Obtaining Cellulose Fibers from Almond Shell by Combining Subcritical Water Extraction and Bleaching with Hydrogen Peroxide.

Almond shell (AS) represents about 33% of the almond fruit, being a cellulose-rich by-product. The use of greener methods for separating cellulose would contribute to better exploitation of this biomass. Subcritical water extraction (SWE) at 160 and 180 °C has been used as a previous treatment to purify cellulose of AS, followed by a bleaching step with hydrogen peroxide (8%) at pH 12. For comparison purposes, bleaching with sodium chlorite of the extraction residues was also studied. The highest extraction temperature promoted the removal of hemicellulose and the subsequent delignification during the bleaching step. After bleaching with hydrogen peroxide, the AS particles had a cellulose content of 71 and 78%, with crystallinity index of 50 and 62%, respectively, for those treated at 160 and 180 °C. The use of sodium chlorite as bleaching agent improved the cellulose purification and crystallinity index. Nevertheless, cellulose obtained by both bleaching treatments could be useful for different applications. Therefore, SWE represents a promising green technique to improve the bleaching sensitivity of lignocellulosic residues, such as AS, allowing for a great reduction in chemicals in the cellulose purification processes.

Using predictive models unravel the potential of titanium oxide-loaded activated carbon for the removal of leachate ammoniacal nitrogen.

The TiO2 nanocomposite efficiency was determined under optimized conditions with activated carbon to remove ammoniacal nitrogen (NH3-N) from the leachate sample. In this work, the facile impregnation and pyrolysis synthesis method was employed to prepare the nanocomposite, and their formation was confirmed using the FESEM, FTIR, XRD, and Raman studies. In contrast, Raman phonon mode intensity ratio ID/IG increases from 2.094 to 2.311, indicating the increase of electronic conductivity and defects with the loading of TiO2 nanoparticles. The experimental optimal conditions for achieving maximum NH3-N removal of 75.8% were found to be a pH of 7, an adsorbent mass of 1.75 mg/L, and a temperature of 30 °C, with a corresponding time of 160 min. The experimental data were effectively fitted with several isotherms (Freundlich, Hill, Khan, Redlich-Peterson, Toth, and Koble-Corrigan). The notably elevated R2 value of 0.99 and a lower ARE % of 14.61 strongly support the assertion that the pseudo-second-order model compromises a superior depiction of the NH3-N reduction process. Furthermore, an effective central composite design (CCD) of response surface methodology (RSM) was employed, and the lower RMSE value, precisely 0.45, demonstrated minimal disparity between the experimentally determined NH3-N removal percentages and those predicted by the model. The subsequent utilization of the desirability function allowed us to attain actual variable experimental conditions.

Optimization Conditions of Malachite Green Adsorption onto Almond Shell Carbon Waste Using Process Design.

Almond shell-based biocarbon is a cheap adsorbent for the removal of malachite green, which has been investigated in this work. FT-IR, DRX, and BET were used to characterize almond shell-based biocarbon. The nitrogen adsorption-desorption isotherms analysis results showed a surface area of 120.21 m2/g and a type H4 adsorption isotherm. The parameters of initial dye concentration (5-600 mg.L-1), adsorbent mass (0.1-0.6 mg), and temperature (298-373 K) of adsorption were investigated. The experiments showed that the almond shell could be used in a wide concentration and temperature range. The adsorption study was fitted to the Langmuir isotherm and the pseudo-second-order kinetic model. The results of the FT-IR analysis demonstrated strong agreement with the pseudo-second-order chemisorption process description. The maximum adsorption capacity was calculated from the Langmuir isotherm and evaluated to be 166.66 mg.g-1. The positive ∆H (12.19 J.mol-1) indicates that the adsorption process is endothermic. Almond shell was found to be a stable adsorbent. Three different statistical design sets of experiments were taken out to determine the best conditions for the batch adsorption process. The optimal conditions for MG uptake were found to be adsorbent mass (m = 0.1 g), initial dye concentration (C0 = 600 mg.L-1), and temperature (T = 25 °C). The analysis using the D-optimal design showed that the model obtained was important and significant, with an R2 of 0.998.

Effects of the amendment with almond shell, bio-waste and almond shell-based biochar on the quality of saline-alkali soils.

This study aimed to evaluate the effect of the amendment with almond shell bio-waste (AS) and almond shell-based biochar (ASB), in different mass ratios (5, 10, and 15%), on the physicochemical properties of three different saline soils, using the growth of arugula seedlings as a bioindicator of the enhancement achieved. Data were analyzed based on a completely randomized design in a factorial arrangement with four replications. The results showed that the low-salinity soil (T1) presented the best physicochemical characteristics and growth parameters. The addition of AS and ASB in low proportions to the saline soils reduced the pH and electrical conductivity values. An increase in the amendment proportion led to an increase in these variables. Moisture, organic matter, and organic carbon increased, and the cation exchange capacity decreased, generating positive effects on soil quality. The values of exchangeable sodium percentage (ESP) showed that T3 presented the highest sodicity, followed by T2 and T1. The treatment with 5% ASB produced better results regarding total plant length, fresh and dry weights, leaf area, and leaf chlorophyll content. Finally, linear regression models were applied to describe the dependence of the agronomic variables on the ratio of biochar added.

Egg White-Mediated Fabrication of Mg/Al-LDH-Hard Biochar Composite for Phosphate Adsorption.

Phosphorus is one of the main causes of water eutrophication. Hard biochar is considered a promising phosphate adsorbent, but its application is limited by its textural properties and low adsorption capacity. Here, an adhesion approach in a mixed suspension containing egg white is proposed for preparing the hybrid material of Mg/Al-layered double hydroxide (LDH) and almond shell biochar (ASB), named L-AE or L-A (with or without egg white). Several techniques, including XRD, SEM/EDS, FTIR and N2 adsorption/desorption, were used to characterize the structure and adsorption behavior of the modified adsorbents. The filament-like material contained nitrogen elements at a noticed level, indicating that egg white was the crosslinker that mediated the formation of the L-AE hybrid material. The L-AE had a higher phosphate adsorption rate with a higher equilibrium adsorption capacity than the L-A. The saturation phosphate adsorption capacity of L-AE was nearly three times higher than that of L-A. Furthermore, the number of surface groups and the density of the positively charged surface sites follow the ASB < L-A < L-AE order, which is consistent with their phosphate adsorption performance. The study may offer an efficient approach to improving hard biochar's adsorption performance in wastewater treatment.

Use of N-Methylmorpholine N-oxide (NMMO) pretreatment to enhance the bioconversion of lignocellulosic residues to methane.

Lignocellulosic residues (LRs) are one of the most abundant wastes produced worldwide. Nevertheless, unlocking the full energy potential from LRs for biofuel production is limited by their complex structure. This study investigated the effect of N-methylmorpholine N-oxide (NMMO) pretreatment on almond shell (AS), spent coffee grounds (SCG), and hazelnut skin (HS) to improve their bioconversion to methane. The pretreatment was performed using a 73% NMMO solution heated at 120 °C for 1, 3, and 5 h. The baseline methane productions achieved from raw AS, SCG, and HS were 54.7 (± 5.3), 337.4 (± 16.5), and 265.4 (± 10.4) mL CH4/g VS, respectively. The NMMO pretreatment enhanced the methane potential of AS up to 58%, although no changes in chemical composition and external surface were observed after pretreatment. Opposite to this, pretreated SCG showed increased porosity (up to 63%) and a higher sugar percentage (up to 27%) after pretreatment despite failing to increase methane production. All pretreatment conditions were effective on HS, achieving the highest methane production of 400.4 (± 9.5) mL CH4/g VS after 5 h pretreatment. The enhanced methane production was due to the increased sugar percentage (up to 112%), lignin removal (up to 29%), and loss of inhibitory compounds during the pretreatment. An energy assessment revealed that the NMMO pretreatment is an attractive technology to be implemented on an industrial scale for energy recovery from HS residues. Supplementary Information: The online version contains supplementary material available at 10.1007/s13399-022-03173-x.

Effect of type of fiber and its physicochemical properties on performance, digestive transit time, and cecal fermentation in broilers from 1 to 23 d of age.

The effects of insoluble fiber (IF) sources differing on particle size and hydration capacity (HC) on growth performance, gastrointestinal tract (GIT) development, cecal fermentation, and digestive transit time were investigated from 1 to 23 d of age in 550 Ross-308 broiler males housed in 50 cages. The experimental design was based on the administration of a common corn-soybean meal nonsupplemented with additional IF sources diet in mash form (Control), and 4 dietary treatments consisting in the Control diet diluted with 1.5% of different IF: lignocellulose (LC), fine-ground straw (FS) and coarse-ground straw (CS), all characterized by high HC; and almond shell (AS) having low HC. Cecal fermentation was assessed by in vitro fermentation of the IF sources using the cecal content of 22-day broilers as inoculum. Compared with control birds, the inclusion of IF sources tended to impair the FCR (P = 0.053), with birds fed the HC-IF sources (LC, FS, and CS) showing lower ADFI (P = 0.005) and ADG (P = 0.001) than those fed the AS diet. The relative weight of gizzard and cecum, small intestine length, and digestive transit time decreased in AS group (P ≤ 0.050) compared with the average value of the groups fed the other IF sources. The inclusion of IF reduced (P = 0.006) the excreta moisture content, with no differences among IF sources. Dietary treatments had no effect either on cecal short fatty acids concentration or on intestinal morphology. As indicated by the in vitro gas production results, both LC and AS were less fermented than FS and CS, although all IF sources were low fermentable. None of the IF sources were able to influence the fermentation capacity of cecal microbiota after 22 d of feeding. In summary, animals fed AS presented smaller gizzard and cecum relative size, showed higher ADFI and ADG, and tended to improve fed conversion ratio in comparison to those fed the rest of IF sources.

Antifungal Susceptibility Assessment of Innovative and Non-Conventional Lime Mortars Incorporating Almond-Shell Powder Bio-Waste Subjected to Particle-Dispersion Technique.

A favorable environment for fungi colonization in building materials' surfaces can emerge when certain hygrothermal conditions occur. Thus, reducing fungal growth susceptibility is of major interest. Furthermore, if the integration of bio-wastes is performed in parallel with the development of innovative materials for this purpose, a more sustainable and environmentally friendly material can be obtained. In this study, the fungal susceptibility of lime mortars incorporating almond-shell powder (ASP) microparticles (2 and 4%, wt.-wt. in relation to the binder content) was evaluated. The particle-dispersion technique was employed to prepare the bio-waste introduced in the mixtures. The fungal susceptibility of ASP samples was compared with nanotitania (n-TiO2) with recognized antifungal properties. Mechanical strength, water absorption, and wettability tests were also performed for a better characterization of the composites. Although the addition of 2% ASP led to mechanical properties reduction, an increase in the compressive and flexural strength resulted for 4% of the ASP content. Difficulties in fungal growth were observed for the samples incorporating ASP. No fungal development was detected in the mortar with 2% of ASP, which may be correlated with an increase in the surface hydrophobic behavior. Furthermore, mortars with ASP revealed a reduction in water absorption by capillarity ability, especially with 4% content, suggesting changes in the microstructure and pore characteristics. The results also demonstrated that an improvement in the physical and mechanical properties of the lime mortars can be achieved when ASP microparticles are previously subjected to dispersion techniques.

Chitosan beads coated with almond and walnut shells for the adsorption of gatifloxacin antibiotic compound from aqueous solutions.

In the present study, chitosan (C), walnut (W), and almond shell (A) powder adsorbent (in different combinations as almond shells:walnut:chitosan 2:1:1 (AWC), chitosan:almond shell:walnut 2:1:1 (CAW), and walnut:almond shells:chitosan 2:1:1 (WAC)) powder were combined in different ratios to produce low-cost composite adsorbent beads for the removal of antibiotics gatifloxacin (GAT) from synthetic wastewater. The beads were characterized by a scanning electron microscope, Fourier transform infrared spectrum spectrophotometer, and energy-dispersive X-ray spectroscopy. The batch adsorption approach was employed to remove the antibiotic from the water. Moreover, isotherm and kinetics were conducted to illustrate the adsorption mechanism. Parameters like the effect of the adsorbent's dosage, pH, initial concentration, and contact time on antibiotic adsorption were evaluated. Adsorption percentage increased slightly with the increase in adsorbent dosage. The optimum pH for GAT adsorption on beads was 5-7. In addition, adsorption increased with initial antibiotic concentration and time rise. The adsorption isotherm data were successfully fitted to Langmuir isotherm for AWC and CAW beads, while WAC beads followed the Freundlich isotherm. The highest adsorption was attained at pH 5 on CAW beads and pH 7 on AWC and WAC beads. The optimal contact time for equilibrium studies was 120 min for all types of beads. The adsorption isotherm data in AWC beads fit well with the Langmuir model and Freundlich adsorption for CAW and WAC beads. The rate of adsorption on beads follows Lagergren pseudo-second-order kinetics. The results indicate that prepared combination beads can be used to remove antibiotics from wastewater.

Hydrothermal carbonization coupled with fast pyrolysis of almond shells: Valorization and production of valuable chemicals.

In this study, it was found that hydrothermal carbonization (HTC) can be an effective method for almond shell (AS) valorization. The severity of HTC treatment had a significant effect on hydrochar yields, with higher severity promoting carbonization but reducing yields. Furthermore, the work found that HTC treatment effectively demineralized biomass samples by removing inorganic material that could catalyze carbonization. As residence time or temperature increased, the amount of carbon increased, while the amount of oxygen decreased. An acceleration in thermal degradation was detected for hydrochars after pretreating for 4 h. The hydrochars showed they had a higher volatile content than untreated biomass, making them potentially useful for producing quality bio-oil through fast pyrolysis. Finally, HTC treatment led to the production of valuable chemicals such as guaiacol and syringol. For syringol production, HTC residence time had more effect than HTC temperature. However, high HTC temperatures benefited levoglucosan production. Overall, the results demonstrated the potential for HTC treatment to be an effective method for valorizing agricultural waste, offering the possibility of producing valuable chemicals.

Microwave-assisted extraction of cellulose nanocrystals from almond (Prunus amygdalus) shell waste.

Almond (Prunus amygdalus) is one of the most common tree nuts on a worldwide basis. This nut is highly regarded in the food and cosmetic industries. However, for all these applications, almonds are used without their shell protection, which is industrially removed contributing approximately 35-75% of the total fruit weight. This residue is normally incinerated or dumped, causing several environmental problems. In this study, a novel cellulose nanocrystal (CNCs) extraction procedure from almond shell (AS) waste by using microwave-assisted extraction was developed and compared with the conventional approach. A three-factor, three-level Box-Behnken design with five central points was used to evaluate the influence of extraction temperature, irradiation time, and NaOH concentration during the alkalization stage in crystallinity index (CI) values. A similar CI value (55.9 ± 0.7%) was obtained for the MAE process, comprising only three stages, compared with the conventional optimized procedure (55.5 ± 1.0%) with five stages. As a result, a greener and more environmentally friendly CNC extraction protocol was developed with a reduction in time, solvent, and energy consumption. Fourier transform infrared (FTIR) spectra, X-ray diffractogram (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) images, and thermal stability studies of samples confirmed the removal of non-cellulosic components after the chemical treatments. TEM images revealed a spherical shape of CNCs with an average size of 21 ± 6 nm, showing great potential to be used in food packaging, biological, medical, and photoelectric materials. This study successfully applied MAE for the extraction of spherical-shaped CNCs from AS with several advantages compared with the conventional procedure, reducing costs for industry.

Recyclability Analysis of Starch Thermoplastic/Almond Shell Biocomposite.

This article is focused on studying the effect of the reprocessing cycles on the mechanical, thermal, and aesthetic properties of a biocomposite. This process is based on starch thermoplastic polymer (TPS) filled with 20 wt% almond shell powder (ASP) and epoxidized linseed oil (ELO) as a compatibilizing additive. To do so, the biocomposite was prepared in a twin-screw extruder, molded by injection, and characterized in terms of its mechanical, thermal, and visual properties (according to CieLab) and the melt flow index (MFI). The analyses carried out were tensile, flexural, Charpy impact tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of the reprocessing were also studied for the biodegradable unfilled TPS polymer. The results showed that TPS and TPS/ASP biocomposite suffer changes progressively on the properties studied after each reprocessing cycle. Furthermore, it was observed that the addition of ASP intensified these effects regarding TPS. However, in spite of the progressive degradation in both cases, it is technically feasible to reprocess the material at least three times without needing to incorporate virgin material.

Enhanced Cu(II) adsorption using sodium trimetaphosphate-modified cellulose beads: equilibrium, kinetics, adsorption mechanisms, and reusability.

The current study is focused on the simple synthesis of two novel biosorbent beads: BASB/STMP and CNFB/STMP, derived respectively from bleached almond shell (BAS) and cellulose nanofiber from almond shell (CNF) by means of chemical crosslinking with sodium trimetaphosphate (STMP). These biosorbents were thoroughly characterized in terms of structure (FTIR), texture (N2 adsorption-desorption), thermal behavior (TGA/DTG), morphology (SEM), and surface properties (XPS). The adsorption kinetics of Cu(II) ions onto BASB/STMP and CNFB/STMP materials proved the chemisorption interaction between Cu(II) ions and the STMP functionalized beads. The BASB/STMP equilibrium data were successfully described by the Redlich-Peterson model and the CNFB/STMP data by the Sips model which disclosed maximum adsorption capacities of 141.44 mg g-1 and 147.90 mg g-1, respectively. Furthermore, the BASB/STMP bioadsorbent offers easy regeneration and better reusability with high efficiency (> 83%). This study sheds light on the preparation of low-cost adsorbents for wastewater treatment in order to improve the competitiveness and eco-friendliness of agrowaste-based processes.

Multilayer Films Based on Poly(lactic acid)/Gelatin Supplemented with Cellulose Nanocrystals and Antioxidant Extract from Almond Shell By-Product and Its Application on Hass Avocado Preservation.

In this work, poly(lactic acid) (PLA)/gelatin/PLA multilayer films supplemented with cellulose nanocrystals and antioxidant extract from almond shell (AS) by-products were developed by solvent casting technique for active food packaging. The almond shell antioxidant extract (ASE) was obtained by microwave-assisted extraction, while cellulose nanocrystals (CNCs) were extracted from AS by a sequential process of alkalization, acetylation and acid hydrolysis. Four formulations were obtained by adding 0 (control), 6 wt.% of ASE (FG/ASE), 4.5 wt.% of CNCs (FG/CNC) and 6 wt.% + 4.5 wt.% of ASE + CNCs, respectively, (FG/ASE + CNC) into fish gelatin (FG). PLA/FG/PLA multilayer films were prepared by stacking two outer PLA layers into a middle FG film. A surface modification of PLA by air atmospheric plasma treatment was optimized before multilayer development to improve PLA adhesion. Complete characterization of the multilayers underlined the FG/ASE + CNC formulation as a promising active reinforced packaging system for food preservation, with low values of transparency, lightness and whiteness index. A good adhesion and homogeneity of the multilayer system was obtained by SEM, and they also demonstrated low oxygen permeability (40.87 ± 5.20 cm3 mm m-2 day) and solubility (39.19 ± 0.16%) values, while mechanical properties were comparable with commercial plastic films. The developed multilayer films were applied to Hass avocado preservation. The initial degradation temperature (Tini), DSC parameters and in vitro antioxidant capacity of the films were in accordance with the low peroxide and anisidine values obtained from avocado pulp after packaging for 14 days at 4 °C. The developed PLA/FG/PLA films supplemented with 6 wt.% ASE+ 4.5 wt.% CNCs may be potential bioactive packaging systems for fat food preservation.

Synergistic immobilization of potentially toxic elements (PTEs) by biochar and nanoparticles in alkaline soil.

Biochar and nanoparticle (NP) have the ability to sorb potentially toxic elements (PTEs) from soil and reduce toxicity and leaching into water bodies. However, there is need to tailor biochar formulations to soil types. In this study, we investigate the mobility and chemical forms of Cd, Cr, Cu, Ni, and Zn in a spiked, alkaline soil after amendment with combination of NPs (nano-Fe (NF), nano-clay (NC)) and biochars (almond shell 500 °C, walnut shell 400 °C) in different doses (0, 2.5, 5, and 10%). Many previous studies concluded biochar immobilized PTEs due to an increase in soil pH, which can be disregarded here (soil pH 7.9). In a twenty-week column leaching experiment biochar addition significantly decreased PTE leaching and NP addition further immobilized PTEs in most cases. On average almond biochar more effectively reduced Zn leaching and walnut biochar was more effective in decreasing the leaching of Cd, Cr, and Ni (e.g. 5% biochar reduced Cr leaching by 68%). Copper was immobilized effectively by both biochars. Nano-clay combined with walnut biochar performed best in all treatments, in particular for Cd, Ni, and Zn (e.g. 10% walnut biochar only and in combination with NC reduced Zn leaching by 14.2% and 58.5%, respectively). After amendment, PTEs were present in the Fe-Mn oxides, organic and residual fractions and less in the exchangeable fraction, reducing PTE availability and leachability. The results demonstrate that even for cationic PTEs that behave similarly in the environment optimal biochar-mineral formulations can differ.

Development and Characterization of Sustainable Composites from Bacterial Polyester Poly(3-Hydroxybutyrate-co-3-hydroxyhexanoate) and Almond Shell Flour by Reactive Extrusion with Oligomers of Lactic Acid.

Eco-efficient Wood Plastic Composites (WPCs) have been obtained using poly(hydroxybutyrate-co-hexanoate) (PHBH) as the polymer matrix, and almond shell flour (ASF), a by-product from the agro-food industry, as filler/reinforcement. These WPCs were prepared with different amounts of lignocellulosic fillers (wt %), namely 10, 20 and 30. The mechanical characterization of these WPCs showed an important increase in their stiffness with increasing the wt % ASF content. In addition, lower tensile strength and impact strength were obtained. The field emission scanning electron microscopy (FESEM) study revealed the lack of continuity and poor adhesion among the PHBH-ASF interface. Even with the only addition of 10 wt % ASF, these green composites become highly brittle. Nevertheless, for real applications, the WPC with 30 wt % ASF is the most attracting material since it contributes to lowering the overall cost of the WPC and can be manufactured by injection moulding, but its properties are really compromised due to the lack of compatibility between the hydrophobic PHBH matrix and the hydrophilic lignocellulosic filler. To minimize this phenomenon, 10 and 20 phr (weight parts of OLA-Oligomeric Lactic Acid per one hundred weight parts of PHBH) were added to PHBH/ASF (30 wt % ASF) composites. Differential scanning calorimetry (DSC) suggested poor plasticization effect of OLA on PHBH-ASF composites. Nevertheless, the most important property OLA can provide to PHBH/ASF composites is somewhat compatibilization since some mechanical ductile properties are improved with OLA addition. The study by thermomechanical analysis (TMA), confirmed the increase of the coefficient of linear thermal expansion (CLTE) with increasing OLA content. The dynamic mechanical characterization (DTMA), revealed higher storage modulus, E', with increasing ASF. Moreover, DTMA results confirmed poor plasticization of OLA on PHBH-ASF (30 wt % ASF) composites, but interesting compatibilization effects.

Effect of Almond Shell Waste on Physicochemical Properties of Polyester-Based Biocomposites.

Polyester-based biocomposites containing INZEA F2® biopolymer and almond shell powder (ASP) at 10 and 25 wt % contents with and without two different compatibilizers, maleinized linseed oil and Joncryl ADR 4400®, were prepared by melt blending in an extruder, followed by injection molding. The effect of fine (125-250 m) and coarse (500-1000 m) milling sizes of ASP was also evaluated. An improvement in elastic modulus was observed with the addition of< both fine and coarse ASP at 25 wt %. The addition of maleinized linseed oil and Joncryl ADR 4400 produced some compatibilizing effect at low filler contents while biocomposites with a higher amount of ASP still presented some gaps at the interface by field emission scanning electron microscopy. Some decrease in thermal stability was shown which was related to the relatively low thermal stability and disintegration of the lignocellulosic filler. The added modifiers provided some enhanced thermal resistance to the final biocomposites. Thermal analysis by differential scanning calorimetry and thermogravimetric analysis suggested the presence of two different polyesters in the polymer matrix, with one of them showing full disintegration after 28 and 90 days for biocomposites containing 25 and 10 wt %, respectively, under composting conditions. The developed biocomposites have been shown to be potential polyester-based matrices for use as compostable materials at high filler contents.

Pb(II) adsorption from aqueous solution by nutshells, green adsorbent: Adsorption studies, regeneration studies, scale-up design, its effect on biological indicator and MLR modeling.

In this paper, agricultural waste nutshells, such as walnut and almond shell, were utilized to treat Pb(II) containing aqueous solution. Lead(II) is a typical poisonous, commercial, water-pollutant, having multiple awful effects on the environment. The effluent of the different industrial wastewater cans is treated by using leftover and excess green waste. This finding is focused on the utilization of walnut and almond shells for Pb(II) removal. These green adsorbents are characterized using SEM, FTIR, pHpzc, and BET analyzer. The operating parameters are first optimized. The pseudo-2nd order kinetic, as well as the Langmuir isotherm model, have better applicability for both nutshells. Chemical sorption processes have been reported at higher temperatures, whereas at a lower temperature, it follows the physical sorption process. Elevated temperature helps to remove the metal ion more efficiently. The sorption process is spontaneous and endothermic for both nutshells. The desorption study shows that adsorbents can be used several times. Deadly effects of Pb(II) have been reported by the RBC count of Gallus gallus domesticus. It's been observed that the treated solution is somewhat less harmful. Application study using industrial effluent is successfully demonstrated. The scale-up design operation has been investigated. Statistical modeling has also been very successfully implemented using the data collected from the experiment. The study indicates that both nutshells have the potential for the removal of Pb(II).

Solid state 13C-NMR methodology for the cellulose composition studies of the shells of Prunus dulcis and their derived cellulosic materials.

Lignocellulosic fibers and microcellulose have been obtained by simple alkaline treatment from softwood almond shells. In particular, the Prunus dulcis Miller (D.A.) Webb. was considered as a agro industrial waste largely available in southern Italy. The materials before and after purification have been characterized by 13C CPMAS NMR spectroscopy methodology. A proper data analysis provided the relative composition of lignin and holocellulose at each purification step and the results were compared with thermogravimetric analysis and FT-IR. To value the possibility of using this material in a circular economy framework, the fibrous cellulosic material was used to manufacture a handmade cardboard. The tensile performances on the prepared cardboard proved its suitability for packaging purposes as a sustainable material. These fibers along with the obtained microcellulose can represent a new use for the almond shells that are mainly used as firewood.

Synthesis and characterization of eco-friendly cellulose beads for copper (II) removal from aqueous solutions.

In this study, novel cellulose-bead-based biosorbents (CBBAS) were successfully synthesized from almond shell using a simple three-step process: (i) dissolution of bleached almond shell in ionic liquid (1-butyl-3-methylimidazolium chloride), (ii) coagulation of cellulose-ionic liquid solution in water and (iii) freeze-drying. Their morphological, structural and physicochemical properties were thoroughly characterized. These biomaterials exhibited a 3D-macroporous structure with interconnected pores, which provided a high number of adsorption sites. It should be noted that CBBAS biosorbents were efficiently employed for the removal of copper (II) ions from aqueous solutions, showing high adsorption capacity: 128.24 mg g-1. The biosorption equilibrium data obtained were successfully fitted to the Sips model and the kinetics were suitably described by the pseudo-second-order model. Besides, CBBAS biosorbents can be easily separated from the solution for their subsequent reuse, and thus, they represent a method for the removal of copper (II) from aqueous solutions that is not only eco-friendly but also economical.