Kinetic Study of Adsorption of Hexavalent Chromium in Aqueous Solution using Bay Leaf (Laurus Nobilis) as New Bio-Adsorbent

Laurus nobilis (Bay leaf), was examined for its capacity to remove hexavalent chromium Cr(VI) poisonous, from aqueous solution. The bio-adsorbent using bay leaf obtained from Laurus nobilis was investigated in batch experiments. The influence of main parameters such as chromium concentration, pH and shaking time are tests. The effect of beginning concentration of Cr(VI) ion (10 to 50 mg/dm ), pH (1 to 6) and shaking time (5 to 180 min) have been reported. The optimum pH was found to be pH 4.. Results show that the most appropriate model was pseudo second-order kinetic and it correlate with the trial statistics well

Metal-organic frameworks (MOFs) based nanofiber architectures for the removal of heavy metal ions

Environmental heavy metal ions (HMIs) accumulate in living organisms and cause various diseases. Metal-organic frameworks (MOFs) have proven to be promising and effective materials for removing heavy metal ions from contaminated water because of their high porosity, remarkable physical and chemical properties, and high specific surface area. MOFs are self-assembling metal ions or clusters with organic linkers. Metals are used as dowel pins to build two-dimensional or three-dimensional frameworks, and organic linkers serve as carriers. Modern research has mainly focused on designing MOFs-based materials with improved adsorption and separation properties. In this review, for the first time, an in-depth look at the use of MOFs nanofiber materials for HMIs removal applications is provided. This review will focus on the synthesis, properties, and recent advances and provide an understanding of the opportunities and challenges that will arise in the synthesis of future MOFs-nanofiber composites in this area. MOFs decorated on nanofibers possess rapid adsorption kinetics, a high adsorption capacity, excellent selectivity, and good reusability. In addition, the substantial adsorption capacities are mainly due to interactions between the target ions and functional binding groups on the MOFs-nanofiber composites and the highly ordered porous structure

Recent advances in electrospun fibrous membranes for effective chromium (VI) removal from water

The accumulation of heavy metals in aquatic environments is a significant environmental threat. Among the available methods for their removal, adsorption using nanofiber has been proven to be the most effective approach. The unique architecture of nanofibers provides them with intriguing features, such as high specific surface area and pore density, which makes them capable of removing harmful metals and a potential solution for various applications, including water treatment. This new generation of highly porous membranes is expected to have a promising future in separation applications due to its unique properties, including 90% porosity and 3D interconnected pore structure. Electrospinning is a well-regarded technique for creating such unique porous membranes. Among the various metal ions, chromium (Cr(VI)) removal has been extensively researched, and electrospun nanofiber membranes have proven to be an effective adsorbent. The objective of this review is to provide up-to-date information on the most common ways that electrospun nanofiber membranes are utilized for the removal of Cr(VI) ions from water. The findings indicate that electrospun fibrous materials are effective in eliminating Cr(VI) and establish their suitability for decontaminating polluted water. However, further attention is required to enhance the stability, mechanical strength, and reusability of these fibrous membranes

Taguchi L25 (54) approach for methylene blue removal by polyethylene terephthalate nanofiber‐multi‐walled carbon nanotube composite

A membrane composed of polyethylene terephthalate nanofiber and multi‐walled carbon nanotubes (PET NF‐MWCNTs) composite is used to adsorb methylene blue (MB) dye from an aqueous solution. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ ray diffraction techniques are employed to study the surface properties of the adsorbent. Several parameters affecting dye adsorption (pH, MB dye initial concentration, PET NF‐MWCNTs dose, and contact time) are optimized for optimal removal efficiency (R, %) by using the Taguchi L25 (54) Orthogonal Array approach. According to the ANOVA results, pH has the highest contributing percentage at 71.01%, suggesting it has the most significant impact on removal efficiency. The adsorbent dose is the second most affected (12.08%), followed by the MB dye initial concentration of 5.91%, and the least affected is the contact time (1.81%). In addition, experimental findings confirm that the Langmuir isotherm is well‐fitted, suggesting a monolayer capping of MB dye on the PET‐NF‐MWCNT surface with a maximum adsorption capacity of 7.047 mg g−1. Also, the kinetic results are well‐suited to the pseudo‐second‐order model. There is a good agreement between the calculated (qe) and experimental values for the pseudo‐second‐order kinetic model

Characterization of Electrospinning Chitosan Nanofibers Used for Wound Dressing

Wound dressings play a crucial role in promoting wound healing by providing a protective barrier against infections and facilitating tissue regeneration. Electrospun nanofibers have emerged as promising materials for wound dressing applications due to their high surface area, porosity, and resemblance to the extracellular matrix. In this study, chitosan, a biocompatible and biodegradable polymer, was electrospun into nanofibers for potential use in wound dressing. The chitosan nanofibers were characterized by using various analytical techniques to assess their morphology and biocompatibility. Scanning electron microscopy (SEM) revealed the formation of uniform and bead-free nanofibers with diameters ranging from tens to hundreds of nanometers. Structural analysis, including Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), elucidated the chemical composition and crystalline structure of the nanofibers. Furthermore, in vitro studies evaluated the cytocompatibility of the chitosan nanofibers with human dermal fibroblasts, demonstrating cell viability and proliferation on the nanofibers. Additionally, antibacterial properties were assessed to evaluate the potential of chitosan nanofibers in preventing wound infections. Overall, the characterization results highlight the promising attributes of electrospun chitosan nanofibers as wound dressings, paving the way for further investigation and development in the field of advanced wound care. This study has been carried out for the first time in our region and has assessed the antibacterial properties of electrospun chitosan nanofiber material. The created mat has shown efficaciousness against bacteria that are both gram-positive and gram-negative

A Novel Nanogold Composite Fabrication, Its Characterization, and Its Application in the Removal of Methylene Blue Dye from an Aqueous Solution

A unique aspect of this research lies in the combination of polyethylene terephthalate (PET) nanofibers with Auo@PPh2-PIILP to create a nanogold composite (NGC). This NGC has proven to be highly efficient in removing methylene blue (MB) from wastewater. The prepared nanogold composite NGC was characterized by Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDAX), and Elements Distribution Mapping (EDM). Several factors were examined in batch adsorption experiments to determine their impact on dye adsorption. These factors included the initial pH range of four to eight, the dosage of NGC adsorbent ranging from 0.001 to 0.008 g, the initial concentration of MB dye ranging from 10 to 50 mg L−1, and the contact period ranging from 10 to 80 min. It has been observed that NGC is more efficient in removing MB from polluted water. The results of the pseudo-second-order model show good agreement between the calculated adsorption capacity (qe)cal. (4.3840 mg g−1) and the experimental adsorption capacity (qe)exp. (4.6838 mg g−1) values. Experimental findings suggest a monolayer capping of MB dye on the NGC surface with a maximum adsorption capacity Qm of 18.622 mg g−1 at 20 °C, indicating that it is well-fitted to the Langmuir isotherm

Low-Cost and Eco-Friendly Hydroxyapatite Nanoparticles Derived from Eggshell Waste for Cephalexin Removal

This work describes the hydroxyapatite nanoparticle (HAP) preparation from eggshell waste and their application as an adsorbent for Cephalexin (Ceph) antibiotic removal from aqueous solutions. Chemical precipitation with phosphoric acid was used to evaluate the feasibility of calcium oxide for HAP preparation. The structural properties of HAP were characterized by X-ray diffraction, which revealed the formation of the hydroxyapatite crystalline phase formation. In addition, transmitting electron spectroscopy showed an irregular shape with a variation in size. The impact of various experimental conditions on the removal efficiency such as the solution’s pH, contact time, HAP mass, solution temperature, and Ceph concentration were studied. Experimental data showed that HAP could remove most Ceph species from aqueous solutions within 1 h at pH = 7 with 70.70% adsorption efficiency utilizing 50 mg of the HAP. The removal process of Ceph species by HAP was kinetically investigated using various kinetic models, and the results showed the suitability of the pseudo-second-order kinetic model for the adsorption process description. Moreover, the removal process was thermodynamically investigated; the results showed that the removal was spontaneous endothermic and related to the randomness increase. The data confirmed that HAP had high efficiency in removing Ceph antibiotics from an aqueous solution