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This study reviews the concept, classifications, and techniques involved in the synthesis of nanocomposites. The environmental and health implications of nanoparticles and composite materials were detailed, as well as the applications of nanocomposites in water remediation, antibacterial application, and printed circuit boards. The study gave insights into the challenges of water pollution treatment and provided a broad list of nanocomposites that have been explored for water remediation. Moreover, the emergence of multi-drug resistance to many antibiotics has made current antibiotics inadequate in the treatment of disease. This has engineered the development of alternative strategies in the drug industries for the production of effective therapeutic agents, comprising nanocomposites with antibacterial agents. The new therapeutic agents known as nanoantibiotics are more efficient and have paved the way to handle the challenges of antibiotic resistance. In printed circuit boards, nanocomposites have shown promising applications because of their distinct mechanical, thermal, and electrical characteristics. The uniqueness of the write-up is that it provides a broad explanation of the concept, synthesis, application, toxicity, and harmful effects of nanocomposites. Thus, it will provide all-inclusive awareness to readers to identify research gaps and motivate researchers to synthesize novel nanocomposites for use in various fields. HIGHLIGHTS The size of nanocomposites makes them ideal for different applications.; The applications of nanocomposites in water treatment, antibacterial activity, and printed circuit boards are detailed.; There are concerns about the environmental and health implications of nanomaterials.; The review gave insights into the challenges, research gaps, future considerations, and health implications of nanocomposites.;

Abstract Many charged organic molecules behave as persistent and hazardous pollutants with harmful effects on human health and ecosystems. They are widely distributed related to their charged molecular structure that provides water solubility. In order to track the fate and behavior of such pollutants, charged dyes with specific absorption in the visible spectra serve as convenient model compounds. We provide a platform of smart adsorbers that efficiently remediate positively and negatively charged dyes (crystal violet and Amaranth) from water. Metal oxide nanoparticles serve as a core with an intrinsically large surface area. The surface potential was tuned towards positive or negative by decorating the cores with self‐assembled monolayers of dedicated long‐chained phosphonic acid derivatives. Selective remediation of the dyes was obtained with corresponding oppositely charged core‐shell nanoparticles. Mixed dye solution can be cleaned by a cascade approach or by applying both particle systems simultaneously. The removal efficiency was determined as a function of particle concentration via UV‐spectroscopy. The results of remediation experiments at different pH values and using superparamagnetic iron oxide nanoparticle cores lead to a simple process with recycling capability.

During the last decades, technologies for agricultural drainage water remediation had been widely explored to oppose the arising intimidation of their pollutants on health, biotas and farming sustainability. The present study targeted to augment the remediation competence of inorganic pollutants and faecal coliforms from agricultural drainage water using different types of clay minerals. Kaolinite, Bentonite, Ball clay and Aswan clay were used either solely or in amalgamation with some biological premeditative amendments (cultures of Phosphate dissolving Bacteria (PDB) and/or Acidithiobacillus sp.] for drainage water remediation of samples delivered from Belbies and Rahawy agricultural drains. Nineteen trails and four groups were implemented for each drain together with a control sample. Water samples were analysed before and after clay minerals' trails application for detection of Cd(II), Cu(II), Ni(II), Zn(II) and As(V) by Atomic Spectroscopy. Total faecal bacteria presence was also quantified through direct culturing on MacConkey agar plates. The obtained results confirmed a significant decrease in the concentrations of Cd, Cu, Ni, Zn and As pollutants as well as a decrease in the faecal coliform intensities under all trailed treatments compared to control samples. Worthy to mention that 4th group and especially T18 (Bentonite + Acidithiobacillus+ phosphate dissolving bacteria) was the most efficient in minimising the hazards of PTEs and the existence of faecal microbes. [ABSTRACT FROM AUTHOR]

The escalating concentration of hazardous Cr-(VI) and pharmaceutical waste in water bodies underscores the imperative need to advance sustainable, cost-effective, and recyclable technologies to eliminate these pollutants from wastewater, thereby ensuring the safety and purity of drinking water supply. We have constructed an amine-rich, highly robust, reusable, porous three-dimensional nanosized (15–35 nm) Zr-(IV) metal–organic framework (1′) for selective and eco-friendly removal of lethal Cr-(VI) oxo-anions and pharmaceutical waste (i.e., ibuprofen) from the aqueous medium at neutral pH (pH 7). 1′ exhibits a highly positive charged surface, entraps toxic anionic Cr-(VI) oxo-anion pollutants over its surface in a reversible manner, and converts them into less toxic Cr-(III) species, within less than 30 s. The equilibrium adsorption capacities (qe) of 1′ for CrO42–, Cr2O72–, and ibuprofen were 223.4, 146.6, and 323.3 mg/g (according to Langmuir fitting), respectively, which are among the highest sorption capacities achieved by MOF adsorbents. With faster adsorption kinetics, 1′ showed a negligible effect in adsorption performance even in the coexistence of 50 times excess concentration of other possible anionic species. Further, the potential removal of CrO42–, Cr2O72–, and ibuprofen from complicated environmental water samples was executed by 1′ with negligible change in efficiency. Furthermore, an ion exchange silica-based reusable column was constructed with a 1% loading of 1′ for efficient and rapid removal of oxo-anions on a larger scale. The ion exchange column efficiently removes Cr-(VI) oxo-anions and enables us to lower the concentration of Cr-(VI) in drinking water to levels below the prescribed threshold (100 ppb, as per US-EPA recommendation). In addition, the probable mechanisms behind the adsorption-based removal of Cr-(VI) oxo-anions and the organic pollutant ibuprofen by cationic 1′ were systematically inspected through various instrumental techniques. [ABSTRACT FROM AUTHOR]

We report the preparation of a Luffa cylindrica/polypyrrole (LC/PPy) composite and its use for the removal of tartrazine dye (E102) from aqueous media. By use of Fourier transform infrared (FTIR) and energy‐dispersive X‐ray (EDX) spectroscopies, X‐ray diffraction (XRD) and scanning electron microscopy (SEM), we were able to confirm that the PPy chains thoroughly coat the LC matrix, with the composite presenting both amorphous and crystalline phases such as pristine LC. We examined the effects of varying parameters, such as the times allotted for the polymerization and the dye–adsorbent interaction, the E102 initial concentration and the temperature and pH of the solution, on the removal capacity (qe) of the composite. The largest adsorption rate was exhibited by the composite resulting from a 30 min polymerization. At 298 K, the highest value of qe (374.2 mg g−1) occurred at pH 2.0, after 360 min of interaction. The adsorption process occurs spontaneously and is favored by an increase in temperature, with qe = 672.4 mg g−1 at 313 K. We determined that the composite could be used in at least five consecutive adsorption–desorption cycles without noticeable losses of properties. Preliminary experiments indicate that good results were also obtained for the removal of the dyes Remazol Black B, methylene blue and toluidine blue. Overall, these results suggest that the LC/PPy composite is a promising material for use in protocols of removal of dyes from aqueous media. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The protection of all environmental compartments (water, soil, air) is of great interest for the normal functioning of life on Earth. The environment is systematically polluted with different concentrations of physical, biological and chemical pollutants. For the purpose of environmental protection, numerous in situ and ex situ biological, chemical and physical remediation techniques have been developed. Most techniques have limitations, such as high cost, processing time or environmental feasibility. In general, biological techniques have proven to be the most environmentally friendly compared to chemical and physical techniques. Furthermore, remediation is an extremely complex procedure due to the complexity of the pollutant composition. Therefore, the implementation of individual physical, biological or chemical remediation techniques is often not sufficient for adequate remediation of the polluted environment. Accordingly, for more economical and efficient environmental remediation, it is recommended to use a combination of techniques that should meet the requirements of efficiency and treatment duration. Ultimately, this review provides a concise overview of the recent application of physical, biological and chemical remediation techniques to all compartments of the polluted environment. A critical review of existing knowledge on environmental remediation through a search of the relevant literature has helped to assess the basic challenges and limitations that arise in the issue of environmental remediation, as well as providing recommendations and guidelines for future research. [ABSTRACT FROM AUTHOR]

Pollution of water sources with heavy metals is a pressing environmental issue. To this end, various procedures are being used to remediate water, including sorption. The aim of this study was to investigate the effectiveness of humic acids (HAs) and fulvic acids (FAs) for the removal of metals from water. Specifically, HA and FA were examined for their potential to be used as sorbent materials for 26 heavy metals, alkali metals, and alkaline earth metals. HA and FA were isolated from lignite samples from two mines (Mavropigi mine and South Field mine, Kozani, West Macedonia, Greece). Experiments were carried out using natural mineral water without pH adjustment, so as to gain a better overview of the sorption efficiency in real-life samples. The results showed that FAs were able to sorb most of the examined metals compared to HAs. Several metals such as Ba (34.22–37.77%), Ca (99.12–99.58%), and Sr (97.89–98.12%) were efficiently sorbed when 900 ppm of FAs from both sources were used but were not sorbed by HAs from any source (≤0.1%). Due to the functional groups on the surface of FA, it is plausible to conclude that it can remove more metals than HA. Meanwhile, lignite from the South Field mine was found to be more efficient for the sorption efficiency in lower concentrations (300–600 ppm), whereas lignite from the Mavropigi mine was more effective in higher concentrations (900 ppm). For instance, higher removal rates were observed in Mo (62.84%), Pb (56.81%), and U (49.22%) when 300 ppm of HAs of South Field mine were used, whilst the employment of 900 ppm of HAs from Mavropigi mine led to high removal rates of As (49.90%), Se (64.47%), and Tl (85.96%). The above results were also reflected in a principal component analysis, which showed the dispersion of the metal parameters near to or far from the HA and FA parameters depending on their sorption capacity. Overall, both HA and FA could be effectively utilized as sorbent materials for metal removal from water samples. The results of the research indicate a potential application to the remediation of water from metals under dynamic conditions in order to protect public health. [ABSTRACT FROM AUTHOR]

The rapid increase in industrialization and human population is leading to critical levels of environmental pollutants, such as agrochemicals or heavy metals, which affect the preservation and integrity of ecosystems, the accessibility to drinking water sources, and the quality of the air. As such, remediation of these issues demands strategies for implementing and designing novel technologies. In that regard, nanomaterials have unique physicochemical properties that make them desirable candidates for the detection and remediation of environmental pollutants. The scope of this review is to provide an analysis of the available nanomaterials that are being used as an approach to detect and remediate hazardous residues, comprising systems such as noble metals, biosensors, cyclodextrin-based polymers, and graphene oxide nanocomposites, to name a few. Furthermore, this work discusses said nanomaterials in terms of their effectiveness, sustainability, and selectivity as a guideline for researchers wishing to indulge in this relevant study area. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) is a highly versatile polymer used for water remediation due to its chemical robustness and processability. By incorporating metal‐organic frameworks (MOFs) into PVDF‐HFP membranes, the material can gain metal‐adsorption properties. It is well known that the effectiveness of these composites removing heavy metals depends on the MOF's chemical encoding and the extent of encapsulation within the polymer. In this study, it is examined how the micro to nanoscale structure of PVDF‐HFP@MOF membranes influences their adsorption performance for CrVI. To this end, the micro‐ and nanostructure of PVDF‐HFP@MOF membranes are thoroughly studied by a set of complementary techniques. In particular, small‐angle X‐ray and neutron scattering allow to precisely describe the nanostructure of the polymer‐MOF complex systems, while scanning microscopy and mercury porosimetry give a clear insight into the macro and mesoporosity of the system. By correlating nanoscale structural features with the adsorption capacity of the MOF nanoparticles, different degrees of full encapsulation‐based on the PVDF‐HFP processing and structuration from the macro to nanometer scale are observed. Additionally, the in situ functionalization of MOF nanoparticles with cysteine is investigated to enhance their adsorption toward HgII. This functionalization enhanced the adsorption capacity of the MOFs from 8 to 30 mg·g−1. [ABSTRACT FROM AUTHOR]

Efficient removal of toxic dyes from wastewater is crucial for environmental protection. Laccases are enzymes that have been proposed as potential solutions to reduce the devastating effects of toxic dyes with recalcitrant structures present in complex wastewater. However, instability of laccases has been identified as a major issue. This study aimed to develop a carrier matrix based on Co-doped NiO NPs to improve the stability of the metagenome-derived laccase PersiLac1 and achieve high removal efficiency of Azo dye-containing wastewater. The immobilization of laccase led to improved enzymatic activity over a broader range of pH and temperature. After 15 reuse cycles, the immobilized enzyme retained 57.99 % of its initial activity. The immobilized enzyme demonstrated great potential for the biodecolorization of Congo red over broad pH and temperature ranges, with 66.23 % decolorization achieved after 60 min under optimal conditions. Treatment with real textile wastewater containing an extremely high concentration of Azo dye resulted in more than 92 % dye removal. After 20 cycles of operation, the immobilized enzyme retained 87.66 % of its initial decolorization capability. This study presents Co-doped NiO NPs-PersiLac1 as an efficient, stable, and cost-effective biocatalytic system for Azo dye-containing removal processes in textile effluents. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent decades, nanoscale zero-valent iron (nZVI) has been extensively studied for application in environmental remediation because it is an eco-friendly, inexpensive nanomaterial with high reactivity. The chemical reduction of iron ions using NaBH4 in a liquid solution is the most frequently used method to obtain nZVI, but its drawbacks are the use of expensive and toxic NaBH4 and the secondary pollution caused by the B(OH)3 by-product. In this study, in order to obtain nZVI in a cleaner manner, we used a reduction method for Fe2O3 using CaH2, which is non-toxic and generates no pollutants. The results of X-ray diffraction, nitrogen adsorption, and scanning electron microscopy for the obtained samples indicated the formation of zero-valent iron nanopowder (22.5 m2/g) that was obtained via reduction at 220 °C for 5 h. The obtained nZVI was finally tested in the catalytic hydrogenation of p-nitrophenol as a model reaction of water remediation, verifying its good catalytic performance. [ABSTRACT FROM AUTHOR]

In this work, the photocatalytic activity of bismuth-doped lanthanum ferrite, La1-xBixFeO3 (0 ≤ x ≤ 0.5), synthesized by high-energy ball milling assisted by annealing, is reported. X-ray diffraction and Rietveld refinement confirmed that pure lanthanum ferrite with an orthorhombic structure (Pbnm) was obtained for dopant levels lower than 0.2 mol Bi3+. Higher dopant levels produce the transformation from LaFeO3 to BiFeO3 with the same orthorhombic structure (Pnma), and consequently, a mixture of phases is present in these compositions. The band gap values obtained from diffuse reflectance spectroscopy show a general decrease as bismuth content increases, from 2.10 eV for undoped to 2.00 eV for 0.5 mol doped. For any increase in Bi3+ concentration, all values indicate visible-light absorption. LaFeO3 synthesized powders show high photocatalytic degradation of methylene blue under visible light. Nevertheless, the synthesized bismuth-doped ferrites show a slight decrease, attributed to (i) the modification in the band gap, (ii) the change in the band gap border, and (iii) the presence of a mixture of phases, inducing a heterojunction effect. [ABSTRACT FROM AUTHOR]

POLLUTION creates world-wide environmental and human health concerns. Biochar (BC) and nanobiochar (NBC) may be used in the production of smart materials that may revolutionize remediation research. BC’s ability to adsorb pollutants makes it an attractive cost-effective soil treatment option. To improve BC properties and composition, it is activated and modified by regulating pyrolysis or with the addition of various compounds such as metal nanoparticles (NPs), magnetite, and nano zero-valent iron. In comparison to BC, NBC has a superior capacity to adsorb contaminants and nutrients, making it a suitable waste management option. Food waste represents one-third of the food produced globally and is a promising potential source of BC. In this review, some trends are identified and assessed, such as production of BC by biomass pyrolysis. Applications in soil and water remediation and their mechanisms are also discussed. The production of BC and NBC from low-cost materials, compared to expensive traditional remediation, provides inexpensive, meaningful treatment options for a range of contaminants in soil and water. We concluded that BC and NBC have high potential to remove contaminants in soil and water due to their distinctive characteristics. [ABSTRACT FROM AUTHOR]

The necessity of mining valuable metals must be balanced with the safe and effective disposal or remediation of the resulting waste. Water, one of our most valuable resources, is a major component of the mining process, and its post-operation storage often results in acid mine drainage. While many remediation methods have been studied, they have low economic feasibility, as minimally active methods alone were inadequate, and thus required additional, costly active methods for effective neutralization. This study looks to neutralize acid mine drainage with only minimally passive methods, through an optimized dosage of lime, fly ash, and aluminum hydroxide. Wastewater samples of pH 3.62 and 5.03, containing 1.36 and 2.21 percent sulfides, respectively, were experimentally treated, with the utilized dosage parameters generated using the Monte Carlo method for neutralizing acidity. The remediated water samples presented 0.01% and 0.16% sulfur content values, which corresponds to 99.3% and 92.8% reductions, respectively. These results present, for the first time, that minimally active methods could achieve a pH of 8.5 without active methods. While future studies should validate these results and provide a more complete characterization of the water samples, the major challenge of neutralization was addressed, and, thus, these results contribute process incentives for mining companies to economically remediate their waste water in order to safeguard their surrounding communities and return valuable water back to the water cycle. [ABSTRACT FROM AUTHOR]

In this study, an innovative approach for the integration of silver nanoparticles (AgNPs) into poly(ethylene glycol) diacrylate (PEGDA) hydrogels is described. The composite material is the first in the literature where AgNPs were doped into PEGDA using photo-polymerization technique for a double function: detection and elimination of Hg(II) ions from water. The doping of AgNPs into PEGDA-based matrices was performed using a photo-polymerizable process. The Hg(II) sensing properties were explored in a concentration range from 0 to 20 mg/L. Notably, a linear dependence was observed up to 1 mg/L, accompanied by a limit of detection of 0.3 mg/L. Beyond sensing, the efficiency of the doped hydrogel in removing Hg(II) ions was also investigated and compared with an undoped PEGDA matrix. The outcome highlighted an enhanced removal efficiency of the doped material of approximately 23%. Finally, the experimental data suggested that the interaction between Hg(II) ions and the modified hydrogel adhered to the Langmuir isotherm model, which suggested that chemisorption was the driving mechanism of the adsorption of Hg(II) onto the modified hydrogel matrix. [ABSTRACT FROM AUTHOR]

Highlights The recent development and implementation of metal–organic frameworks (MOFs) and MOF-based materials in electrochemical water applications are reviewed. The critical factors that affect the performances of MOFs in the electrochemical reactions, sensing, and separations are highlighted. Advanced tools, such as pair distribution function analysis, are playing critical roles in unraveling the functioning mechanisms, including local structures and nanoconfined interactions. Abstract Metal–organic frameworks (MOFs), a family of highly porous materials possessing huge surface areas and feasible chemical tunability, are emerging as critical functional materials to solve the growing challenges associated with energy–water systems, such as water scarcity issues. In this contribution, the roles of MOFs are highlighted in electrochemical-based water applications (i.e., reactions, sensing, and separations), where MOF-based functional materials exhibit outstanding performances in detecting/removing pollutants, recovering resources, and harvesting energies from different water sources. Compared with the pristine MOFs, the efficiency and/or selectivity can be further enhanced via rational structural modulation of MOFs (e.g., partial metal substitution) or integration of MOFs with other functional materials (e.g., metal clusters and reduced graphene oxide). Several key factors/properties that affect the performances of MOF-based materials are also reviewed, including electronic structures, nanoconfined effects, stability, conductivity, and atomic structures. The advancement in the fundamental understanding of these key factors is expected to shed light on the functioning mechanisms of MOFs (e.g., charge transfer pathways and guest–host interactions), which will subsequently accelerate the integration of precisely designed MOFs into electrochemical architectures to achieve highly effective water remediation with optimized selectivity and long-term stability.

Pesticides pose a significant threat to nontargeted organisms, and their pervasive use makes avoidance challenging. We employed nitrogen-doped carbon cryogels for the removal of organophosphate pesticides. The materials were synthesized and characterized using SEM, Raman spectroscopy, XPS, and BET analysis. Results revealed mesoporous cryogels with pore diameters ranging from 3 to 13 nm. Interestingly, the specific surface area did not change systematically with increasing nitrogen content. All investigated materials have similar composition and structural disorder. Dimethoate, malathion, and chlorpyrifos removal was investigated under stationary and dynamic conditions. Stationary conditions demonstrated successful removal of aliphatic dimethoate and malathion by all investigated materials. Conversely, the materials with the lowest and highest nitrogen content proved ineffective with aromatic chlorpyrifos. Under dynamic conditions, all materials effectively removed malathion and chlorpyrifos while exhibiting suboptimal performance for dimethoate adsorption. Application of nitrogen-doped carbon cryogels to tap water spiked with pesticides yielded successful results under the same conditions. Toxicity testing of treated samples revealed a consistent decrease in toxicity, indicating that contact with cryogels reduces the initial solution’s toxicity. This result also confirms that material–pesticide interaction does not lead to the formation of more toxic byproducts. The demonstrated efficacy suggests the potential application of these materials in water treatment.

Endophytic microorganisms contribute significantly to water bioremediation by enhancing pollutant degradation and supporting aquatic plant health and resilience by releasing bioactive compounds and enzymes. These microorganisms inhabit plant tissues without causing disease or any noticeable symptoms. Endophytes effectively aid in eliminating contaminants from water systems. Nanoparticles serve as potent enhancers in bioremediation processes, augmenting the efficiency of pollutant degradation by increasing surface area and bioavailability, thereby improving the efficacy and rate of remediation. Their controlled nutrient release and ability to stabilize endophytic colonization further contribute to the enhanced and sustainable elimination of contaminated environments. The synergistic effect of endophytes and nanoparticles in water remediation has been widely explored in recent studies, revealing compelling outcomes. Water pollution poses significant threats to human health, ecosystems, and economies; hence, the sixth global goal of the Sustainable Development Agenda 2030 of the United Nations aims to ensure the availability and sustainable management of water resources, recognizing their crucial importance for current and future generations. Conventional methods for addressing water pollution exhibit several limitations, including high costs, energy-intensive processes, the production of hazardous by-products, and insufficient effectiveness in mitigating emerging pollutants such as pharmaceuticals and microplastics. Noticeably, there is an inability to effectively remove various types of pollutants, thus resulting in incomplete purification cycles. Nanoparticle-enhanced water bioremediation offers an innovative, eco-friendly alternative for degrading contaminants. A growing body of research has shown that integrating endophytic microorganisms with nanoparticles for water bioremediation is a potent and viable alternative. This review examines the potential of using endophytic microorganisms and nanoparticles to enhance water remediation, exploring their combined effects and applications in water purification. The paper also provides an overview of synthetic methods for producing endophyte–nanoparticle composites to optimize their remediation capabilities in aqueous environments. The final section of the review highlights the constraints related to integrating endophytes with nanoparticles.

Contamination by pharmaceuticals adversely affects the quality of natural water, causing environmental and health concerns. In this study, target drugs (oxazepam, OZ, 17-α-ethinylestradiol, EE2, and drospirenone, DRO), which have been extensively detected in the effluents of WWTPs over the past decades, were selected. We report here a new photoactive system, operating under visible light, capable of degrading EE2, OZ and DRO in water. The photocatalytic system comprised glass spheres coated with nanostructured, solvothermally treated WO3 that improves the ease of handling of the photocatalyst and allows for the implementation of a continuous flow process. The photocatalytic system based on solvothermal WO3 shows much better results in terms of photocurrent generation and photocatalyst stability with respect to state-of-the-art WO3 nanoparticles. Results herein obtained demonstrate that the proposed flow system is a promising prototype for enhanced contaminant degradation exploiting advanced oxidation processes.

We modified C3-symmetric benzene-1,3,5-tris-amide (BTA) by introducing flexible linkers in order to generate an N-centered BTA (N-BTA) molecule. The N-BTA compound formed gels in alcohols and aqueous mixtures of high-polar solvents. Rheological studies showed that the DMSO/water (1:1, v/v) gels were mechanically stronger compared to other gels, and a similar trend was observed for thermal stability. Powder X-ray analysis of the xerogel obtained from various aqueous gels revealed that the packing modes of the gelators in these systems were similar. The stimuli-responsive properties of the N-BTA towards sodium/potassium salts indicated that the gel network collapsed in the presence of more nucleophilic anions such as cyanide, fluoride, and chloride salts at the MGC, but the gel network was intact when in contact with nitrate, sulphate, acetate, bromide, and iodide salts, indicating the anion-responsive properties of N-BTA gels. Anion-induced gel formation was observed for less nucleophilic anions below the MGC of N-BTA. The ability of N-BTA gels to act as an adsorbent for hazardous anionic and cationic dyes in water was evaluated. The results indicated that the ethanolic gels of N-BTA successfully absorbed methylene blue and methyl orange dyes from water. This work demonstrates the potential of the N-BTA gelator to act as a stimuli-responsive material and a promising candidate for water purification.

Introduction: One of the most attractive fields for cellulose aerogels is water remediation, basically in the pollutant’s adsorption and oil/water separation. There are different sources to extract cellulose, but the extraction from paper waste is an excellent option for impulse circular materials applications.Methods: We obtained cellulose from office waste paper through a simple alkali method and used it to fabricate an aerogel by freeze-drying based on the materials’ circularity. To increase lipophilicity, the aerogel was modified using two different coatings: polycaprolactone (WOPP) and candelilla wax (WOPW), extracted from a Mexican plant. The aerogels were analyzed by several physicochemical techniques such as Scanning Electronic Microscopy, Infrared spectroscopy, and thermal analysis.Results and Discussion: To our knowledge, this is the first time that candelilla wax has been reported as aerogel modification. The highly porous aerogels showed a density of around 0.1 g/cm3 and a fibrous structure. Furthermore, the contact angle of the aerogels was measured to compare the hydrophobicity of the surfaces, showing values around 120° in the modified aerogels compared with the hydrophilic behavior of pristine cellulose aerogel. The achieved recycled mineral oil absorption capacity for WOPW was 6.1 g/g, while for WOPP was 4.88 g/g. Thus, we obtained a natural coating aerogel with a high water/oil separation potential.

Abstract Poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) is a highly versatile polymer used for water remediation due to its chemical robustness and processability. By incorporating metal‐organic frameworks (MOFs) into PVDF‐HFP membranes, the material can gain metal‐adsorption properties. It is well known that the effectiveness of these composites removing heavy metals depends on the MOF's chemical encoding and the extent of encapsulation within the polymer. In this study, it is examined how the micro to nanoscale structure of PVDF‐HFP@MOF membranes influences their adsorption performance for CrVI. To this end, the micro‐ and nanostructure of PVDF‐HFP@MOF membranes are thoroughly studied by a set of complementary techniques. In particular, small‐angle X‐ray and neutron scattering allow to precisely describe the nanostructure of the polymer‐MOF complex systems, while scanning microscopy and mercury porosimetry give a clear insight into the macro and mesoporosity of the system. By correlating nanoscale structural features with the adsorption capacity of the MOF nanoparticles, different degrees of full encapsulation‐based on the PVDF‐HFP processing and structuration from the macro to nanometer scale are observed. Additionally, the in situ functionalization of MOF nanoparticles with cysteine is investigated to enhance their adsorption toward HgII. This functionalization enhanced the adsorption capacity of the MOFs from 8 to 30 mg·g−1.

The paper emphases on the removal of Reactive Blue 194 dye (RB-194) using different process variables alone and in combination as well. A Cs-137 γ-radiation source was used to treat RB-194 at a dose rate of 669 Gy/h (Gray/h) with 1-10 kGy irradiation dose in the presence of (0.2-0.6 mL) hydrogen peroxide. The optimization of various process variables such as pH, γ-radiations absorbed dose, initial concentration of RB-194 and concentration of H2O2 were done to achieve thoroughgoing degradation. The dye was considerably degraded (79%) by γ-radiation but the addition of 0.6 mL H2O2 increased the degradation to 97% at a 10 kGy irradiation dose in acidic pH. The Fourier-transform infrared spectroscopy technique confirmed the presence of various useful groups. The fragmented by-products of RB-194 produced by irradiation at a 10 kGy dose were identified by liquid chromatography-mass spectrometry. The results revealed that dye molecules are degraded after decolorization to lower molecular weight substances, primarily organic acids, and carbon dioxide. The findings demonstrated that RB-194 could be efficiently removed from wastewater using γ-radiations along H2O2. [ABSTRACT FROM AUTHOR]

Heavy metals present in industrial effluents, when discharged into water channels, not only affect humans but also negatively impact plants and aquatic organisms. Sawdust is available readily in developing countries and can be used by small-scale industries for effluent water treatment containing low concentrations of bivalent zinc ions. This study explores the potential of sawdust-derived biosorbents, after boiling (SDB), chemical modification with formaldehyde (SDF), and sulfuric acid (SDS), for sequestration of Zn(II) from simulated wastewater as well as industrial effluents. The morphological analysis of the three biosorbents indicated a suitable porous structure with a pore size of 232.928 m2/g (SDB), 291.102 m2/g (SDF), and 498.873 m2/g (SDS). The functional analysis of native and metal-laden biosorbents indicated the role of − OH, − C = O, and − NH functional groups in Zn(II) binding. The process parameters were optimized and the spontaneous adsorption of Zn(II) was found to proceed by multilayer formation by following pseudo-second-order kinetics. SDS adsorbent (0.1 g) exhibited a greater potential for removal of Zn(II) from industrial effluents as compared to SDB and SDF at pH = 6.0 with the equilibrium adsorption capacity of 45.87 mg/g. Therefore, SDS could be a promising adsorbent for the treatment of wastewater in small-scale industries. [ABSTRACT FROM AUTHOR]

Herein, we describe a surfactant‐catalyzed green methodology for electrophilic substitution reaction of 6‐aminouracil derivatives with various aldehydes that were neither reported earlier nor produced using conventional routes. Optimized results show the importance of anionic surfactant (SDS) on the reaction between hydrophilic and hydrophobic compounds in aqueous medium. All synthesized compounds were characterized by various spectroscopic methods like FTIR, NMR, HRMS, and SC‐XRD. Furthermore, the surfactant remediation from the reaction mixture was done using graphene oxide (GO). The results from batch‐adsorption studies indicate prominent sorption of SDS onto the surface of GO with an adsorption efficiency of ~84.9 %. The SDS adsorbed onto GO were analyzed using UV‐vis, FT‐IR, Raman, and HRTEM analysis. Next, the synthesized compounds were screened for their potential anti‐SARS‐CoV2 activity due to their structural resemblance with pyrimidine analogs acting as anti‐viral agents. The in‐silico results indicate that the synthesized compounds exhibit the highest inhibitory activity towards RdRp with binding energy −9.55 kcal/mol. In contrast, Remdesivir showed only −6.45 kcal/mol. In addition, upon preliminary screening of the compounds for possible antimicrobial activity (antifungal and anti‐leishmanial), 4 bf showed moderately high inhibitory activity with IC50 values of 205.48 μM and 124.97 μM for fungal and leishmanial strains, respectively. [ABSTRACT FROM AUTHOR]

In this investigation, batch adsorption was utilized to get rid of the anionic azo dye from an aqueous solution. Adsorbents based on zeolite NaX were used. The results showed that zeolite NaX adsorbents achieved greater removal efficiency with values of 72.34%. According to the findings, with R² = 0.9958, adsorption model using the Langmuir isotherm showed a greater correlation coefficient. When the Freundlich, Temkin, and Langmuir isotherm adsorption models were assessed. According to type Langmuir isotherm adsorption, 0.42187 mg/g was established as the maximal absorption of azo dye. The Langmuir isotherm model's equilibrium parameter (RL) values showed that all RL values were between 0 and 1, demonstrating the favorability of the Langmuir isotherm. Pseudo-first-order and pseudo-second-order models were used to examine adsorption kinetics. It was discovered that the pseudo-first-order kinetics of the zeolite NaX adsorption rates were supported, with R² values of 0.9894 for the high connection. The outcomes demonstrated zeolite NaX's moderate dye removal efficiency. [ABSTRACT FROM AUTHOR]

The use of biodegradable polymers for the production of membranes to be used in wastewater treatment has attracted increasing interest considering the possibility of reducing the risk of second pollution. In this work, porous fibrous membranes based on polylactic acid and polyethylene oxide (PEO) blends were prepared. The solutions were electrospun using two approaches: (i) conventional coaxial electrospinning followed by leaching treatment (double-step, DS); (ii) coaxial wet electrospinning with in situ leaching (single-step, SS). By varying PEO type and processing method it was possible to control membranes structure and porosity. DS leaching treatment lead to surface porosity (i.e. shell leaching), while SS allowed obtaining hollow and porous fibers (i.e. with shell and core leaching). Process, properties and structure relationships of devices were analysed trough rheological, morphological, mechanical and surface characterizations. Furthermore, the influence of the different porous structures on oil sorption capacity and reusability of the membranes was evaluated. Results reveal that different porosities lead to a variation in membranes mechanical performance, in their wettability and, consequently, in their oil spill cleanup capacity. Membranes obtained with SS displayed higher performance in oil removal if compared to the DS ones, due to their hollow structure and higher surface area. [ABSTRACT FROM AUTHOR]

Harmful algal blooms (HABs) are a global concern because they harm aquatic ecosystems and pose a risk to human health. Various physical, chemical, and biological approaches have been explored to control HABs. However, these methods have limitations in terms of cost, environmental impact, and effectiveness, particularly for large water bodies. Recently, the use of nanoparticles has emerged as a promising strategy for controlling HABs. Briefly, nanoparticles can act as anti-algae agents via several mechanisms, including photocatalysis, flocculation, oxidation, adsorption, and nutrient recovery. Compared with traditional methods, nanoparticle-based approaches offer advantages in terms of environmental friendliness, effectiveness, and specificity. However, the challenges and risks associated with nanoparticles, such as their toxicity and ecological impact, must be considered. In this review, we summarize recent research progress concerning the use of nanoparticles to control HABs, compare the advantages and disadvantages of different types of nanoparticles, discuss the factors influencing their effectiveness and environmental impact, and suggest future directions for research and development in this field. Additionally, we explore the causes of algal blooms, their harmful effects, and various treatment methods, including restricting eutrophication, biological control, and disrupting living conditions. The potential of photocatalysis for generating reactive oxygen species and nutrient control methods using nanomaterials are also discussed in detail. Moreover, the application of flocculants/coagulants for algal removal is highlighted, along with the challenges and potential solutions associated with their use. This comprehensive overview aims to contribute to the development of efficient and sustainable strategies for controlling HAB control. [ABSTRACT FROM AUTHOR]

Two responsive PEI hydrogels (P1.5E and P2E) were synthesized through a click reaction using linear PEI polymers with different cross‐linker contents (ethylene glycol diglycidyl ether—EGDE) and avoiding organic solvents. Through 13C HRMAS NMR and DSC studies the presence of residual epoxy groups and different protonation states of the linear PEI segments in the hydrogel were detected. The swelling and rheological behavior was dependent on the cross‐linking degree. The hydrogel with the lower cross‐linking degree (P1.5E) presented higher swelling values, but it was less resistant to the deformation. Besides, the swelling capacity and the resistance to deformation were found to be dependent on the interchain repulsions and charge of the amine groups, which endowed the hydrogels with stimuli‐responsive behavior to pH or ionic strength changes. For both hydrogels, the swelling capacity and rheological properties were inversely proportional and directly proportional to the pH increase, respectively. Both materials presented adsorption capacity for the azo dye methyl orange (MO) and Cu2+ ions. The interaction of the materials with the pollutants was also dependent on the cross‐linking degree, being P1.5E the one that presented higher sorption capacities. Furthermore, the hydrogels did not release toxic molecules, as assessed by lettuce seeds germination experiments. [ABSTRACT FROM AUTHOR]

Herein, ethylene glycol (EG)-modified Zn/Cu hydroxy double salts (HDS) were synthesized using a facile synthetic approach. The formation of layered structure and presence of EG in the interlayer region were confirmed using PXRD and FTIR techniques. Furthermore, XPS analysis was used to confirm presence of metal ions in synthesized HDS. The surface area and pore size diameter of the HDS was found to be 32.30 m2 g−1 and 2.22 nm, respectively, using BET. The role of HDS was evaluated for its potential application as a sorbent for Congo red (CR) dye uptake. Batch studies were conducted to examine the impact of key variables, i.e., pH, time, adsorbent dosage and dye concentration on adsorption efficiency of HDS. Linear-nonlinear isotherm and kinetic models were employed for detailed analysis of experimental data. Langmuir, Freundlich and Temkin isotherm models were subsequently utilized to fit equilibrium data, among which Langmuir demonstrated to be most accurate. The maximum monolayer adsorption capacity estimated using Langmuir model was computed to be 181.81 mg g−1. The kinetic data follows pseudo-second-order model having good R2 value (0.999). Additionally, thermodynamic study suggested spontaneous and endothermic nature of adsorption process having reusability up to 5 cycles with removal efficiency more than 85%. [ABSTRACT FROM AUTHOR]

This study reviews the concept, classifications, and techniques involved in the synthesis of nanocomposites. The environmental and health implications of nanoparticles and composite materials were detailed, as well as the applications of nanocomposites in water remediation, antibacterial application, and printed circuit boards. The study gave insights into the challenges of water pollution treatment and provided a broad list of nanocomposites that have been explored for water remediation. Moreover, the emergence of multi-drug resistance to many antibiotics has made current antibiotics inadequate in the treatment of disease. This has engineered the development of alternative strategies in the drug industries for the production of effective therapeutic agents, comprising nanocomposites with antibacterial agents. The new therapeutic agents known as nanoantibiotics are more efficient and have paved the way to handle the challenges of antibiotic resistance. In printed circuit boards, nanocomposites have shown promising applications because of their distinct mechanical, thermal, and electrical characteristics. The uniqueness of the write-up is that it provides a broad explanation of the concept, synthesis, application, toxicity, and harmful effects of nanocomposites. Thus, it will provide all-inclusive awareness to readers to identify research gaps and motivate researchers to synthesize novel nanocomposites for use in various fields. [ABSTRACT FROM AUTHOR]

Herein, a novel, effective and bio-based Fenton-like catalyst by in situ incorporation of Fe 2 O 3 nanoparticles on the surface of nanocellulose (NCs) was synthesized from sugar beet pulp (SBP) and utilized for efficient removal of three different dyes. Firstly, different NC samples were synthesized by acid hydrolysis of two different biomass (SBP and Q-quinoa husk) at various concentrations of H 2 SO 4. The characterization analyses of samples showed that SBP-based NCs prepared using 60% concentration of H 2 SO 4 (1 h string at 50 °C) showed the highest crystallinity (56.7%), lowest aggregation, highest surface negative charge (−38.5 mV), and largest surface area (13.9 m2/g) compared to the Q-based NCs. Both SBP and Q-based nanocatalyst utilized for degradation of dyes (methylene blue (MB), crystal violet (CV), and congo red (CR)), and SBP-based sample (Fe/NC-S3) displayed the best results in dye removal due to its larger specific surface area (39.8 vs. 9.2 m2/g), and higher content of magnetic nanoparticles (6.7 vs. 3.7 at% of Fe) than Q-based catalyst. At optimum conditions, Fe/NC-S3 nano-catalyst (2 g/L), in the presence of H 2 O 2 (30 mM) removed MB, CV, and CR dyes (30 mg/L), in 30 min, at neutral pH, with 98%, 96%, and 62% removal efficiencies, respectively. Kinetic studies revealed that pseudo-first-order model was appropriate model to explain the decolorization of dyes at these conditions, and the rate constants were 0.0217, 0.018, and 0.0113 min−1 for the degradation of MB, CV, and CR, respectively. Moreover, raising the temperature from 15 ºC to 35 ºC resulted in enhancement of removal performance of nano-catalyst for all dyes. Fe/NC-S3 nano-catalyst showed proper reusability (just around 20% decrease for removal of all three dyes after ten consecutive reuse runs). Treatment of real water effluent (collected from a textile factory) containing mixture of all three dyes by Fe/NC-S3 and H 2 O 2 approved the practical application of nano-catalyst in dye removal from complex matrixes even after nine reusing cycles. The results confirmed that SBP biomass could effectively turn to valuable NC nanocarriers for synthesis of advanced and innovative catalysts with proficient catalytic activity, stability, and recyclability. [ABSTRACT FROM AUTHOR]

The improper disposal of toxic and carcinogenic organic substances resulting from the manufacture of dyes, drugs and pesticides can contaminate aquatic environments and potable water resources and cause serious damage to animal and human health and to the ecosystem. In this sense, heterogeneous photocatalysis stand out as one effective and cost-effective water depollution technique. The use of metal oxide nanocomposites (MON), from the mixture of two or more oxides or between these oxides and other functional semiconductor materials, have gained increasing attention from researchers and industrial developers as a potential alternative to produce efficient and environmentally friendly photocatalysts for the remediation of water contamination by organic compounds. Thus, this work presents an updated review of the main advances in the use of metal oxide nanocomposites-based photocatalysts for decontamination of water polluted by these substances. A bibliometric analysis allowed to show the evolution of the importance of this research topic in the literature over the last decade. The results of the study also showed that hierarchical and heterogeneous nanostructures of metal oxides, as well as conducting polymers and carbon materials, currently stand out as the main materials for the synthesis of MON, with better photocatalysis performance in the degradation of dyes, pharmaceuticals and pesticides. [ABSTRACT FROM AUTHOR]

Nanofiltration (NF) is one of the emerging technologies that is very promising for water purification among many other applications. 2D boron nitride (BN) based nanomaterials are excellent building blocks for NF membranes. In our work, BN nanosheets (BNNS) have been functionalized with magnetic nanoparticles (MNPs) to form BNNS–MNP nanocomposites. It was found that the nanocomposites are stable with the MNPs giving very good coverage with both magnetite and cobalt ferrite MNPs and showing good attachment and stability to sonication. These nanocomposites have been tested for removal of methylene blue (MB) dye and MNPs from water. BNNS–magnetite nanocomposites showed higher removal efficiency of the MB from water than the corresponding pure BNNS, while the BNNS–cobalt ferrite removal efficiency was slightly less than the pure BNNS. The BNNS–cobalt ferrite material was regenerated by burning off the MB and recycled to show the recyclability of this material. The BNNS membranes were tested for filtration of 14 ± 4 nm magnetite MNPs and were found to capture 100% of the nanoparticles with no MNPs left in the filtrate. Thus, we have developed magnetic nanocomposite membranes, which have demonstrated great potential for water remediation. We believe that this research opens up promising ways for production of 2D nanocomposite materials with multiple applications. [ABSTRACT FROM AUTHOR]

Peroxymonosulfate‐based advanced oxidation processes (PMS‐AOPs) for in situ persistent organic pollutant (POP) remediation in aqueous solutions can be a promising technology. However, this technology is constrained by its high toxicity and cost of metal oxide and non‐metal catalysts for PMS activation. Here, we investigated the catalytic performance of a widely available natural mineral, manganese ore (MO), for PMS activation. A series of natural MO samples in an aqueous solution were prepared via the Fenton‐like reaction. The samples' crystalline structure, surface morphology, textural properties, and other surface characteristics of the selected MO were systematically characterized. The effects of PMS concentration and process parameters on the degradation performance of four chosen model pollutants, that is, phenol, tetrabromobisphenol A (TBBPA), rhodamine B (RhB), and methylene blue (MB), were evaluated. The experimental results showed that natural MO increased catalytic activity and enhanced the PMS oxidation processes, with 98%, 90%, and 75% removal efficiencies on phenol, TBBPA, and RhB, respectively, within 1.5 h. The reduction in the initial pH solution from 10 to 7 and the increase in temperature from 15 to 45°C enhanced the MB degradation rate (decolorization) by 55 and 46%, respectively, within 2 h. During the PMS activation process, SO4•−, •OH, and 1O2 species were generated, but only SO4•− and •OH radicals with strong oxidative potentials contributed to the catalytic degradation. The dissolved metals from the experiments were found well within the limit of drinking water standards, verifying that the MO + PMS catalytic system is suitable for commercial applications. This work provides insights into the development potential and prospects of using natural minerals for PMS activation and POP degradation, which can accelerate their industrial applications. [ABSTRACT FROM AUTHOR]

This paper puts forward the use of “low-cost/low-end” hydroxyapatite-based adsorbing materials prepared from Tambaqui fish cleaning residues (i.e., bones) by grinding and/or thermal annealing. The nature of raw materials and treatments practically resulted in a “zero-cost” adsorbent for atrazine pesticide and Co2+ ion remediation in an aqueous solution. Despite the distinctive character of the two contaminants, all adsorptions were found to follow pseudo-second order kinetics and Freundlich isotherm models. Pristine hydroxyapatite proved to be more effective in adsorbing atrazine at low concentrations due to interactions with collagen residues. Conversely, heat-treated materials demonstrated better adsorption performances for cobalt due to the removal of organic residues hindering access to the surface. On the other hand, lower adsorption affinities resulted into a faster and more efficient Co2+ release into water. The different behavior in terms of phosphate and cobalt release shown by the three hydroxyapatite-based absorbents can be exploited for differential liberation of targeted nutrients, with high seed germination rates. Considering circular economic principles, waste-derived hydroxyapatites may be potentially attractive for removing ionic species, minimizing water pollution stemming from heavy industry, and for their subsequent targeted release to edible plants, enhancing agricultural availability of mineral nutrients for soil fertilization.

Electrocatalysis is a promising way to treat water contaminated by harmful organic compounds. The combination of nanoparticles supported on a conductive substrate allows degradation to occur under less energetic conditions. This work evaluated the effect of deposition of bismuth vanadate (BVO) particles on pencil-type graphite electrodes. BVO particles were obtained by ultrasonic irradiation with coprecipitation. Then, they were deposited on the surface of a graphite electrode by the impregnation method. A 23-design was used to optimize electrode fabrication. Matter Dispersion Spectroscopy (SEM/EDS), X-Ray Diffraction (XRD) and Dynamic Light Scattering (DLS) were used for characterization. Electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The results confirmed the synthesis of BVO@C (BVO/graphite). Furthermore, BVO@C significantly increased the electroactive surface area of the electrode, decreased the electron transfer resistance, and significantly increased the electron transfer rate to a greater extent than the electrode without any modification. To prove that the performance of BVO@C is better than the pure electrode, photoelectrocatalysis (PEC) and electrocatalysis (EC) were performed in a rhodamine B (RhB) solution. The results showed that in 5 min of treatment with unmodified electrode, BVO@C EC system and BVO@C PEC system, there was degradation of 31.53%, 46.09% and 58.17% respectively, reaching 95%, 98% and 99.64%, respectively, in 30 min. The reaction rate constants were calculated and to be found k = 0.10272 m−1, k = 0.12221 m−1 and k= 0.15022 m−1 for the unmodified graphite, BVO@C EC System and BVO@C PEC system, respectively. These results demonstrate that the BVO@C electrodes are efficient for application in a wide range of treatments, including the treatment of organic pollutants.