Adsorption Agent Research Articles

Fabrication of 3D flower-shaped MgAl-LDHs with inducing CuMOF for improving its adsorption and antibacterial performance

Chronic and inappropriate use of antibiotics, antibiotic residue, and bacterial infections present a significant threat to both the environment and human health. This study focused on the effective remediation of wastewater contaminants through the synthesis of Cu-based metal-organic framework (CuMOF) conjugated with layered double hydroxide (LDHs) via hydrothermal processing, resulting in the development of a novel three-dimensional (3D) flower-shaped CuMOF@LDHs (Fc-LDHs) hybrid materials. After being characterized by SEM, FT-IR, XRD, zeta potential and BET, the obtained Fc-LDHs was applied to adsorption of antibiotics, and its antibacterial activity was also investigated. It indicated that Fc-LDHs exhibited excellent performance in both adsorption and antibacterial activity. Utilizing tetracycline (TC) as a representative antibiotic, the influence of various parameters on the adsorption efficiency was examined. The study revealed that an adsorbent mass of 0.08 g could achieve a removal efficiency of 94.2 % for TC at an initial concentration of 50 mg/L within 90 min, with the removal rate remaining at 72.6 % after four cycles of adsorption-desorption. It was also found that the adsorption mechanism was consistent with the Freundlich isothermal model and the pseudo-second-order kinetic model. The exceptional adsorption properties were primarily ascribed to the synergistic effects of electrostatic interactions, pore filling, chelation and hydrogen bonding interactions between Fc-LDHs and TC. Simultaneously, the antibacterial rates of Fc-LDHs reached to 90.3 % and 95.7 % against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. In conclusion, Fc-LDHs proved to be a highly efficient remedy for addressing antibiotic and antibacterial pollution, functioning both as a proficient adsorbent and antibacterial agent.

Exploration of Optimization Strategies for Locking Sulfur in 2D Layered/Polymer-Enveloped Cathode Composite for High Power Li-S Batteries.

In Lithium sulfur (Li-S) batteries the sulfur host material is a significant area of research that could impart enhanced conductivity and alleviate the shuttling of polysulfides. In the present study, graphene oxide- sulfur, GO-S was synthesized in melt diffusion method by exploring the two different strategies: Ambient (G2-M) and Inert (G2-T) conditions. Within the cathode, efficient storage of S with sufficient space in GO interlayers was outperformed by G2-T method. Further with PEDOT nanostructures enveloped by oxidative polymerisation proves to be a robust conductive layer and an adsorbing agent. It is evidenced physicochemically by XRD, FTIR, TGA, HR-SEM. Moreover, in addition to the supporting studies, high binding energies of 168.3 and 169.5 eV confirms the superior performance of PEDOT/GO-S (G3-T) as most suitable cathode within the system. The electrochemical behaviour of G3-T possess very low cell impedance with an excellent cyclic reversibility in CV during (de)lithiation process. At 0.1 C, an initial discharge capacity of 868 mAh g-1 has been achieved confirming a high catalytic activity with a low polarisation potential of (ΔE=0.25) inducing fast reaction kinetics. Thus potential locking of sulfur under inert condition is explored with a proven OCV of 2.3 V with red LED glow.

Development of nanocomposite-selenium filter for water disinfection and bioremediation of wastewater from Hg and AgNPs

Selenium nanoparticles (SeNPs) are used in several sectors as antitumor, antimicrobial, and environmental adsorbents. Thus, the present research objective was the production of bacterial-SeNPs as an active and environmentally-friendly antibacterial and adsorbent agents and application into novel nanocomposite filter. From a total of 25 samples (soil, wastewater, and water) obtained from different locations in Egypt, 60 selenium-resistant bacterial isolates were obtained (on a mineral salt medium supplemented with selenium ions). After screening (based on the conversion of selenium from ionic form to nanoform), a superior bacterial isolate for SeNPs formation was obtained and molecular identified as Bacillus pumilus isolate OR431753. The high yield of SeNPs was noted after optimization (glucose as carbon source, pH 9 at 30 °C). The produced SeNPs were characterized as approximately 15 nm-diameter spherical nanoparticles, in addition to the presence of organic substances around these particles like polysaccharides and aromatic amines (protein residues). Also, they have antibacterial activity increased after formation of nanocomposite with nano-chitosan (SeNPs/NCh) against several pathogens. The antibacterial activity (expressed as a diameter of the inhibitory zone) averaged between 2.1 and 4.3, 2.7 and 4.8 cm for SeNPs and SeNPs/NCh, respectively compared with 1.1 to 1.8 cm for Amoxicillin. The produced nanoselenium/chitosan was used as a biofilter to remove mercury (Hg) and AgNPs as model chemicals with serious toxicity and potential pollutant for water bodies in many industries. The new SeNPs/NCh biofilter has proven highly effective in individually removing mercury and AgNPs from their synthetic wastewaters, with an efficiency of up to 99%. Moreover, the removal efficiency of AgNPs stabilized at 99% after treating them with the syringe filter-Se nanocomposite for 4 cycles of treatment (5 min each).

Quality by Design Optimization of Telmisartan-loaded Self-nanoemulsifying Drug Delivery Systems

Aim: This study aimed to develop a QbD-based SNEDDS for Telmisartan to enhance its biopharmaceutical performance. Background: Quality by Design (QbD) was incorporated by selecting the Critical Process Pa-rameters (CPPs) as influential variables upon the desired responses. Using Design of Experiments (DoE) software, oil, and S/CoS were tested for pre-isotropic compatibility and formulation im-provement. A heating-cooling cycle and phase separation were used to determine the formula-tions' dispersibility, self-emulsifying time, mean globule size, and stability. Objective: Using Design of Experiments (DoE) software, oil (Capmul MCM C-10) and surfactant (Labrasol)/co-surfactant (Tween-20, and PEG-600) (S/CoS) ratios were optimized for pre-isotropic compatibility and formulation improvement. Methods: Aerosil-200, Sylysia-350, 550, and 730 were used as porous carriers, and Neusilin US2 as an adsorbing agent resulted in free-flowing granules of self-nano emulsifying drug delivery systems. The SNEDDS was further formulated into tablets using a direct compression technique with enhanced disintegration properties. Results: The prepared SNEDDS tablets exhibited a 71% increase in drug dissolution as compared to the pure drug and marketed formulation after the in vitro dissolution studies. Conclusion: This QbD approach offers a promising strategy for developing SNEDDS formula-tions for poorly soluble drugs like Telmisartan.

Catalyst-Free Extraction of U(VI) in Solution by Tribocatalysis.

Extraction of U(VI) in water is of great significance in energy and environmental fields. However, the traditional methods usually fail due to the indispensable extra addition of catalyst, adsorbent, precipitant, or sacrificial agents, which may lead to enhanced extraction costs and secondary pollution. Here, a new efficient uranium extraction strategy is proposed based on triboelectricity without adding a catalyst or other additives. It is found only under the friction between the microbubbles (generated under ultrasonication) and the water flow, that reactive oxygen species (ROS) can largely be generated, which thus contributes to the solidification of U(VI) from water. In addition, the magnetic field can affect the phase of the product. Under mechanical stirring, the product contains (UO2)O2·2H2O, while which contains UO2(OH)2 and (UO2)O2·4H2O under the magnetic stirring. Quenching experiments are also carried out to explore the influence of environmental factors. Most importantly, it shows great potential in the extraction of U(VI) from seawater. This work proposes a catalyst-free and light-free strategy toward the solidification of U(VI) from water, which avoids the secondary pollution of the catalyst to the environment and is low-cost, and has great potential in the real application.

Unveiling the Preparation and Characterization of Lercanidipine Hydrochloride in an Oral Solid Self-Nanoemulsion for Enhancing Oral Delivery.

Chronic kidney disease (CKD) is becoming increasingly prevalent worldwide, particularly among the elderly, along with an increase in the incidence of hypertension and cardiovascular disorders. Developing lipid-based oral dosage forms with a higher expected bioavailability of antihypertensive drugs with nephroprotective effects poses a challenge. Lercanidipine hydrochloride (LRCH) is a newer type of third-generation dihydropyridine calcium channel blocker that functions as an antihypertensive and has significant nephroprotective effects. Due to its extensive first-pass metabolism, its bioavailability is about 10% and increases to 3-4 times when taken with a high-fat meal. Targeting this drug to the lymphatic system using the solid self-nano-emulsifying drug delivery system (SSNEDDS) is a promising approach for improving LRCH's bioavailability and dispersion rate. SSNEDDS combines the benefits of both liquid self-emulsifying and solid dosage forms, improving drug stability and extending storage time. In this study, liquid SNEDDS composed of 10% peppermint oil, 67% Tween 20, and 22.5% propylene glycolwas solidified using two adsorbent agent mixtures (SSNEDDS1: Avicel PH 101 and Aerosil 200) and (SSNEDDS2: Avicel PH 102 and Aerosil 200) separately. The prepared formulations were evaluated for powder flow, drug content, and an in-vitro dispersion test in comparison to the brand-marketed tablet as a standard or pure drug. DSC and X-ray diffraction analysis were also used. The SSNEDDS2 shows excellent flowability, a higher drug content (99.761%), and a significantly higher and faster dispersion rate of 100% within 10 minutes compared to 92% of the marketed LRCH tablet and 18.1% of the pure drug for 60 minutes. The solid-state characterization of the formulation composed of SSNEDDS2 confirmed that the LRCH was in an amorphous form inside the solidified nano system without interacting with the excipient. This study successfully prepared LRCH using the promising strategy of SSNEDDS as a hard gelatin capsule with a higher dispersion rate. It improved its stability and expected bioavailability compared to the brand-marketed tablet as the standard.

Testing S. sonnei GMMA with and without Aluminium Salt-Based Adjuvants in Animal Models.

Shigellosis is one of the leading causes of diarrheal disease in low- and middle-income countries, particularly in young children, and is more often associated with antimicrobial resistance. Therefore, a preventive vaccine against shigellosis is an urgent medical need. We have proposed Generalised Modules for Membrane Antigens (GMMA) as an innovative delivery system for Shigella sonnei O-antigen, and an Alhydrogel formulation (1790GAHB) has been extensively tested in preclinical and clinical studies. Alhydrogel has been used as an adsorbent agent with the main purpose of reducing potential GMMA systemic reactogenicity. However, the immunogenicity and systemic reactogenicity of this GMMA-based vaccine formulated with or without Alhydrogel have never been compared. In this work, we investigated the potential adjuvant effect of aluminium salt-based adjuvants (Alhydrogel and AS37) on S. sonnei GMMA immunogenicity in mice and rabbits, and we found that S. sonnei GMMA alone resulted to be strongly immunogenic. The addition of neither Alhydrogel nor AS37 improved the magnitude or the functionality of vaccine-elicited antibodies. Interestingly, rabbits injected with either S. sonnei GMMA adsorbed on Alhydrogel or S. sonnei GMMA alone showed a limited and transient body temperature increase, returning to baseline values within 24 h after each vaccination. Overall, immunisation with unadsorbed GMMA did not raise any concern for animal health. We believe that these data support the clinical testing of GMMA formulated without Alhydrogel, which would allow for further simplification of GMMA-based vaccine manufacturing.

Cadmium removal efficiency from synthetic wastewater using sawdust as a sustainable adsorbent

Adsorption is one of the method that can be used to remove heavy metals from polluted water. Many adsorbents are naturally available and showed high performance in removing various pollutants. This study aimed to evaluate the performance of sawdust as a natural adsorbent agent to remove Cd ions from simulated wastewater and, also, to assess the improvement of sawdust adsorption capacity after activation by sulfuric acid (H2SO4). Many factors such as pH, contact time, temperature, and weight of the adsorbent were investigated in this study to evaluate their effect on the adsorption process. The results indicated a significant improvement of sawdust after modification (95.51% removal) compared to raw sawdust (82.22% removal). Equilibrium adsorption isotherms and kinetic study have been also carried out. Compared to the Langmuir adsorption isotherm model, the Freundlich isotherm model was best represented the experimental data of the sawdust. The experimental results of this sorbent were suitable for a pseudo-second order kinetic model. Moreover, the result pointed out that the process of adsorption was an endothermic and increasing the temperature resulted in a higher removal rate. Additionally, FTIR results revealed that the groups of carboxyl and hydroxyl contributed to the metal ions' ability to bind to surfaces. Finally, images of the surface structure of the sawdust before and after modification were obtained by using scanning electron microscopy (SEM) to analyze the surface morphology of both raw and treated sawdust.

Deep eutectic solvents applications aligned to 2030 United Nations Agenda for Sustainable Development

Sustainable living means understanding how lifestyle choices impact the world and how the livelihoods of current and future generations can be sustained. If the current production and processing patterns are switched to sustainable ones, this will contribute to diminishing adverse effects such as pollution and climate change. Deep eutectic solvents (DESs) are biodegradable, biocompatible, low cost and tunable green solvents extensively analyzed in different areas to replace traditional harsh organic solvents. DESs are rapidly emerging in numerous applications owing to their green character and physicochemical properties, leading to their used, not only as solvent systems, but as catalysts, adsorbent agents, electrolytes or nanocarriers for the encapsulation of anticancer drugs, and in very diverse areas. Therefore, DESs can contribute to developing sustainable processes from different points of view. This review presents the main applications of DESs aligned to the United Nations 2030 Agenda for Sustainable Development, specifically to those related to energy efficiency improvement, sustainable production patterns and action to combat climate change. Giving an overview about the implementation of DESs for process intensification and sustainable production, and in some cases how authors reconfigured processes using DESs to obtain cost effective, less labor-intensive, ecofriendly, safe, and highly effective approaches.

Activated sodium bentonite as an adsorbent for efficient removal of hexavalent chromium: Statistical optimization using Box–Behnken design

AbstractAt present, developing countries, including Ethiopia, are undergoing a phase of industrial transformation. As a result, there has been a significant rise in the presence of harmful pollutants in groundwater. The release of deleterious heavy metals, such as Cr (VI), into the surrounding ecosystem is a result of various industrial operations. The present investigation utilized activated sodium bentonite clay as an adsorbent agent to facilitate the elimination of Cr (VI). The clay was subjected to acidification and thermal modification techniques to enhance its adsorption capacity. The investigation involved an examination of the particular surface area, capacity for cation exchange, crystalline properties, functional groups on the surface, and structural morphology. The methylene blue test method was employed to ascertain the maximum specific surface area and cation exchange capacity of the adsorbent, which were found to be 512 m2/g and 65.5 meq/100 g, respectively. The clay mineral composition was analyzed using X‐ray diffraction, which indicated that the primary constituent was montmorillonite. The presence of impurities such as quartz, feldspar, muscovite, cristobalite, and hematite was also detected. The study employed response surface methodology, Box–Benkhen design (RSM‐BBD) to investigate the impact of operational parameters, including agitation time, initial Cr (VI) concentration, and adsorbent dosage. Under the optimal conditions, a removal efficiency of 98.05% was achieved for Cr (VI) for a contact duration of 120 min, a dosage of 3.913 g/L, and an initial concentration of 50 mg/L. The sodium bentonite clay that was activated demonstrated a maximum capacity for adsorption of 22.72 mg/g in regards to the adsorption of Cr (VI). The experimental data were best fitted by the Langmuir isotherm, which exhibited a correlation coefficient of 0.9699. The adsorption kinetics were assessed and determined to adhere to a pseudo‐second‐order pattern, exhibiting a coefficient of determination (R2) value of 0.999. Furthermore, the activated sodium bentonite clay demonstrated remarkable potential for repeated utilization in the adsorption of Cr (VI) ions in aqueous solutions.

Remediation of Ex-Unlicensed Gold Mining Using Rice Husk Biochar: its Effect on Reducing Mercury Levels

: The dangers of mercury in nature cause negative impacts on the environment and humans. The nature of mercury is bioaccumulative and toxic, and it cannot be degraded quickly but only through valence transformation. One effort that can be made to reduce the level of toxicity from mercury is to use biochar as an adsorbent agent in the soil. This article's goal is to review data regarding the use of biological charcoal (biochar) as a soil adsorbent for mercury. In order to clean up soil that has been contaminated with mercury (Hg), rice husk biochar plays a crucial function. Other than that, by using these organic materials instead of synthetic ones, soil production can be increased while environmental impact is reduced by 56%. Mercury is absorbed by biochar through a number of different mechanisms, including: (1) electrostatic bonds; (2) K+ and Na+ with Hg2+ and Hg+ ions simultaneously; (3) covalent reduction of mercury from Hg2+ to Hg+ and Hg0; (4) formation of a mineral complex (Hg2(OH)2) through precipitation of Hg2+ with carboxyl groups, such as lactones; and (5) complexation reactions on oxygen-containing functional groups such as - In comparison to soil alone, the use of biochar along with other organic elements can boost the capacity of heavy metal adsorption. With this combination, mercury levels were reduced to 12.45 ppm while soil pH increased dramatically from 0.3 to 1.33 units, near to neutral.

Polycaprolactone Composites/Blends and Their Applications Especially in Water Treatment

Biodegradable poly(ɛ-caprolactone) (PCL) and its composites or blends have received a lot of attention in the last decade because of their potential applications in human life and environmental remediation. Greater efforts have been made to develop biodegradable chemical materials as adsorbents that do not pollute the environment in order to replace traditional materials. Among the numerous types of degradable materials, PCL is currently the most promising, the most popular, and the best material to be developed, and it is referred to as a “green” eco-friendly material. Membranes and adsorbents for water treatment, packaging and compost bags, controlled drug carriers, and biomaterials for tissues such as bone, cartilage, ligament, skeletal muscle, skin, cardiovascular and nerve tissues are just some of the applications of this biodegradable polymer (PCL). The goal of this review is to present a brief overview of PCL, syntheses of PCL, its properties, PCL composites, and PCL blends and to provide a detailed investigation into the utility of PCL/PCL-based adsorbing agents in the removal of dyes/heavy metal ions. Overall, it can be confirmed that PCL blends and composites were found to be significant competitors to other well-known adsorbents in the treatment of wastewaters, necessitating a thorough investigation of their manufacture.

Designing an Oxygen Scavenger Multilayer System Including Volatile Organic Compound (VOC) Adsorbents for Potential Use in Food Packaging.

Oxygen scavengers are valuable active packaging systems because several types of food deterioration processes are initiated by oxygen. Although the incorporation of oxygen scavenger agents into the polymeric matrices has been the trend in recent years, the release of volatile organic compounds (VOC) as a result of the reaction between oxygen and oxygen scavenger substances is an issue to take into account. This is the case of an oxygen scavenger based on a trans-polyoctenamer rubber (TOR). In this work, the design of an oxygen scavenger multilayer system was carried out considering the selection of appropriate adsorbents of VOCs to the proposed layer structure. Firstly, the retention of some representative organic compounds by several adsorbent substances, such as zeolites, silicas, cyclodextrins and polymers, was studied in order to select those with the best performances. A hydrophilic silica and an odor-adsorbing agent based on zinc ricinoleate were the selected adsorbing agents. The principal VOCs released from TOR-containing films were carefully identified, and their retention first by the pure adsorbents, and then by polyethylene incorporated with the selected compounds was quantified. Detected concentrations decreased by 10- to 100-fold, depending on the VOC.

Bioremediation of malachite green dye using sodium alginate, Sargassum latifolium extract, and their silver nanoparticles

IntroductionThe textile, paper, rubber, plastic, leather, cosmetics, pharmaceutical, and food sectors extensively use malachite green (MG). In spite of this, it has mutagenic, carcinogenic, teratogenic, and, in some circumstances causes chronic respiratory disease.ObjectivesIn this work, we used sodium alginate, Sargassum latifolium aqueous extract, and their silver nanoparticles to test their potential as inexpensive adsorbent agents to remove malachite green dye from aqueous solutions.MethodsThe removal rate of MG was determined using a series of bioadsorption experiments. Besides, the effect of different factors on bioadsorption, such as pH, adsorbent dose, contact time (min), and different concentrations of MG dye was investigated.ResultsThe removal efficiency of MG dye by alginate nanoparticles, alginate, Sargassum latifolium aqueous extract, and S. latifolium aqueous extract nanoparticles was 91, 82, 84, and 68 respectively. The optimal conditions for bioadsorption of malachite green dye were pH 7, a contact time of 180 min, and an adsorbent dose of 0.02 g. The adsorption isotherm was fitted to Langmuir and Freundlich isotherm. Also, UV and FT–IR before and after the bioadsorption of MG were performed to confirm the bioadsorption process.ConclusionOur results indicated that alginate nanoparticles were the most effective bioadsorbent agent.

Study of Adsorption Kinetics of Fe Metal in Batik Cual Waste using Chitosan of Rice Crab Shells

Fe metal is one of the heavy metal composition contained in cual batik waste. The content of these metal has potency as pollutan and can increase the risk of chemical substance stored in various aquatic biota and very dangerous for human consumption because it is toxic in the long term. In this research, batik waste treatment has been carried out by decadarizing Fe metal using adsorbent agent based from citosan. Paddy crab shell was extracted through demineralization, deproteination, decolorization, and deacetylation to become chitosan powder. Chitosan powder becomes an adsorbent in the adsorption process with adsorption data collection patterns for various contact times of 30, 60, 90, 120, 150, 180, 210, and 240 minutes. The adsorption results were kinetic modeled using the kinetic model of first order, second order, and BMG. From that three models obtained the R2 value that is closest to 1 is the BMG kinetic model, which is 0.999602. In addition, this model has the advantage that is it can find out the magnitude of the decolorization decay constant and the rate of decolorization of Fe metal.

Design and Development of Fe3O4@Prussian Blue Nanocomposite: Potential Application in the Detoxification of Bilirubin.

Prussian blue nanoparticles (PBNPs) due to their high solubility, stability, flexible molecular structure, tunable size, easy synthesis, and surface modification have attracted the attention of researchers as high-efficiency therapeutic agents. Recently, it has been reported that magnetic nanoparticles can be to bind pathogenic substances on their surface, followed by a recollection by magnetic separation. Considering the potential application of PB and magnetic nanoparticles, in the current study we aimed to strategically design and synthesize a highly efficient nano-magnetic bilirubin scavenger system based on iron oxides@prussian blue nanocomposites (Fe3O4@PB) NCs. The Fe3O4@PB NCs were synthesized by an improved shell-growing procedure and identified using advanced characteristic techniques TEM, SEM, XRD, DLS, and Zeta potential. Synthesized Fe3O4@PB NCs showed good magneton properties and also demonstrated dramatic absorbent properties that empower use as an eco-friendly adsorbent nano agent for the detoxification of toxins. In addition, Fe3O4@PB nanoparticles showed high performance of bilirubin absorption in the serum and blood of sickle cell anemia patients. (Temp. 37.7 ºC, the dose of adsorbent: 1 mg/mL, incubation time 30 min, and initial concentration: 0.25 mg/mL). The results demonstrated an ideal adsorption capacity (86%) of Fe3O4@PB NCs which is significant compared to the reported adsorbents agents. These results pave the way for the application of Fe3O4@PB NCs for the effective purification of toxins from patients' body fluids.

Preparation of water‐based flexography printing ink by KMnO4 modified activated carbon for fruit ripening control application

AbstractEthylene is a type of gas that fruits and vegetables can produce naturally. The release of ethylene gas from fruits and vegetables causes them to ripen and undergo physical, chemical and biological changes, such as changes in the appearance in terms of shape and colour, changes in firmness and texture, changes in taste and changes in nutritional value. Furthermore, it also facilitates the growth of microorganisms. These changes lead to spoilage if the fruit or vegetables are left to over ripen. Therefore, the prevention and reduction of damage caused by the ripening of fruits and vegetables entail reducing or slowing down the release of ethylene gas produced by them. This research project aimed to study the properties of activated carbon and potassium permanganate (KMnO4) modified activated carbon, applied as a printing layer on plastic materials for bananas, in terms of their adsorption and decomposition of ethylene. Active and water‐based flexography printing inks were prepared from water‐based binder and ethylene adsorbing and scavenging agents (activated carbon and KMnO4 modified activated carbon) at various concentrations of active agents, that is, 0.0, 5.0, 7.5 and 10.0%w/v. Then, those inks were printed on polypropylene plastic substrate. The delayed ripening of fruits results showed that the plastic materials coated with modified activated carbon inks delayed the physiology disorder (colour and firmness changing about 250% and 226%) and prolonged the storage time up to 14 days when compared with control. In addition, the functional ink layer also presented a high efficiency of abrasion resistance of about 75 cycles of rubbing at 1.8 kg. The products that stem from this research can be applied as packaging for fruits and vegetables in the form of bags, stickers and product pads that can help extend the life and slow the ripening of fruits and vegetables.

Hydrothermal modification of ceramic waste: Characterization, optical properties and low-cost adsorbent agent for removal organic dyes

Hydrothermal modification of ceramic waste: Characterization, optical properties and low-cost adsorbent agent for removal organic dyes

Magnetic polyacrylonitrile/ZIF-8/Fe3O4 nanocomposite bead as an efficient iodine adsorbent and antibacterial agent

The efficient adsorption of radioactive iodine (129I and 131I) as nuclear waste is of great importance. Polymer nanocomposites consist of metal–organic frameworks (MOFs) developing for various pollutions sorption and separation have attracted much attention. This study reports the fabrication of magnetic polyacrylonitrile (PAN)/zeolitic imidazolate frameworks (ZIF-8) nanocomposites, PAN/ZIF-8(x%)/Fe3O4, x = 30 and 50, as iodine capture adsorbents. The PAN/ZIF-8(x%)/Fe3O4 nanocomposite beads were fabricated via the phase inversion method, and their potential for iodine capture and separation in solution and vapor was investigated through UV–vis and weighing methods, respectively. Also, antibacterial activity of the as-prepared beads was assessed against E. coil and S. aureus. The as-fabricated compounds were studied by various techniques such as Fourier-transform infrared, X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy mapping, transmission electron microscope, N2 adsorption isotherm, and vibrating sample magnetometer. The iodine capture results showed that the efficiency of nanocomposites is remarkably higher than the pure PAN beads. Additionally, the as-prepared nanocomposite adsorbents displayed higher capture capacities for iodine vapor (1524–4345 mg·g−1) than iodine solution (187–295 mg·g−1). The as-obtained magnetic nanocomposites can be successfully separated from polluted media by simple filtration or an external magnet, regenerated through washing with ethanol, and reused. Fast capturing, high sorption capacity, rapid separation, and good reusability make the PAN/ZIF-8(x%)/Fe3O4 nanocomposites highly effective adsorbents for the separation of iodine from wastewater. Additionally, PAN/ZIF-8(50%)/Fe3O4 bead can be considered as a potential new antibacterial agent for water and wastewater treatment.

Is imogolite a suitable adsorbent agent for the herbicides like diuron and atrazine?

Nanotubular minerals are gained researchers’ interest for environmental applications and their use as adsorbents due to their structural characteristics. Imogolite mineral belongs to aluminosilicates and can be characterised as a promising sorbent due to its abundant nature as it has both natural and synthetic origins. In the present study, the potential interactions of imogolite mineral with the herbicides diuron and atrazine have been investigated via theoretical approaches to characterise the mineral as a potential adsorbent for water or soil treatment applications. Force Field calculations showed stronger interactions between imogolite outer surface and herbicides. Diuron molecules had a better adaptation to the nanotubular shape by torsion, unlike atrazine molecules, when herbicides interacted with the inner surface due to their molecule length and rigidity. The release of the herbicides from the imogolite nanotube showed the unstable nature of both herbicides when they were loaded on the inner part of imogolite, which is in agreement with the sorption studies that proved the preference for herbicides on the outer surface and the edges of the minerals. Water molecules played a crucial role in the complexes related to imogolite properties as its inner surface is more hydrophilic. When herbicides were loaded on the outer surface, water molecules were the intermediate medium for the sorption of herbicides creating hydrogen bonds. In contrast, on the inner surface, the herbicide molecules had a competed behaviour to water. From a theoretical point of view, imogolite is a feasible sorbent for herbicides, especially when loaded on the mineral's outer part, creating high stability of complexes.