Removal of lead ions from wastewater using magnesium sulfide nanoparticles caged alginate microbeads.

In this study, an adsorbent made of alginate (Alg) caged magnesium sulfide nanoparticles (MgS) microbeads were used to treat lead ions (Pb2+ ions). The MgS nanoparticles were synthesized at low temperatures, and Alg@MgS hydrogel microbeads were made by the ion exchange process of the composite materials. The newly fabricated Alg@MgS was characterized by XRD, SEM, and FT-IR. The adsorption conditions were optimized for the maximum removal of Pb2+ ions by adjusting several physicochemical parameters, including pH, initial concentration of lead ions, Alg/MgS dosage, reaction temperature, equilibration time, and the presence of co-ions. This is accomplished by removing the maximum amount of Pb2+ ions. Moreover, the adsorbent utilized more than six times with a substantial amount (not less than 60%) of Pb2+ ions was eliminated. Considering the ability of sodium alginate (SA) for excellent metal chelation and controlled nanosized pore structure, the adsorption equilibrium of Alg@MgS can be reached in 60 min, and the highest adsorption capacity for Pb2+ was 84.7 mg/g. The sorption mechanism was explored by employing several isotherms. It was found that the Freundlich model fits the adsorption process quite accurately. The pseudo-second-order model adequately described the adsorption kinetics.

Titanium lanthanum three oxides decorated magnetic graphene oxide for adsorption of lead ions from aqueous media.

The current study presents a viable and straightforward method for synthesizing titanium lanthanum three oxide nanoparticles (TiLa) and their decoration onto the ferrous graphene oxide sheets to produce FeGO-TiLa as efficient magnetic adsorbent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibration sample magnetometer (VSM) were used to evaluate the physical and chemical properties of the produced nanocomposites. The FeGO-TiLa was used to enhance the removal of lead ions from aqueous solution. The FeGO-TiLa nanocomposite exhibited a much higher removal efficiency (93%) for lead ions than pure TiLa nanoparticles (81%) and magnetic graphene oxide (74%). The influence of FeGO-TiLa dosage, contact time, solution pH, solution temperature, and starting quantity on the lead ions was evaluated and adjusted. The investigations demonstrated that a pH 6 with 40 mg adsorbent resulted in >91% removal of lead ions at ambient temperature after 120 min. Isotherm models were used to analyze experimental results, and Langmuir model fitted the data well as compared Freundlich model with a maximum adsorption capacity of 109.89 mg g-1. Kinetic and studies are performed the lead adsorption over FeGO-TiLa follow pseudo-second-order rate. Langmuir and Free energy suggested the lead ions uptake with FeGO-TiLa was monolayer and physical adsorption mechnaism, respectively. Finally, the FeGO-TiLa nanocompoiste can be used as an alternative adsorbent for water remediation.

Sulfur-Doped Binary Layered Metal Oxides Incorporated on Pomegranate Peel-Derived Activated Carbon for Removal of Heavy Metal Ions.

In this study, a novel biomass adsorbent based on activated carbon incorporated with sulfur-based binary metal oxides layered nanoparticles (SML-AC), including sulfur (S2), manganese (Mn), and tin (Sn) oxide synthesized via the solvothermal method. The newly synthesized SML-AC was studied using FTIR, FESEM, EDX, and BET to determine its functional groups, surface morphology, and elemental composition. Hence, the BET was performed with an appropriate specific surface area for raw AC (356 m2·g−1) and modified AC-SML (195 m2·g−1). To prepare water samples for ICP-OES analysis, the suggested nanocomposite was used as an efficient adsorbent to remove lead (Pb2+), cadmium (Cd2+), chromium (Cr3+), and vanadium (V5+) from oil-rich regions. As the chemical structure of metal ions is influenced by solution pH, this parameter was considered experimentally, and pH 4, dosage 50 mg, and time 120 min were found to be the best with high capacity for all adsorbates. At different experimental conditions, the AC-SML provided a satisfactory adsorption capacity of 37.03−90.09 mg·g−1 for Cd2+, Pb2+, Cr3+, and V5+ ions. The adsorption experiment was explored, and the method was fitted with the Langmuir model (R2 = 0.99) as compared to the Freundlich model (R2 = 0.91). The kinetic models and free energy (<0.45 KJ·mol−1) parameters demonstrated that the adsorption rate is limited with pseudo-second order (R2 = 0.99) under the physical adsorption mechanism, respectively. Finally, the study demonstrated that the AC-SML nanocomposite is recyclable at least five times in the continuous adsorption−desorption of metal ions.

Sweet cherry tree (Prunus avium) exudate gum-based film modification in a photoreactor: Effects of hydrogen peroxide oxidation, UV irradiation, and TiO2 nanoparticles.

The fabrication possibility of nanocomposite film from sweet cherry tree exudate gum (SCG) was studied. To improve SCG film properties, oxidation with hydrogen peroxide, ultraviolet irradiation (UV-A and UV-C), and TiO2 nanoparticles (T-NPs) were used. Hydrogen peroxide oxidation at higher amounts decreased the water vapor permeability (WVP) and thickness and increased the mechanical properties and transparency. In comparison with the UV-A, UV irradiation of the C-type increased permeability, and elongation at break (EAB) and thickness, but reduced the tensile strength (TS), solubility, and transparency. The permeability and tensile strength were increased and elongation at break was decreased at a longer time of irradiation. The transparency values of fabricated films ranged from 65.3 to 79.5 % and WVP were in the range of 2.32-4.72 (×10-10 g/m.s.Pa). The measured TS of the SCG films were between 2.2 and 5 MPa and the EAB of the SCG films was between 35 and 68.7 %. The FTIR spectrum and SEM images revealed that the treatments could affect the bonds and the smoothness of the film surface, respectively. Images provided by AFM showed that the roughness of the films was increased by the addition of T-NPs. The incorporation of T-NPs increased the TS and decreased EAB and WVP. These results indicated that oxidation, UV irradiation and nanomaterials incorporation could be used to improve SCG film properties that are related to food packaging material.

Recent functionality developments of carboxymethyl chitosan as an active food packaging film material.

In recent years, environmental concerns regarding the persistence of petroleum-based plastic food packaging have increased, prompting the exploration of biopolymer alternatives. Carboxymethyl chitosan (CMCS), a derivative of chitosan, exhibits superior water-soluble film properties, making it an ideal material for degradable food packaging applications. This study comprehensively examines the synthesis methods and properties of CMCS, with a particular emphasis on recent advancements in CMCS-based food packaging films. Various functionalized CMCS-based food packaging films, including coblended, nanoparticle composite, plant extract composite, and cross-linked films, were reviewed. The practical applications of CMCS-based food packaging films and edible coatings in food preservation are also showcased. This study emphasizes that the notable compatibility of CMCC with a range of polymers and additives has facilitated the development of multifunctional packaging films. These innovations, including antibacterial, antioxidant, and smart-indicating variants, have demonstrated remarkable efficacy in preserving fruits, aquatic products, poultry, and other perishable goods.

Comprehensive structural and functional characterization of a new protein-polysaccharide conjugate between grass pea protein (Lathyrus sativus) and xanthan gum produced by wet heating.

The purpose of this work was to use a controlled wet-heating process to promote Maillard reaction (MR) between grass pea protein (GPPI) and xanthan gum (XG), and then analyse structural, functional and antioxidant properties of the conjugate (GPPI-XGCs). During heating, the degree of glycation of all conjugated samples was raised (up to 37.43 %) and, after heating for 24 h, the lightness of the samples decreased by 24.75 %. Circular dichroism showed changes in secondary structure with lower content of α-helix and random coil in conjugates. XRD patterns showed that MR destroyed the crystalline structure of the protein. In addition, Lys and Arg content of the produced conjugates decreased by 16.94 % and 6.17 %, respectively. Functional properties including foaming capacity and stability were increased by 45.17 % and 37.17 %, and solubility reached 98.88 %, due to the protein unfolding driven by MR. GPPI-XGCs showed significantly higher antioxidant activities with maximum ABTS-RS value of 49.57 %. This study revealed how MR can improve GPPI's properties, which can aid the food industry in producing a wide range of plant-based foods. Especially, among other characteristics, the foaming properties were significantly improved and the final product can be introduced as a promising foaming agent to be used in food formulation.

Cold Plasma-Assisted Extraction of Phytochemicals: A Review.

In recent years, there has been growing interest in bioactive plant compounds for their beneficial effects on health and for their potential in reducing the risk of developing certain diseases such as cancer, cardiovascular diseases, and neurodegenerative disorders. The extraction techniques conventionally used to obtain these phytocompounds, however, due to the use of toxic solvents and high temperatures, tend to be supplanted by innovative and unconventional techniques, in line with the demand for environmental and economic sustainability of new chemical processes. Among non-thermal technologies, cold plasma (CP), which has been successfully used for some years in the food industry as a treatment to improve food shelf life, seems to be one of the most promising solutions in green extraction processes. CP is characterized by its low environmental impact, low cost, and better extraction yield of phytochemicals, saving time, energy, and solvents compared with other classical extraction processes. In light of these considerations, this review aims to provide an overview of the potential and critical issues related to the use of CP in the extraction of phytochemicals, particularly polyphenols and essential oils. To review the current knowledge status and future insights of CP in this sector, a bibliometric study, providing quantitative information on the research activity based on the available published scientific literature, was carried out by the VOSviewer software (v. 1.6.18). Scientometric analysis has seen an increase in scientific studies over the past two years, underlining the growing interest of the scientific community in this natural substance extraction technique. The literature studies analyzed have shown that, in general, the use of CP was able to increase the yield of essential oil and polyphenols. Furthermore, the composition of the phytoextract obtained with CP would appear to be influenced by process parameters such as intensity (power and voltage), treatment time, and the working gas used. In general, the studies analyzed showed that the best yields in terms of total polyphenols and the antioxidant and antimicrobial properties of the phytoextracts were obtained using mild process conditions and nitrogen as the working gas. The use of CP as a non-conventional extraction technique is very recent, and further studies are needed to better understand the optimal process conditions to be adopted, and above all, in-depth studies are needed to better understand the mechanisms of plasma-plant matrix interaction to verify the possibility of any side reactions that could generate, in a highly oxidative environment, potentially hazardous substances, which would limit the exploitation of this technique at the industrial level.

Betalains as promising natural colorants in smart/active food packaging.

Betalains are water-soluble nitrogen pigments with beneficial effects, including antioxidant, antimicrobial, and pH-indicator properties. The development of packaging films incorporated with betalains has received increasing attention because of pH-responsive color-changing properties in the colorimetric indicators and smart packaging films. As such, intelligent and active packaging systems based on biodegradable polymers containing betalains have been recently developed as eco-friendly packaging to enhance the quality and safety of food products. Betalains could generally improve the functional properties of packaging films, such as higher water resistance, tensile strength, elongation at break, and antioxidant and antimicrobial activities. These effects are dependent on betalain composition (about its source and extraction), content, and the kind of biopolymer, film preparation method, food samples, and storage time. This review focused on betalains-rich films as pH- and ammonia-sensitive indicators and their applications as smart packaging to monitor the freshness of protein-rich foods such as shrimp, fish, chicken, and milk.

Magnetic sporopollenin supported polyaniline developed for removal of lead ions from wastewater: Kinetic, isotherm and thermodynamic studies.

This study evaluated the synthesis of novel binary functionaladsorbent based on sporopollenin, magnetic nanoparticles, and polyaniline to produce MSP-PANI. The MSP-PANI was applied to enhance uptake of lead ions (Pb2+) from wastewater samples. The functionalities, surface morphology, magnetic properties, and elemental composition of the newly synthesized nanocomposite were investigated using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibration sample magnetometer (VSM), and energy-dispersive X-ray spectroscopy (EDX), respectively. The experimental condition for the adsorption process was MSP/PANI ratio 1:1, pH ∼6, adsorbent dosage 40 mg, and contact time 90 min at room temperature. Under the proposed condition, lead ions removal were obtained as 83%, 88% and 95% for MSPE, PANI, and MSP/PANI, respectively. Based on the experimental and predicted data, the adsorption was corresponded to the psudo-second-order (R2 = 0.999) kinetics model, and the adsorption equilibrium corresponded to the Langmuir model (R2 = 0.996). Langmuir isotherm showed the maximum adsorption capacity of MSP-PANI for lead ions was 163 mg/g and followed the monolayer pattern. Hence, thermodynamic model under Van't Hoff equation suggested that the adsorption mechanism was physio-sorption with endothermic nature. Therefore, this research can help the researchers to use magnetic nanoparticles for lead removal in highly polluted areas.

Development of a rapid efficient solid-phase microextraction: An overhead rotating flat surface sorbent based 3-D graphene oxide/ lanthanum nanoparticles @ Ni foam for separation and determination of sulfonamides in animal-based food products.

In this study, an overhead rotating flat surface sorbent based solid-phase microextraction was developed as a rapid and efficient method for simultaneous separation and determination of sulfonamides in animal based-food products. 3D graphene oxide/ lanthanum nanoparticles @ Ni foam was introduced as a novel selective sorbent. SEM-EDX and FT-IR techniques were applied for characterization of the sorbent. At optimum conditions, the linear ranges of 0.4-700.0 (µg L-1), 0.3-900.0 (µg L-1), and 0.25-500 (µg L-1) and the enrichment factors of 606.8, 604.3, 608.9 were obtained for SDZ, SMX, and SMZ, respectively. The LOD (S/N = 3) of 0.14, 0.11, 0.08 (µg L-1) were achieved for SDZ, SMX, and SMZ, respectively. The intra-day and inter-day precision (%) (five days, n = 7) for the concentration of 100 µg L-1 were less than 4.3 and 3.8, respectively. The recoveries over 90.0 % revealed high capability of the method for utilization in complex matrixes.

An efficient 3D adsorbent foam based on graphene oxide/AgO nanoparticles for rapid vortex-assisted floating solid phase extraction of bisphenol A in canned food products.

In this study, a three-dimensional adsorbent was developed based on graphene oxide/AgO nanoparticles over interconnected nickel foam (GO/AgO@Ni foam) for rapid and efficient vortex assisted floating solid phase extraction of bisphenol A in canned food products prior to high performance liquid chromatography with a fluorescence detector. The analytical techniques scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FT-IR) were used for characterization of the synthetized GO/AgO@Ni foam. The effect of proficiency factors including pH, foam size, vortexing time, salt addition, sample volume, desorption type and volume, and desorption time on the extraction efficiency of bisphenol A were explored through the matrix match method. Under the above experimental conditions, the figures of merit of the method were acquired as LODs (S/N = 3) of 0.18-0.84 µg kg-1, LOQs of 0.61-2.81 µg kg-1 (S/N = 10), linear ranges of 0.5-500 µg kg-1, and enrichment factors of 235.5-244.9. The inter-day precision values (RSD%, n = 7) of 2.5-3.6 and the intra-day precision (%) of (5 days and seven replicates for each day) 2.8-3.8 were achieved for bisphenol A at a concentration of 50 µg kg-1. The relative recoveries of 94.0% to 99.6% were obtained for the canned food samples.

Development of a colorimetric pH indicator based on bacterial cellulose nanofibers and red cabbage (Brassica oleraceae) extract.

This work aimed to develop and characterize a smart label for pH monitoring based on bacterial cellulose (BC) nanofibers doped with anthocyanins extracted from red cabbage (Brassica oleracea). The relationship between the concentration of anthocyanins (32 and 193mgL-1) and the morphological properties and color response efficiency of pH indicator labels was investigated. The FT-IR results reflected that some new interactions have occurred between BC membrane and anthocyanins. The XRD analyses showed a decrease in diffraction intensities of BC by addition of concentrated form of anthocyanins. SEM results indicated that concentrated anthocyanins caused to partial disintegration and deformation of the cellulose microfibrils with more cracks on the labels. But the intrinsic morphology and structure of the BC nanofibers were preserved by addition of diluted anthocyanins. A concentration dependent decrease was observed in the tensile strength of anthocyanin loaded labels but elongation percentage and moisture absorption of BC was increased by addition of anthocyanins. The color variation in different pH range (2-10) was measured with the CIELab methodology. The label containing diluted anthocyanins showed a more clear response to pH variation. Therefore, it has potential to be used as a visual indicator of the pH variations during storage of packaged food.