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In this study, artificial neural network (ANN) tools were employed to forecast the adsorption capacity of Malachite green (MG) by baru fruit endocarp waste (B@FE) under diverse conditions, including pH, adsorbent dosage, initial dye concentration, contact time, and temperature. Enhanced adsorption efficiency was notably observed under alkaline pH conditions (pH 10). Kinetic analysis indicated that the adsorption process closely followed a pseudo-second-order model, while equilibrium studies revealed the Langmuir isotherm as the most suitable model, estimating a maximum adsorption capacity of 57.85 mg g−1. Furthermore, the chemical adsorption of MG by B@FE was confirmed using the Dubinin–Radushkevich isotherm. Thermodynamic analysis suggested that the adsorption is spontaneous and endothermic. Various ANN architectures were explored, employing different activation functions such as identity, logistic, tanh, and exponential. Based on evaluation metrics like the coefficient of determination (R2) and root mean square error (RMSE), the optimal network configuration was identified as a 5–11-1 architecture, consisting of five input neurons, eleven hidden neurons, and one output neuron. Notably, the logistic activation function was applied in both the hidden and output layers for this configuration. This study highlights the efficacy of B@FE as an efficient adsorbent for MG removal from aqueous solutions and demonstrates the potential of ANN models in predicting adsorption behavior across varying environmental conditions, emphasizing their utility in this field. NOVELTY STATEMENT: The innovative aspect of this study lies in the utilization of a new and effective adsorbent for the removal of Malachite Green (MG), derived from the fruit endocarp of baru (Dipteryx alata Vog.). The baru fruit endocarp, typically discarded as solid waste during processing, was found to possess favorable characteristics for adsorption processes and provides an adsorption capacity that exceeds that of most other similar adsorbents. Additionally, integrating Artificial Neural Networks (ANNs) enables accurate modeling of the adsorption process, eliminating the need for extensive laboratory experiments. This contributes significantly to wastewater treatment research, enhancing effectiveness and sustainability in unwanted dye removal. [ABSTRACT FROM AUTHOR]

The present study focuses on the elaboration of magnetic nanocomposites by the in situ incorporation of magnetite (Fe3O4) nanoparticles (NPs) with spherical and nanoflower-like morphologies in graphitic carbon nitride (g-C3N4) sheets using two different synthetic routes. Nanomaterials are characterized by TEM, SEM, XRD, FTIR, BET, zetametry, vibrating sample magnetometry, and UV–vis absorption spectroscopy. The decoration of the carbon nitride matrix with the magnetic NPs enhanced optical and textural properties. The influence of the morphology of the magnetic NPs on the adsorptive and photocatalytic properties of the nanocomposites under different pH conditions (4.5, 6.9, and 10.6) was assessed from batch tests to remove methylene blue (MB) from aqueous solutions. In extreme pH conditions, the nanocomposites exhibited lower or equivalent MB removal capacity compared to the pure g-C3N4. However, at neutral medium, the nanocomposite with incorporated Fe3O4 nanoflowers showed a significantly higher removal efficiency (80.7%) due to the combination of a high adsorption capacity and a good photocatalytic activity in this pH region. The proposed nanocomposite is a promising alternative to remove cationic dyes from water by magnetic assistance, since no pH adjustment of the polluted effluent is required, reducing costs and environmental impact in the dyeing industry. [ABSTRACT FROM AUTHOR]

Preparation, recovery, and regeneration of low-cost bioadsorbents are recognized as a sustainable solution for wastewater treatment. In this study, low-cost byproducts from Carpobrutus edulis plant were used as bioadsorbents for industrial dyes, Rhodamine B, and Congo Red from aqueous solutions. The adsorbents were obtained after chemical treatment of the plant by HCl (HMCE) and NaOH solutions (NMCE) and characterized by SS, SEM, EDX, FT-IR, pHZ, COD, and BOD5. The effect of adsorbent doses, contact time, solution pH, initial concentration, ionic strength, and temperature parameters, on adsorption efficiency, was studied. The results show that more than 70% of the organic matter (COD and BOD5) released into the aqueous solution by the biomaterial was reduced after chemical treatment. The kinetic data revealed that the adsorption of two dyes onto the bioadsorbents follows the pseudo-second-order model, and the equilibrium data correlated well with the Langmuir isotherm. The maximum adsorption capacities of RB and CR onto HMCE were 90.9 and 27.3 mg/g, while onto NMCE; it was 103.1 and 31.15 mg/g, respectively. The thermodynamic study indicates that, for both dyes, the adsorption process onto bioadsorbents was endothermic and spontaneous. The biomaterial could be used up to five adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

Activated carbon has been extensively utilized in a broad spectrum of applications, including catalyst support, energy storage, separation and adsorptive removal of various species. In the synthesis of activated carbon, microwave treatment is a beneficial heating technique for the activation and thermochemical processing of precursors due to various advantages, including uniform heating, shortened processing time, reduced energy consumption and reduced consumption of activating agents. This study aims to present an extensive review on the utilization of common, abundantly available and low-cost biomass wastes to prepare microwave-induced activated carbons and to investigate their dye adsorption characteristics. The methodology for activated carbon synthesis from biowastes, the effects of synthesis conditions, and the influencing factors, such as microwave power level, irradiation time, type of activator, and chemical impregnation ratio, for the efficient adsorption of dyes are discussed. This review highlights the feasibility of using microwave-induced biowaste-derived activated carbons, which supports their potential use as effective and economical dye adsorption materials. [ABSTRACT FROM AUTHOR]

In the present article, pectin-supported zirconium tungstosilicate hybrid ion exchanger (PZTS) was synthesized and characterized the same using Fourier transform infrared spectroscopy, X-ray diffractometry, energy-dispersive X-ray spectroscopy, scanning electron microscopy and transmission electron microscopy. Ion exchange capacity (IEC), elution behavior and effects of eluent concentration on IEC, thermal and chemical effects on IEC and distribution studies have been performed. From these studies, it is found that PZTS has an IEC approximately equal to 1.22 meq/g which is found to be relatively higher than its inorganic counterpart zirconium tungstosilicate (ZTS). Apart from that, PZTS was discovered to be thermally stable as it possesses 42.63 % IEC of its initial value even at 500 °C. According to distribution studies, PZTS was found to be relatively higher selective for Pb2+. Furthermore, based on distribution coefficient values, binary separations of metal ions were accomplished on the PZTS ion exchanger column. The applicability of PZTS was also examined for methylene blue (MB) dye removal from an aqueous solution. This experiment depicts that 0.6 g adsorbent removes approximately 97 % of the MB dye from 20 ppm dye solution at 9 pH within 80 min of mixing. The data are best fitted in Langmuir isotherm (with R2 = 0.9996) and pseudo-second-order kinetic model. Thermodynamic studies show that the removal of MB by PZTS is spontaneous and exothermic. It was also determined that PZTS has antimicrobial properties against Escherichia coli. [ABSTRACT FROM AUTHOR]

The Current study aimed at valorizing carrot pomace (CP), an abundant waste from the juice industry. A water-soluble fraction of CP was separated from solid fraction of CP (SFCP) and employed as feedstock for producing fungal biomass (FB) in bench-scale bioreactors. FB combined with SFCP were used to develop mycelium-based papers (MBP) using the wet-laid method. The potential and capacity of FB, SFCP and MBP to remove dye (methylene blue) from wastewater was then investigated. The maximum achieved dye removal was 92% when using a mixture of SFCP and FB in their suspended forms. The MBP with the lowest density (549 kg/m3) reached 83% dye elimination. The findings of this study support the valorization of carrot pomace, through environmentally benign processes, to mycelium-based papers with potential application in wastewater treatment. [ABSTRACT FROM AUTHOR]

Wastewater is discharged in large amounts from different industries; thus, wastewater treatment is currently one of the main concerns, advanced oxidation is a promising technique for wastewater treatment. This research aims to synthesize magnetite nanoparticles and study their application in wastewater treatment via adsorption and advanced oxidation processes. Magnetite nanoparticles were synthesized via coprecipitation technique between ferric and ferrous sulfate at a molar ratio of 2:1. The prepared sample was characterized using FTIR, XRD, TEM, BET surface area, zeta potential, VSM, and UV‒visible spectroscopy. XRD confirmed the formation of a single face-centered cubic (FCC) spinel structure of Fe3O4. TEM revealed an average particle size of 29.2 nm and a BET surface area of 70.1 m2 g−1. UV‒visible spectroscopy revealed that the UV–visible peak of the sample was obtained at 410 nm. VSM confirmed the attraction of the sample to a magnet with a magnetization of 60 (emu/g). The removal efficiency of methylene blue was studied using adsorption and advanced oxidation methods. For adsorption, the studied parameters were dye concentration 2–10 ppm, 3–10 pH, and 50:300 mg Fe3O4/L. For advanced oxidation, peroxide was used with nanomagnetite as a catalyst, and the studied parameters were pH 2–11, magnetite dose 20–200 PPM, and peroxide dose 500–2000 PPM. The removal efficiency by adsorption reached 95.11% by adding 50 mg of Fe3O4/L and 10 ppm dye conc at 6.5 pH; on the other hand, in advanced oxidation, it reached 98.5% by adding 110 PPM magnetite and 2000 ppm H2O2 at pH 11. The magnetite nanoparticles were reused for ten cycles of advanced oxidation, for a 10% reduction in removal efficiency at the tenth cycle. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTThis research examined the effectiveness of using Albizia lebbeck seed pods (ALB) as an adsorbent to remove dye effluents and clean up wastewater. More specifically, the binding capacity of methylene blue (MB) and Congo red (CR) dyes from aqueous solution using unmodified Albizia lebbeck seed pods (UALB) and citric acid modified Albizia lebbeck seed pods (CALB) were compared. The adsorbents underwent characterization via the use of Fourier transform infrared spectroscopy and scanning electron microscopy. Several operational factors were investigated using batch tests to ascertain their effects. These parameters included pH, adsorbent dose, interaction duration, and initial dye concentration. The residual dye concentrations were determined, and the data generated were fitted to equilibrium and kinetic models. In CALB and UALB, MB adsorption ideal pH values were 10 and 12, whereas CR optimal pH values were 3 and 2. Also, MB and CR equilibrium durations were 360 and 240 min, respectively. Temkin model best described the adsorption in CALB (r2 = 0.9916, 0.9484) whereas Freundlich worked well for UALB in MB and CR (r2 = 0.9626, 0.9871). Kinetic modeling of the adsorption data showed that the pseudo-second-order kinetic model provided the best fit (r2 = 0.9998, 0.9999) for CALB and (r2 = 1, 0.9992) for UALB for both MB and CR dyes. Maximum adsorption for MB was 9.499 mg/g and for CR it was 8.628 mg/g, and the findings showed a positive linear correlation between the concentration of dye-ions and their adsorption ability. The CALB also demonstrated superior efficacy in the removal of MB (4.661 mg/g) dye relative to CR (4.113 mg/g). The results of this study demonstrate that the use of ALB, in both modified and unmodified forms, is a cost-effective and efficient approach for the removal of MB and CR from the aqueous environment.In this study, Albizia lebbeck seed pod (ALB), an agricultural waste, was used in both its unmodified (UALB) and modified (CALB) forms to remove cationic MB and anionic CR dyes from aqueous solution. The study showed that ALB proved to be an excellent low-cost alternative adsorbent for the removal of MB and CR dyes from an aqueous solution. However, the adsorption capacity was higher for MB (9.499 mg/g) compared to CR (8.628 mg/g). According to the results, CALB also proved to be more efficient in the removal of MB dye (4.661 mg/g) compared to CR (4.113 mg/g). [ABSTRACT FROM AUTHOR]

In this work, silver nanoparticles (AgNPs) were synthesized from cashew nutshell liquid (CNSL) by varying the concentration of silver ions and the pH of the CNSL extract. The synthesized AgNPs were further characterized to study their surface, structural, and morphological properties and tested for the removal of methylene blue (MB) dye. The results of this study showed that depending on the conditions, particles of various sizes, ranging from 1 to 60 nm, and different degrees of stabilization and agglomeration were produced. The concentration of silver ions equal to 3 mM and the pH of the extract of ~4.5 (AgNP3) resulted in the most efficient synthesis, where particles appeared to be highly stabilized and homogeneously distributed on the surface, exhibiting a small average particle size and a narrow particle size distribution (6.7 ± 6.5 nm). Such particles further showed the highest percent removal of MB, where up to 80% removal was recorded within the first 20 min. Higher concentrations of silver ions and higher pH of the extract resulted in substantial particle agglomeration and particles being over-capped by the CNSL biomolecules, respectively, which further negatively affected the ability of particles to remove MB. Finally, the fact that visible light showed no significant effect on the removal of MB, with the average removal rates found to be about the same as in the dark, suggests the strong catalytic nature of AgNPs, which facilitates the electron transfer reactions leading to MB reduction. [ABSTRACT FROM AUTHOR]

Currently, there is an increasing need to find new ways to purify water by eliminating bacterial biofilms, textile dyes, and toxic water pollutants. These contaminants pose significant risks to both human health and the environment. To address this issue, in this study, we have developed an eco-friendly approach that involves synthesizing a cobalt-doped cerium iron oxide (CCIO) nanocomposite (NC) using an aqueous extract of Gossypium arboreum L. stalks. The resulting nanoparticles can be used to effectively purify water and tackle the challenges associated with these harmful pollutants. Nanoparticles excel in water pollutant removal by providing a high surface area for efficient adsorption, versatile design for the simultaneous removal of multiple contaminants, catalytic properties for organic pollutant degradation, and magnetic features for easy separation, offering cost-effective and sustainable water treatment solutions. A CCIO nanocomposite was synthesized via a green co-precipitation method utilizing biomolecules and co-enzymes extracted from the aqueous solution of Gossypium arboreum L. stalk. This single-step synthesis process was accomplished within a 5-h reaction period. Furthermore, the synthesis of nanocomposites was confirmed by various characterization techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and energy dispersive X-ray (EDX) technology. CCIO NCs were discovered to have a spherical shape and an average size of 40 nm. Based on DLS zeta potential analysis, CCIO NCs were found to be anionic. CCIO NCs also showed significant antimicrobial and antioxidant activity. Overall, considering their physical and chemical properties, the application of CCIO NCs for the adsorption of various dyes (~91%) and water pollutants (chromium = ~60%) has been considered here since they exhibit great adsorption capacity owing to their microporous structure, and represent a step forward in water purification. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate the unique role of ionic liquids (ILs) as dye aggregation and precipitation promoter. Specifically, we have observed that the presence of small amount of IL such as 1‐butyl‐3‐methylimidazolium hexaflurophosphate ([bmim][PF6]), 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2N]), 1‐butyl‐3‐methylimidazolium trifluoromethanesulfonate ([bmim][OTf]), 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim][BF4]) and 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyrr][Tf2N]) in aqueous milieu can help in the conversion of a cyanine dye 1,1'‐Diethyl‐2,2'‐carbocyanine iodide (Pinacyanol iodide) into J‐ and H‐aggregates followed by time dependent precipitation of the dye. The anion of the added IL strongly affects the aggregation process in aqueous solution. Addition of small amount of BF4− anion based IL [bmim][BF4] to aqueous solution of the dye initially induces J‐ and H‐aggregation followed by quick precipitation of the dye in time dependent manner. Presence of small amount of other anion containing ILs such as ([bmim][PF6]), ([bmim][OTf]), ([bmim][Tf2N]) and ([bmpyrr][Tf2N]) strongly supports H‐aggregation of the dye in aqueous solution whereas higher wt % of added ILs also caused precipitation of the dye in a time dependent manner. The nature of the IL anion, wt % of added IL and temperature conditions decides efficiencies of aggregation and precipitation processes. The dual yet unique behavior of ILs as an additive influence the aggregation of cyanine dyes and precipitation has been demonstrated. The observed results can contribute towards various application for dye aggregates and in the removal of dyes from water. The developed process can find potential applications in the field of material science, wastewater treatment, future light harvesting systems, and opto‐electronics related fields. [ABSTRACT FROM AUTHOR]

Tanned leather is a product of high intrinsic value and a sign of luxury. Chromium-tanned leather shavings are abundantly produced wastes which contain chromium that could be revalorized. The present research proposes the use of alkaline hydrolysis, aided by an inorganic anion, to promote the hydrolysis of the Cr–O bond. De-chromed solids were employed to synthesize carbon material, which subsequently was applied for dye removal from aqueous solution, while the chromium-rich solution was used as a re-tanning agent. The results demonstrated that it is possible to develop a method of chromium-protein separation, with a minimum degree of hydrolyzation. When an activating agent was employed, the prepared carbon had a surface area of 585 m2/g, with trace levels of chromium (< 0.1%), present mainly as Cr2O3 particles. The materials displayed an adsorption capacity of up to 47.60 mg/g and 27.58 mg/g for methylene blue and Congo red respectively. The chromium-rich solution contained proteins and amino acids that aid in its employment as a re-tanning agent. Leather that was re-tanned with this solution had a similar tear strength and a superior and tensile strength (38%), superior elongation at break (10%), and improved elongation at break (47%) than traditional Cr33-tanned leather. The present study represents a major step in the development of cleaner production of leather. [ABSTRACT FROM AUTHOR]

The primary focus of the current investigation was to assess the removal of Rhodamine B dye (RhB) from aqueous solutions using pomegranate peel as a green adsorbent. The chemical and morphological characterization of pomegranate peel was conducted through ATR-FTIR spectroscopy and SEM microscopy. The study also investigated various reactional parameters, kinetic, and adsorption isotherm in a batch system. The results revealed that RhB adsorption reaches equilibrium in about 2 hours, with an adsorption capacity of 19.41 mg/g observed at a 50 mg/L of initial RhB concentration. To model the kinetic of RhB adsorption, two well-known models (pseudo-first-order and pseudo-second-order) were applied. The pseudo-second-order model yielded a superior fit for the kinetic data, as evidenced by analyses of R2, RMSE, ARE, and χ² values. Additionally, the findings suggest that the adsorption process is not solely governed by intraparticle diffusion. Furthermore, isotherm analysis revealed that the Langmuir model offered a more accurate fit to the equilibrium data, estimating the maximum removal capacity to be 47.17 mg/g. These findings suggest that pomegranate peel offers a promisingly eco-friendly and cost-effective solution for sustainable remediation of textile dyeing effluents. [ABSTRACT FROM AUTHOR]

A polymer network system has been made by microwave-assisted free radical co-polymerization of N-hydroxyethylacrylamide (HEAAm) and N,N-methylenebisacrylamide (MBA) in the presence of banana pseudostem (BPS) as the supporting material. The grafting of poly(HEAAm-co-MBA) on BPS resulted in a gel BPS-g-PHEAAm that was characterized using FTIR, TGA, SEM, EDS, and XRD techniques. A pH-responsive swelling was observed. The water transport was found to be of Fickian type. The material was evaluated for the adsorptive removal of cationic dyes from aqueous solutions using two model dyes. Maximum adsorptions of 88.94 and 76.82 mg/g were observed for Methylene blue (MB) and Crystal violet (CV), respectively. Kinetic and isotherm studies revealed the adsorption to be a pseudo-second-order kinetic process that fits well with the Freundlich adsorption isotherm model. The adsorption was found to be a spontaneous and endothermic process. Desorption studies indicated complete desorption in acidic medium. Further, the gel BPS-g-PHEAAm was observed to be biodegradable. Thus, the developed material appears to be a promising adsorbent for the treatment of wastewater contaminated with cationic dyes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dyes present in textile wastewater can pose various environmental problems, including toxicity, carcinogenicity and mutagenicity, when released into receiving environments. Sulfidogenic bacteria play a crucial role in wastewater treatment by reducing sulfate and producing sulfide through the utilization of organic compounds in water. The resulting sulfide often transfers its electrons to another electron acceptor. This study focused on the treatment of real textile wastewater using an up‐flow sulfidogenic column bioreactor. RESULTS: The reactor was acclimated to sulfate‐reducing conditions when influent chemical oxygen demand and sulfate concentrations were 1742 and 2000 mg L−1, respectively. Subsequently, a gradual transition was made from sulfate‐reducing conditions to dye‐reducing conditions. Throughout the study, the hydraulic retention time was maintained at 1 day. CONCLUSION: The influent dye concentration was 2722 Pt‐Co, and an impressive dye removal efficiency of approximately 90 ± 2% was achieved. This corresponds to a removal rate of 2450 Pt‐Co L−1 day−1. Although the sulfide concentration in the reactor decreased in the last period, investigating the extent to which this sulfide participates in the dye removal may expand the use of sulfidogenic reactors in the treatment of real textile industry wastewater. © 2024 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Among carbon-based nanoparticles, graphene has garnered significant attention since its discovery as a carbon allotrope, owing to its unique two-dimensional structure and outstanding characteristics. In this research study, we present an environmentally friendly, cost-effective technique with the potential for mass production of valuable products such as graphene nanosheets. Graphene was derived from a mixture of wood sawdust and polyethylene–terephthalate bottles as the feedstock, along with a combination of sand and plant fertilizer that was modified by oxalic acid acting as a catalyst. The feedstock was successfully converted to graphite using a two-step fluidized-bed co-pyrolysis technology. Firstly, an experiment was conducted under a nitrogen atmosphere, subjecting the mixture to 500 °C for 30 min at a ramping rate of 5 °C/min, resulting in the synthesis of a black-charged residue. In the second step, graphite was obtained by subjecting the residue to 800 °C for 2 h at a ramping rate of 10°C/min, using the acid-modified catalyst in a nitrogen atmosphere. Finally, graphene nanosheets were produced from graphite through microwave-assisted liquid phase exfoliation. Due to the exceptional features of the synthesized graphene, it was used as an adsorbent for the removal of two organic dyes rhodamine B (RB) and malachite green (MG) from an aqueous solution. The effects of various factors on the adsorption capacity were studied in detail. The chemical structure and morphology of the synthesized samples were analyzed using advanced characterization techniques like XRD, FTIR, EDX, TGA, DTGA, and ZETA to determine the structure of graphene nanosheets and the degree of graphitization. The two models (Freundlich and Langmuir) were used to explain the experimental data obtained three different temperatures (298, 318, and 338 K) with a certain amount of graphene concentrate (0.04 g); the result showed the maximum adsorption capacity of RB and MG solution are 6.25 mg/g and 3 mg/g, respectively. The percentage of dye adsorbed for RB and Mg is 62.5 and 30%, respectively, in the optimum temperature 338 K, and optimum concentration for RB and MG is 25 and 12 ppm, respectively; as a result, the graphene considers as an ideal adsorbent (environmentally friendly and cost-effective) for removal of cationic types of dyes. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) and its composites have been widely studied for environmental applications, including for dye removal. In this study, various GO‐based materials namely GF, GFA, and GFC were successfully synthesized and characterized by FTIR, Raman spectroscopy, FESEM, BET, and TGA methods before and after being used to adsorb methylene blue from aqueous solutions. The BET results reveal that MB molecules most filled in the pores at the size of 100–300 nm of the materials. The adsorption process followed the pseudo‐first‐order equation and Sips isothermal model for all the materials. However, GFA showed the maximum adsorption capacity (Qmax=739 mg/g) and the most negative value of ΔG while the least effective material was GFC. The experiment revealed that GF and GFA could remove up to 95.0 % color on the real textile wastewater sample, and the materials are very promising for dye removal application. [ABSTRACT FROM AUTHOR]

The development of superlyophobic materials in liquid systems, enabling synchronous oil/water separation and dye removal from water, is highly desirable. In this study, we employed a novel superwetting array-like BiOBr nanosheets anchored on waste rock wool (RW) fibers through a simple neutralization alcoholysis method. The resulting BiOBr/RW fibers exhibited superoleophilic and superhydrophilic properties in air but demonstrated underwater superoleophobic and underoil super-hydrophobic characteristics. Utilizing its dual superlyophobicity, the fiber layer demonstrated high separation efficiencies and flux velocity for oil/water mixtures by prewetting under a gravity-driven mechanism. Additionally, the novel BiOBr/RW fibers also exhibited excellent dual superlyophobicity and effective separation for immiscible oil/oil systems. Furthermore, the BiOBr/RW fibers could serve as a filter to continuously separate oil/water mixtures with high flux velocity and removal rates (>93.9%) for water-soluble dye rhodamine B (RhB) simultaneously by directly activating peroxymonosulfate (PMS) in cyclic experiments. More importantly, the mechanism of simultaneous oil/water separation and RhB degradation was proposed based on the reactive oxygen species (ROS) quenching experiments and electron paramagnetic resonance (EPR) analysis. Considering the simple modified process and the waste RW as raw material, this work may open up innovative, economical, and environmentally friendly avenues for the effective treatment of wastewater contaminated with oil and water-soluble pollutants. [ABSTRACT FROM AUTHOR]

1D nanomaterials have attracted great attention due to their outstanding anisotropic and linear structures. A facile method is developed to fabricate 1D copper metal–organic framework nanowires (Cu‐MOF‐NW) through steam‐assisted conversion from Cu‐MOF precursors. During the steam‐assisted conversion, Cu‐MOF precursor gradually dissolves in methanol steam, and then recrystallized into Cu‐MOF‐NW, which shows high aspect ratio of about 600 and identical crystal structure of MOF‐74. As‐prepared Cu‐MOF‐NW with multiscale porous structure can effectively remove cationic dyes even in dye mixture. Moreover, Cu‐MOF‐NW, as an ideal template, is calcined to form Cu nanoparticle‐doped carbon nanofiber with maintaining its 1D morphology, which shows excellent electrocatalytic activity for the non‐enzymatic sensing of glucose. [ABSTRACT FROM AUTHOR]

In this research, the alginate doped graphene oxide (GO)-Fe3O4-TiO2 photomagnetic nanocomposite was synthesised through a three-step method. For comparison, alginate-GO was also prepared. The synthesised materials were characterised through FTIR, XRD, TGA, SEM, EDX, and TEM techniques. The photomagnetic properties of the resultant nanocomposite were evaluated by VSM. Degradation of Malachite green as a dye pollutant was studied in the presence of alginate (Alg), Alg-GO, and Alg-GO-Fe3O4-TiO2 nanocomposite using a sonophotocatalysis technique. The results showed, that, Alg-GO-Fe3O4-TiO2 nanocomposite has high efficiency in the removal of Malachite green. Recycling experiments displayed that the degradation efficiency dropped only by 12%, after five successive runs. and makes it a promising catalyst for efficient degradation of dye pollutants in the practical applications. [ABSTRACT FROM AUTHOR]

The biomass filtrate of the endophytic bacterial strain Bacillus amyloliquefaciens Fa.2 was utilized for the eco-friendly production of silver nanoparticles (Ag-NPs). The yellowish-brown color's optical properties showed a maximum surface plasmon resonance at 415 nm. The morphological and elemental composition analysis reveals the formation of spherical shapes with sizes of 5–40 nm, and the Ag ion comprises the major component of the produced Ag-NPs. X-ray diffraction confirmed the crystalline structure, whereas dynamic light scattering reveals the high stability of synthesized Ag-NPs with a polydispersity index of 0.413 and a negative zeta potential value. The photocatalytic experiment showed the efficacy of Ag-NPs to degrade methylene blue with maximum percentages of 73.9 ± 0.5 and 87.4 ± 0.9% under sunshine and UV irradiation, respectively, compared with 39.8% under dark conditions after 210 min. Additionally, the reusability of Ag-NPs was still more active for the fifth run, with a percentage decrease of 11.6% compared with the first run. Interestingly, the biogenic Ag-NPs showed superior antimicrobial activity against different pathogenic Gram-negative bacteria (MIC = 6.25 µg mL−1), Gram-positive bacteria (MIC = 12.5 µg mL−1), and uni- and multicellular fungi (MIC = 12.5 µg mL−1). Moreover, the biosynthesized Ag-NPs could target cancer cells (Pc3 and Mcf7) at low concentrations compared with normal cell (Vero) lines. The IC50 of normal cells is 383.7 ± 4.1 µg mL−1 compared with IC50 Pc3 (2.5 ± 3.5 µg mL−1) and McF7 (156.1 ± 6.8 µg mL−1). Overall, the bacterially synthesized Ag-NPs showed multifunctional features to be used in environmental catalysis and biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, the removal efficiencies of MR GRL dye were investigated using different Fenton reactions such as Fenton and photo-Fenton processes. Various variables such as the amount of H2O2 and Fe+2, reaction time, pH, and dye concentration were examined to determine the most suitable conditions for removal. Three different light sources, namely UV-A, UV-B, and UV-C, were used as UV radiation. The optimum conditions for the study were determined to be 50 mg/L Fe+2, 150 mg/L H2O2, t 30 minutes, pH 3, and dye concentration of 100 mg/L. The removal efficiencies obtained in the study for Fenton and photo-Fenton (UV-A, UV-B, and UV-C) processes were 94.2%, 95.4%, 96.2%, and 97.3%, respectively. This study is particularly important for demonstrating the effect of different UV lamps on the removal of MR GRL dye. The study has shown that Fenton processes can be used as a highly efficient and reliable method for the removal of MR GRL. [ABSTRACT FROM AUTHOR]

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Efficient removal of methylene blue (MB) dye from aqueous solutions is crucial for addressing environmental pollution. This study investigates the potential of Melamine-maleic acid polyamide adduct/polyacrylonitrile (ME-MA amide polymer/PAN) nanofibers as a novel adsorbent for MB dye removal. Characterization via scanning electron microscopy (SEM) revealed surface morphology changes, with fiber diameters ranging from 1 to 3 μm. Thermal stability analysis demonstrated enhanced stability for ME-MA/PAN compared to pure PAN fibers. Fourier transform infrared (FT-IR) analysis confirmed the presence of hydroxyl, amide, and thiol groups on the nanoparticle surface, covalently attached to the nanofiber surface. Through electrospinning, ME-MA/PAN composites were synthesized, showing promising capabilities for dye removal. Optimal conditions were observed at pH 12 and a ME-MA PAN dose of 0.02 g. MB removal efficiency increased with higher initial dye concentrations, peaking at 30 mg/L, and higher temperatures up to 40°C. Adsorption isotherm models indicated Langmuir adsorption capacity (Qm) of 111.10 mg g−1 and a separation factor (RL) of 0.297, with Freundlich constants (1/n) and KF values of 0.418 and 22.9, respectively. Kinetic and thermodynamic studies revealed favorable conditions for MB dye removal, validating ME-MA amide polymer/PAN nanofiber composites as environmentally friendly and effective materials for eliminating toxic MB dye from aqueous solutions. This research highlights the potential of ME-MA/PAN nanofibers in addressing dye pollution, suggesting their application in wastewater treatment for sustainable environmental management. Further investigation into regeneration methods and scalability is recommended for practical implementation in real-world scenarios. [ABSTRACT FROM AUTHOR]

This study presents a one-step synthetic method utilizing oak pericarp treated with FeCl3 and ZnCl2 as a precursor for the production of magnetic activated carbon (MAC). Characterization techniques including FTIR, SEM-EDX, TGA, XRD, VSM, BET, and pHpzc confirm the integration of biochar characteristics and magnetic properties of iron oxides in the MAC composite. Batch adsorption tests investigate the adsorption capacity of Rhodamine B (RhB) and Rose Bengal (RB) dyes by MAC under varied conditions, including adsorbent dose, contact time, solution pH, ionic strength, temperature, and initial dye concentration. Optimal adsorption conditions for RhB and RB are identified at pH 2 and 7, with adsorbent doses of 0.75 g/L and 1 g/L, and equilibrium times of 180 min and 120 min, respectively. Adsorption isotherm models (Langmuir, Freundlich, and Temkin) are employed, with the Freundlich model providing the best fit. MAC demonstrates a maximum monolayer adsorption capacity of 198.529 mg.g−1 for RhB and 42.551 mg.g−1 for RB at 20 °C. Kinetic data align with the pseudo-second-order model, and thermodynamic parameters confirm the spontaneous and endothermic nature of the adsorption process. In conclusion, this study successfully synthesizes magnetic biochar with enhanced efficacy in dye adsorption. The one-step method proves efficient for treating industrial dye effluents, as evidenced by batch desorption studies over four cycles, establishing the reusability of the MAC. [ABSTRACT FROM AUTHOR]

BACKGROUND: The encapsulation technique was applied to efficiently eliminate Congo red (CR) from aqueous solutions. During the ionotropic gelation between calcium (Ca2+) ions and alginate (AL), CR was effectively entrapped within the AL nanocapsules in a one‐step process. Suitable conditions for efficient CR removal via encapsulation were revealed by the systematic optimization of parameters including pH, time and stirring speed, etc. RESULTS: According to the experimental observations, the stirring rate and temperature were found to have an insignificant effect on the encapsulation of CR molecules. When the pH value of the medium was 3, the highest level of encapsulation efficiency was achieved in a period of 15 min. At a preliminary CR concentration of 2000 mg L−1 and pH 3, the encapsulation efficiency was calculated at ≈98.9%, with an encapsulation capacity of 2800 mg dye g−1 AL. The zeta potential values of AL and CR/AL nanocapsules were determined to be +7.05 eV and −14.9 eV, respectively, and the results showed that the particles tended to agglomerate. TEM micrographs also showed that the nanocapsules were nanosized and agglomerated. Soil and UV degradation studies showed that the dye‐entrapped nanocapsules degraded remarkably. These results highlighted the great potential of encapsulation for dye removal in economical and practical applications. CONCLUSION: Encapsulation was confirmed to be an economical and practical technique for effectively eliminating CR from aqueous solutions. Under UV light irradiation, the dye molecules entrapped within alginate nanocapsules displayed photodegradation. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

It is necessary to treat textile effluents before discharging them into natural water bodies as they harm the environment. Compared to conventional treatment methods, catalytic ozonation has gained attention due to its effectiveness in removing refractory organic pollutants. In this study, the coprecipitation method was used to synthesize a composite metal oxide of silver and cerium oxide, and the synthesized catalyst was used to eliminate the Reactive Black 5 (RB5) dye. X-ray diffraction, scanning electron microscopic, and Brunauer–Emmett–Teller surface area analyses were performed to characterize the synthesized catalyst. Afterwards, relevant experimental parameters, such as pH, ozone and catalyst dosages, and initial dye concentration, were investigated. The experiments revealed that the optimal experimental conditions were a pH value of 10, a catalyst dosage of 0.7 g/L, and an ozone dosage of 60 L/h. In these optimized conditions, the RB5 dye was entirely removed, and a chemical oxygen demand removal efficiency of 88% was achieved within a reaction time of 80 min. Furthermore, the recycling potential of the catalyst was tested for three cycles, and no deterioration in its activity was observed. Additionally, studies were conducted using a hydroxyl radical scavenger in order to understand the reaction pathway of the system. As a result, the indirect pathway was more dominant than the direct pathway in the system.

Abstract Wastewater is discharged in large amounts from different industries; thus, wastewater treatment is currently one of the main concerns, advanced oxidation is a promising technique for wastewater treatment. This research aims to synthesize magnetite nanoparticles and study their application in wastewater treatment via adsorption and advanced oxidation processes. Magnetite nanoparticles were synthesized via coprecipitation technique between ferric and ferrous sulfate at a molar ratio of 2:1. The prepared sample was characterized using FTIR, XRD, TEM, BET surface area, zeta potential, VSM, and UV‒visible spectroscopy. XRD confirmed the formation of a single face-centered cubic (FCC) spinel structure of Fe3O4. TEM revealed an average particle size of 29.2 nm and a BET surface area of 70.1 m2 g−1. UV‒visible spectroscopy revealed that the UV–visible peak of the sample was obtained at 410 nm. VSM confirmed the attraction of the sample to a magnet with a magnetization of 60 (emu/g). The removal efficiency of methylene blue was studied using adsorption and advanced oxidation methods. For adsorption, the studied parameters were dye concentration 2–10 ppm, 3–10 pH, and 50:300 mg Fe3O4/L. For advanced oxidation, peroxide was used with nanomagnetite as a catalyst, and the studied parameters were pH 2–11, magnetite dose 20–200 PPM, and peroxide dose 500–2000 PPM. The removal efficiency by adsorption reached 95.11% by adding 50 mg of Fe3O4/L and 10 ppm dye conc at 6.5 pH; on the other hand, in advanced oxidation, it reached 98.5% by adding 110 PPM magnetite and 2000 ppm H2O2 at pH 11. The magnetite nanoparticles were reused for ten cycles of advanced oxidation, for a 10% reduction in removal efficiency at the tenth cycle.

Dye pollutants, mainly discharged from the textile industry, have caused severe risks to human health and the ecosystem because of their toxicity, non-biodegradability, and carcinogenicity. This study investigated the use of commercial biochar derived from melaleuca wood as an adsorbent for the removal of methylene blue (MB) using a packed-bed column. The selected biochar was characterized by nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy, and scanning electron microscopy. The experiments were performed to determine breakthrough curves (BTCs) with varying pH (3–9), inflow rate (5–20 mL min–1), bed height (16–65 cm), and initial MB concentration (0.75–9 mg L–1). The biochar (particle size of 1–2 mm) exhibited a low adsorption capacity for MB (~21 mg kg–1), resulting in a short breakthrough time. The Thomas, Bohart-Adams, Yoon-Nelson, and Bed Depth Service Time models were quite suitable for describing the experimental BTCs, with R2-values ranging from 0.92 to 0.98. The obtained BTCs were not in the typical S-shape, which characterizes diffusion-controlled adsorption. Therefore, a serial logistic-exponential model, which accounts for both the mass transfer and interaction contributions, was proposed. The experimental data effectively fit this proposed model, as indicated by high R2-values (>0.998). The dominant influence of mass transfer compared to interaction in controlling the adsorption rate of MB was highlighted.

The primary focus of the current investigation was to assess the removal of Rhodamine B dye (RhB) from aqueous solutions using pomegranate peel as a green adsorbent. The chemical and morphological characterization of pomegranate peel was conducted through ATR-FTIR spectroscopy and SEM microscopy. The study also investigated various reactional parameters, kinetic, and adsorption isotherm in a batch system. The results revealed that RhB adsorption reaches equilibrium in about 2 hours, with an adsorption capacity of 19.41 mg/g observed at a 50 mg/L of initial RhB concentration. To model the kinetic of RhB adsorption, two well-known models (pseudo-first order and pseudo-second order) were applied. The pseudo-second-order model yielded a superior fit for the kinetic data, as evidenced by analyses of R², RMSE, ARE, and χ² values. Additionally, the findings suggest that the adsorption process is not solely governed by intraparticle diffusion. Furthermore, isotherm analysis revealed that the Langmuir model offered a more accurate fit to the equilibrium data, estimating the maximum removal capacity to be 47.17 mg/g. These findings suggest that pomegranate peel offers a promisingly eco-friendly and cost-effective solution for sustainable remediation of textile dyeing effluents.

Organic dye pollutants present in wastewater pose a significant global challenge. Among pollutants, the synthetic dye Rhodamine B (RB) stands out due to its non-biodegradable nature and associated neurotoxic, carcinogenic, and respiratory irritant properties. Extensive research has been conducted on the efficacy of adsorption and photodegradation techniques for the removal of RB from wastewater. While adsorption and advanced oxidation processes (AOPs) have gained considerable attention for their effectiveness in recent years, the underlying behaviors and mechanisms of these technologies remain incompletely understood. Therefore, a comprehensive summary of recent research progress in this domain is imperative to clarify the basics and present the up-to-date achievements.This review provides an in-depth exploration of the fundamentals, advancements, and future trajectories of RB wastewater treatment technologies, mainly encompassing adsorption and photodegradation. This work starts with a general introduction of outlining the sources, toxicity, and diverse applicable removal strategies. Subsequently, it thoroughly examines crucial techniques within non-photochemical, photochemical, and adsorption technologies, such as UV light assisted AOP, catalyst assisted AOP, ozonation, Fenton system, electrochemical AOP, and adsorption technology. The primary objective is to furnish a broad overview of these techniques, elucidating their effectiveness, limitations, and applicability. Following this, the review encapsulates state-of-the-art computational simulations pertaining to RB adsorption and interactions with clays and other adsorbents. Lastly, it delves into column adsorption of RB dye, and elucidates various influencing factors, including bed height, feed concentration, pollutant (RB) feeding or flow rate, and column regeneration. This panoramic review aims to provide valuable insights into suitable techniques, research gaps, and the applicability of non-photochemical, photochemical, and adsorption technologies in the treatment of wastewater containing RB dye.

Water contamination is a major health issue that can be addressed by using carbonaceous materials to adsorb and filter pollutants, yet adsorption mechanisms need to be better understood to improve the adsorption efficiency. Here we review the models that are used to study the mechanisms of adsorption of drugs, dyes and metal ions on carbonaceous materials, with emphasis on classical and advanced isotherms. We discuss the fitting frequency, lignocellulosic and fossil fuel-derived adsorbents, biomass composition, activating agents, surface functions, the carbonization temperature, the medium temperature effect and the use of several isotherms to explain the same mechanism. The adsorption capacity can reach up to 2651 mg of contaminant per g of lignocellulosic materials and 1274 mg of contaminant per g of fossil materials. Isotherm validation commonly depends on several parameters. The adsorption on lignocellulosic carbonaceous materials is best described by the Langmuir isotherm. In contrast, adsorption on fossil materials is best described by the Redlich-Peterson isotherm. Advanced and classical isotherms are in good agreement in 44% of reports. [ABSTRACT FROM AUTHOR]

Abstract Nowadays, the use of natural wastes and adsorbents along with their modification by simple and new methods based on metal oxides to remove dye pollutants has been the focus of many researchers. In this study, for the first time, simple and low-cost modification of eggshell (EGS) with tungsten oxide (WO3) based on the photochemical modification method as a green, ultra-fast, cost-effective, and biodegradable adsorbent is reported to remove of methylene blue (MB) dye pollutant. The EGS modified by WO3 was investigated by EDX, EDX mapping, XRD, FE-SEM, and UV–Vis Diffuse Reflectance (DRS) analyses. The obtained results show that the modified EGS by WO3 has more than ten times (78.5%) the ability to remove MB dye pollutant within 3 min compared to bare EGS (11%). Various parameters including dye pollutant pH, dye concentration, adsorbent dosage, and reusability of the WO3/EGS adsorbent for removal of MB dye pollutant were investigated and the result show that the adsorbent capacity of WO3/EGS is 1.64 mg g−1. EGS adsorbent The synthesis of WO3/EGS adsorbent with a novel photochemical method as a fast and very cheap adsorbent with excellent efficiency can be a promising alternative adsorbent for various purposes in removing dye pollutants from water environments.

Abstract In the modern era, with the rapid growth of various industries, the issues of energy crisis and environmental pollution have garnered increasing attention. One significant source of industrial pollution is printing and dyeing wastewater. This wastewater often contains dyes that have aromatic structures and azo groups, such as Methyl orange (MO), which are both toxic and difficult to degrade. If these dyes are released into the wastewater stream without any treatment, they can have adverse effects on ecological balance and human health. Therefore, it is crucial to identify suitable treatment strategies to efficiently remove dyes from wastewater systems before discharge. In this study, the Methyl orange (MO) azo dye has been removed from dyes-contaminated wastewater, for the first time, using a novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel (AECMC). Different characterization methods, including FTIR, TGA, and DSC were used to characterize the generated AECMC compounds. The water absorption and cationic exchange capacities were assessed. Factors affecting the MO anions adsorption including MO concentration, adsorption pH, temperature, time, adsorbent dose, and agitation speed have been investigated. Moreover, the kinetics of the adsorption process was assessed by the use of three models: pseudo-first-order, Pseudo-second-order, and Elovich. Moreover, the mechanism of the adsorption process was monitored using the Intraparticle diffusion and Boyd models. Additionally, the adsorption isotherm was examined using established models such as Langmuir, Freundlich, and Temkin isotherms. The thermodynamic characteristics of the MO adsorption process have been investigated at various adsorption temperatures using the Van't Hoff model. The results obtained from the study indicate that the process of MO adsorption adhered to the Pseudo-second-order kinetic model, the Langmuir isotherm model was found to be applicable, and spontaneous and exhibited an endothermic character. In conclusion, the developed novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogels (AECMC) have successive in the removal of the MO anionic dye from contaminated wastewater.

Abstract The present investigation explores the efficacy of green algae Ulva lactuca biochar-sulfur (GABS) modified with H2SO4 and NaHCO3 in adsorbing methylene blue (MB) dye from aqueous solutions. The impact of solution pH, contact duration, GABS dosage, and initial MB dye concentration on the adsorption process are all methodically investigated in this work. To obtain a thorough understanding of the adsorption dynamics, the study makes use of several kinetic models, including pseudo-first order and pseudo-second order models, in addition to isotherm models like Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich. The findings of the study reveal that the adsorption capacity at equilibrium (q e) reaches 303.78 mg/g for a GABS dose of 0.5 g/L and an initial MB dye concentration of 200 mg/L. Notably, the Langmuir isotherm model consistently fits the experimental data across different GABS doses, suggesting homogeneous adsorption onto a monolayer surface. The potential of GABS as an efficient adsorbent for the extraction of MB dye from aqueous solutions is highlighted by this discovery. The study’s use of kinetic and isotherm models provides a robust framework for understanding the intricacies of MB adsorption onto GABS. By elucidating the impact of various variables on the adsorption process, the research contributes valuable insights that can inform the design of efficient wastewater treatment solutions. The comprehensive analysis presented in this study serves as a solid foundation for further research and development in the field of adsorption-based water treatment technologies.

Abstract In recent years, using nanomaterials based on multi-wall carbon nanotubes (MWCNT) through the activation of peroxymonosulfate (PMS) has attracted more attention to the degradation of organic pollutants. This research presented a new route for the synthesis of MWCNT/CoMn2O4 nanocomposite for the degradation of picric acid using advanced oxidation processes (AOPs). Firstly, CoMn2O4 nanoparticles were prepared and then loaded on MWCNT using ultrasonic waves. The results of various analyzes confirmed the successful loading of nanoparticles on carbon nanotubes. As the degradation process proceeds through oxidation processes, the high electronic conductivity of MWCNT and the active sites of Mn and Co in the nanocomposite play an essential role in activating PMS to generate reactive oxygen species (ROS). An investigation of the reaction mechanism in different conditions showed that the highest speed of picric acid decomposition in the presence of nanocomposite (98%) was in 47 min. However, the scavenger test showed that HO· and SO4 ·− radicals are more important in the degradation process. Meanwhile, the results showed that removing picric acid using MWCNT/CoMn2O4 was more effective than CoMn2O4 alone and confirmed the interaction effect of MWCNT nanotubes with AB2O4 nanocatalyst.

Abstract In this study, the objective was to examine the utilization of the pyrolyzed by-products biomass as an adsorbent for extracting the dye Basic Red 46 (BR 46) from a solution. The pyrolyzed by-product containing Pleurotus mutilus biomass was characterized by thermogravimetric analysis (TGA), FTIR and µXRF. Different parameters effects such as, adsorbent dose, solution pH, contact time, temperature and initial dye concentration on the adsorption capacity of the pyrolyzed by-product biomass were examined. The solution was analyzed before and after the adsorption studies. With adsorbent dose of 1 g/L, contact time of 14 min, and solution pH of 7.5, the optimum yield of 88% was achieved. In order to fit the equilibrium data, the Langmuir, Freundlich, Temkin, and Khan isotherm models were used, and in order to fit the kinetics data, the pseudo-first-order, pseudo-second-order, Elovich, and Ritchie models were employed. Statistical analysis such as R 2, RMSE, $${\chi }^{2}$$ χ 2 and ARE was used to assess which model has the best fit with the experimental data. The results demonstrated that the experimental equilibrium data are well described by the Langmuir model, and the kinetic studies indicated that the adsorption of BR46 followed the Ritchie model. The greatest BR 46 adsorption capacity determined from experimental equilibrium data was around 135 mg/g at pH = 7.5, adsorbent dosage of 1 g/L. Moreover, thermodynamic analysis has demonstrated that the adsorption process was physical, exothermic, and spontaneous in nature. These results indicated that pyrolyzed by-product biomass might be used as a cheap material to extract textile colors out of aqueous effluents.

This study describes the modification of a Polyethersulfone (PES)-based membrane by embedding TiO2 nanoparticles. The prepared composite membranes are then characterized and applied for Melechate Green Dye (MG) filtration from water to asses its filtering capabilities. The effect of TiO2 contents on the morphology and filtration performance of the prepared composite membranes was evaluated by Fourier transform infrared (FTIR), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) analysis. The blended membranes displayed improved water permeability and dye rejection compared to the plain PES. The membrane characterization results showed that compared to the plain PES membrane, the porosity of pure membrane increased from (15.1% to 34.7%) with increasing the percentage of the embedded TiO2. Then, the optical performance of the prepared membranes was examined in a cross-flow filtration system to separate MG dye from water. The filtration experiments showed that the composite PES/TiO2 membrane of 1.5 % TiO2 has the best separation performance (permeate flux of 45 L/m2.hr and dye removal efficiency of 80%)

Abstract This study explores the potential of photocatalytic degradation using novel NML-BiFeO3 (noble metal-incorporated bismuth ferrite) compounds for eliminating malachite green (MG) dye from wastewater. The effectiveness of various Gaussian process regression (GPR) models in predicting MG degradation is investigated. Four GPR models (Matern, Exponential, Squared Exponential, and Rational Quadratic) were employed to analyze a dataset of 1200 observations encompassing various experimental conditions. The models have considered ten input variables, including catalyst properties, solution characteristics, and operational parameters. The Exponential kernel-based GPR model achieved the best performance, with a near-perfect R2 value of 1.0, indicating exceptional accuracy in predicting MG degradation. Sensitivity analysis revealed process time as the most critical factor influencing MG degradation, followed by pore volume, catalyst loading, light intensity, catalyst type, pH, anion type, surface area, and humic acid concentration. This highlights the complex interplay between these factors in the degradation process. The reliability of the models was confirmed by outlier detection using William’s plot, demonstrating a minimal number of outliers (66–71 data points depending on the model). This indicates the robustness of the data utilized for model development. This study suggests that NML-BiFeO3 composites hold promise for wastewater treatment and that GPR models, particularly Matern-GPR, offer a powerful tool for predicting MG degradation. Identifying fundamental catalyst properties can expedite the application of NML-BiFeO3, leading to optimized wastewater treatment processes. Overall, this study provides valuable insights into using NML-BiFeO3 compounds and machine learning for efficient MG removal from wastewater.

Nowadays, the use of natural wastes and adsorbents along with their modification by simple and new methods based on metal oxides to remove dye pollutants has been the focus of many researchers. In this study, for the first time, simple and low-cost modification of eggshell (EGS) with tungsten oxide (WO3) based on the photochemical modification method as a green, ultra-fast, cost-effective, and biodegradable adsorbent is reported to remove of methylene blue (MB) dye pollutant. The EGS modified by WO3 was investigated by EDX, EDX mapping, XRD, FE-SEM, and UV–Vis Diffuse Reflectance (DRS) analyses. The obtained results show that the modified EGS by WO3 has more than ten times (78.5%) the ability to remove MB dye pollutant within 3 min compared to bare EGS (11%). Various parameters including dye pollutant pH, dye concentration, adsorbent dosage, and reusability of the WO3/EGS adsorbent for removal of MB dye pollutant were investigated and the result show that the adsorbent capacity of WO3/EGS is 1.64 mg g−1. EGS adsorbent The synthesis of WO3/EGS adsorbent with a novel photochemical method as a fast and very cheap adsorbent with excellent efficiency can be a promising alternative adsorbent for various purposes in removing dye pollutants from water environments. [ABSTRACT FROM AUTHOR]

The present study demonstrates the preparation of reduced graphene oxide (rGO) incorporated zirconium oxide (ZrO2) nanocomposite by using reflux method. The ZrO2/rGO was confirmed by using UV‐Vis, FT‐IR, XRD, SEM, and EDAX techniques. In photocatalysis examination, the selected Rose Bengal (RB) was degraded effectively using ZrO2/rGO composite (76 %) at 180 minutes which follows first order kinetics. The antioxidant property against 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals was found to be 97 % activity with IC50 value of 314.53 mg/mL. Electrode reversibility (EO‐ER), diffusion coefficient (D) and capacitance of rGO, ZrO2 and ZrO2/rGO were measured by cyclic voltammetry method (CV). The electrochemical sensor detection of rGO, ZrO2 and ZrO2/rGO composite were assessed in 1 M NaCl electrolyte using tartaric acid and grape juice green sensors. The prepared electrode material plays a significant role for improving dye removal, electrochemical, antioxidant and sensor detection. [ABSTRACT FROM AUTHOR]

Fruit peels from prickly pears (FPPPs), a common agricultural waste, were utilized as an inexpensive adsorbent to extract cationic dye (PTZQ) from solution via adsorption. The effects of adsorbent dose (30–500 mg), pH (2–12), temperature (25–75 °C), time of contact (30–180 min), and all these variables were investigated. pH 8.0, temperature 25 °C, the time of contact of 90 min, and the dose of adsorbent 100 mg were the ideal circumstances for the removal efficiencies of dye (96%). Prickly pear fruit peels (FPPPs) powder was identified as a possible cationic dye adsorbent in solution based on the values of equilibrium thermodynamic and kinetic parameters computed after adding the data of adsorption. The Freundlich and Langmuir models were utilized to analyze the data from the experiment and the data of the isotherm fit with the isotherm of Langmuir with an adsorption capacity for monolayers of 155 mg/g. The data collected from kinetics were examined utilizing a pseudo-first-order and pseudo-second-order equation at different doses as well as an equation for intraparticle diffusion. The data of experimental fit the kinetic model with pseudo-second order extremely well. FPPP was discovered to be a very successful adsorbent for the adsorption of PTZQ. [ABSTRACT FROM AUTHOR]

This study addresses the critical issue of removing toxic dyes from industrial wastewater to protect the environment and human health. To address this challenge, a bio‐based composite hydrogel was synthesized using gamma irradiation, 20 kGy, incorporating multiwalled carbon nanotubes@pectin/κ‐carrageenan/polyacrylic acid (MWCNTs PC/KC/PAAc) for removing methylene blue (MB) dye from aqueous solutions. The prepared composites underwent characterization through Fourier‐transform infrared spectroscopy, x‐ray diffraction, and thermogravimetric analyses. Brunauer–Emmett–Teller analysis demonstrated a significant increase in surface area upon the addition of MWCNTs. Specifically, the surface area increased from 342.5 m2 g−1 for PC/KC/PAAc to 689.5 m2 g−1 when 0.175 wt% of MWCNTs were added. Also, scanning electron microscopy and atomic force microscopy were utilized to examine the surface topography of PC/KC/PAAc and MWCNTs@PC/KC/PAAc. The results reveal that at 0.175 wt% of MWCNTs, there was a more uniform surface topography with well‐distributed MWCNTs within the matrix. In the adsorption study of MB dye, it was found that the highest MB removal efficiency was achieved at pH 11, with values of 68.21% and 96% for PC/KC/PAAc and MWCNTs@PC/KC/PAAc, respectively. Furthermore, upon studying the effect of MWCNTs (%), the results showed that the removal (%) of PC/KC/PAAc was 68.21 ± 1.02%, and this percentage increased rapidly with the addition of MWCNTs, reaching a maximum of 96 ± 0.85% when 0.175 (wt%) of MWCNTs was added. Isotherm and kinetic modeling demonstrated that MB adsorption follows the Freundlich isotherm for PC/KC/PAAc and the Redlich–Peterson isotherm for MWCNTs@PC/KC/PAAc, both following a pseudo‐second‐order kinetics model. In addition, from AFM data, after MB removal, the height increased significantly from 322 nm for PC/KC/PAAc to 810 nm for MWCNTs@PC/KC/PAAc (0.175 wt%), indicating a substantially higher adsorption of MB by MWCNTs@PC/KC/PAAc. [ABSTRACT FROM AUTHOR]

The development of superior thin‐film nanocomposite (TFN) membranes with good separation performance and anti‐fouling capacity is required to address the larger‐scale freshwater need. In this study, a new citric acid‐functionalized FSM‐16 (CA‐FSM‐16) mesoporous was successfully synthesized and characterized. Subsequently, it was introduced on the surface of the sodium hydroxide/cyanuric chloride‐activated PES membrane to fabricate the CA‐FSM‐16 TFN membrane. It was investigated how various CA‐FSM‐16 loadings affected the overall physicochemical characteristics and performance of the membrane. The SEM analysis confirmed the TFN structure of the fabricated membranes. All manufactured membranes displayed improved hydrophilicity and flux. For the pristine membrane, the salt (Na2SO4) rejection was measured 73.20 ± 2.10%, whereas for the TFN‐0.08 membrane, it was measured 91.40 ± 1.80%. The dye rejection experiment in cross‐flow filtration showed that the TFN‐0.08 membrane had the maximum licorice retention among the membranes (99.10 ± 2.00%). In addition, the CA‐FSM‐16 TFN membranes demonstrated superior antifouling performance, especially the optimum membrane (TFN‐0.08), which showed a high flux recovery ratio (FRR) of 97.10 ± 1.90% and a low irreversible fouling ratio (DRir) of 2.90%. The introduction of CA‐FSM‐16 on the surface of the PES membrane via the surface modification method was a potentially useful technology to fabricate a high‐performing TFN membrane for water treatment applications. [ABSTRACT FROM AUTHOR]

Wastewater from the textile and dyeing industries contains hazardous dyes. This study aims to determine the effectiveness of magnetic biochar nanocomposites synthesized from khat leftovers (KLs) and coffee husks (CHs) in removing methylene blue (MB) from wastewater. Magnetic biochar nanocomposites were synthesized by pretreating 25 g of biomass with a 12.5 mmol mixture of FeS and FeCl3 at a 1:1 molar ratio, followed by pyrolyzing at 300°C for 1 h. The resulting products were analyzed using X‐ray diffraction, Fourier transform infrared, scanning electron microscope, and Brunauer‐Emmett‐Teller. The results showed that the adsorbents are amorphous, and the activated biochars, are more porous and contain various functional groups such as C‐O, C = C, O‐H, C‐H, and Fe‐O. When 0.2 g of pristine biochars of CH and KL were applied to 20 mL aqueous solutions containing 20 mg/L of MB at pH 7.5 and 25°C, they removed 44.73% and 75.26% of MB, respectively. However, the resulting nanocomposites exhibited a maximum removal efficiency of 99.10% and 99.23% with magnetic iron oxide‐CH biochar nanocomposite (Fe3O4‐CHBNC) and magnetic iron oxide‐KL biochar nanocomposite (Fe3O4‐KLBNC), respectively, with maximum adsorption capacities of 51.02 and 78.13 mg/g. The reusability study also showed removal efficiencies of 77.57% and 83.49% up to six‐cycle reuse. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of a copper-based layered double hydroxide (Cu-LDH) composite via the coprecipitation method. The composite material aimed to effectively remove the anionic dye "Coomassie Brilliant Blue" (CBB) and exhibit antibacterial properties against both gram-positive and gram-negative bacteria. The synthesized nanocomposites were characterized using various techniques. The adsorption of CBB dye was investigated by studying various physicochemical variables, including contact time, pH of the dye solution, and initial dye concentration. The optimal dosage and contact time for efficient CBB dye removal were determined as 0.07 g and 10 min, respectively. The results showed that Cu-LDHs exhibited a high adsorption capacity for CBB dye, with a maximum removal efficiency of 85% which could be achieved within 10 min, and the Cu-LDHs improved an experimental adsorption capacity at equilibrium qmax = 80 mg/g. The adsorption process followed a pseudo-second-order kinetic model. The Langmuir isotherm model provided a good fit to the equilibrium data, indicating monolayer adsorption. Furthermore, the antibacterial activity of Cu-LDHs was assessed against various bacterial strains using a diffusion method. The results demonstrated the inhibitory effects of Cu-LDHs and CBB-Cu-LDHs on bacterial growth at a dosage of 10 mg, indicating the potential of Cu-LDHs as antibacterial agents. The underlying mechanisms responsible for dye adsorption and antibacterial activity were discussed. [ABSTRACT FROM AUTHOR]

Psidium guajava (Guava) is a commonly cultivated fruit in tropical regions that has been long recognized for its therapeutic applications. The leaves host diverse bioactive compounds, including phenols, flavonoids, terpenoids like gallic acid, and watersoluble tannins. This intricate chemical profile, particularly gallic acid, imparts the leaves with remarkable inhibitory effects against various pathogens, including bacteria and fungi. Compounds such as pyrocatechol, taxifolin, psiguadials, guaijaverin, and avicularin, among others, contribute to their hypoglycemic, antioxidant, anticancer, and antidiarrheal effects, showcasing the leaves' multifaceted therapeutic potential. Apart from having therapeutic potential, guava leaves have also been implicated in adsorbing heavy metals such as zinc, cadmium, arsenic, lead, iron, and chromium, as well as dyes such as methylene blue, congo red, brilliant green, amaranth, auramine, nile blue and photocatalytic dyes from contaminated water sources owing to their porous structure and presence of functional groups. The leaves contain compounds acting as natural coagulants and adsorbents, aiding in flocculation, sedimentation, and removal of impurities. This review aims to provide an overview of the phytochemical profile of guava leaves and further discusses its potential as a therapeutic drug and bioremediation targeting heavy metals and dyes. This eco-friendly approach offers numerous advantages, including affordability, accessibility, and biodegradability, thereby reducing reliance on synthetic adsorbents and promoting sustainability. This amalgamation of traditional medicinal significance with innovative environmental applications underscores the inherent potential of guava leaves as a sustainable and versatile botanical resource. Moreover, the various ongoing studies and the diverse properties of guava discussed herein may serve as a guide for the discovery of new pharmaceutics by the scientific fraternity. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils/poly(N-Isopropylacrylamide) semi-interpenetrating networks (MMCNF-PNAs) were synthesized using an in situ fabrication (semi-IPN). The polymerization of N-isopropylacrylamide (NIPAM) (free radical) was conducted in the presence of magnetic modified cellulose nanofibrils (MMCNFs). The adsorption behaviors and surface morphology of the synthesized adsorbents were investigated systematically. The adsorption behaviors of the as-prepared MMCNF-PNA towards methylene blue (MB, as the model contaminant) dye was studied, and the optimal adsorption conditions were also studied. The adsorption processes could be well fitted using pseudo-second-order and Elovich kinetic models. Meanwhile, Langmuir and Freundlich isotherm models were used to fit the adsorption which occurred at 25, 37 and 65 °C. The corresponding results showed that the Freundlich isotherm model fitted the adsorption process better, indicating that the dye's adsorption happened via heterogeneous adsorptive energies on the prepared MMCNF-PNAs. Their desorption and reusability were also studied to verify magnetic responsivity. To sum up, MMCNF-PNAs are promising magnetic and thermal stimuli-responsive adsorbents, showing a controlled adsorption/desorption process. [ABSTRACT FROM AUTHOR]