Exploring recyclable alginate-enhanced GCN-LDO sponge for U(VI) and Cd(II) removal: Insights from batch and column studies

Developing effective water treatment materials, particularly through proven adsorption methods, is crucial for removing heavy metal contaminants. This study synthesizes a cost-effective three-dimensional material encapsulating graphitic carbon nitride-layered double oxide (GCN-LDO) in sodium alginate (SA) through the freeze-drying method. The material is applied to remove uranium (U(VI)) and cadmium (Cd(II)) in real water systems. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analyses conclusively verified the elemental composition and successful encapsulation of GCN-LDO within the SA matrix. Removal effectiveness was tested under various conditions, including adsorbent dose, ionic strength, contact time, temperature, different initial pollutant concentrations, and the impact of co-existing ions. The adsorption of U(VI) and Cd(II) conformed to the pseudo-second-order (PSO) kinetic model, signifying a chemical interaction between the sodium alginate-graphitic carbon nitride-layered double oxide (SA-GCN-LDO) sponge and the metal ions. The Langmuir isotherm indicated monolayer, homogeneous adsorption for U(VI) and Cd(II) with capacities of 158.25 and 165.00 mg/g. SA-GCN-LDO recyclability was found in up to seven adsorption cycles with a removal efficacy of 70%. The temperature effect study depicts the exothermic nature of the U(VI) and Cd(II) ion removal process. Various mechanisms involved in U(VI) and Cd(II) removal were proposed. Further, continuous fixed bed column studies were performed, and Thomas and the Yoon-Nelson model were studied. These insights from this investigation contribute to advancing our knowledge of the material's performance within the context of U(VI) and Cd(II) adsorption, paving the way for optimized and sustainable water treatment solutions.

Synthesis, molecular docking studies and biological evaluation of N-(4-oxo-2-(trifluoromethyl)-4H-chromen-7-yl) benzamides as potential antioxidant, and anticancer agents

A series of novel chromone derivatives of (N-(4-oxo-2-(trifluoromethyl)-4H-chromen-6-yl) benzamides) were synthesized by treating 7-amino-2-(trifluoromethyl)-4H-chromen-4-one with K2CO3 and/or NaH, suitable alkyl halides and acetonitrile and/or 1,4-dioxane. The obtained products are in high yields (87 to 96%) with various substituents in short reaction times with no more by-products and confirmed by FT-IR, 1H, and 13C-NMR Spectral data. The in vitro cytotoxic activity was examined against two human cancer cell lines, namely the human lung adenocarcinoma (A-549) and the human breast (MCF-7) cancer cell line. Compound 4h showed promising cytotoxicity against both cell lines with IC50 values of 22.09 and 6.40 ± 0.26 µg/mL respectively, compared to that of the standard drug. We also performed the in vitro antioxidant activity by DPPH radical, hydrogen peroxide, NO scavenging, and total antioxidant capacity (TAC) assay methods, and they showed significant activities. The possible binding interactions of all the synthesized chromone derivatives are also investigated against selective pharmacological targets of human beings, such as HERA protein for cytotoxic activity and Peroxiredoxins (3MNG) for antioxidant activity which showed closer binding free energies than the standard drugs and evidencing the above two types of activities.

Insights into kinetics, thermodynamics, and mechanisms of chemically activated sunflower stem biochar for removal of phenol and bisphenol-A from wastewater

This study synthesized a highly efficient KOH-treated sunflower stem activated carbon (KOH-SSAC) using a two-step pyrolysis process and chemical activation using KOH. The resulting material exhibited exceptional properties, such as a high specific surface area (452 m2/g) and excellent adsorption capacities for phenol (333.03 mg/g) and bisphenol A (BPA) (365.81 mg/g). The adsorption process was spontaneous and exothermic, benefiting from the synergistic effects of hydrogen bonding, electrostatic attraction, and stacking interactions. Comparative analysis also showed that KOH-SSAC performed approximately twice as well as sunflower stem biochar (SSB), indicating its potential for water treatment and pollutant removal applications. The study suggests the exploration of optimization strategies to further enhance the efficiency of KOH-SSAC in large-scale scenarios. These findings contribute to the development of improved materials for efficient water treatment and pollution control.

Extracellular synthesis of silver nanoparticle using yeast extracts: antibacterial and seed priming applicationss

The evolution and rapid spread of multidrug-resistant (MDR) bacterial pathogens have become a major concern for human health and demand the development of alternative antimicrobial agents to combat this emergent threat. Conventional intracellular methods for producing metal nanoparticles (NPs) using whole-cell microorganisms have limitations, including binding of NPs to cellular components, potential product loss, and environmental contamination. In contrast, this study introduces a green, extracellular, and sustainable methodology for the bio-materialization of silver NPs (AgNPs) using renewable resource cell-free yeast extract. These extracts serve as a sustainable, biogenic route for both reducing the metal precursor and stabilizing the surface of AgNPs. This method offers several advantages such as cost-effectiveness, environment-friendliness, ease of synthesis, and scalability. HR-TEM imaging of the biosynthesized AgNPs revealed an isotropic growth route, resulting in an average size of about ~ 18 nm and shapes ranging from spherical to oval. Further characterization by FTIR and XPS results revealed various functional groups, including carboxyl, hydroxyl, and amide contribute to enhanced colloidal stability. AgNPs exhibited potent antibacterial activity against tested MDR strains, showing particularly high efficacy against Gram-negative bacteria. These findings suggest their potential role in developing alternative treatments to address the growing threat of antimicrobial resistance. Additionally, seed priming experiments demonstrated that pre-sowing treatment with AgNPs improves both the germination rate and survival of Sorghum jowar and Zea mays seedlings. KEY POINTS: •Yeast extract enables efficient, cost-effective, and eco-friendly AgNP synthesis. •Biosynthesized AgNPs showed strong antibacterial activity against MDR bacteria. •AgNPs boost seed germination and protect against seed-borne diseases.

Improving U(VI) retention efficiency and cycling stability of GCN-supported calcined-LDH composite: Mechanism insight and real water system applications

The synthesis and characterization of graphitic carbon nitride (GCN) and its composites with calcined layered double hydroxide (CLDH) were examined in this investigation. The goal was to assess these composites' maximum adsorption capacity (qmax) for U(VI) ions in wastewater. Several different characterization methodologies were utilized to examine the fabricated substances. These methods encompass X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The GCN-CLDH composite displayed enhanced adsorption ability towards U(VI) ions due to its high surface functionality. Langmuir adsorption isotherm analysis showed that more than 99% of U(VI) ions were adsorbed, with a qmax of 196.69 mg/g. The kinetics data exhibited a good fit for a pseudo-second-order (PSO) model. Adsorption mechanisms involving precipitation and surface complexation via Lewis's acid-base interactions were proposed. The application of the GCN-CLDH composite in groundwater demonstrated adsorption below the maximum permissible limit established by USEPA, indicating improved cycling stability. These observations underscore the capacity of the GCN-CLDH composite's proficiency in adsorbing U(VI) aqueous solutions containing radioactive metals.

Development of ultra-high surface area polyaniline-based activated carbon for the removal of volatile organic compounds from industrial effluents

Removing volatile organic compounds (VOCs) from aqueous solutions is critical for reducing VOC emissions in the environment. Activated carbons are widely used for removal of VOCs from water. However, they show less application feasibility and low removal due to less surface area. Here, a cost-effective and high surface area activated carbonized polyaniline (ACP) was synthesized to sustainable removal of VOCs from water. The ACP microstructure, surface properties, and pore structure were investigated using Brunauer-Emmett-Teller (BET) theory, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The specific surface area of ACP6:1 (2988.13 m2/g) was greater than that of commercial activated carbon (PAC) (1094.49 m2/g), indicating that it has excellent VOC adsorption capacity. The effects of pH, initial VOC concentration, time, temperature, and ionic strength were studied. According to kinetic and thermodynamic studies on VOCs adsorption, it is an exothermic and spontaneous process involving rate-limiting kinetics. Adsorption isotherms follow the Freundlich isotherm model, suggesting that the adsorbent surface is heterogeneous with multilayer adsorption and maximum ACP adsorption capacities of 1913.9, 2453.3, 1635.8, and 3327.0 mg/g at 293 K for benzene, toluene, ethylbenzene, and perchloroethylene, respectively, representing a 3- to 5-fold improvement over PAC. ACP is a promising adsorbent with a high adsorption efficiency for VOC removal.

Exploring Modified Rice Straw Biochar as a Sustainable Solution for Simultaneous Cr(VI) and Pb(II) Removal from Wastewater: Characterization, Mechanism Insights, and Application Feasibility

This study aimed to investigate the efficacy of a rice straw biosorbent in batch adsorption for the removal of chromium (Cr(VI)) and lead (Pb(II)) heavy-metal ions from wastewater. The biosorbent was chemically synthesized and activated by using concentrated sulfuric acid. The produced biosorbent was then characterized by using Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses, which provided insights into surface morphology and functional groups. The study examined the effects of pH, rice straw dose, ion concentration, and contact time on metal ion adsorption. Optimal conditions for efficient removal (95.57% for Cr(VI) and 85.68% for Pb(II)) were achieved at a pH of 2.0, a biosorbent dose of 2 g/L, an initial concentration of 20 mg/L, and a contact time of 50 min in synthetic solutions. The isotherms and kinetics model fitting results found that both metal ion adsorption processes were multilayer on the hetero surface of rice straw biosorbent via rate diffusion kinetics. Thermodynamic investigations were conducted, and the results strongly indicate that the adsorption process is endothermic and spontaneous. Notably, the results indicated that the highest desorption rate was achieved by adding 0.3 N HCl to the system.

Efficiency of Ppy-PA-pani and Ppy-PA composite adsorbents in Chromium(VI) removal from aqueous solution

In this study, first time the combination of composites with Phytic acid (PA) as the organic binder cross-linker is reported. The novel use of PA with single and double conducting polymers (polypyrrole (Ppy) and polyaniline (Pani)) were tested against removal of Cr(VI) from wastewater. Characterizations (FE-SEM, EDX, FTIR, XRD, XPS) were performed to study the morphology and removal mechanism. The adsorption removal capability of Polypyrrole - Phytic Acid - Polyaniline (Ppy-PA-Pani) was deemed to be higher than Polypyrrole - Phytic Acid (Ppy-PA) due to the mere existence of Polyaniline as the extra polymer. The kinetics followed 2nd order with equilibration at 480 min, but Elovich model confirmed that chemisorption is followed. Langmuir isotherm model exhibited maximum adsorption capacity of 222.7-321.49 mg/g for Ppy-PA-Pani and 207.66-271.96 mg/g for Ppy-PA at 298K-318K with R2 values of 0.9934 and 0.9938 respectively. The adsorbents were reusable for 5 cycles of adsorption-desorption. The thermodynamic parameter, ΔH shows positive values confirmed the adsorption process was endothermic. From overall results, the removal mechanism is believed to be chemisorption through Cr(VI) reduction to Cr(III). The use of phytic acid (PA) as organic binder with combination of dual conducting polymer (Ppy-PA-Pani) was invigorating the adsorption efficiency than just single conducting polymer (Ppy-PA).

Development of Novel Peptide-Modified Silver Nanoparticle-Based Rapid Biosensors for Detecting Aminoglycoside Antibiotics

The detection and monitoring of aminoglycoside antibiotics (AGAs) have become of utmost importance due to their widespread use in human and animal therapy, as well as the associated risks of exposure, toxicity, and the emergence of antimicrobial resistance. In this study, we successfully synthesized casein hydrolysate peptides-functionalized silver nanoparticles (CHPs@AgNPs) and employed them as a novel colorimetric analytical platform to demonstrate remarkable specificity and sensitivity toward AGAs. The colorimetric and spectral response of the CHPs@AgNPs was observed at 405 and 520 nm, showing a linear correlation with the concentration of streptomycin, a representative AGA. The color changes from yellow to orange provided a visual indication of the analyte concentration, enabling quantitative determination for real-world samples. The AgNP assay exhibited excellent sensitivity with dynamic ranges of approximately 200-650 and 100-700 nM for streptomycin-spiked tap water and dairy whey with limits of detection found to be ∼98 and 56 nM, respectively. The mechanism behind the selective aggregation of CHPs@AgNPs in the presence of AGAs involves the amine groups of the target analytes acting as molecular bridges for electrostatic coupling with hydroxyl or carboxyl functionalities of adjacent NPs, driving the formation of stable NP aggregates. The developed assay offers several advantages, making it suitable for various practical applications. It is characterized by its simplicity, rapidity, specificity, sensitivity, and cost-effectiveness. These unique features make the method a promising tool for monitoring water quality, ensuring food safety, and dealing with emergent issues of antibiotic resistance.

Graphitic carbon nitride (g-C3N4)-assisted materials for the detection and remediation of hazardous gases and VOCs

Graphitic carbon nitride (g-C3N4)-based materials are attracting attention for their unique properties, such as low-cost, chemical stability, facile synthesis, adjustable electronic structure, and optical properties. These facilitate the use of g-C3N4 to design better photocatalytic and sensing materials. Environmental pollution by hazardous gases and volatile organic compounds (VOCs) can be monitored and controlled using eco-friendly g-C3N4- photocatalysts. Firstly, this review introduces the structure, optical and electronic properties of C3N4 and C3N4 assisted materials, followed by various synthesis strategies. In continuation, binary and ternary nanocomposites of C3N4 with metal oxides, sulfides, noble metals, and graphene are elaborated. g-C3N4/metal oxide composites exhibited better charge separation that leads to enhancement in photocatalytic properties. g-C3N4/noble metal composites possess higher photocatalytic activities due to the surface plasmon effects of metals. Ternary composites by the presence of dual heterojunctions improve properties of g-C3N4 for enhanced photocatalytic application. In the later part, we have summarised the application of g-C3N4 and its assisted materials for sensing toxic gases and VOCs and decontaminating NOx and VOCs by photocatalysis. Composites of g-C3N4 with metal and metal oxide give comparatively better results. This review is expected to bring a new sketch for developing g-C3N4-based photocatalysts and sensors with practical applications.

Reutilization of carbon of waste filter cartridge after its surface modification for the fluoride removal from water by continuous flow process

In the present study, the waste carbon cartridge of the water filter was modified and reutilized for defluoridation of water. The modified carbon was characterized by particle size analysis (PSA), Fourier transformed infrared spectroscopy (FTIR), zeta potential, pHzpc, energy-dispersive X-ray (EDS), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray crystallography (XRD). The adsorptive nature of modified carbon was investigated with pH (4-10), dose (1-5 g/L), contact time (0-180 min), temperature (25-55 °C), fluoride concentration (5-20 mg/L), and the effect of the competitive ions. Adsorption isotherm, kinetics, thermodynamics, and breakthrough studies were evaluated for fluoride uptake on surface-modified carbon (SM*C). Fluoride adsorption on the carbon accepted Langmuir model (R2 = 0.983) and pseudo-second-order kinetic (R2 = 0.956). The presence of HCO3- in the solution reduced the elimination of fluoride. The carbon was regenerated and reused four times; the removal percentage was decreased from 92 to 31.7%. This adsorption phenomenon showed exothermic behavior. The maximum fluoride uptake capacity of SM*C achieved 2.97 mg/g at 20 mg/L of initial concentration. The modified carbon cartridge of the water filter was successfully employed for fluoride removal from water.

Preparation, Characterization, and Chemically Modified Date Palm Fiber Waste Biomass for Enhanced Phenol Removal from an Aqueous Environment

The date palm tree is extensively cultivated in Middle Eastern countries such as Saudi Arabia, generating a large amount of waste in the form of leaves, seeds, and fibrous materials. This study examined the feasibility of using raw date palm fiber (RDPF) and NaOH chemically modified date palm fiber (NaOH-CMDPF) obtained from discarded agricultural waste for the removal of phenol in an aqueous environment. The adsorbent characterization was performed by using different techniques, i.e., particle size analysis; elemental analyzer (CHN); and BET, FTIR, and FESEM-EDX analysis. The FTIR analysis revealed the presence of various functional groups on the surface of the RDPF and NaOH-CMDPF. The results showed that chemical modification by NaOH increased the phenol adsorption capacity that was well-fitted by the Langmuir isotherm. Higher removal was obtained with NaOH-CMDPF (86%) than with the RDPF (81%). The RDPF and NaOH-CMDPF sorbents' maximum (Q_m) adsorption capacities were more than 45.62 mg/g and 89.67 mg/g and were comparable to the sorption capacities of various other types of agricultural waste biomass reported in the literature. The kinetic studies confirmed that the adsorption of phenol followed the pseudo-second-order kinetic process. The present study concluded that the RDPF and NaOH-CMDPF were eco-friendly and cost-effective in promoting sustainable management and the reuse of the Kingdom's lignocellulosic fiber waste material.

Mangiferin-Enriched Mn-Hydroxyapatite Coupled with β-TCP Scaffolds Simultaneously Exhibit Osteogenicity and Anti-Bacterial Efficacy

Biphasic calcium phosphate (BCP) containing β-tricalcium phosphate and manganese (Mn)-substituted hydroxyapatite (HAP) was synthesized. Biomedical scaffolds were prepared using this synthesized powder on a sacrificial polyurethane sponge template after the incorporation of mangiferin (MAN). Mn was substituted at a concentration of 5% and 10% in HAP to examine the efficacy of Mn at various concentrations. The phase analysis of the as-formed BCP scaffold was carried out by X-ray diffraction analysis, while the qualitative observation of morphology and the osteoblast cell differentiation were carried out by scanning electron microscopy and confocal laser scanning microscopy techniques. Gene expressions of osteocalcin, collagen 1, and RUNX2 were carried out using qRT-PCR analyses. Significantly higher (p < 0.05) levels of ALP activity were observed with extended osteoblast induction on the mangiferin-incorporated BCP scaffolds. After characterization of the specimens, it was found that the scaffolds with 10% Mn-incorporated BCP with mangiferin showed better osteogenicity and simultaneously the same scaffolds exhibited higher anti-bacterial properties as observed from the bacterial viability test. This study was carried out to evaluate the efficacy of Mn and MAN in BCP for osteogenicity and antibacterial action.

Recent trends in the applications of sonochemical reactors as an advanced oxidation process for the remediation of microbial hazards associated with water and wastewater: A critical review

Water is one of the major sources that spread human diseases through contamination with bacteria and other pathogenic microorganisms. This review focuses on microbial hazards as they are often present in water and wastewater and cause various human diseases. Among the currently used disinfection methods, sonochemical reactors (SCRs) that produce free radicals combined with advanced oxidation processes (AOPs) have received significant attention from the scientific community. Also, this review discussed various types of cavitation reactors, such as acoustic cavitation reactors (ACRs) utilizing ultrasonic energy (UE), which had been widely employed, involving AOPs for treating contaminated waters. Besides ACRs, hydrodynamic cavitation reactors (HCRs) also effectively destroy and deactivate microorganisms to varying degrees. Cavitation is the fundamental phenomenon responsible for initiating many sonochemical reactions in liquids. Bacterial degradation occurs mainly due to the thinning of microbial membranes, local warming, and the generation of free radicals due to cavitation. Over the years, although extensive investigations have focused on the antimicrobial effects of UE (ultrasonic energy), the primary mechanism underlying the cavitation effects in the disinfection process, inactivation of microbes, and chemical reactions involved are still poorly understood. Therefore, studies under different conditions often lead to inconsistent results. This review investigates and compares other mechanisms and performances from greener and environmentally friendly sonochemical techniques to the remediation of microbial hazards associated with water and wastewater. Finally, the energy aspects, challenges, and recommendations for future perspectives have been provided.

New insights into MXene applications for sustainable environmental remediation

Multiple ecological contaminants in gaseous, liquid, and solid forms are vented into ecosystems due to the huge growth of industrialization, which is today at the forefront of worldwide attention. High-efficiency removal of these environmental pollutants is a must because of the potential harm to public health and biodiversity. The alarming concern has led to the synthesis of improved nanomaterials for removing pollutants. A path to innovative methods for identifying and preventing several obnoxious, hazardous contaminants from entering the environment is grabbing attention. Various applications in diverse industries are seen as a potential directions for researchers. MXene is a new, excellent, and advanced material that has received greater importance related to the environmental application. Due to its unique physicochemical and mechanical properties, high specific surface area, physiological compatibility, strong electrodynamics, and raised specific surface area wettability, its applications are growing. This review paper examines the most recent methods and trends for environmental pollutant removal using advanced 2D Mxene materials. In addition, the history and the development of MXene synthesis were elaborated. Furthermore, an extreme summary of various environmental pollutants removal has been discussed, and the future challenges along with their future perspectives have been illustrated.

Stable and recyclable lanthanum hydroxide-doped graphene oxide biopolymer foam for superior aqueous arsenate removal: Insight mechanisms, batch, and column studies

In this study, a graphene oxide-based lanthanum hydroxide/chitosan foam (CSGOL foam) was synthesized for arsenate (As(V)) remediation in surface water. The synthesized CSGOL foam texture and purity was assessed using scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) studies. The results proved that the foam was highly porous, stable, and had high surface functionality that facilitated adsorption for water pollutant removal. The sorption results proved that the As(V) removal was high (146.20 mg/g at pH 6 with 0.5 g/L CSGOL foam) when compared to the similar type of materials, endothermic chemisorption due to the production of monodentate and bidentate inner-sphere complexes. Furthermore, continuous column results indicated that the As(V) concentration in real surface waters was reduced to WHO standards (less than 10 μg As/L of water) of As(V) in drinking water for up to 10,000 bed volume. Further it can be used up to four cycles without loss of efficacy less than 93%. Because of its excellent removal capabilities and simple synthesis technique, CSGOL foam shows significant promise for treating As(V)-containing water. Further, the XPS analysis and batch studies results suggests that As(V) removal mechanism was involved electrostatic and surface complexation through chemical interaction predominately.

Rapid growth of MXene-based membranes for sustainable environmental pollution remediation

Water consumption has grown in recent years due to rising urbanization and industry. As a result, global water stocks are steadily depleting. As a result, it is critical to seek strategies for removing harmful elements from wastewater once it has been cleaned. In recent years, many studies have been conducted to develop new materials and innovative pathways for water purification and environmental remediation. Due to low energy consumption, low operating cost, and integrated facilities, membrane separation has gained significant attention as a potential technique for water treatment. In these directions, MXene which is the advanced 2D material has been explored and many applications were reported. However, research on MXene-based membranes is still in its early stages and reported applications are scatter. This review provides a broad overview of MXenes and their perspectives, including their synthesis, surface chemistry, interlayer tuning, membrane construction, and uses for water purification. Application of MXene based membrane for extracting pollutants such as heavy metals, organic contaminants, and radionuclides from the aqueous water bodies were briefly discussed. Furthermore, the performance of MXene-based separation membranes is compared to that of other nano-based membranes, and outcomes are very promising. In order to shed more light on the advancement of MXene-based membranes and their operational separation applications, significant advances in the fabrication of MXene-based membranes is also encapsulated. Finally, future prospects of MXene-based materials for diverse applications were discussed.

Insights into manganese ferrite anchored graphene oxide to remove Cd(II) and U(VI) via batch and semi-batch columns and its potential antibacterial applications

The bioaccumulation, non-biodegradability, and high toxicity of Cd(II) and U(VI) in water is a serious concerns. Manganese ferrite/graphene oxide (GMF) nanocomposites were synthesized, characterized, and used to efficiently remove Cd(II) and U(VI) from an aqueous solution in this study. X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) analyses, respectively, confirmed the formation of GMF and the adsorptive removal mechanism. The XRD results revealed an amorphous structure when MnFe₂O₄ was loaded onto the GO surface. XPS results suggest that C = C, C-OorOH, and metal oxides are responsible for the removal of Cd(II) and U(VI) via electrostatic and chemical interaction. According to the Brunauer Emmett and Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) characterization analysis, GMF has a high surface area (117.78 m²/g) and a spherical shape with even distribution. The kinetics data were successfully reproduced by a pseudo-second-order non-linear model indicating the complexity of the sorption mechanism was rate-limiting. The maximum Langmuir uptake ability of GMF for Cd(II) and U(VI) was calculated to be 232.56 mg/g and 201.65 mg/g, respectively. Using external magnetic power, the prepared GMF can easily separate from the aqueous solution and can keep both metal ions under Environmental protection agency standards in water for up to six cycles of re-use of GMF. Finally, the GMF nanocomposite demonstrated significant promise as an adsorbent for removing Cd(II) and U(VI) from actual contaminated water samples. The antibacterial test was expanded to include gram-negative E. coli and gram-positive S. aureus to better understand GMF's bacterial inhibition efficacy.

Experimentally and spectroscopically evidenced mechanistic study of butyl peroxyacid oxidative degradation of benzo[a]pyrene in soil

Benzo[a]pyrene (BaP) is a major indicator of soil contamination and categorized as a highly persistent, carcinogenic, and mutagenic polycyclic aromatic hydrocarbon. An advanced peroxyacid oxidation process was developed to reduce soil pollution caused by BaP originating from creosote spills from railroad sleepers. The pH, organic matter, particle size distribution of soil, and concentrations of BaP and heavy metals (Cd, Cu, Zn, Pb, and As) in the BaP-contaminated soils were estimated. A batch experiment was conducted to determine the effects of organic acid type, soil particle size, stirring speed, and reaction time on the peroxyacid oxidation of BaP in the soil samples. Additionally, the effect of the organic acid concentration on the peroxyacid degradation of BaP was investigated using an oxidizing agent in spiked soil with and without hydrogen peroxide. The results of the oxidation process indicated that BaP and heavy metal residuals were below acceptable Korean standards. A significant difference in the oxidative degradation of BaP was observed between the spiked and natural soil samples. The formation of a peroxyacid intermediate was primarily responsible for the enhanced BaP oxidation. Further, butyric acid could be reused thrice without losing the efficacy (<90%). The systematic peroxyacid oxidative degradation mechanism of BaP was also discussed. A qualitative analysis of the by-products of the BaP reaction was conducted, and their corresponding toxicities were determined for possible field applications. The findings conclude that the developed peroxyacid oxidation method has potential applications in the treatment of BaP-contaminated soils.

Highly efficient surface sequestration of Pb2+ and Cr3+ from water using a Mn3O4 anchored reduced graphene oxide: Selective removal of Pb2+ from real water

Owing to the ubiquitous existence of detrimental heavy metals in the environment, simple adsorption-oriented approaches are becoming increasingly appealing for the effective removal of Pb²⁺ and Cr³⁺ from water bodies. These techniques use nanocomposites (NC) of reduced graphene oxide (rGO) and Mn₃O₄ (rGO-Mn₃O₄), they employ a hydrothermal technique featuring NaBH₄ and NaOH solutions. Here, spectroscopic and microscopic instrumental techniques were used to evaluate the morphological and physicochemical characteristics of prepared reduced graphene oxide manganese oxide (rGO-Mn₃O₄), revealing that it possessed a well-defined porous structure with a specific surface area of 126 m² g^-1. The prepared rGO-Mn₃O₄ had significant adsorption efficiencies for Pb²⁺ and Cr³⁺, achieving maximum sequestration capacities of 130.28 and 138.51 mg g^-1 for Pb²⁺ and Cr³⁺, respectively, according to the Langmuir model. These adsorption capacities are comparable to or greater than those of previously reported graphene-based materials. The Langmuir isotherm and pseudo-second-order models adequately represented the experimental results. Thermodynamic analysis revealed that adsorption occurred through spontaneous endothermic reactions. Recycling studies showed that the developed r-GO-Mn₃O₄ had excellent recyclability, with <70% removal at the 5th cycle; its feasibility was evaluated using industrial wastewater, suggesting that Pb²⁺ was selectively removed from Pb²⁺ and Cr³⁺ contaminated water. The instrumental analysis and surface phenomena studies presented here revealed that the adsorptive removal processes of both heavy metals involved π electron donor-acceptor interactions, ion exchange, and electrostatic interactions, along with surface complexation. Overall, the developed rGO-Mn₃O₄ has the potential to be a high-value adsorbent for removing heavy metals.

Predictive capability evaluation and optimization of Pb(II) removal by reduced graphene oxide-based inverse spinel nickel ferrite nanocomposite

Pb(II) is a heavy metal that is a prominent contaminant in water contamination. Among the different pollution removal strategies, adsorption was determined to be the most effective. The adsorbent and its type determine the adsorption process's efficiency. As part of this effort, a magnetic reduced graphene oxide-based inverse spinel nickel ferrite (rGNF) nanocomposite for Pb(II) removal is synthesized, and the optimal values of the independent process variables (like initial concentration, pH, residence time, temperature, and adsorbent dosage) to achieve maximum removal efficiency are investigated using conventional response surface methodology (RSM) and artificial neural networks (ANN). The results indicate that the initial concentration, adsorbent dose, residence time, pH, and process temperature are set to 15 mg/L, 0.55 g/L, 100 min, 5, and 30 °C, respectively, the maximum removal efficiency (99.8%) can be obtained. Using the interactive effects of process variables findings, the adsorption surface mechanism was examined in relation to process factors. A data-driven quadratic equation is derived based on the ANOVA, and its predictions are compared with ANN predictions to evaluate the predictive capabilities of both approaches. The R² values of RSM and ANN predictions are 0.979 and 0.991 respectively and confirm the superiority of the ANN approach.

Separation of vanadium and tungsten from synthetic and spent catalyst leach solutions using an ion-exchange resin

Vanadium and tungsten ion adsorption and desorption characteristics and separation conditions were investigated using a simple porous anion-exchange resin. Initially, systematic experimental research was performed using synthetic aqueous vanadium and tungsten solutions. To evaluate the vanadium and tungsten (50-500 mg L^-1) isotherm parameters, adsorption was performed at pH 7.0 using 0.5 g of ion-exchange resin at 303 K for 24 h. Well-known adsorption models such as Langmuir, Freundlich, and Temkin were used. Vanadium was desorbed from the resin using HCl and NaOH solutions. In contrast, tungsten was not desorbed by the HCl solution, which enabled the separation of the two ions. The desorption reaction reached equilibrium within 30 min of its start, yielding over 90% desorption. We investigated the adsorption mechanism and resin stability with the aid of spectroscopic and microscopic analysis, as well as adsorption results. The applicability and feasibility of the resin was tested via recovery of both metals from real spent catalysts. The applicability and reusability results indicated that the resin can be used for more than five cycles with an efficacy of over 90%.

Magnetic-watermelon rinds biochar for uranium-contaminated water treatment using an electromagnetic semi-batch column with removal mechanistic investigations

Biosorption using modified biochar has been increasingly adopted for the sustainable removal of uranium-contaminated from an aqueous solution. In this research study, the facile preparation and surface characteristics of magnetized biochar derived from waste watermelon rind to treat U(VI) contaminated water were investigated. The porosity, specific surface area, adsorption capacity, reusability, and stability were effectively improved after the magnetization of biochar. The kinetics and isotherm studies found that the U(VI) adsorption was rate-limiting monolayer sorption on the homogeneous surface of magnetized watermelon rind biochar (MWBC). The maximum adsorption capacity was found to be 323.56 mg of U(VI) per g of MWBC at pH 4.0 and 293 K that was higher than that of watermelon rind biochar (WBC) (135.86 mg g^-1) and other sourced biochars. The surface interaction mechanism, environmental feasibility, applicability for real-filed water treatment studied in the electromagnetic semi-batch column, and reusability of MWBC were also explored. Furthermore, salient raised the ion exchange and complexation action capacity of MWBC due to the presence of Fe oxide. The overall results indicated that MWBC was not only inexpensive and had a high removal capacity for U(VI), but it also easily enabled phase separation from an aqueous solution, with more than three times reusability at a minimum removal capacity of 99%.

Polyvinyl Alcohol Polymer Functionalized Graphene Oxide Decorated with Gadolinium Oxide for Sequestration of Radionuclides from Aqueous Medium: Characterization, Mechanism, and Environmental Feasibility Studies

Uranium (U(VI)) and thorium (Th(IV)) ions produced by the nuclear and mining industries cause water pollution, thereby harming the environment and human health. In this study, gadolinium oxide-decorated polyvinyl alcohol-graphene oxide composite (PGO-Gd) was developed using a simple hydrothermal process to treat U(VI) and Th(IV) ions in water. The developed material was structurally characterized by highly advanced spectroscopy and microscopy techniques. The effects of pH, equilibration time and temperature on both radionuclides (U(VI) and Th(IV)) adsorption by PGO-Gd were examined. The PGO-Gd composite adsorbed both metal ions satisfactorily, with adsorption capacities of 427.50 and 455.0 mg g-1 at pH 4.0, respectively. The adsorption properties of both metal ions were found to be compatible with the Langmuir and pseudo-second-order kinetic models. Additionally, based on the thermodynamic characteristics, the adsorption was endothermic and spontaneous. Furthermore, the environmental viability of PGO-Gd and its application was demonstrated by studying its reusability in treating spiked surface water. PGO-Gd shows promise as an adsorbent in effectively removing both radionuclides from aqueous solutions.

Removal of arsenic from aqueous solution by novel iron and iron-zirconium modified activated carbon derived from chemical carbonization of Tectona grandis sawdust: Isotherm, kinetic, thermodynamic and breakthrough curve modelling

The aim of the present study was: development of activated carbon modified with iron (Fe@AC) and modified with iron and zirconium (Fe-Zr@AC) from the Tectona grandis sawdust (TGS) waste biomass and its potential applicability for the removal of As (III) from contaminated water by batch and column mode. The biomass waste was pre-treated with ferric chloride (FeCl₃) and the mixture of FeCl₃ and zirconium oxide (ZrO₂) and then pyrolyzed at 500 °C for 2 h. The properties of both bioadsorbents were comprehensively characterized by using Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), Particle Size analysis (PSA), point of zero charge (pH_ZPC), Brunauer-Emmett-Teller (BET) to prove successful impregnation of the Fe and Zr on the surface of AC of TGS. FTIR analysis clearly indicates the Fe and Fe-Zr complexation on biosorbents surface and biosorption of As (III). The results revealed that maximum As (III) removal was achieved 86.35% by Fe-Zr@AC (3 g/L dose, pH-7.0, temperature-25 °C and concentration 0.5 mg/L). However, maximum removal of As (III) was attained ~75% by Fe@AC (with dose-4g/L, pH-7.0, temperature-25 °C and concentration 0.5 mg/L) at the initial concentration of 0.5 mg/L of As (III). Fe-Zr@AC exhibits higher efficiency with q_max value 1.206 mg/g than Fe@AC with the q_max value 0.679 mg/g for the removal of As(III). While in the column study, Fe-Zr@AC exhibited 98.8% removal at flow rate of 5 mL/min and bed height of 5 cm. Biosorption Isotherm and Kinetics were fitted good with Langmuir isotherm (R² ≥ 0.99) and followed pseudo-second-order (R² ≥ 0.99). The regeneration study indicates that the prepared biosorbents efficiently recycled up to five cycles. Therefore, Fe@AC and Fe-Zr@AC derived from TGS has been showed to be novel, effective, and economical biosorbent. The collective benefits of easy development, good affinity towards As (III), good separability, reusability, and inexpensive of magnetized Fe@AC and Fe-Zr@AC make it a novel biosorbent. The application of Fe-Zr@AC for the removal of As (III) from the water was very efficient its concentration in the solution after treatment was found below the 10 μg/L as per the guideline WHO.

An overview of molecular biology and nanotechnology based analytical methods for the detection of SARS-CoV-2: promising biotools for the rapid diagnosis of COVID-19

Currently, the 2019 novel coronavirus (2019-nCoV) is drastically affecting 214 countries, causing severe pneumonia in patients, which has resulted in lockdown being implemented in several countries to stop its local transmission. Considering this, the rapid screening and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; 2019-nCoV) play an essential role in the diagnosis of COVID-19, which can minimize local transmission and prevent an epidemic. Due to this public health emergency, the development of ultra-fast reliable diagnostic kits is essential for the diagnosis of COVID-19. Recently, molecular biology and nanotechnology based analytical methods have proven to be promising diagnostic tools for the rapid screening of 2019-nCoV with high accuracy and precision. The main aim of this review is to provide a retrospective overview on the molecular biology tools (reverse transcription polymerase chain reaction (RT-PCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP)) and nanotechnology based analytical tools (enzyme-linked immunosorbent assay (ELISA), RT-PCR, and lateral flow assay) for the rapid diagnosis of COVID-19. This review also presents recent reports on other analytical techniques including paper spray mass spectrometry for the diagnosis of COVID-19 in clinical samples. Finally, we provide a quick reference on molecular biology and nanotechnology based analytical tools for COVID-19 diagnosis in clinical samples.

Facile synthesis of economical feasible fly ash-based zeolite-supported nano zerovalent iron and nickel bimetallic composite for the potential removal of heavy metals from industrial effluents

Heavy metals contamination of water is one of the environmental issue globally. Thus prepared fly ash-based zeolite (FZA)-supported nano zerovalent iron and nickel (nZVI/Ni@FZA) bimetallic composite from low-cost fly ash waste for the potential treatment of anion (Cr(VI) and cation Cu(II)) heavy metals from industrial effluents at pH 3 and 5, respectively in this study. The systematic interaction between FZA and nZVI/Ni and the adsorptive removal mechanism was studied. The mean surface area of the nZVI/Ni@FZA (154.11 m²/g) was much greater than that of the FZA (46.6 m²/g) and nZVI (4.76 m²/g) independently, as determined by BET-N₂ measurements. The effect of influence factors on the removal of Cr(VI) and Cu(II) by nZVI/Ni@FZA, such as pH effect, initial concentration effect, time effect, temperature effect, coexisting metals, and ionic strength, and cumulative loading ability, were discussed. The maximum adsorption capacity of nZVI/Ni@FZA was 48.31 mg/g and 147.06 mg/g towards Cr(VI) and Cu(II), respectively. These were higher than those of nZVI@FZA and FZA. It demonstrated that Ni could play an important role in enhancing the reduction ability of nZVI. Furthermore, isothermal and kinetic results revealed that both heavy metal adsorption processes were rate limiting monolayer Langmuir adsorption on homogeneous surfaces. Thermodynamic results suggested that the adsorptive removal of metal ions was endothermic with spontaneity. The applicability of nZVI/Ni@FZA on real industrial wastewater treatment results demonstrate that the concentration of heavy metals were removed under the acceptable standard levels. Further the adsorption capacity of nZVI/Ni@FZA was higher than the nZVI@FZA and FZA. The overall results demonstrated that nZVI/Ni@FZA was a promising, efficient, and economically feasible sorbent for potential wastewater treatment. Moreover this is first report on the preparation nZVI/Ni@FZA bimetallic composite.

Facile synthesis of economical feasible fly ash-based zeolite-supported nano zerovalent iron and nickel bimetallic composite for the potential removal of heavy metals from industrial effluents

Heavy metals contamination of water is one of the environmental issue globally. Thus prepared fly ash-based zeolite (FZA)-supported nano zerovalent iron and nickel (nZVI/Ni@FZA) bimetallic composite from low-cost fly ash waste for the potential treatment of anion (Cr(VI) and cation Cu(II)) heavy metals from industrial effluents at pH 3 and 5, respectively in this study. The systematic interaction between FZA and nZVI/Ni and the adsorptive removal mechanism was studied. The mean surface area of the nZVI/Ni@FZA (154.11 m²/g) was much greater than that of the FZA (46.6 m²/g) and nZVI (4.76 m²/g) independently, as determined by BET-N₂ measurements. The effect of influence factors on the removal of Cr(VI) and Cu(II) by nZVI/Ni@FZA, such as pH effect, initial concentration effect, time effect, temperature effect, coexisting metals, and ionic strength, and cumulative loading ability, were discussed. The maximum adsorption capacity of nZVI/Ni@FZA was 48.31 mg/g and 147.06 mg/g towards Cr(VI) and Cu(II), respectively. These were higher than those of nZVI@FZA and FZA. It demonstrated that Ni could play an important role in enhancing the reduction ability of nZVI. Furthermore, isothermal and kinetic results revealed that both heavy metal adsorption processes were rate limiting monolayer Langmuir adsorption on homogeneous surfaces. Thermodynamic results suggested that the adsorptive removal of metal ions was endothermic with spontaneity. The applicability of nZVI/Ni@FZA on real industrial wastewater treatment results demonstrate that the concentration of heavy metals were removed under the acceptable standard levels. Further the adsorption capacity of nZVI/Ni@FZA was higher than the nZVI@FZA and FZA. The overall results demonstrated that nZVI/Ni@FZA was a promising, efficient, and economically feasible sorbent for potential wastewater treatment. Moreover this is first report on the preparation nZVI/Ni@FZA bimetallic composite.

An overview of molecular biology and nanotechnology based analytical methods for the detection of SARS-CoV-2: promising biotools for the rapid diagnosis of COVID-19

Currently, the 2019 novel coronavirus (2019-nCoV) is drastically affecting 214 countries, causing severe pneumonia in patients, which has resulted in lockdown being implemented in several countries to stop its local transmission. Considering this, the rapid screening and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; 2019-nCoV) play an essential role in the diagnosis of COVID-19, which can minimize local transmission and prevent an epidemic. Due to this public health emergency, the development of ultra-fast reliable diagnostic kits is essential for the diagnosis of COVID-19. Recently, molecular biology and nanotechnology based analytical methods have proven to be promising diagnostic tools for the rapid screening of 2019-nCoV with high accuracy and precision. The main aim of this review is to provide a retrospective overview on the molecular biology tools (reverse transcription polymerase chain reaction (RT-PCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP)) and nanotechnology based analytical tools (enzyme-linked immunosorbent assay (ELISA), RT-PCR, and lateral flow assay) for the rapid diagnosis of COVID-19. This review also presents recent reports on other analytical techniques including paper spray mass spectrometry for the diagnosis of COVID-19 in clinical samples. Finally, we provide a quick reference on molecular biology and nanotechnology based analytical tools for COVID-19 diagnosis in clinical samples.

Potential of the magnetic hollow sphere nanocomposite (graphene oxide-gadolinium oxide) for arsenic removal from real field water and antimicrobial applications

Potential of the magnetic hollow-sphere nanocomposite, graphene oxide-gadolinium oxide (GO-Gd₂O₃) for arsenic (As) removal from real field water with developing a continuous operating system and antimicrobial activity were investigated. The characterization results suggest that the prepared GO-Gd₂O₃ is a hallow sphere wool-like nanocomposite having 50.91 m² g^-1 surface area. The sorption studies revealed that a high adsorption capacity (216.70 mg g^-1) can be achieved using GO-Gd₂O₃ (0.1 g L^-1) at a pH of 6.0, and temperature of 293 K. The main and novel observations from the loading of Gd₂O₃ are that the GO adsorption efficiency, adsorbent separation rate from aqueous solutions, and the stability of the composite have been altered. Thus, the developed material can overcome the separation and stability issues associated with the bare GO, and exhibits an enhanced adsorption capacity toward arsenic was higher or comparable with existing magnetic material. In addition, the developed adsorption method was well applied for real field water samples collected from the mining area of South Korea where the GO-Gd₂O₃ can reduce the quantity of arsenic under the maximum accepted concentration of arsenic considered fit for drinking water stipulated by environmental protection agencies. Furthermore, the GO-Gd₂O₃ nanocomposite shows a high bacterial photocatalytic inactivation and was comparable with other reports.

Correction: Progress of electrospray ionization and rapid evaporative ionization mass spectrometric techniques for the broad-range identification of microorganisms

Correction for ‘Progress of electrospray ionization and rapid evaporative ionization mass spectrometric techniques for the broad-range identification of microorganisms’ by Suresh Kumar Kailasa et al., Analyst, 2019, 144, 1073–1103, DOI: 10.1039/C8AN02034E.

Corn husk derived magnetized activated carbon for the removal of phenol and para-nitrophenol from aqueous solution: Interaction mechanism, insights on adsorbent characteristics, and isothermal, kinetic and thermodynamic properties

In this study, waste corn husk was used for the synthesis of an effective adsorbent (cornhusk activated carbon, CHAC) and by treating at two different temperatures, 250 °C (CHAC-250) and 500 °C (CHAC-500) to check adsorption efficiency. The synthesized adsorbents were characterized with the help of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy, Particle size analysis and x-ray diffraction (XRD), which revealed the different properties of the two adsorbents. The synthesized adsorbents were applied for the removal of phenol and p-nitrophenol (PNP) from aqueous solution. CHAC-500 was more efficient than the CHAC-250. The maximum adsorptions of phenol and PNP by CHAC-500 were ∼96% and ∼94%, respectively, while the maximum adsorptions of phenol and PNP by CHAC-250 were ∼81% and ∼84%, respectively. The adsorption processes were best fitted with the Langmuir adsorption isotherm and the pseudo-second-order kinetic model. The adsorption of phenol was an exothermic process, while that of PNP was an endothermic process, on both adsorbents.

Removal of U(VI) by sugar-based magnetic pseudo-graphene oxide and its application to authentic groundwater using electromagnetic system

Uranium U(VI) is toxic even at trace levels in aqueous solution and has adverse impacts on the health of human beings. In this study, a sugar-based magnetic pseudo-graphene oxide (SMGO) composite was prepared for the removal of U(VI) from groundwater by graphitization of sugar and ozonation, as well as synthesis with nano-size magnetite particles. To investigate the applicability of SMGO, U(VI)-spiked groundwater as well as U(VI)-contaminated groundwater samples were used in electromagnetic system. The pH-edge adsorption results suggest that adsorption occurs via an inner-sphere surface complex with an optimized pH of 4, where UO₂²⁺ is the dominant U(VI) species. The adsorption isotherm results confirmed that the adsorption of U(VI) onto SMGO occurred via a monolayer process on the homogeneous surface of SMGO and the maximum removal capacity of U(VI) was 28.2 mg/g. The high-gradient magnetic separation (HGMS) principle was applied to U(VI) removal using SMGO to facilitate recovery and the repeated use of the adsorbent during multiple batch cycles. The results indicated that the initial U(VI) concentration (439.1 μg/L) was reduced to a value less than the standard level of U(VI) for drinking water (30 μg/L) during six batch cycles and the separation efficiency was 95.2%. As such, SMGO and electromagnetic system using the HGMS principle are promising technologies for the removal of U(VI) in groundwater.

A comprehensive review of applications of magnetic graphene oxide based nanocomposites for sustainable water purification

With the rapid growth of industrialization, water bodies are polluted with heavy metals and toxic pollutants. In pursuit of removal of toxic pollutants from the aqueous environment, researchers have been developed many techniques. Among these techniques, magnetic separation has caught research attention, as this approach has shown excellent performance in the removal of toxic pollutants from aqueous solutions. However, magnetic graphene oxide based nanocomposites (MGO) possess unique physicochemical properties including excellent magnetic characteristics, high specific surface area, surface active sites, high chemical stability, tunable shape and size, and the ease with which they can be modified or functionalized. As results of their multi-functional properties, affordability, and magnetic separation capability, MGO's have been widely used in the removal of heavy metals, radionuclides and organic dyes from the aqueous environment, and are currently attracting much attention. This paper provides insights into preparation strategies and approaches of MGO's utilization for the removal of pollutants for sustainable water purification. It also reviews the preparation of magnetic graphene oxide nanocomposites and primary characterization instruments required for the evaluation of structural, chemical and physical functionalities of synthesized magnetic graphene oxide nanocomposites. Finally, we summarized some research challenges to accelerate the synthesized MGO's as adsorbents for the treatment of water pollutants such as toxic and radioactive metal ions and organic and agricultural pollutants.

Adsorptive Removal of Fluoride from Aqueous Solution by Biogenic Iron Permeated Activated Carbon Derived from Sweet Lime Waste

In this study, biogenic activated carbon were successfully synthesized from Citrus limetta pulp residue, and applied to remove fluoride from an aqueous solution. For the synthesis activated carbon of biosorbents, raw materials were heated in muffle furnace at two different temperatures i.e. (250 °C and 500 °C) and were noted as ACP-250 and ACP-500. The prepared biosorbents were characterized through scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). Batch adsorption studies were performed with varying temperature, dosage, pH, and various initial concentrations. Adsorption isotherms and the reaction kinetics were also analyzed in order to understand the adsorption mechanism. The results of this study shows that the maximum removal achieved was approximately (86 and 82) % of ACP-500 and ACP-250, respectively. The isotherm results show that the Langmuir isotherm model fitted better, with monolayer adsorption capacity of 12.6 mg/g of fluoride. However, for kinetic study, the pseudo-second-order kinetics fitted well. The synthesized materials at different temperature were highly effective for the removal of fluoride from water, with reusability of three to four times.

Progress of electrospray ionization and rapid evaporative ionization mass spectrometric techniques for the broad-range identification of microorganisms

Electrospray ionization and rapid evaporative ionization mass spectrometric techniques have attracted much attention in the identification of microorganisms, and in the diagnosis of bacterial infections from clinical samples.

Phytochemical-assisted synthetic approaches for silver nanoparticles antimicrobial applications: A review

Silver nanoparticles (Ag NPs) have recently emerged as promising materials in the biomedical sciences because of their antimicrobial activities towards a wide variety of microorganisms. Nanomaterial-based drug delivery systems with antimicrobial activity are critical as they may lead to novel treatments for cutaneous pathogens. In this review, we explore the recent progress on phytochemical-mediated synthesis of Ag NPs for antimicrobial treatment and associated infectious diseases. We discuss the biological activity of Ag NPs including mechanisms, antimicrobial activity, and antifungal/antiviral effects towards various microorganisms. The advent of Ag NP-based nanocarriers and nano-vehicles is also described for treatment of different diseases, along with the mechanisms of microbial inhibition. Overall, this review will provide a rational vision of the main achievements of Ag NPs as nanocarriers for inhibition of various microbial agents (bacteria, fungus, and virus).

Preparation and characterization of porous reduced graphene oxide based inverse spinel nickel ferrite nanocomposite for adsorption removal of radionuclides

For the removal of uranium(VI) (U(VI)) and thorium(IV) (Th(IV)), graphene oxide based inverse spinel nickel ferrite (GONF) nanocomposite and reduced graphene oxide based inverse spinel nickel ferrite (rGONF) nanocomposite were prepared by co-precipitation of GO with nickel and iron salts in one pot. The spectral characterization analyses revealed that GONF and rGONF have a porous surface morphology with an average particle size of 41.41nm and 32.16nm, respectively. The magnetic property measurement system (MPMS) studies confirmed the formation of ferromagnetic GONF and superparamagnetic rGONF. The adsorption kinetics studies found that the pseudo-second-order kinetics was well tune to the U(VI) and Th(IV) adsorption. The results of adsorption isotherms showed that the adsorption of U(VI) and Th(IV) were due to the monolayer on homogeneous surface of the GONF and rGONF. The adsorptions of both U(VI) and Th(IV) were increased with increasing system temperature from 293 to 333±2K. The thermodynamic studies reveal that the U(VI) and Th(IV) adsorption onto GONF and rGONF was endothermic. GONF and rGONF, which could be separated by external magnetic field, were recycled and re-used for up to five cycles without any significant loss of adsorption capacity.

Mechanism and comparison of needle-type non-thermal direct and indirect atmospheric pressure plasma jets on the degradation of dyes

Purified water supply for human use, agriculture and industry is the major global priority nowadays. The advanced oxidation process based on atmospheric pressure non-thermal plasma (NTP) has been used for purification of wastewater, although the underlying mechanisms of degradation of organic pollutants are still unknown. In this study we employ two needle-type atmospheric pressure non-thermal plasma jets, i.e., indirect (ID-APPJ) and direct (D-APPJ) jets operating at Ar feed gas, for the treatment of methylene blue, methyl orange and congo red dyes, for two different times (i.e., 20 min and 30 min). Specifically, we study the decolorization/degradation of all three dyes using the above mentioned plasma sources, by means of UV-Vis spectroscopy, HPLC and a density meter. We also employ mass spectroscopy to verify whether only decolorization or also degradation takes place after treatment of the dyes by the NTP jets. Additionally, we analyze the interaction of OH radicals with all three dyes using reactive molecular dynamics simulations, based on the density functional-tight binding method. This investigation represents the first report on the degradation of these three different dyes by two types of NTP setups, analyzed by various methods, and based on both experimental and computational studies.

Porous graphene oxide based inverse spinel nickel ferrite nanocomposites for the enhanced adsorption removal of arsenic

Porous nanocomposites, graphene oxide based-inverse spinel nickel ferrite (GONF) and reduced graphene oxide based-inverse spinel nickel ferrite (rGONF), were prepared by co-precipitation of graphene oxide (GO) with nickel and iron salts at one pot.