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Abstract Introduction: Nowadays, due to the reduction of fresh water resources and the increase in demand in the world, the removal of various pollutants, such as dyes, from industrial wastewaters to reuse them has received much attention. Methods: In this research, activated carbon (AC) was synthesized by the chemical activation of apricot kernel shell, and then, this adsorbent was modified by iron-containing functional groups (FeOOH-AC) and used as an adsorbent in the removal of methyl orange from the aqueous solution. The properties of these adsorbents were characterized using BET, SEM, XRD, and FT-IR analyses. Findings: The matching of the equilibrium data with the Langmuir model showed that the adsorption process is single-layer and the maximum adsorption capacity of AC and FeOOH–AC absorbents equal 174.6 mg/g and 249 mg/g, respectively. The increase in adsorption capacity after modification is due to the positive adsorption sites of iron (Fe-O-H2+) on the surface of the modified adsorbent, which adsorb the methyl orange by electrostatic mechanism. Also, the physical adsorption due to the porous structure of the adsorbent and π-π interaction are the effective mechanisms in the adsorption of methyl orange on the FeOOH-AC adsorbent. The analysis of kinetic data with different models showed that the pseudo-second-order kinetic model is consistent with the experimental result. The spontaneity and exothermic nature of the adsorption process were determined by determining the thermodynamic parameters. Conclusion: The successive cycles of adsorption and desorption indicate the ability to regenerate and reuse the synthesized adsorbent, which can be a suitable option for use on the industrial scale.

The main goal of this research was to develop highly durable, low-cost eco-friendly biocomposites from apricot kernel shell (AKS) wastes and ultrasonic characterization of AKS-based obtained biocomposites. Natural AKS wastes were chemically modified using 5 wt% sodium hydroxide (NaOH) and 99 wt% glacial acetic acid (AA). These modified apricot kernel shells (MAKS) and unmodified apricot kernel shells (UMAKS) were added into bisphenol-A type epoxy resin (ER) in varied compositions such as 10–50 wt% to prepare the MAKS/ER and the UMAKS/ER biocomposites. The epoxy resin-mixture in the weight ratios of resin/hardener/accelerator was 100:30:1. The effect of AKS powder ratios and modifiers on the elastic properties (Young's moduli [E], bulk moduli [K], longitudinal moduli [L], shear moduli [G], and Poisson's ratio [µ]), density (ρ), damping properties (attenuation coefficient [α], loss tangent [tanδ], and quality factor [Q]), ultrasonic micro-hardness (H), and acoustic impedance (Z) of biocomposites was investigated by the ultrasonic testing (UT) method. The morphological structure of the ER and biocomposites was figured out using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). The results revealed an increase in elastic properties of most of the AKS/ER biocomposites compared to the neat ER. On the other hand, results have shown that SEM and XRD images' analysis confirmed the amorphous structure of ER and biocomposites. The highest ρ, vL, vS, L, G, E, H, and Z values were obtained in MAKS-AA/ER-5 biocomposite. Thus, it can be stated that the MAKS-AA/ER-5 biocomposite sample has the best mechanical properties. Also, the results revealed that the MAKS-AA/ER-1 sample can be used as an alternative material for its high Q-factor value instead of wood in producing musical tools. [ABSTRACT FROM AUTHOR]

Research shows that there is an increasing interest in alternative friction materials that do not harm human health and the environment, especially after the harmful effects of asbestos were revealed and its use was banned. This study evaluates the potential of apricot kernel shell, an agricultural waste, to be used as a bio-material in brake pad compositions. Composites containing different granule sizes and amounts of apricot kernel shell were experimentally tested for friction performance using a dynamometer. The addition of apricot kernel shell to the brake pad compositions slightly increased the noise level but improved the coefficient of friction. These findings reveal the potential of using apricot kernel shells as an economical and environmentally friendly material in brake pad compositions. [ABSTRACT FROM AUTHOR]

For the first time, a comprehensive review of the literature data on the use of apricot (Prunus armeniaca) biomass components as a sorption material for the treatment of wastewater and environmental water from various pollutants is carried out in the present study. In addition to a comprehensive analysis of contemporary studies, the current work carried out its own microstructural and energy dispersive studies. It shows that apricot kernel shell is a promising raw material for obtaining sorption materials that can be used to extract various pollutants from aqueous media. The parameters of sorption interaction are presented, at which the highest rate of removal of pollutants was achieved. It is shown that the sorption capacity of apricot biomass components can be increased by modifying it with various chemical reagents, as well as other physical and physicochemical methods. We reveal that most publications consider the use of the latter as a raw material for the production of activated carbons. It is established that the surface area and total pore space of activated carbons from apricot kernel shells depend on the modes of carbonization and activation. It is shown that activated carbons are effective adsorbents for removing various pollutants (metal ions, dyes, oil and oil products) from aqueous media. It was found that the adsorption isotherms of pollutants in most cases are best described by the Langmuir and Freundlich models, and the process kinetics is most often described by the pseudo-second-order model. The possibility of improving the sorption characteristics of apricot biomass during chemical or physicochemical treatment is also shown. [ABSTRACT FROM AUTHOR]

The objectives of this study are to determine the effects of nano-biochar produced from waste sludge (industrial and municipal) and a hybrid combination of municipal sewage sludge biochar and lignocellulosic biochar (apricot kernel shell) on the fresh state (flow) and mechanical properties (compressive strength, flexural strength, and fracture energy) of mortar. As methodology, the biochar was produced by a pyrolysis process at 500 °C and ground to 200 nm average particle size by ball milling. Detailed characterization of biochars with X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), X-ray diffraction (XRD), BET (Brunauer-Emmett-Teller) analysis, and the strength activity index test was conducted. Mortar mixtures were designed by adding single and hybrid nano-biochar with different volume percentages (between 0.04–0.15%). Flow, flexural strength and compressive strength tests were performed on mortar samples along with microstructural SEM investigations. As major findings, the addition of 0.06% municipal sewage sludge nano-biochar (BCSS) resulted in an increase in flexural strength by 23% while an increase in fracture energy by 100% compared to the control mortar. The addition of 0.12% BCSS increased the compressive strength by 17% and the compressive fracture energy by 28%. The hybrid nano-biochar additions also improved the strength and ductility. Sewage sludge nano-biochar and hybrid combinations have the potential to enhance the performance of the cement composites. The mechanisms governing the nano-biochar effect on mortar were enlightened as: pore filler effect, crack bridging and divergence, hydration initiation cite, internal curing of mortar. Novelty of this work are: the use of nanoscale biochar in cement composite; the use of nano-biochar derived from sewage and industrial sludge in cement composite; the investigation of the effect of a hybrid nano-biochar on the properties of cement composites. The use of nano-biochars in cement composites can enable waste recycling while improving environment protecting and the mechanical properties of cement composites. [Display omitted] • Nano-biochar effects on flow, compressive and flexural strengths, fracture energy determined. • Micro structure-property relationship were enlightened. • Governing phenomena of nano-biochar effects on mechanical properties reported. • Optimal nano-biochar volume percentages for highest strength and ductility were presented. • Effects of hybrid nano-biochars on mechanical properties were determined. [ABSTRACT FROM AUTHOR]

For the first time, a comprehensive review of the literature data on the use of apricot (Prunus armeniaca) biomass components as a sorption material for the treatment of wastewater and environmental water from various pollutants is carried out in the present study. In addition to a comprehensive analysis of contemporary studies, the current work carried out its own microstructural and energy dispersive studies. It shows that apricot kernel shell is a promising raw material for obtaining sorption materials that can be used to extract various pollutants from aqueous media. The parameters of sorption interaction are presented, at which the highest rate of removal of pollutants was achieved. It is shown that the sorption capacity of apricot biomass components can be increased by modifying it with various chemical reagents, as well as other physical and physicochemical methods. We reveal that most publications consider the use of the latter as a raw material for the production of activated carbons. It is established that the surface area and total pore space of activated carbons from apricot kernel shells depend on the modes of carbonization and activation. It is shown that activated carbons are effective adsorbents for removing various pollutants (metal ions, dyes, oil and oil products) from aqueous media. It was found that the adsorption isotherms of pollutants in most cases are best described by the Langmuir and Freundlich models, and the process kinetics is most often described by the pseudo-second-order model. The possibility of improving the sorption characteristics of apricot biomass during chemical or physicochemical treatment is also shown.

In this study, grinded apricot kernel shell (GAKS) biobased waste was used for the first time as a cost-effective, efficient, green and metal-free catalyst for hydrogen generation from the hydrolysis reaction of sodium borohydride (NaBH 4). For the hydrogen production by NaBH 4 hydrolysis reaction, GAKS was treated with various acids (HCl, HNO 3 , CH 3 COOH, H 3 PO 4), salt (ZnCl 2) and base (KOH). As a result, the phosphoric acid (H 3 PO 4) demonstrated better catalytic activity than other chemical agents. The hydrolysis of NaBH 4 with the GAKS-catalyst (GAKS cat) was studied depending on different parameters such as acid concentration, furnace burning temperature and time, catalyst amount, NaBH 4 concentration and hydrolysis reaction temperature. The obtained GAKS cat was characterized by ICP-MS, elemental analysis, TGA, XRD, FT-IR, Boehm, TEM and SEM analyses and was evaluated for its catalytic activity in the hydrogen production from the hydrolysis reaction of NaBH 4. According to the results, the optimal H 3 PO 4 percentage was found as 15%. The maximum hydrogen generation rate from the hydrolysis of NaBH 4 with the GAKS cat was calculated as 20,199 mL min−1 g cat −1. As a result, it can be said that GAKS treated with 15% H 3 PO 4 as a catalyst for hydrogen production is an effective alternative due to its high hydrogen production rate. • Apricot kernel shell was utilized as a free-metal catalyst for NaBH 4 hydrolysis reaction. • Biobased waste as green catalyst was treated with 15% H 3 PO 4. • Environmentally friendly hydrogen energy was obtained from the hydrolysis of NaBH 4. • The maximum hydrogen generation rate was calculated as 20,199 mL min−1 g cat −1. • The activation energy was equal to 30.23 kJ mol−1. [ABSTRACT FROM AUTHOR]

Magnetic modified biochar was prepared using pomelo peel and apricot kernel shell as the feedstock. The effects of temperature on the physicochemical properties of the magnetic modified biochar materials were investigated. Magnetic biochar was obtained through the process of initially loading iron chemicals on the raw biomass by combining with the impregnation and co-precipitation and then carbonization under different temperatures. In the magnetic biochar, iron was distributed heterogeneously, more in the outer layer than in the inner layer. The iron existed mainly in the form of Fe3O4, and a small amount in the form of complex metal oxides with aluminum, magnesium. The contents of ash and volatile matter in the magnetic biochar was increased compared to the native biochar obtained at the same temperature; while the fixed carbon contents and heating values were significantly reduced. The augment/reduction effects of magnetic modification were intensified with increasing temperature. The specific surface area and total pore volume of magnetic biochar were both increased. The specific surface area of biochar derived from pomelo peel increased from 4.163 3-5.782 7 to 4.793 7- 24.887 8 m2/g with the magnetic modification. For the apricot kernel shell, the specific surface area was elevated from 3.540 4-27.192 8 to 22.291 4-41.953 1 m2/g. The total pore volume was improved from 0.025 7-0.031 4 to 0.027 8- 0.062 2 cm3/g for the biochar derived from pomelo peel and from 0.025 3-0.065 7 to 0.0888-0.0792 cm3/g for the biochar derived from apricot kernet shell. The average pore size was overall decreased by the modification, with the mesopores still dominant. The magnetic modification treatment improved the pH values of these two feedstocks (4.82/4.78 vs. 6.26/5.38) as well as with the pH values of biochar derived from pomelo peel being pyrolyzed at temperature of 400-600 ℃, while the pH values of the magnetic biochar derived from apricot shell were generally lowered compared to the native biochar. The pH values were boosted from 9.59-10.09 to 10.24-10.75 for pomelo peel biochar pyrolyzed at temperatures of 400-600 ℃ by the magnetic modification. The values were reduced from 7.39-9.05 to 6.26-8.86 for the apricot kernel shell biochar pyrolyzed at temperature of 300-500 ℃. The contents of oxygen-containing functional group in the magnetic apricot kernel biochar were increased, which was indicated by the enhancement of characteristic peak of carbonyl and phenolic hydroxyl stretching vibration and explained why the pH values reduced with the increment of ash content. These results revealed that the effects of magnetic modification on the pyrolysis of pomelo peel and apricot kernel shell were very different. [ABSTRACT FROM AUTHOR]

For the first time the extract of the plant of Salvia hydrangea was used to green synthesis of Pd nanoparticles (NPs) supported on Apricot kernel shell as an environmentally benign support. The Pd NPs/Apricot kernel shell as an effective catalyst was prepared through reduction of Pd 2+ ions using Salvia hydrangea extract as the reducing and capping agent and Pd NPs immobilization on Apricot kernel shell surface in the absence of any stabilizer or surfactant. According to FT-IR analysis, the hydroxyl groups of phenolics in Salvia hydrangea extract as bioreductant agents are directly responsible for the reduction of Pd 2+ ions and formation of Pd NPs. The as-prepared catalyst was characterized by Fourier transform infrared (FT-IR) and UV–Vis spectroscopy, field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray spectroscopy (EDS), Elemental mapping, X-ray diffraction analysis (XRD) and transmittance electron microscopy (TEM). The synthesized catalyst was used in the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), Methylene Blue (MB), Rhodamine B (RhB), and Congo Red (CR) at room temperature. The Pd NPs/Apricot kernel shell showed excellent catalytic activity in the reduction of these organic dyes. In addition, it was found that Pd NPs/Apricot kernel shell can be recovered and reused several times without significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Apricot kernel shell was utilized as a potential feedstock to produce bio-oil. [•] The maximum bio-oil yield was obtained as 26.3% at optimum conditions. [•] The bio-oil has an empirical formula of CH1.53O0.31N0.01, H/C atomic ratio of 1.53. [•] The heating value of the bio-oil is 27.19MJ/kg. [•] The BET surface area of char was determined as 195m2/g. [ABSTRACT FROM AUTHOR]