In this study, dried orange peel powder DOPP is chemically modified with nanosilica (SiO2) employing sonication technique to produce nanobioadsorbent SiO2@DOPP. SiO2@DOPP This nanoadsorbent was ...evaluated for Cd2+ removal from aqueous systems. Successful functionalization of DOPP into nanosilica was confirmed by various analytical techniques like XRD, FTIR, SEM, EDX, TEM, DLS, pHzpc and TGA. XRD, FTIR and EDX confirmed the emergence of new peaks after modification of DOPP by nanosilica and adsorption of Cd2+ onto SiO2@DOPP. Further, TGA spectrum suggested that SiO2@DOPP nanoadsorbent is thermally more stable than DOPP. pH plays a major role to Cd2+ adsorption onto SiO2@DOPP. The optimum conditions for Cd2+ removal include pH = 6.5 and 0.03g adsorbent dose with 100 min contact time. Different adsorption isotherms models best fitted-(Langmuir adsorption model), adsorption kinetics best fitted–(Pseudo second order and Intraparticle diffusion) were examined for the removal of Cd2+. The maximum monolayer adsorption capacity qmax was 142 mg/g. Thermodynamic evaluation indicates the endothermic and spontaneous nature of Cd2+ adsorption onto SiO2@DOPP. Furthermore complexation mechanism of Cd2+ onto SiO2@DOPP is discussed in detail. The results indicate involvement of functional group interactions, π–metal interactions, proton exchange, chelate complexes and electrostatic interactions during adsorption of Cd2+ onto SiO2@DOPP. Based on the results it has been inferred that SiO2@DOPP is a promising nanobioadsorbent to manage environment burden of Cd2+ from aqueous systems.
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•Dried orange peel powder (DOPP) is chemically modified with nanosilica.•Functionalized nanobioadsorbent SiO2@DOPP has immense active binding sites for Cd2+ complexation.•SiO2@DOPP is thermally more stable than raw DOPP.•Six membered chelate co-ordination complex of Cd2+ is formed and its possible mechanism has been described.•The maximum monolayer adsorption capacity (Qmax) is 142 mg/g.
This study aims to develop active and intelligent packaging films based on starch/polyvinyl alcohol incorporated with betalains-rich red pitaya (Hylocereus polyrhizus) peel extract. The ...microstructure, physical and functional properties of the films with different contents of the extract (0.25, 0.50 and 1.00 wt% on starch basis) were measured. Results showed betacyanins were the main components in the extract, which presented significant color changes under alkaline conditions. Scanning electron microscopy observation revealed the compactness of the films was improved by the extract addition. Fourier transform infrared spectroscopy revealed that betacyanins in the extract could interact with starch, polyvinyl alcohol and glycerol through hydrogen bonds. The incorporation of the extract enhanced the water vapor barrier and ultraviolet–visible light barrier ability, and mechanical, antioxidant and antimicrobial potential of the films. The film containing 1.00 wt% of the extract was more sensitive to ammonia than other films. When applied to monitor the freshness of shrimp, the film containing 1.00 wt% of the extract presented visible color changes due to the accumulated volatile nitrogen compounds during the spoiling process of shrimp. Our results suggest the film containing 1.00 wt% of the extract can be used as active and intelligent packaging in food industry.
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•Red pitaya peel extract was added into starch/polyvinyl alcohol film matrix.•Addition of the extract resulted in compact inner microstructures of the films.•The extract improved the antioxidant and antimicrobial abilities of the films.•The film containing 1 wt% of the extract was much sensitive to ammonia.•The film containing 1 wt% of the extract could monitor the freshness of shrimp.
Pomegranate peels contain a considerable amount of bioactive chemicals, such as phenolic compounds including gallic acid and ellagic acid. The current study aims to optimize the extraction of total ...phenolic content (TPC) and its antioxidant capacity from a Pomegranate peel using various approaches involving enzyme and ultrasound, also focusing on process intensification using combination. The optimal parameters for ultrasound treatment were established as treatment time of 25 min, 130 W power, 50 % duty cycle, and a liquid–solid ratio of 50:1 at a fixed 22 kHz frequency, resulting in maximum TPC (21.521 mg GAE/ml) and antioxidant capacity (17.962 mg GAE/ml). Similarly, enzymatic treatment was optimized resulting in best conditions of a time of 55 min, 50 °C as temperature, pH of 5, and a 2 % enzyme concentration. Ultrasound-assisted enzymatic extraction (UAEE) experiments revealed that combining 25 min of ultrasonic treatment with 25 min of enzymatic treatment yielded the highest TPC (30.608 mg GAE/ml) and antioxidant capacity (27.703 mg GAE/ml). It was clearly demonstrated that UAEE outperformed EAE and UAE in terms of Total Phenolic Compound extraction and antioxidant capacity, with the order of efficiency being UAEE > EAE > UAE.
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•Cellulose nanofiber-based environmental repairing materials were prepared by hydrogen peroxide.•POCNF-PEI has excellent Cu(Ⅱ) adsorption properties with maximum adsorption capacity ...of 74 mg/g.•POCNF-PEI has excellent MG adsorption ability with maximum adsorption capacity of 530 mg/g.•POCNF-PEI can be recycled four times with larger adsorption capacity of 65–72 mg/g.
Carboxylated nanocellulose hold great application potential and research value in environmental remediation owing to its eco-friendly nature, high specific surface area, high density of functional groups and abundant reserves properties. In present work, a new type of cellulose nanofibers (CNF) with high aspect ratio and high density of carboxyl groups were prepared by directly thermo-oxidizing natural wasted pomelo peel with H2O2. The effects of reaction time on the content of carboxyl groups, morphology, and thermal stability of CNF were investigated. It is found that pomelo-CNF (POCNF) with larger aspect ratio of 169 and carboxyl group contents of 1.711 ± 0.173 mmol/g was fabricated by reacting at 60 °C for 6 h. Furthermore, the high density of carboxyl groups of POCNF allowed it to graft functional polyetherimide (PEI) on the surface of nanocellulose, and the resulting PNOCNF-PEI showed excellent adsorption performance to pollutants, such as malachite green (MG) and Cu(II), with adsorption capacity of 530 mg/g to MG and 74.2 mg/g to Cu(II). Moreover, the adsorbent showed excellent reusability. Besides, the possible adsorption kinetics/mechanism of nanocelluloses to various pollutants has been provided. The simple preparation process and excellent properties of POCNF made it become a viable candidate as environmental remediation material.
The utilization of neglected agro-industrial waste is essential for mitigating environmental impacts. This study aims to characterize the products of using sweet potato peels, leaves and stems via ...pyrolysis and torrefaction techniques. Additionally, the study examined the impact of the torrefaction pre-treatment on pyrolysis products. Solid, liquid, and gaseous products were characterized. Results indicated that torrefaction pre-treatment increased biochar yield but diminished bio-oil and gas yields. Thermal treatments had minimal impact on the specific surface area of formed solids and biochars. Bio-oils showed a proclivity towards basicity with increasing temperature. Phenols predominated in the organic fraction of bio-oils, with torrefaction pre-treatment resulting in reduced alcohol and increased hydrocarbon concentration. Gas composition revealed elevated CO2 levels during torrefaction, while torrefaction pre-treatment amplified CH4 concentration. These findings suggest potential for extracting chemical inputs like phenolic resins and biocides from sweet potato waste bio-oils, though further treatments are required for effective solid adsorption.
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•Torrefaction pre-treatment increases biochar yield, reduces bio-oil and gas.•Bio-oils tend towards basicity with increasing temperature.•Phenols dominate organic fraction; torrefaction reduces alcohol and increases hydrocarbons.•Potential for deriving chemical inputs from sweet potato waste.•Optimal process conditions are crucial for desired products.
Neuraminidase (NA) has been well-studied as a therapeutic target for Influenza. However, resistance to the influenza virus has been observed recently. Out of special interest in the utilization of ...dietary antivirals from citrus, in vitro inhibition activity against NA and in silico studies including molecular docking, molecular dynamic simulation, and a predictive ADMET study, were performed on five citrus-derived flavanones. Encouragingly, citrus-derived flavanones displayed comparable or even more potent in vitro inhibitory activity than oseltamivir carboxylate against NA. Orange peel extract exhibited higher activity than hesperidin. Among the tested compounds, neohesperidin, forming strong hydrogen-bonding interactions with key arginine residues, exhibited the most effective inhibitory activity against NAs from C. perfringens, consistent with the results of molecular dynamics simulations. Although the molecular docking results were inconsistent with the in vitro activity, the binding energy was identical against the wild-type and mutant, suggesting a lower likelihood of developing drug resistance. Moreover, predictive ADMET studies showed favorable pharmacokinetic properties for the tested compounds. Overall, citrus fruit peel emerges as a promising dietary supplement for prevention and treatment of influenza. These findings elucidate the impact of flavanones on NA activity, and the analysis of their binding modes provides valuable insights into the mechanism of NA inhibition.
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•Citrus-derived flavanones exhibited similar or greater activity than OSC in NA inhibitory activity.•Five flavanones may exhibit a lower likelihood of developing drug resistance by molecular docking.•This study provides a partial theoretical basis for the application of citrus-derived extracts on dietary therapy in influenza patients.
Application of biochars to remove inorganic nitrogen (NH4+, NO2−, NH3, NO, NO2, N2O) from wastewater and agricultural fields has gained a significant interest. This study aims to investigate the ...relationship between ammonium sorption and physicochemical properties of biochars derived from different kinds of fruit peel. Biochars from three species of fruit peel (orange, pineapple and pitaya) were prepared at 300, 400, 500 and 600 °C with the residence time of 2 h and 4 h. Their characteristics and sorption for ammonium was evaluated. The results show a clear effect of pyrolysis conditions on physicochemical properties of biochars, including elemental composition, functional groups and pH. The maximum NH4+ adsorption capacities were associated with biochars of orange peel (4.71 mg/g) and pineapple peel (5.60 mg/g) produced at 300 °C for 2 h. The maximum NH4+ adsorption capacity of the pitaya peel biochar produced at 400 °C for 2 h was 2.65 mg/g. For all feedstocks, biochars produced at low temperatures showed better NH4+ adsorption capacity. It was found that biochars had better adsorption efficiency on ammonium at a pH of 9. Adsorption kinetics of ammonium on biochars followed the pseudo-second-order kinetic model while Langmuir isotherm model could well simulate the adsorption behavior of ammonium on biochars. The adsorption mechanism of ammonium on biochars predominantly involved surface complexation, cation exchange and electrostatic attraction. Conclusively, the fruit peel-derived biochars can be used as an alternative to conventional sorbents in water treatment.
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•Biochars from three kinds of fruit peel were prepared.•Biochar derived from pineapple peel had a higher sorption capacity for NH4+.•Elemental and functional groups play a critical role in adsorption of NH4+.•Biochar has better adsorption capacity for ammonium at low temperature.•Chemical adsorption is the dominant mechanism of NH4+ adsorption.
The broad versatility of the T-peel test, widely used for characterizing adhesion across a plethora of adhesives, adherends, and geometries, results in a range of responses that may complicate ...meaningful interpretation. This research effort, involving several specific specimen types, was undertaken to investigate concerns that commonly used configurations may not always result in plateaus in the force-displacement response. An experimental and numerical study is conducted on debonding of T-peel specimens having 75 mm bond length and 0.81 mm thick adherends made of either 6061 aluminum (Al) or one of the three steels (G70 70U hot dip galvanized, E60 elctrogalvanized (EGZ), 1010 cold-rolled steel) bonded with either LORD® 406 or Maxlok™ acrylic adhesive. For the EGZ and the Al adherends, specimens with a bond length of 250 mm and adherend thickness of 1.60 mm are also examined. Effects of adherend materials and thicknesses, bond lengths, and adhesives on test results are examined using three metrics to interpret the T-peel bond performance. A limited correlation is found between the commonly used “T-peel strength” and the energy dissipated per unit debond area. For these two metrics, the relative performances of the CRS and the Al specimens are quite different. Quasi-static plane strain deformations of the test specimens are analyzed by the finite element method (FEM) and a cohesive zone model using the commercial software, ABAQUS, to help interpret the test data. Numerical results provided energies required to elastically and plastically deform the adherends, and help determine the transition from non-steady-state to steady-state debonding. The FE simulations also facilitate determination of the fraction of the crosshead displacement at which steady-state debonding occurs. Results reported herein could help engineers select appropriate peel specimen dimensions for extracting meaningful data for the adhesive performance and comparisons.
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