Sunflower Stalks Research Articles

The mechanical properties and the freeze-thaw resistance of an ecological micro concrete made with sunflower stalks

The aim of this study was to analyze the density, compressive strength, tensile strength and the freeze-thaw resistance of a cement micro concrete made with sunflower stalks that replaced 20%, 35%, 50%, 60%, 80% and 100% of the sand from its composition. The results showed, in general, a decrease of the analyzed properties, but the use of 20% and 35% sunflower stalk aggregates led to the improvement of the splitting tensile strength. A significant advantage of this type of micro concrete was its density, being obtained a lightweight building material, with up to 822 kg/m3.

Bioethanol production from sunflower stalk: application of chemical and biological pretreatments by response surface methodology (RSM)

The present paper discusses response surface methodology (RSM) as an efficient tactic for predictive model and optimization of the whole experimental methods of reducing sugar and energy. In this work, the application of RSM presented for optimizing reducing sugar and energy as compared with production between chemical and biological pretreatments. All experiments applied statistical designs in order to develop a statistic multivariate analysis model that provides to consider the effect of different parameters on a process and describe the optimum values of these variables to optimize the response. Dred sunflower stalks were pretreated by sodium hydroxide (NaOH) and Trichoderma reesei as a function of two variables: concentration of NaOH (%) and T. reesei (%) and time for pretreatment (Day) to receive reducing sugar and energy. The chemical pretreatment model was characterized by 13 runs, varying the variables at two factors, NaOH (1, 1.5, 2%) and Day (1, 2, 3). The biological pretreatment model was characterized by 13 runs, varying the variables at two factors, T. reesei (1, 1.5, 2%) and Day (1, 2, 3), by central composite design experimental design. In the chemical pretreatment, experiments performed at 2% (w/v) of NaOH for 3 days were used. The chemical pretreatment model at 2% NaOH for a 3-day release reduced sugar by 5.812 g/L and energy by 92.992 kJ/L; on the other hand, biological pretreatment model at 2% T. reesei for a 3-day release reduced sugar by 3.891 g/L and energy by 62.256 kJ/L, reducing sugar starter for fermentation by 49.0670 ± 6.4660 g/L and fermentation efficiency by 71.60% at 48 h fermented time.

A Comparative Investigation on Lithium Storage Performance of Carbon Microsphere Originated from Agriculture Bio-waste Materials: Sunflower Stalk and Walnut Shell

With the aggravation of environmental pollution and the reduction of fossil fuels, the need of developing green and environmentally sustainable energy materials is becoming urgent. Novel porous carbon microsphere materials derived from waste biomass sunflower steam and walnut shell were prepared based on acidolysis-hydrothermal method, and the morphology, structure and electrochemical performance of the products were characterized by scanning electron microscope, transmission electron microscopy, Raman, X-ray diffraction measurements, nitrogen adsorption, X-ray photoelectron spectroscopy, galvanostatic charge–discharge, cyclic voltammograms and electrochemical impedance spectroscopy. Different electrochemical performance for Li-ion storage was demonstrated owing to the variation of physical property and electrode interface behavior. As an anode material for lithium-ion batteries, the carbon material derived from walnut shell exhibits higher initial coulombic efficiency, cycling stability and rate performance. It can retain charge capacity of 235.3 mAh g−1 after 50 cycles, which is obviously higher than that of carbon microsphere from sunflower steam, 145.9 mAh g−1, and the capacity retention of walnut shell material is 2.5 times that of sunflower steam. It is believed that the superior electrochemical performance may be attributed to the higher graphitization degree and larger pore path of walnut shell-derived carbon materials with average particle size of 3–5 μm, and higher conductivity of SEI film formed on the surface of electrode, which can enhance the conductivity of bulk material and accelerate the migration of lithium ion through bulk material and electrode/electrolyte interface.

SYNERGIC EFFECTS OF SUNFLOWER STALKS AND SODIUM SILICATE IN DEVELOPING AN ECOLOGICAL CONCRETE

Building industry is a very large domain in the global economy and it has a lot of consequences over the environment through many and different aspects. These consequences are various, from the more and more extended area of construction up to gas emissions released during materials manufacture and transportation, construction process, exploitation of buildings and, finally, their deconstruction. The concrete, the most used material in construction industry all over the world, must become greener and greener every passing day. Involving natural and renewable raw materials in concrete composition is a variant to develop an ecological concrete that sustain a healthier environment by using less of depleting mineral resources and by decreased gas emissions released into the atmosphere. This research has a high degree of novelty due to its aim to study the effects of sunflower stalks used as partial replacement of the mineral aggregates from the concrete composition, combined with the effects of sodium silicate used as additive. There were developed concrete recipes with sunflower stalks shredded and treated with 40% sodium silicate solution as 20%, 50% and 80% replacement of mineral aggregates with regular concrete additives and then was supplementary added sodium silicate in 5% of the cement volume from the concrete composition. Tests were carried out on the density and compressive strength of the concrete at 28 days and 3 months and on its flexural and splitting tensile strength at 28 days. The results showed that the sodium silicate addition has positive effects on the concrete compressive strength and had no or a small negative effect on its density and tensile strength.

Biogas Production from Sunflower Head and Stalk Residues: Effect of Alkaline Pretreatment

Sunflower residues are considered a prominent renewable source for biogas production during anaerobic digestion (AD). However; the recalcitrant structure of this lignocellulosic substrate requires a pretreatment step for efficient biomass transformation and increased bioenergy output. The aim of the present study was to assess the effect of alkaline pretreatment of various parts of the sunflower residues (e.g., heads and stalks) on their methane yield. Experimental data showed that pretreatment at mild conditions (55 °C; 24 h; 4 g NaOH 100 g−1 total solids) caused an increase in the biochemical methane potential (BMP) of both heads and stalks of the sunflower residues as determined in batch tests. The highest methane production (268.35 ± 0.11 mL CH4 g−1 volatile solids) was achieved from the pretreated sunflower head residues. Thereafter; the effect of alkaline pretreatment of sunflower head residues was assessed in continuous mode; using continuous stirred-tank reactors (CSTRs) under two operational phases. During the first phase; the CSTRs were fed with the liquid fraction produced from the pretreatment of sunflower heads. During the second phase; the CSTRs were fed with the whole slurry resulting from the pretreatment of sunflower heads (i.e., both liquid and solid fractions). In both operating phases; it was observed that the alkaline pretreatment of the sunflower head residues had a negligible (phase I) or even a negative effect on biogas production; which was contradictory to the results of the BMP tests. It seems that; during alkaline pretreatment; this part of the sunflower residues (heads) may release inhibitory compounds; which induce a negative effect on biogas production in the long term (e.g., during continuously run digesters such as CSTR) but not in the short-term (e.g., batch tests) where the effect of the inoculum may not permit the inhibition to be established.

The properties of biochars derived from different plant residue and different pyrolysis temperatures

By determining the degraded and limiting properties of the soil, producing solutions for the improvement of these properties will be able to provide sustainable and efficient use of soil. Especially, low organic matter content of soils causes many problems. Studies on increasing the organic matter content of soils by using various plant residues and organic fertilizers constituted the subject of many researches. However, in recent years, the use of biochar obtained by pyrolysis of various plant materials at high temperatures has become popular. With the use of biochar, both the characteristics of soil are improved, and greenhouse effect is reduced. Furthermore, it provides the production of various biofuels. The attributes of obtained biochar vary with pyrolysis material and temperature. The aim of this study was to produce biochar by pyrolyzing diverse plant residues in different temperature conditions and determine some physical and chemical properties of the biochar. For this purpose, sunflower stalk, sunflower head, corn stalk, corn cob and wheat straw were converted to biochar’s at 300 °C, 400 °C, 500 °C, and 600 °C temperatures. Biochar yield, surface area, C/N ratio, pH and electrical conductivity (EC) values and water holding capacities of the experimental samples were determined. In the light of results, the highest surface area was found in sunflower stalk at 300 °C, while the lowest surface area was detected as in wheat straw at 300 °C. The C/N ratios increased in all the samples except corn stalk and corn cob.

Xylitol Production from Agricultural Wastes by Candida tropicalis

Xylan produced various agricultural residues including wheat (Furat, Abugraib and Abaa), Papyrus and Sunflower stalks in different ways, including the use of diluted acid, dilute base and self-degradation. The results showed that the acidic method in the production of xylan from various agricultural residues compared with other methods was superior, the highest quantity of xylan 187.6 µg.ml-1 was obtained from the agricultural waste of Papyrus, while it was 157.6, 157.6, 161.6 and 161.3 µg.ml-1 of wheat category of furat, wheat Abu Ghraib, wheat Abaa and sunflower stalks respectively, based on the results obtained, the xylan produced by the acidic method of the different agricultural residues was selected to determine the optimal carboon source for production of xylanase using bacteria Bacillus subtilis strain RS1 locally isolated. After the production of xylitol, the descriptive diagnosis was performed using an HPLC device, depending on the time of the 38.4 minute time lapse reaction of the standard Xylitol and compared with the time of the production of Candida tropicalis, the amount of the processed xylitol was 8.3 µg.ml-1, the calculated xylitol was compared standard xylitol

Characteristics of Anti-Fungal Activity to Alternaria alternate of Different Proportion of Extraction from Sunflower Discs and Stalks

The characteristics of anti-fungal activity to Alternaria alternate of three fractions of water, ethyl acetate, petroleum ether of sunflower discs and stalks have been studied. The fractions of water, ethyl acetate, petroleum ether of sunflower disc and petroleum ether fraction of sunflower stalk have good anti-fungal activity to A. alternate. The best concentrations of anti-fungal activity to A. alternate of water, ethyl acetate, petroleum ether fractions and petroleum ether fraction of sunflower stalk were 320 mg/mL, 240 mg/mL, 160 mg/mL and 160 mg/mL, respectively. The anti-fungal activities to A. alternate of these four kinds of extract are increased with the increase in concentration and arrive at stability after the best concentration of anti-fungal activity to A. alternate. The ethyl acetate fraction and petroleum ether fraction of sunflower stalk had no anti-fungal activity to A. alternate.

Sunflower Stalk Based Activated Carbon for Supercapacitors

In this study, a combination of physical and chemical activation was used to produce activated carbon from sunflower stalks. The NaOH activated carbon possess a high specific surface area of 2658 m2/g. The micropore fraction and surface area obtained is much higher than a commercial activated carbon. The electrodes from the activated carbons were electrochemically analyzed in a two-electrode supercapacitor cell with 1 M H2SO4 electrolyte. The results show that the high surface area of sunflower activated carbon resulted in significantly high specific capacitance of 207 F/g at 0.05 A/g current density. Moreover, a high energy density of 18.4 Wh/kg was obtained at the power density of 80 W/kg. The results also showed the importance of pore structure on the supercapacitor performance.

Fattening calves using vegetable waste and sunflower

The results of wholesale on the use of waste of vegetable crops and sunflower when fattening gobies of the black-and-white breed are given. Six groups of uncastrated bulls were formed: control, I experienced, II experienced, III experienced, IV experienced and V experienced (on the principle of analogous groups, taking into account age and body weight and origin). All gobies (control and experimental groups) were given 17.2 kg of silage from cereal perennial grasses and 3.65 kg of mixed feed and 9.5 kg of brewer’s grain, 80g of fodder chalk each. The gobies of the experimental groups were given various wastes of vegetable crops and sunflower (at 30 g / head / day): I experienced — did not feed them, II experienced — pepper stalks, III experimental — sunflower stalks, IV experimental — cucumber stalks, V experimental — stalks tomatoes (in the form of flour). The live weight of bulls when removed from fattening for the control group is 297.0 ± 0.19 kg, the experienced ones - from 304.6 ± 0.12 kg (hay with KKS and without feed additives) to 317.7 ± 0.24 kg (114.7%, tomato stalks). Average daily gains in live weight are from 801 ± 14.6 g (hay with CCR) to 874 ± 16.7 (tomato stalks, P <0.001) versus 762 ± 16.4 g in the gobies of the control group.

Influential degree of polymerization of sugar extraction on alkali pretreatment from sunflower stalk wastes by applied statistical modelling

This paper presents application of influence of degree of polymerization (DP) on optimally pretreated using a response surface methodology (RSM) approach for decreased DP level of optimal chemical and biological pretreatments from sunflower stalk. All experiments in this paper are applied by statistical designs for developing a statistic multifunction analysis model that focus on the effect of dissimilar factors for describing of the optimum values of the changed surface response on any variables. The process parameters of chemical model (Sodium Hydroxide concentration and Time) to pretreat for DP. The chemical pretreatment model was certified by 13 runs, at two factors, NaOH (1, 1.5, 2%) and Day (1, 2, 3) by central composite design (CCD). DP value of the chemical model was estimated by a Design Expert program version 11 trial: chemical model of DP highest and lowest of 25.80 and 6.16, consecutively. The aim of this experiments to investigate only DP from the chemical model of pretreatment. The procedure there are effective on sugar conversion and DP of the lignocellulosic biomass. Which pretreatment is a challenge for cost and competitive technology on large-scale of fermentable sugar in the step of hydrolysis.

Sunflower stalk-derived biochar enhanced thermal activation of persulfate for high efficient oxidation of p-nitrophenol.

Sunflower stalk-derived biochars (BC) were prepared at various temperatures (i.e., 500, 650, and 1000 °C) and demonstrated as a highly efficient catalyst in persulfate (PS) activation for the oxidation of p-nitrophenol (PNP) at 60 °C. The apparent PNP oxidation rate constant in the BC500 (0.1543 L mol-1 S-1), BC650 (0.6062 L mol-1 S-1), or BC1000 (2.1379 L mol-1 S-1) containing PS system was about 2, 8 and 28 times higher than that in PS/PNP (0.0751 L mol-1 S-1) system, respectively. The effect of reaction temperature on PNP oxidation was also investigated. Furthermore, the radical quenching tests and electron paramagnetic resonance spectroscopy (EPR) were employed to investigate the sulfate and hydroxyl radicals for PNP oxidation. The Raman results suggested that the defective sites on biochars possess vital role for oxidation of PNP in PS system. The possible activation pathway of PS/BC was proposed that the defective sites on BC were involved for weakening the O-O bond in PS and subsequently cleaving O-O bond by heat to generate sulfate radical. The oxidation of PNP at low concentration (below 100 μg L-1) was completely removed in urban wastewater by PS/BC system within 30 min. This work would provide new insights into PS activation by BC catalyst and afford a promising method for organic pollutant removal in high-temperature wastewater.

Deeper insight into the morphological features of sunflower stalk as Biorefining criteria for sustainable production

AbstractEffective utilization of fibrous materials plays a major role in techno-economic viability of the resources. Sunflower stalk (SS) as one of highest bio-fibrous waste was assessed respect to fiber features in biorefinery approach. The lumen diameter, wall thickness and fiber length were measured as (∼12 µm), (5.25 µm) and (1.58 mm), respectively. The wider lumen diameter makes its suitable for chemical treatments and purification. The applied Pulping conditions decreased the fiber length and wall thickness, with the least reduction by soda-anthraquinone. Derived indices involved rigidity and flexibility coefficients, aspect and Runkel ratios, solid and Luce’s shape factors were also calculated based on the measured values. The aspect ratio (77.5) put SS fibers as very good resources for lignocellulosic products and composites. The flexibility coefficient (57) belongs to the elastic category and was not altered by pulping. The Runkel ratio was lesser than 1 (&gt;0.9) but decreased by the pulping, to some extent. The Luceʼs shape factor was nearly calculated 0.5, near to the bagasse and eucalyptus species. Solid factor (0.17) and rigidity coefficient (0.51) were considered to be good fiber resource. Totally due to the SS fiber characteristics, the agricultural waste suitability for value adding bio-based production could be reported.

XYLANASE PRODUCTION FROM LOCAL BACTERIAL ISOLATE

Seventeen local isolates of Bacillus were isolated from soil to produce extracellular xylanase under submerged fermentation process by using xylan as carbon sole source. All isolates were subjected to quantitative scanning to select the most efficient one. The highest activity of xylanase (2680u/ml) was obtained from isolate Bacillus sp RS1. The isolate identified by 16SrRNA gene sequence of Bacillus subtilis ( accuracy of 99%)which was matched with sequence of Bacillus subtilis VBN25 that recorded in Genebank under the Accession Number of MG027675.1.Extracted xylan from agricultural waste by acidic method(papyrus, sun flower stalks, Ibaa Wheat type, Furat wheat type and Abo Ghraib wheat type)were used as the substrate for xylanase production from Bacillus. The results showed that the papyrus gave the highest amount of xylan (187.6 µg/ml) as compared with that of the sun flower stalks, Ibaa Wheat type, Furat wheat type and Abo Ghraib wheat type(161.3, 161.6, 157.6, 157.2) µ g/ml respectively. The results indicated that the highest xylanase activity was 2800 u/ml produced by Bacillus subtilus when Papyrus xylan was used.

Polysaccharides from sunflower stalk pith: Chemical, structural and functional characterization

Polysaccharides from sunflower stalk pith (SSP) were extracted by hot water and sodium hexametaphosphate (SHMP). Chemical analyses suggested both fractions dominated in galacturonic acids with a small amount of neutral sugars, indicating their identity as pectins. The weight average molecular weight and intrinsic viscosity for water-extractable pectin (WEP) and SHMP-extractable pectin (SEP) were 57.2 kDa, 0.48 dL/g and 23.1 kDa, 0.50 dL/g, respectively. The degree of esterification (DE) was calculated to be 92% and 64%, respectively. Methylation analysis demonstrated that 1,4-GalpA residues dominated all the sugar linkages, while other linkage types including 1,2-Rhap, 1,2,4-Rhap, 1,4-Galp and 1,5-Araf were also present in WEP and SEP. NMR spectroscopy further revealed WEP and SEP mainly demonstrated homogalacturonan (HG) structure and a small fraction of rhamnogalacturonan-I (RG-I) structure. The microstructure and water- and oil-holding capacity (WHC and OHC) of SSP was also examined. SSP was a microporous powder. Both WHC and OHC increased with particle size of the SSP, reaching up to over 40 g liquid/g fibre at particle size of 30 mesh (0.595 mm). However, the oil-SSP mixtures showed oil loss after absorption on filter paper for 24 or 48 h. Oil loss increased with SSP particle size decrease. 30 mesh SSP reduced oil loss in peanut butter by 74% with 2.2% addition.

Ultrasound-assisted mild sulphuric acid ball milling preparation of lignocellulose nanofibers (LCNFs) from sunflower stalks (SFS)

Cellulose nanomaterials have properties that make them renewable materials of choice for various applications. However, the utilization of concentrated alkaline, acids, oxidizing or reducing agents in their production presents significant challenges to the environment. To mitigate this challenge and ensure the efficient industrialization of cellulose nanomaterials, lignocellulose nanofibers (LCNFs) were prepared through an easy, feasible and environment friendly method relative to conventional techniques. 1–3% Sulphuric acid was used in combination with ball milling and ultrasound to produce cellulose nanofibers containing about 92% of the original lignin content. The microstructure and morphology of the nanofibers were studied while thermal analysis showed that the LCNFs can withstand between 225–251 °C and lose only 5% of their weight. Interestingly, despite the binding force of lignin, the nanofibers showed high electrostatic repulsion up to − 47 mV between the fibers. The translucent nanofilms produced from the LCNFs are less hydrophilic having water contact angles around 76°–62°. These LCNFs were synthesised without passing through any pre-treatment process and their hydrophobic properties have been found to be better than conventional cellulose nanomaterials while their thermal properties are comparable.

Lignocellulosic Composites from Acetylated Sunflower Stalks

Sunflower stalks could be an alternative raw material for use in the particleboard industry since the requirements of P1 general purpose boards for use in dry conditions and P2 boards for interior fitment for use in dry conditions are easily satisfied. Acetylation of sunflower stalks is found to greatly improve the thickness swelling (TS) value, with acetylated boards showing 19.7% weight gain, meeting the TS requirements of P3 Non-Load-Bearing—Humid and P4 Load Bearing—Dry criteria; however, acetylation adversely affects the internal bond strength (IBS). It is suggested that combinations of industrial wood chips with sunflower raw material may be used for the overall improvement performance of the particleboards.

Investigation of Miscanthus and Sunflower Stalk Fiber‐Reinforced Composites for Insulation Applications

The development of materials based on renewable and low‐cost resources is today’s crucial interest for civil engineering. This work intends to investigate two new vegetable fibers as composite reinforcement for insulation application in the building industry. Miscanthus and sunflower stalk have mainly been selected for their high fiber content, low water content after harvesting, and availability. These criteria lead to good structural properties and allow a reduction in production and transportation costs. This study aims at demonstrating the feasibility to produce cohesive panels from these lignocellulosic fibers and their related interesting mechanical and thermal properties according to various natural binders.

Adsorption Study of Acid Red 114 and Basic Blue 3 on Sunflower Stalk

The aim of this work was to evaluate the sunflower stalk (SS) as an adsorbent in the removal of red acid 114 (AR 114) and basic blue 3 (BB 3) in aqueous solutions, without any physicochemical treatment, where temperature and concentration were the studied variables. The research was developed by using the batch processing mode; the contact time was one hour, with constant agitation of 200 rpm and pH of 7000 ± 0.050, using a central composite design. The adsorbent was characterized through BET, SEM, acid sites and basic sites, charging point, and infrared. The results indicated that the sunflower stalk was a viable and economical alternative for the removal of water that had been contaminated by dyes, showing a better performance for the AR 114 dye, reaching a 71.96% of removal with respect to the initial load. In addition, the EPI Web software was used to model the environmental performance of colorants.

Effects of Coatings Containing Organic Ashes on the Corrosion Performance of Reinforcements

The aim of this study is to investigate the corrosion performance of reinforcement steels coated with a coating containing wheat straw, sunflower stalk, and corn stalk ashes and moreover to discuss the effect of the coating on the concrete durability. By replacing calcite with different amounts of these organic ashes in the dye production, innovative corrosion inhibitive coating types were introduced. These coating types have been applied both on the reinforcement steels and concrete surface. In order to understand the effects of the coating types produced with these organic ashes, the steel bars coated with them containing 6% of the organic ashes as fine aggregate were embedded into concrete samples. The samples were cured both in tap water and 3.5% NaCl solution for 180 days, and the mass losses of the steel bars were determined. Also, the inhibition efficiency of the coating was determined by using the galvanic cell method and accelerated corrosion tests. Furthermore, mass loss, compressive strength, abrasion resistance, freeze‐thaw property, and capillary water permeability of the reinforced concrete samples with the produced coating were investigated. Test results showed that the minimum mass loss ratio in reinforcement was observed as 0.185% in samples coated with all three organic ash‐added mixes. Also, for the same samples compressive strength loss was the lowest as 14%. As a result, the durability of concrete and the corrosion resistance of steel bars improve with the addition of wheat straw, sunflower stalk, and corn stalk ashes into the coating and they could be used as environment‐friendly corrosion inhibitors.