synthesized material. The as-prepared rGO-ZrO2 nanocomposite was employed as a photocatalyst for the decomposition of rhodamine blue (RhB) and crystal violet (CV) dyes, and ciprofloxacin (CIP) antibiotic by illumination with direct sunlight. The RhB and CV were degraded to maximum extent of around 86 and 90%, respectively, over the rGO-ZrO2 nanocomposite after exposure to direct sunlight for 120min. On the other hand, the degradation of CIP was approximately 93.1% over the rGO-ZrO2 nanocomposite in 240min under same experimental conditions. Further studies were performed regarding the role of parameters like pH, catalyst dose, and scavengers, in order to understand the superiority of rGO-ZrO2 nanocomposite in degrading organic pollutants. Moreover, the intermediate products and plausible CIP degradation mechanisms were examined using liquid chromatography-mass spectrometry (LC-MS). Moreover, the catalyst was easily separated from the solution and demonstrated good stability and reusability. The RhB, CV, and CIP removal efficiency were 80%, 83%, and 88%, respectively, after five cycles.

Efficient detoxification of textile wastewater by applying Chenopodium album nanoparticles and its application in simulated metal-bearing effluents removal.

Large-scale pollution of water and soils bodies is associated with the discharge of the untreated textile industry effluents. Halophytes grows on saline lands and accumulate secondary metabolites and other stress protective compounds. Utilization of Chenopodium album (halophytes) to synthesize zinc oxide (ZnO) and their efficiency to treat different concentrations of textile industry waste water is proposed in this study. Potential of nanoparticles textile industry waste water effluents was also analyzed by exposing different concentrations of nanoparticles (0 (control), 0.2, 0.5, 1mg) and time intervals of 5, 10, and 15days. The absorption peaks by UV region, FTIR and SEM analysis were used characterized on ZnO NPs for the first time. FTIR analysis showed the preens of various functional groups and vital phytochemicals that can play its role in the formation of nanoparticles that can be used for trace elements removal and bioremediation. SEM analysis indicated that the pure ZnO NPs synthesis ranged from 30 to 57nm. Results shows that the green synthesis of halophytic nanoparticles presents maximum removal capacity after 15days exposure to 1mg of ZnO NPs. Hence, the prepared ZnO Nps from halophytes can be a viable solution for treating the textile industry effluents before they are discharged into water bodies for sustainable environmental growth and environmental safety.

Adsorption of methylene blue from textile industrial wastewater using activated carbon developed from Rumexabyssinicus plant

Methylene blue (MB) is abundantly found in textile industrial effluent which can cause severe health problems for public and environmental ecology. Therefore, this study aimed to remove MB from textile wastewater using the activated carbon developed from Rumexabyssinicus. The adsorbent was activated using chemical and thermal methods, and then it was characterized by SEM, FTIR, BET, XRD, and pH zero-point charge (pHpzc). The adsorption isotherm and kinetics were also investigated. The experimental design was composed of four factors at three levels (pH (3, 6, and 9), initial MB concentration (100, 150, and 200 mg/L), adsorbent dosage (20, 40, and 60 mg/100 mL), and contact time (20, 40, and 60 min)). The adsorption interaction was evaluated using response surface methodology. The characterization of a Rumexabyssinicus activated carbon was found to have multiple functional groups (FTIR), an amorphous structure (XRD), crack with ups and down morphology (SEM), pHpzc of 5.03 and a high BET-specific surface area of 2522 m2/g. The optimization of MB dye removal was carried out using the Response Surface methodology coupled with the Box Behnken approach. The maximum removal efficiency of 99.9% was recorded at optimum conditions of pH 9, MB concentration of 100 mg/L, the adsorbent dosage of 60 mg/100 mL, and contact time of 60 min. Among the three adsorption isotherm models, the Freundlich isotherm model was the best fit with an experimental value at R2 0.99 showing the adsorption process was heterogeneous and multilayer whereas the kinetics study revealed that pseudo-second-order at R2 0.88. Finally, this adsorption process is quite promising to be used at an industrial level.

Adsorption of textile dyes from aqueous solutions onto clay: Kinetic modelling and equilibrium isotherm analysis.

The commercial activated carbon commonly uses to reduce of dye amount in the textile industry effluents. In this study has focused on the use of a natural clay sample as low cost but potential adsorbent. For this purpose the adsorption of commercial textile dyes, Astrazon Red FBL and Astrazon Blue FGRL, onto clay was investigated. The physicochemical and topographic characteristics of natural clay sample were determined by scanning electron microscopy (SEM), X-Ray fluorescence spectrometry (XRF), X-Ray diffraction (XRD), thermogravimetric analysis (TGA), and cation exchange capacity measurements. It was determined that the major clay mineral was smectite with partial impurities. The effects of several operational parameters such as contact time, initial dye concentration, temperature, and adsorbent dosage on the adsorption process were evaluated. The adsorption kinetics was interpreted with pseudo-first order, pseudo-second order, and intra-particle diffusion models. The equilibrium adsorption data were analyzed using Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherm models. It was determined that the adsorption equilibrium was reached in the first 60min for each dye. The amount of adsorbed dyes onto clay decreased with increasing temperature, similarly, it decreased with increasing sorbent dosage. The kinetic data were well described by pseudo-second order kinetic model, and adsorption equilibrium data was followed both Langmuir and Redlich-Peterson models for each dyes. The adsorption enthalpy and entropy values were calculated as -10.7kJ.mol-1 and -13.21J.mol-1.K-1 for astrazon red and those for astrazon blue -11.65kJ.mol-1 and 37.4J.mol-1.K-1, respectively. The experimental results support that the physical interactions between clay particles and dye molecules have an important role for the spontaneous adsorption of textile dyes onto the clay. This study revealed that clay could effectively be used as an alternative adsorbent with high removal percentages of astrazon red and astrazon blue.

Adsorptive Removal of Reactive Yellow 145 Dye from Textile Industry Effluent Using Teff Straw Activated Carbon: Optimization Using Central Composite Design

This study aimed to optimize the preparation condition of activated carbon using Teff straw as a precursor material via evaluating its potential in terms of maximizing the adsorptive removal of Reactive Yellow 145 dye (RY 145) from aqueous solutions. Selective factors, such as activation time, activation temperature, and impregnation ratio on the preparation of Teff Straw-based Activated Carbon (TSAC) were optimized using response surface methodology (RSM). A quadratic regression model with estimated coefficients was developed by RSM and it was observed that model predictions were matched with experimental value with an acceptable R2 value (0.98). Further, the TSAC prepared at optimal condition was characterized using Fourier-transform infrared (FTIR), Scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. The TSAC prepared at optimal condition showed anionic nature with a BET surface area of 627.7 m2/g. In addition, important adsorptive parameters (contact time, solution pH, adsorbent dose, and dye concentration) were evaluated through batch experiments. In such a way, it was determined that 2 h for activation time, 539 °C for activation temperature, and impregnation ratio of 5 g of phosphoric acid per 1 g of TSAC were optimal for efficient adsorption with maximum removal of 98.53% for RY 145 dye. In addition, the TSAC was subjected to test in order to determine its adsorptive performance by treating real textile industry effluent for examining its Chemical Oxygen Demand (COD) removal potential. The results showed that 76% COD was removed from the real textile effluent, which met Ethiopian Environmental Protection Authority (EPA) standard. The finding of this paper asserts that this material is a good and low-cost bio-sorbent that can be used for the removal of pollutants from textile wastewater. Nevertheless, additional investigations of the adsorbents including regeneration options are advisable to draw explicit conclusions.

Synthesis of copper‐oxide nanoparticles from Euphorbia antiquorum extract and evaluation of its dye degradation capacity

AbstractDye discharge from industrial textile effluent is hazardous to the environment. Hence, the removal of dye has become important as it affects both human and aquatic life, even if it is present in minimal amounts. In comparison to the physio‐chemical technique, photocatalytic degradation of the dye using nanoparticles that are generated biologically provides a feasible method for the breakdown of environmental pollutants. Unlike other metal oxides, Copper oxide nanoparticles (CuONPs) have attracted the attention of many researchers due to their potential to act as photocatalyst and also because of their enormous surface area. Euphorbia antiquorum (triangular spurge) is a common thorny succulent found all over peninsular India, primarily in dry areas. The aqueous extract of the selected plant was employed to synthesis CuONPs, which were then analyzed using SEM‐EDX, FTIR, XPS, and XRD. The present study describes how CuONPs derived from the extract of E. antiquorum degrade major commercial dyes such as Congo Red (CR), Coomassie Brilliant Blue (CBB R‐250 dye, and Reactive Black (RB). The photocatalytic degradation efficiency of synthesized CuONPs has been demonstrated for a wide range of dyes used in the textile industry. Dye degradation of RB using synthesized CuONPs showed 93% efficiency.

Preparation and Physio–Chemical characterisation of activated carbon derived from prosopis juliflora stem for the removal of methylene blue dye and heavy metal containing textile industry effluent

An experimental work endeavoured and presented in this article focuses on the removal of Methylene Blue (MB) dye and Heavy Metals (HM) such as lead and copper from textile industry effluent by the adsorption process with ZnCl2-activated carbon. Initially, carbon was prepared using the cheapest and environmentally hazardous precursor of Prosopis Juliflora plant (Stem) and called Prosopis Juliflora Stem Carbon (PJSC). Then the PJSC was chemically activated by impregnating ZnCl2 with a ratio of 1:0.5 at a temperature of 800 °C in muffle furnace about 1 h and named as ZnCl2-activated Prosopis Juliflora Stem Carbon (ZAPJSC). The physio–chemical characteristics such as yield, pH, conductivity, bulk density, moisture content, ash content, volatile matter, fixed carbon content, as well as solubility in acid and water were calculated. Surface textures of PJSC and ZAPJSC were characterised by Scanning Electron Microscopy (SEM); functional group characterisation was performed by Fourier Transform Infrared Spectroscopy (FTIR); elements in the adsorbents were identified by Energy Dispersive X-Ray Analysis (EDX); and Brunauer-Emmett-Teller (BET) surface area analysis was carried out to find the surface area, pore volume, and pore radius of the adsorbents. Surface area was found to be 252.730 m2/g which showed that ZAPJSC was having enormous bores meanwhile surface area of PJSC was 85.508 m2/g. In this context, the central composite design (CCD) approach-based response surface methodology (RSM) was performed to investigate and optimise the effects of process parameters on the adsorption of MB by ZAPJSC. The optimum level of process parameters such as contact time of 5.4 min and dosage of 85 mg were achieved with MB adsorption efficiency of 99.05%. Further, pseudo-first-order and pseudo-second-order models were used to fit the present experimental data. Pseudo-second-order rate equation was perfectly fit to provide a realistic description of adsorption kinetics. Equilibrium isotherms were investigated by Langmuir and Freundlich equations. Langmuir equation was found to best represent the equilibrium data for MB-ZAPJSC system. Thermodynamic study showed that the adsorption of MB on ZAPJSC (with a more negative Gibbs free energy value) was more favoured. Next, batch adsorption experiments for methylene blue dye and heavy metals (lead, copper, manganese, iron, cobalt) were carried out as parameters of effect of contact time and adsorbent dosage. Lastly, ZAPJSC adsorbent showed a reuse efficiency of 73.34% after four consecutive adsorption-desorption cycles in MB removal. These results indicate that the ZAPJSC could provide base for more low-cost activated carbon to be used as adsorbents for MB dye removal and heavy metals.

A bimetallic nanocatalyst from carbonaceous waste for crystal violet degradation

The contamination of wastewater by cationic dyes has caused considerable environmental problems, such as an imbalance in the aquatic ecosystem and a decrease in photosynthetic activity. In this context, this study aims to synthesize and characterize a bimetallic nanocatalyst (MMT@TiO2-NPs/ZnO-NPs), as well as to evaluate its photocatalytic activity in crystal violet (CV) dye degradation. The samples were characterized by X-ray diffraction (XRD), Field Emission Gun – Scanning Electron Microscope (FEG-SEM), N2 physisorption (BET/BJH methods), UV–Vis Diffuse Reflectance Spectroscopy (DRS), zeta potential (ZP), and zero charge point (pHZCP). Central composite rotational design (CCRD 2³) was used for the experimental design to obtain the ideal condition. The diffractograms showed characteristic peaks of MMT (analcime and neighborite), ZnO-NPs (zincite) and TiO2-NPs (anatase) with an average crystallite size determined in the range of 10–50 nm. The MMT@TiO2-NPs/ZnO-NPs showed a high surface area (98.8 ± 0.6 m2 g−1) with IV-type isotherm characteristic of porous materials. Moreover, a heterogeneous morphology with an average particle size of around 16 nm. ZP showed a negative charge (−3.84 ± 0.07 mV) and pHZCP ≈ 5.80, favoring interactions with the CV dye. Ideal condition was [CV] = 32.5 g L−1, [MMT@TiO2-NPs/ZnO-NPs] = 1.75 g L−1 and pH = 12, with a CV removal of 99.97% (k = 0.0789 min−1) under visible radiation. Regarding reuse, MMT@TiO2-NPs/ZnO-NPs showed great photocatalytic stability after six cycles with 90.62% for the CV degradation. Therefore, MMT@TiO2-NPs/ZnO-NPs showed great potential for use in the treatment of industrial textile effluents, helping in the waste management strategy from mid-to long-term perspectives.