Almond Shell Research Articles

Fabrication of magnetic activated carbon by carbothermal functionalization of agriculture waste via microwave-assisted technique for cationic dye adsorption

The agriculture shell wastes were carbothermally converted to magnetic activated carbon by a microwave-assisted decoration of iron oxide nanoparticles onto the shell surface. The influence of ternary catalytic mixtures, including zinc, iron II and III chlorides on the cationic dye adsorption efficiency was addressed by the composite impregnations onto the almond or walnut shell powders, explored to the carbonization. The efficiency was maximized by determination the proportions of used salts. The best results were obtained with loading FeCl3 onto the walnut shell in which the proportion of salt was 50%. Although the load of magnetic particles onto the adsorbent normally lead to decrease in efficiency, the prepared powder exhibited the appropriate performance above 99%. It should be point out that the dye adsorption efficiency of magnetic activated carbons fabricated by carbothermal functionalization was 7–10% higher than those produced in the nitrogen atmosphere. The adsorbent displayed the nano-porous structure with average pore diameter about 2 nm, providing a surface area around 1000 m2·g−1 for the removal of dye in a dynamic system. The maximum adsorption capacity was determined to be 130 mg·g−1 in the neutral condition.

Study of the Influence of the Almond Shell Variety on the Mechanical Properties of Starch-Based Polymer Biocomposites.

This article is focused on the development of a series of biodegradable and eco-friendly biocomposites based on starch polymer (Mater-Bi DI01A) filled with 30 wt% almond shell (AS) of different varieties (Desmayo Rojo, Largueta, Marcona, Mollar, and a commercial mixture of varieties) to study the influence of almond variety in the properties of injected biodegradable parts. The different AS varieties are analysed by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The biocomposites are prepared in a twin-screw extruder and characterized in terms of their mechanical (tensile, flexural, Charpy impact, and hardness tests) and thermal properties (differential scanning calorimetry (DSC) and TGA). Despite observing differences in the chemical composition of the individual varieties with respect to the commercial mixture, the results obtained from the mechanical characterisation of the biocomposites do not present significant differences between the diverse varieties used. From these results, it was concluded that the most recommended option is to work with the commercial mixture of almond shell varieties, as it is easier and cheaper to acquire.

RSM optimized adsorptive removal of erythromycin using magnetic activated carbon: Adsorption isotherm, kinetic modeling and thermodynamic studies

Erythromycin molecules are resistant in the environment due to the structure of its aromatic-ring that makes it hard to remove or degradation. Nowadays, the presence of ERY in water and wastewater has been reported are above the standard level in various researches. Therefore, the removal and degradation of residues of ERY from wastewaters is important. The magnetic activated carbon is fabricated from Gogan almond shells and characterized and then applied to removal erythromycin from wastewater and water. Several techniques such as XRD, SEM, TEM, Raman, VSM, TGA, and BET were applied to characterize the adsorbent (MAC). Four important factors of sorbent weight, contact time, initial drug concentration, and temperature were optimized by the Response Surface Methodology technique. The maximum adsorption of 95.125% is attained at the initial drug concentration of 65 mg L-1, sorbent weight of 1.55 g L-1, the contact time of 76.25 min, and at the temperature of 35 °C. The results show that the experimental data exhibits the best agreement with the isotherm model of Freundlich. In the kinetics study, the experimental data fit well to the kinetic model of pseudo-second-order. The calculated thermodynamic variable factors designated that the adsorption of erythromycin on magnetic activated carbon is endothermic and spontaneous. Finally, the outcomes of this study display that the magnetic activated carbon from Gogan almond shells is an efficient and effective reusable sorbent for the erythromycin removal from the wastewater.

New functionalization approach synthesis of Sulfur doped, Nitrogen doped and Co-doped porous carbon: Superior metal-free Carbocatalyst for the catalytic oxidation of aqueous organics pollutants

New green synthesis methods of novel commercially applicable carbocatalysts suitable for the catalytic oxidation of organic pollutants, remain a challenge. Herein, Nitrogen doped (N-PC), Sulfur doped (S-PC) and Co-doped (N, S-PC) porous carbon, were synthesized via a new facile environmentally functionalization approach followed by pyrolysis. Thus, Almond Shell (AS) as Bio-sourced material was used for porous carbon (PC) preparation as support. Thereafter, the introduction of Melamine, Diphenyl Disulfide and Thiourea on the PC matrix with high -COCl− and -CCl− groups facilitated the surface functionalization, and allowed us the introduction of high N and S heteroatoms contents in the PC networks surface. It was found that the optimized carbocatalysts could effectively activate PS, and exhibited excellent catalytic performances for the organic pollutants degradation, with an exceptionally low activation energy and fast kinetic reaction. Based on a systematic comparison, it was found that the N-PC exhibited the superior catalytic activity for activating the PS and degrading various organic pollutants. Such superior catalytic activity of the N-PC Carbocatalyst resulted from its high surface area, its low defect degree with the higher content of Graphitic-N. In addition, all experimental and theoretical investigations demonstrated the critical role of graphitic–N for the PS activation. It is expected that the doping process by N will significantly break the chemical inertness of the PC network and will make the N-PC surface more positively charged accelerating hence its interaction with the negatively charged S2O82−. Furthermore, the 1O2 was found to be the predominant reactive oxygen species (ROS) as assessed by radical scavenging tests and EPR experiments. The carbocatalysts were not easily influenced by the water aqueous phase, which give us more obvious advantages over the PS activation.

Effect of the Purification Treatment on the Valorization of Natural Cellulosic Residues as Fillers in PHB-Based Composites for Short Shelf Life Applications

In this work the effect of a combined NaOH + peracetic acid (PAA) purification treatment on the valorization of almond shell (AS) and rice husk (RH) lignocellulosic residues as fillers in PHB-based composites for short shelf life applications has been studied. The efficiency of the treatment at removing the non-cellulosic components of the fibers has been evaluated by SEM, FTIR, WAXS and TGA taking a commercial cellulose as reference. The influence of the untreated and treated fibers on the morphology, thermal, crystallization, tensile properties, fracture toughness and dynamo mechanical behavior of the PHB/fiber composites has been studied. The treatment has demonstrated its ability at removing the lignin, hemicelluloses and waxes allowing the obtention of fibers with relative crystallinity, thermal stability and composition similar to the commercial cellulose. The different agro-food based lignocellulosic residues used resulted in two suitable reinforcing fillers for a PHB matrix. Hence, composites prepared with the treated fibers presented better thermal and mechanical performance than those prepared with the untreated ones. Therefore, the so-obtained purified residue fibers are comparable to a pure cellulose as a filler for PHB composites.

Fused Deposition Modeling of Poly (lactic acid)/Nutshells Composite Filaments: Effect of Alkali Treatment

In this work, four kinds of nutshells (including walnut, almond, macadamia and wild almond shell powder (WSP, ASP, MSP and WASP) were composed with poly (lactic acid) (PLA). Fused deposition modeling technology was used to prepare the PLA/nutshell composite filaments. Nutshells were investigated by means of Fourier transform infrared spectroscopy regardless of the treatment with alkali. The composites were characterized by using: differential scanning calorimetry, thermogravametric, scanning electron microscopy. Meanwhile, the water-resistance and tensile properties were examined. The results showed that the thermal stability, water-resistant ability and tensile properties of untreated composites got worse comparing with that of PLA, but were enhanced dramatically after NaOH treatment. PLA/treated WASP has the highest degradation temperature. The crystallization degree of PLA/treated MSP and PLA/treated WASP was improved, when compared with that of PLA. The tensile strengths of PLA/MSP-Na and PLA/WASP-Na were almost close to that of PLA. PLA/MSP composite was the most water-resistant regardless of surface treatment. Those results indicated that the four kinds of composites have a potential application to manufacture structural parts with lighter weight.

Evaluation of Recycled Materials as Hydroponic Growing Media

Conventional soilless growing media, such as perlite, are mined from nonrenewable resources and can only be disposed of in landfills after limited use. There is a need to investigate novel, sustainable growing media adapted from waste or engineered to be reused over multiple cycles. This study investigated waste almond shells and a recycled plastic drainage plank as hydroponic growing media alternatives. Physiochemical properties were evaluated, and a germination and greenhouse growth trial was conducted to understand the effect these media have on production and nutritional quality of lettuce (Lactuca sativa L. cv. Catalogna Verde). Drought testing was carried out to understand how the media affected the lettuce’s response to water stress. In comparison to perlite, yields under regular irrigation were reduced by 52% in almond shells and 72% in plastic planks, although lettuce grown in almond shells still obtained commercially relevant yields. Reduced yields in almond shells were likely caused by the shell’s high salinity. Lettuce growth in plastic planks was limited by impeded root growth and low water-holding capacity. In conclusion, with minor alterations, almond shells could be used as a sustainable growing media alternative to perlite in hydroponic lettuce production. More research is needed to manufacture the planks to be conducive to plant growth.

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.

Multiproduct biorefinery based on almond shells: Impact of the delignification stage on the manufacture of valuable products

In this work, an integral valorisation of almond shells through a biorefinery approach was studied. The three main components of almond shells were extracted, isolated and characterised. The autohydrolysis process permitted the extraction of the hemicellulosic fraction obtaining a liquor rich in xylooligosaccharides (22.12 g/L). Then, two different delignification processes, alkaline and organosolv treatments, were proposed to obtain a very high purity lignin (≈90%) which could be further valorised for a wide variety of applications. The valorisation of the high cellulosic content of the delignified solids was carried out using two different methods. On the one hand, producing cellulose nanocrystals and on the other hand obtaining glucose by an enzymatic hydrolysis as well as a spent solid mainly composed by lignin (≈78 wt%). Thus, the proposed biorefinery approach could contribute to a circular economy as all the main components of the almond shells could be revalorised by environmentally friendly procedures.

Torrefied Biomass as an Alternative in Coal-Fueled Power Plants: A Case Study on Grindability of Agroforestry Waste Forms

The use of biomass as a renewable energy source is currently a reality, mainly due to the role it can play in replacing fossil energy sources. Within this possibility, coal substitution in the production of electric energy presents itself as a strong alternative with high potential, mostly due to the possibility of contributing to the decarbonization of energy production while, at the same time, contributing to the circularization of energy generation processes. This can be achieved through the use of biomass waste forms, which have undergone a process of improving their properties, such as torrefaction. However, for this to be viable, it is necessary that the biomass has a set of characteristics similar to those of coal, such that its use may occur in previously installed systems. In particular, with respect to grindability, which is associated with one of the core equipment technologies of coal-fired power plants—the coal mill. The objective of the present study is to determine the potential of certain residues with agroforestry origins as a replacement for coal in power generation by using empirical methods. Selected materials—namely, almond shells, kiwifruit pruning, vine pruning, olive pomace, pine woodchips, and eucalyptus woodchips—are characterized in this regard. The materials were characterized in the laboratory and submitted to a torrefaction process at 300 °C. Then, the Statistical Grindability Index and the Hardgrove Grindability Index were determined, using empirical methods derived from coal analysis. The results obtained indicate the good potential of the studied biomasses for use in large-scale torrefaction processes and as replacements for coal in the generation of electrical energy. However, further tests are still needed, particularly relating to the definition of the ideal parameters of the torrefaction process, in order to optimize the grindability of the materials.

Experimental investigation of syngas composition variation along updraft fixed bed gasifier

Fixed bed gasification represents a convenient pathway for exploiting lignocellulose since it can be carried out on a small scale, while current technology is robust and fairly simple. Updraft gasifier is characterized by higher efficiency and is flexible towards feedstock, compared to the downdraft gasifier. The hydrogen to carbon monoxide ratio is the decisive parameter for determining syngas quality. Present contribution for the first time reports the evolution of the syngas composition at different heights of the reactive biomass bed in a pilot plant operating in a continuous mode, i.e. 20–30 kg/h of biomass feed. This was achieved by probing syngas streams directly from the core and analysing it onsite to measure the content of hydrogen, carbon monoxide, carbon dioxide, light hydrocarbons, nitrogen and oxygen, whilst the tar content was analysed offline. The addition of steam deeply affected the evolution of the chemical species and thermal profile. The syngas chemical composition was related to the thermal profile provided by in bed measurements of six thermocouples at the same locations. In the tests, almond shells were gasified with air or air and superheated steam mixture at equivalence ratio of 0.20 ± 0.01 and various steam to biomass ratios between 0 and 0.16 kg/kg. Addition of steam stabilized thermal profile inside the gasifier below 900 °C, improved the production of hydrogen up to 37.5 g/kg of biomass and the cold gas efficiency up to 72.5%. The use of steam positively affected the molar ratio of hydrogen to carbon monoxide that reached a steady value of 0.77 during the gasification operated at steam to biomass ratio of 0.11 kg/kg, versus the value of 0.46 measured in the corresponding test operated only with air. On the other hand, steam addition increased tar production up to 163 g/kg in air/steam gasification compared to the 137 g/kg with air gasification. Obtained data of the syngas composition along the bed height provide insight into the underlying physical and chemical phenomena and can be further used for the improvement and validation of gasification mathematical models.

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).

Development and Performance of a Multi-Fuel Residential Boiler Burning Agricultural Residues

The combustion behaviour of selected agricultural residues (olive and peach kernels, almond and walnut shells) and their blends was investigated in a prototype low-investment combustion unit of nominal capacity 65kWth. Blending ratio varied up to 50%. Flue gas temperatures, inlet and outlet water temperatures of the boiler and gaseous emissions were measured at specific feed and air flow rates and combustion and boiler efficiencies were determined. CO and NOx emissions from all fuels during the whole operation of the unit were below legislation limits, while SO2 emissions were negligible. Combustion efficiencies were satisfactory, ranging between 84 and 86%. Peach kernels burned with the highest efficiency. By blending olive kernels with peach kernels, almond or walnut shells at percentages up to 50%, the overall efficiency of the system in terms of emissions and degree of combustion was improved. The best performance was achieved by olive kernels/peach kernels 50:50 blend.

Analysis of the spontaneous combustion and self-heating of almond shells

Self-heating/spontaneous combustion of almond shells in a laboratory oven with control of temperature and weight variation was studied. Two processes were considered: water vapor sorption and chemical oxidation. Different runs were made to analyze the vapor sorption at different oven temperatures, measuring weight gain due to sorption and the variation in internal temperature. With respect to oxidation kinetics, three studies were carried out: the rate of weight variation with temperature, the variation of temperature in a runaway test carried out with a spherical sample wrapped in perforated aluminum foil, and a series of runs to analyze temperatures within spherical samples.A simulation program was developed for the analysis of the sorption run and the kinetic run. In addition, the simulation program was used for the expected runaway condition for a 3–4 m diameter body, discussing the influence of the presence of water vapor.

Binary Blends Versus Ternary Blends in Steam Cogasification by Means of TGA–MS: Reactivity and H2/CO Ratio

Cogasification of olive pomace, almond shell, and petcoke was carried out by thermogravimetric analysis coupled with mass spectrometry. Binary and ternary blends were compared in terms of their rea...

Multi-criteria analysis for selecting the optimum blend in the co-gasification process

Co-gasification is an efficient process for obtaining valuable by-products from blending different raw materials. However, selecting the optimum blend is complicated to establish as it depends on the criterion selected. In this study, the Analytical Hierarchy Process was used for obtaining the optimum blend in the co-gasification of olive pomace, almond shells and petcoke. Thus, four criteria (H2/CO ratio, gasification reactivity, CO2 burden and raw material price) and fifteen alternatives were proposed. Moreover, a sensitivity analysis was made to determine potential changes in the alternatives ranking. At this point, 29 scenarios were considered for evaluating all possible interactions between the criteria. The optimal sample depended on the scenario studied, which meant criteria weightages were significant. Moreover, a normalized priority ranking was calculated by taking all scenarios into consideration. Finally, the olive pomace and the blend of 75wt. % of olive pomace and 25wt. % of petcoke presented the best results.

EFFECT OF ALMOND SHELL PARTICLES ON TENSILE PROPERTY OF PARTICLEBOARD

The objective of the study was to fabricate particleboard using almond shell. The significance of the study is that it can result in creating raw material for panel industry which is in shortage these days. Different particleboards were made based on almond shell particles ratios mixed with epoxy resin. In this study, we investigated the resulting shell particleboard tensile properties. Results shows that when added with almond shell, the tensile properties of the resulting panel showed greater performance. For example, it showed better hardness which is a desirable quality.

Bioreactors for brine denitrification produced during polluted groundwater desalination in fertigation areas of SE Spain: batch assays for substrate selection.

Increasing knowledge of nitrate removal using denitrifying bioreactors has illustrated the usefulness of this management practice for treating discharge water from agricultural land uses. The objective of this study was to assess the viability of almond shell, chopped carob, olive bone, and citrus woodchip as carbon media for denitrification of brine with high nitrate load (EC ≈ 20 dS m-1, NO3--N concentration ≈ 65-80 mg NO3--N L-1) in bioreactors. To the authors' knowledge, this is the first test of denitrifying brine using organic wastes as the carbon substrate, and the first use of these carbon media for that purpose. Nitrate removal efficiency and efficiency:cost ratio were considered. The results indicated that the best removal efficiency and cheapest cost were provided by citrus woodchip (3.02 ± 0.15 mg NO3--N m-3 d-1) at a cost of ≈ 6€ m-3, followed by almond shell (1.54 ± 0.20 mg NO3--N m-3 d-1) at a cost of ≈ 19€ m-3. Chopped carob and olive bone showed negligible nitrate removal in the brine; chopped carob generated acidic leachate with extremely high dissolved organic carbon, and olive bone resulted in a highly saline leachate. Of the four media tested, the results of this study indicated that citrus woodchip was the most suitable media for denitrification of the brine.

Indigenous waste plant materials: An easy and cost-effective approach for the removal of heavy metals from water

The waste plant materials, including neem wood, eucalyptus, pine cone wood, almond shell, walnut shell and sawdust, were used as biosorbents to remove heavy metals from the water. The % removal efficiency of each biosorbent for copper (Cu), zinc (Zn), manganese (Mn), lead (Pb), chromium (Cr) and arsenic (As) was estimated at various pH and for different contact hours by using atomic absorption spectrometer. All biosorbents have shown poor efficiencies for arsenic removal, while their % removal efficiencies towards other metals were found appropriate at near drinking water pH (7.5) and at a contact time of 3 ​h. Among all biosorbents, pine cone, eucalyptus and neem wood have shown comparatively more significant removal of Cu, Zn, Mn, Pb and Cr. The overall % removal efficiencies were found greater with pine cone wood and the value reached to 99% for Cu removal. For arsenic removal, the sawdust was modified by chemical treatment and significant removal up to 80% was found.

Badem Kabuğu İle Sulu Çözeltilerden Bentazon ve Metalaxyl Giderimi

Bentazon ve Metalaxyl pestisitlerinin sulu çözeltilerden giderimi için tarımsal atık olan badem kabuğunun adsorbent olarak kullanılabilirliği incelenmiştir. Box-Behnken deneysel tasarım yöntemi uygulanarak, her bir pestisit için, pH, adsorbent konsantrasyonu, pestisit konsantrasyonu ve adsorpsiyon süresi parametrelerinin adsorpsiyon üzerindeki etkileri incelenmiş ve adsorpsiyon proseslerinin optimizasyonu gerçekleştirilmiştir. Belirlenen optimum proses koşullarında % 70.3 Bentazon ve % 33.3 Metalaxyl giderimi sağlanmıştır. Ayrıca her bir adsorpsiyon prosesi için proses parametrelerinin ve bu parametrelerin birbirleriyle etkileşimlerinin adsorpsiyon üzerindeki etkilerini gösteren model denklemler elde edilmiştir. Gerçekleştirilen kinetik ve denge çalışmaları sonucunda, badem kabukları ile Bentazon ve Metalaxyl adsorpsiyonunun yalancı 2. mertebe kinetik ve Freundlich izoterm modelleri ile ifade edilebileceği belirlenmiştir.