Industrial Wastewater Effluents Research Articles

Synthesis and characterization of AlxCu0.7Mn0.3Fe2-xO4 ferrite and its application in adsorption of dyes

The increasing presence of artificial dyes in industrial wastewater has necessitated the development of efficient and sustainable adsorption materials. This work explores the synthesis and characterization of Al-doped Cu-Mn (AlxCu0.7Mn0.3Fe2-xO4, where x = 0.1, 0.3, 0.5, 0.7, and 0.9) ferrite as a new adsorbent for the removal of dyes from aqueous solutions. The Al-doped Cu-Mn ferrite was prepared using the solution combustion method and meticulously characterized using various physiochemical techniques, including scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffractometer (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmer-Teller (BET). Adsorption studies tested the material's ability to remove hazardous dyes such as congo red, methyl orange, methylene blue, and crystal violet from aqueous solutions. The effects of various parameters, including temperature, contact time, and initial dye concentration, were systematically studied. To understand the mechanism of interaction between the adsorbent and the dyes, the adsorption isotherms were examined using the Langmuir, Temkin, D-R, and Freundlich models. The Freundlich isotherms provided the best fit for the experimental data. To clarify the kinetics of the adsorption process, kinetic experiments were conducted using pseudo-first and pseudo-second-order. According to the results of the kinetics analysis, pseudo-second-order kinetics fit the data better, with a higher coefficient of determination values (R2 = 0.981, 0.983, 0.984 & 0.984). Thermodynamic parameters, including enthalpy, Gibbs free energy, and entropy changes, were calculated to determine the nature of the adsorption process, and the result demonstrates that the adsorption process was endothermic and naturally spontaneous. The results indicate that Al-doped Cu-Mn ferrite exhibits high adsorption capacities and favourable thermodynamic properties, making it a promising material for the removal of dyes from industrial wastewater effluents. The study contributes to the field by providing insights into the adsorption mechanisms and potential applications of Al-doped Cu-Mn ferrite in environmental remediation.

Enhanced photocatalytic performance of rGO/UiO-66(Zr)/Ag3PO4 composite for degradation of methyl orange (MO) under visible light irradiation

Industries like textile, plastic, pulp, and paper produce dye-containing waste waters that have harmful effect on the environment as well as human health. This work presents a series of binary and ternary composites formed by reduced graphene oxide (rGO), silver phosphate (Ag3PO4) and the nanocrystalline MOF, UiO-66(Zr). The composites exhibit the best of their catalytic features to achieve efficient photocatalysis to remove the model dye methyl orange (MO) from aqueous solution as well as dyes from a real industrial wastewater effluent. The composites were prepared under sustainable conditions, at room temperature. XRD characterization shows that the prepared MOF is one of the most nanocrystalline reported UiO-66(Zr), becoming even more nanocrystalline in the composite formation. Different physicochemical characterization techniques indicated the existence of such interaction. Thus, DRS-UV-vis spectroscopy makes clear the reduction of the band-gap of the composites compared with the individual components; the band intensity of the photoluminescence (PL) spectra is substantially reduced in composites, confirming the diminution of electron-hole recombination; and electrochemical impedance spectroscopy (EIS) shows that the electrodes modified with ternary composites present faster electron transfer ability. The selected composite rGO/UiO-66(Zr)/Ag3PO4 exhibits high efficiency on the photodegradation of the model MO dye compared to the binary and single counterparts. It could be attributed to its high surface area, enhanced visible light absorption, efficient charge transfer process, as well as the synergetic effect between its components. A degradation mechanism is proposed based on the estimated band-gaps and on the scavenging study with strategically-chosen species.

Environmental Pollution Monitoring via Capillary Zone Electrophoresis and UHPLC Simultaneous Quantification of Some Antipsychotic Drug Residues in Industrial Wastewater Effluents

Monitoring and measuring pharmaceutical pollutants in environmental samples is a vital and complex task due to their potential detrimental effects on human health, even at low levels. Using capillary zone electrophoresis (CZE) and ultra-high-performance liquid chromatography (UHPLC), it was possible to separate and measure three commonly used antipsychotic drugs, chlorpromazine (CPZ), haloperidol (HAL), and risperidone (RIS), in wastewater of the pharmaceutical industry. The technique of solid-phase extraction (SPE) was developed and implemented as a very effective method for preparing samples prior to analysis. The settings of the capillary electrophoretic and chromatographic techniques were adjusted to obtain the most efficient separation profile for the medications being studied. The concentration of all the medicines being investigated ranged from 0.5 to 50 µg/mL. SPE was used to treat real wastewater samples after a thorough validation process that followed the rules set by ICH-Q2B. The developed assays were then effectively employed to identify the tested antipsychotic substances in the real wastewater samples. The provided methodologies may be efficiently utilized to monitor the extent of environmental contamination caused by the investigated pharmaceuticals.

Exploring Trichoderma Species in Industrial Wastewater: Morphological and Molecular Insights from Isolates.

The genus Trichoderma holds economic significance due to its widespread distribution and diverse applications, including biological control, enzyme production, and various biotechnological uses. The accurate identification of Trichoderma species is crucial given their close association with human activities. Despite previous efforts in classification, a comprehensive analysis combining morphological and molecular approaches is necessary. This study focuses on the isolation of four Trichoderma species from industrial wastewater in Pakistan, expanding on the known diversity in the region; isolation involved collecting samples from industrial wastewater effluents at specific sites in Punjab, Pakistan. Trichoderma strains were cultured and purified on solid media, with subsequent biomass production for bisorptional activity. Morphological characterization included colony features and microscopic examinations. DNA extraction, polymerase chain reaction (PCR), and sequencing of the internal transcribed spacer (ITS) region were conducted for molecular analysis. Phylogenetic analysis was performed using the Maximum Likelihood Algorithm. The study identified three Trichoderma species, viz. T. citrinoviride, T. erinaceum, and T. longibrachiatum. Each species was characterized morphologically and supported by molecular-phylogenetic analysis. Illustrations of microscopic features and a phylogenetic tree based on the ITS-nrDNA region were recorded. T. citrinoviride and T. longibrachiatum, isolated from steel mill and tanneries wastewater, respectively, were differentiated based on morphological characteristics such as phialides and conidia. The combination of morphological and molecular techniques enhances the accuracy of species identification. The study highlights the significance of Trichoderma in industrial wastewater environments and underscores the need for continued research in this area. Future research should focus on exploring the ecological roles and potential applications of the newly identified Trichoderma species. Additionally, further investigations into the biotechnological potential of these species, including enzyme production and bioremediation capabilities, would contribute to their practical applications.

Novel Crosslinked Anion Exchange Membranes Based on Thermally Cured Epoxy Resin: Synthesis, Structure and Mechanical and Ion Transport Properties.

Limitations in existing anion exchange membranes deter their use in the efficient treatment of industrial wastewater effluent. This work presents an approach to fabricating novel anion-conducting membranes using epoxy resin monomers like hydrophobic or hydrophilic diglycidyl ether and quaternized polyethyleneimine (PEI). Manipulating the diglycidyl ether nature, the quantitative composition of the copolymer and the conditions of quaternization allows control of the physicochemical properties of the membranes, including water uptake (20.0-330%), ion exchange capacity (1.5-3.7 mmol/g), ionic conductivity (0.2-17 mS/cm in the Cl form at 20 °C), potentiostatic transport numbers (75-97%), as well as mechanical properties. A relationship was established between copolymer structure and conductivity/selectivity trade-off. The higher the quaternized polyethyleneimine, diluent fraction, and hydrophilicity of diglycidyl ether, the higher the conductivity and the lower the permselectivity. Hydrophobic diglycidyl ether gives a much better conductivity/selectivity ratio since it provides a lower degree of hydration than hydrophilic diglycidyl ether. Different mesh and non-woven reinforcing materials were also examined. The developed membranes demonstrate good stability in both neutral and acidic environments, and their benchmark characteristics in laboratory electrodialysis cells and batch-mode dialysis experiments are similar to or superior to, commercial membranes such as Neosepta© AMX, FujiFilm© Type1, and Fumasep FAD-PET.

Eficiencia de los bioindicadores de toxicidad sobre contaminantes de aguas residuales industriales

In this paper, we present some important biological factors that modify the efficiency of toxicity bioindicators used to evaluate the harmful effect of industrial wastewater pollutants on biological organisms and processes, such as reproduction, growth and development. The Lactuca sativa model was analyzed and proposal for new biological parameters with fungi, bacteria, plants and animals that can be used as bioindicators of toxicity and ecotoxicity that do not directly compromise the survival of organisms in bioassays and environments contaminated with industrial wastewater effluents.

The Effects of Wastewater Reuse on Smallmouth Bass (Micropterus dolomieu) Relative Abundance in the Shenandoah River Watershed, USA.

Municipal and industrial wastewater effluent is an important source of water for lotic systems, especially during periods of low flow. The accumulated wastewater effluent flows-expressed as a percentage of total streamflow (ACCWW%)-contain chemical mixtures that pose a risk to aquatic life; fish may be particularly vulnerable when chronically exposed. Although there has been considerable focus on individual-level effects of exposure to chemical mixtures found in wastewater effluent, scaling up to population-level effects remains a challenging component needed to better understand the potential consequences of exposure in wild populations. This may be particularly important under a changing climate in which wastewater reuse could be essential to maintain river flows. We evaluated the effects of chronic exposure to wastewater effluent, as measured by ACCWW%, on the relative abundance of young-of-year (YOY), juvenile, and adult smallmouth bass (Micropterus dolomieu) populations in the Shenandoah River Watershed (USA). We found that increases in ACCWW% in the previous year and during the prespawn period were negatively correlated with the relative abundance of YOY, resulting in an average 41% predicted decrease in abundance (range = 0.5%-94% predicted decrease in abundance). This lagged effect suggests that adult fish reproductive performance may be compromised by chemical exposure during periods of high ACCWW%. No relationships between ACCWW% and juvenile or adult relative abundance were found, suggesting that negative effects of ACCWW% on YOY abundance may be offset due to compensatory mechanisms following higher ACCWW% exposure. Understanding the effects of wastewater effluent exposure at multiple levels of biological organization will help in the development of management strategies aimed at protecting aquatic life. Environ Toxicol Chem 2024;43:1138-1148. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Combined advanced oxidation dye-wastewater treatment plant: design and development with data-driven predictive performance modeling

The recalcitrant nature of the industrial dyes poses a significant challenge to existing treatment technologies due to the stringent environmental regulations. This combined with the inefficiency of a single treatment method has led to the implementation of the combination of primary, secondary, and tertiary treatment processes, which fails during complex secondary aeration processes due to variable pH loads of industrial effluent wastewater. This article presents a modified design methodology of a pilot-scale micro-pre-treatment unit using a solar-triggered advanced oxidation process reactor that both effectively controls the influent variability at the source and mitigates textile effluents for making the discharge reusable for different industrial purposes. The proposed modified combination technique of controlled serial processes inclusive of primary, secondary, and tertiary treatment steps with ZnO/ZnO-GO NanoMat-based advanced oxidation process demonstrates complete remediation of industrial grade effluent with effective reuse of the discharge. Further, a reliable prediction model for estimating water quality parameter using machine learning models are proposed. Multi-linear regression and Artificial Neural network modeling provide simple, accurate, and robust prediction capabilities, which are evaluated for the efficiency of the processes. The generated prediction models capture the output parameters within an acceptable level of accuracy (Radj2>0.90)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$({{\\boldsymbol{R}}}_{{adj}}^{{\\bf{2}}}\\, >\\, 0.90)$$\\end{document} and allow compliance with the discharge Inland Water Discharge Standards (IWDS).

Metal-organic framework-intercalated graphene oxide nanofiltration membranes for enhanced treatment of wastewater effluents

Graphene oxide membranes (GO) hold immense potential in the field of water purification. However, when applied directly to real wastewater effluents, pure GO membranes suffer from drawbacks such as fouling sensitivity and limited stability. To address these challenges and unlock the full potential of GO membranes, novel nanocomposite membranes have been developed by the intercalation of GO with nanoparticles of ZIF-8 (a type of zeolitic imidazolate framework). The prepared GO/ZIF-8 (GZ) nanocomposite membranes have exhibited enhanced hydrophilicity and exceptional water purification capabilities. Specifically, the GZ membranes have demonstrated a permeance enhancement of over two-fold when compared to the pristine GO reference membrane. This enhancement is coupled with anti-fouling performance and competitive rejection rates for both salts and organic pollutants. GZ membranes have been effectively employed for the purification by cross-flow filtration of 3 industrial wastewater effluents. They have shown improved separation performance compared to the pristine GO reference membrane, and high stability under cross-flow conditions. The origin of the high performances of the GZ membrane has been clarified using structural and morphological analyses. This work highlights the significant progress made in the field of water treatment using graphene-based membranes.

Green synthesis of magnetic chitosan composite hydrogel (Fe3O4@CS photocatalyst) for the solar light driven catalytic degradation of organic contaminants

Ecofriendly magnetic chitosan composite hydrogel (Fe3O4@CS photo-catalyst) was prepared by using an aqueous extract of Boerhevia procombens leaves for the solar light mediated catalytic degradation of lethal organic Congo red dye. The prepared composite hydrogel was structurally studied using Fourier transform infrared spectroscopy (FT-IR) which reveals the formation of the Fe3O4@CS photocatalyst. The X-ray diffraction (XRD) investigation of the composite hydrogel signified high crystallinity of photocatalyst and crystallite structure of 53 nm for magnetite nanoparticles (Fe3O4 NPs). The surface investigation suggests multilayered porous photocatalyst owing to the presence of cavities offering more photoactive sites for the photodecomposition of dye molecules. The energy dispersive X-ray (EDX) scanning supports the fabrication of Fe3O4@CS photocatalyst due to the perseverance of carbon, nitrogen, oxygen, and iron. The thermogravimetric analysis (TGA) together with vibrating sample magnetometry (VSM) certifies the preparation of thermally stable and magnetic composite hydrogel. The fabricated Fe3O4@CS photocatalyst possess low bandgap energy of 2.36 eV, supporting the excellent disintegration of dye molecules in the sunlight irradiations. The photocatalyst exhibited a maximum degradation efficacy of 99.1% for Congo red dye in the solar light irradiations with refined states of 70 min radiation time, dye concentration of 20 mg/L, pH 6, and 200 mg photocatalyst amount obeying the second-order kinetic model (R2 = 0.9959). The Fe3O4@CS photocatalyst displayed a little decrease in dissociation efficiency of dye molecules after five repeated cycles owing to the coverage or rupturing of photoactive sites. Conclusively, the results support Fe3O4@ CS to be an economical and biocompatible magnetic catalyst for the catalytic decontamination of Congo red dye molecules and other organic contaminants in domestic and industrial wastewater effluents.

Assessment of Industrial Wastewater on Environment and Human Health in Nigeria: Effects and Treatments

This paper aims to examines the environmental and health impacts of untreated industrial wastewater effluents in Nigeria. Industrial wastewater is frequently dumped into the environment in underdeveloped nations such as Nigeria with minimal or no treatment, resulting in serious environmental and health issues. Untreated or improperly treated effluents degrade water bodies by promoting eutrophication and creating circumstances conducive to dangerous microorganisms and toxin-producing cyanobacteria. This poses a risk to relaxation center water users and may result in epidemics of water-borne infections. Furthermore, wastewater frequently contains toxic anthropogenic substances, including those that alter endocrine systems. To counteract these effects, it is critical to develop proper wastewater treatment techniques, follow regulations, and conduct regular monitoring.

Microfibres Release from Textile Industry Wastewater Effluents Are Underestimated: Mitigation Actions That Need to Be Prioritised

The release of microfibres (MFs) from textiles has been observed in various environments, pointing towards the impact of human activities on natural systems. Synthetic textile microfibres, a subset of microplastic fibres (MPFs), are reported to be the primary contributor to microplastic pollution. With the forecasted growth in textile production, the problem of MF pollution is expected to worsen and become more challenging to address. Wastewater treatment plants (WWTPs) are crucial in managing microfibre pollution as they can act as a sink and source of these pollutants. Studies have shown that textile industrial effluent can contain MFs at a rate of up to a thousand times higher than municipal wastewater. As more garments are made than sold and worn, the impact of industrial MF release could be higher than predicted. The detection and quantification of microfibres released in industrial wastewater effluents do not have a standard test method, and legislation to address this issue is not yet feasible. To tackle this issue, it is crucial to raise awareness in the industry and tackle it using a more holistic approach. With its urgency, but still being an underdeveloped research area, priorities for mitigation actions are examined where efforts are needed to accelerate. These include the need to raise awareness and encourage more investigations from industry and academia. A consistent protocol will help us to compare studies and find solutions of high impact and measure MFs in WWTPs, which can help define the maximum limit for MF releases and support legislation implementation.

Assessing industrial wastewater effluent toxicity using boosting algorithms in machine learning: A case study on ecotoxicity prediction and control strategy development

Trace heavy metals have a tendency to persist in the effluent of industrial wastewater treatment facilities, leading to toxic effects on downstream water bodies. Traditional assessment methods relied on animal testing, but ethical concerns have rendered them unacceptable. An alternative solution is to evaluate wastewater toxicity using trophic-level aquatic organisms as bioassays. However, these bioassay methods involve costly and time-consuming chemical and biological analytical experiments. In this study, an artificial intelligence-powered water quality assessment (AiWA) approach is proposed for predicting industrial effluent ecotoxicity to further enhance the quick and cost-effective ecotoxicity assessment process. Initially, 99 samples were collected from industrial wastewater treatment plants representing 21 different industries in the Republic of Korea. Fourteen parameters were measured, encompassing both physicochemical and ecotoxicological aspects. Boosting algorithms, especially extreme gradient boosting (XGBoost) and adaptive boosting (AdaBoost), were employed for model development. XGBoost outperformed AdaBoost in terms of model performance. Feature selection analysis revealed that conductivity, copper, lead, selenium, pH, and zinc concentrations were the most suitable inputs for training the boosting model. The innovated XGBoost-based AiWA model demonstrated significantly higher performance (i.e., up to 80%) compared to conventional models with an R2 value of exceeding 0.94 and root mean square error of 3.5 toxicity unit for predicting the integrated toxicity unit (ITU). Additionally, pH and conductivity emerged as crucial indicators for reflecting ecotoxicity levels. Specially, this case study indicated that non-toxic/directly dischargeable levels (TU ≤ 1) were achieved when the pH ranged from 6.8 to 8.4 and the conductivity remained below 1651 μS/cm. These findings are expected to facilitate rapid and cost-effective detection of heavy metal ecotoxicity in industrial wastewater effluents, aiding decision-making in wastewater management.

Biodegradation Assay of Heavy Metals and Dyes Decolorization in Textile Industrial Effluent using Laccase Isolated from Pleurotus ostreatus

This study focused on the isolation of laccase enzyme from the fungus Pleurotus ostreatus and its application in the biodegradation of various pollutants present in textile industrial effluent, including chemicals, ions, salts, heavy metals, brittle metals, total suspended solids, total dissolved solids, chemical oxygen demand, biological oxygen demand, minerals, total hardness, total alkalinity, turbidity, electrical conductivity, and dyes. Textile industrial effluent poses a significant threat to the environment, contaminating water bodies and posing risks to human, animal, and plant life. This study employed an economical and ecofriendly biological approach for wastewater treatment, distinguishing it from traditional physical and chemical methods. The optimum temperature of laccase is found to be 30 degree Celsius and pH is 3. Enzyme activity of laccase is 7.25 U/ml. This fugal laccase decolorizes textile Industrial dye effluent containing various dyes, such as Turquoise VG, Black B, Yellow R, Methyl red, Trypan blue, and Acid Orange 7. Laccase depicts maximum decolorization efficacy on Black B dye. Similarly, Laccase from P.ostreatus shows higher decolorization efficacy when compared to other fungal laccase. Additionally, the study assessed the biodegradation of various wastewater quality parameters, including physical and chemical parameters like toxic heavy metals and ions. This research of isolation, characterization, and utilizing laccase from P. ostreatus for the bioremediation of textile industrial effluent wastewater containing dyes, toxic chemicals, ions and metals is effective, economical and ecofriendly.

Metabolomics revealed disruptions in amino acid and antioxidant biochemistry in Daphnia magna exposed to industrial effluents associated with plastic and polymer production

Industrial wastewater effluents are a major source of chemicals in aquatic environments, and many of these chemicals may negatively impact aquatic life. In this study, the crustacean Daphnia magna, a common model organism in ecotoxicity studies, was exposed for 48 h to nine different industrial effluent samples from manufacturing facilities associated with the production of plastics, polymers, and coating products at a range of dilutions: 10, 25, 50, 100% (undiluted). A targeted metabolomic-based approach using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify polar metabolites from individual daphnids that survived the 48 h exposure. Multivariate analyses and metabolite changes revealed metabolic perturbations across all effluent samples studied, with non-monotonic responses and both up and downregulation relative to the unexposed control. Pathway analyses indicated the disruption of similar and distinct pathways, mostly connected to protein synthesis, amino acid metabolism, and antioxidant processes. Overall, we observed disruptions in Daphnia biochemistry that were similar across the effluent samples, but with unique features for each effluent sample. Additionally, non-monotonic heightened responses suggested additive and/or synergistic interactions between the chemicals within the industrial effluents. These findings demonstrate that targeted metabolomic approaches are a powerful tool for the biomonitoring of aquatic ecosystems in the context of complex mixtures, such as industrial wastewater effluents.

Use of the Box–Behnken Experimental Design for the Optimization of Orange II (Acid Orange 7) Adsorption on Aloe vera

Industrial wastewater effluents containing dyes are considered to pollute and be harmful to the environment. Among the various removal techniques, the adsorption process using low-cost adsorbents has been successfully used to remove pollutants. In this work, Aloe vera leaves (AVs) have been used as adsorbent for the removal of Orange II (O-II). A three-level three-factor Box–Behnken factorial design, including three replicates of center points, was applied to investigate the main parameters affecting the biosorption of O-II dye in aqueous solutions by AVs. The selected parameters were adsorbent dose, initial dye concentration, and contact time. The Box–Behnken experiment design has given a satisfactory result for the optimization of the adsorption process. The obtained value of R2 (0.9993) shows that the quadratic response model adequately represents the relationship between each response and the chosen variables. The pH influences the adsorption capacity, obtaining at pH 2 the maximum adsorption capacity value. From the kinetic models studied, the one that best describes the adsorption of Orange II on Aloe vera is the Bangham model (ARE = 1.06%). The isotherm model that best represents the experimental data is the Toth model. The maximum adsorption capacity obtained by this model was 15.9 mg·g−1.

The Use of Fly Ash and Bottom Ash to Reduce COD, TSS, and Color in Textile Industry Wastewater Effluent

The textile industry wastewater effluent contains some levels of COD, TSS, and color, it must be reprocessed as a tertiary treatment using the filtration method. The goal of this research was to examine the ability of fly ash and bottom ash as filtration media to reduce the pollutant / organic load of COD, TSS, and color in textile industry wastewater effluent. The slow sand filter method was used in this study, and the filter media was derived from coal combustion waste. The variation used in this study is a variation of filter media (fly ash and bottom ash), with fly ash diameters of 0.11 and 0.35 mm, bottom ash diameters of 0.85 - 1.50 mm, and media thickness of 1.50 - 2.00 mm (10 cm and 20 cm). The study’s findings demonstrated that using bottom ash and fly ash media in the filtration process with a slow sand filter system could maximize the efficiency of reducing COD, TSS, and color levels in textile industry wastewater effluent. In fly ash media, it can reduce COD, TSS, and Color by 90.58%, 81.87%, and 100%. Meanwhile, Bottom Ash filter media has an average COD, TSS, and Color reduction of 87.80%, 81.87%, and of 100%.

Black sand as a cost-effective catalyst for methylene blue photo-remediation under visible light

Methylene blue (MB) is commonly a persistent and perilous pollutant in industrial wastewater effluent. While MB has a massive negative effect on human and ecology safety. The neutralization of such harmful material would save a huge clean water amount. This work proposes the natural and abundant black sand as a catalyst for MB photodegradation. The sand sample was calcined at three temperatures of 300°, 400°, and 600 °C. The properties of samples were analyzed with different micro- as well as spectroscopic techniques. The experimental data revealed the sample's main composition of SiO2, Fe2O3, and Al2O3. XRD and XPS results proved the formation of mixed oxides composites due to calcination, especially at 400 °C. The UV–vis analysis conducted showed that samples can absorb light in the visible range. The photodegradation reached a maximum of 975.3%, 82.7%, and 75.7% for BS400, BS600, and BS300 respectively; by illumination for 2.5 h in the visible range. The observed distinguishable catalytic performance was discussed via the spectroscopic analysis and oxygen availability in the catalyst lattice. When AO, t-BuOH, and BQ are used as scavengers instead of just BQ during the photodegradation of MB dye over BS400 catalyst, the photodegradation rate drops significantly. The degradation % of MB dye diminished to 60%, and 70% by using AO, t-BuOH, and BQ scavengers; respectively. This proved that rather than hydroxyl radicals, superoxide radicals or positive hole production is the main determining step in MB photo-degradation over BS400 catalyst.

Removal of direct dyes from wastewater using chitosan and polyacrylamide blends

This study investigated the feasibility of employing neat chitosan powder, polyacrylamide, and chitosan micro-beads as adsorbents for the rapid and efficient removal of Direct Blue 78 dye from textile industrial wastewater. A series of batch experiments were conducted to examine the impact of adsorbent dose, contact time, and pH on the adsorption process. The physicochemical analysis, including FTIR, zeta potential analysis, and SEM were performed to identify the adsorption mechanism of chitosan powder and micro-beads. It was found that increasing the powder chitosan dose to 4.5 g/L and contact time up to 40 min resulted in achieving a significant increase in dye removal efficiency up to 94%. The highest removal efficiency of 94.2% was achieved at an initial dye concentration of 50 mg/L, a chitosan dosage of 4.5 g/L, and an optimized contact time of 60 min. Utilizing a polyacrylamide gel dose of 45 mL/L reduced the sedimentation time of chitosan from 8 h to 5 min. Equilibrium studies showed an initial L-shaped equilibrium curve, indicating that the adsorption process primarily arises from electrostatic interactions between dye molecules and adsorbent particles (physical forces). The Langmuir isothermal model demonstrated the best fit to the equilibrium data. Combining chitosan powder with polyacrylamide gel emerges as an economically viable choice for dye removal in industrial wastewater effluents, offering a cost-effective alternative to pricey commercial adsorbents. The results of the study revealed that the presence of polyacrylamide dye enhanced the removal efficiency and settling time of DB78 dye using chitosan.

Fenton and photo-assisted advanced oxidative degradation of ionic liquids: a review.

Ionic liquids (ILs) are the class of materials which are purely ionic in nature and liquid at room temperature. Their remarkable properties like very low vapour pressure, non-inflammable and high heat resistance are responsible for their use as a very appealing solvent in a variety of industrial applications in place of regular organic solvents. Because ILs are water soluble to a certain extent, the industrial wastewater effluents are found to contaminate with their traces. The non-biodegradability of ILs attracts the attention of the researchers for their removal or degradation from wastewater. Numbers of methods are available for the treatment of wastewater. However, it is very crucial to use the most efficient method for the degradation of ILs. Advanced oxidation process (AOP) is one of the most important techniques for the treatment of ILs in wastewater which have been investigated during last decades. This review paper covers the cost-effective Fenton, photochemical and photocatalytic AOPs and their combination that could be applied for the degradation of ILs from the wastewater. Theoretical explanations of these AOPs along with experimental conditions and kinetics of degradation or removal of ILs from water and wastewater have been reported and compared. Finally, future perspectives of IL degradation are presented.