Wheat Straw Residues Research Articles

Study of Purified Cellulosic Pulp and Lignin Produced by Wheat Straw Biorefinery

With the world population rising, wheat straw production is expected to reach 687–740 million tons per year by 2050. Its frequent application as a fuel source leads to air, water, and soil pollution. Limited literature exists on methods for separating components of residual wheat straw. Optimal conditions for organosolv pulping of hydrolyzed wheat straw include 3% FeCl3·6H2O as a catalyst, a biomass-to-solvent ratio of 1:15 (m/v), and 50% ethanol:water as cooking liquor at 200 °C for 30 min. Desilication conditions involve extraction with 7.5% Na2CO3 at a biomass-to-solvent ratio of 1:20 (m/v) treated at 115 °C for 60 min. Lignin from hydrolyzed wheat straw showed similar properties to organosolv lignin from untreated straw, with minimal lignin alteration during hydrolysis. Hydrolysis significantly degraded cellulose. A 41% lignin recovery rate with 95% purity was achieved from pre-extracted hydrolyzed straw. Recovered cellulose after silica removal had 2% ash and 87% purity. The innovation of this process lies in the development of a comprehensive, sustainable, efficient, and economically viable biorefinery process that efficiently separates key components of wheat straw, i.e., xylose, lignin, cellulose, and silica, while addressing environmental pollution associated with its traditional use as fuel.

Relay-cropping enhances the availability of low iLUC risk lignocellulosic feedstock for advanced biofuels

The relay-cropping (R) of a winter cereal and a high biomass yielding legume for advanced biofuel production can enlarge the legume growing season, thus increase its biomass yield and synchronize nitrogen (N2)-fixation capacity to uptake. The aim of the present study was to evaluate the biomass and food yield of two sunn hemp (Crotalaria juncea L.; cv. Ecofix) – wheat (Triticum aestivum L.; cv. Bologna) relay-cropping systems compared to double-cropping, in order to explore the impact on grain and biomass yield of the variable crops overlapping periods. The evaluated relay-cropping systems foreseen an early November wheat sowing into no till bare soil with: i) sunn hemp harvested at full flowering (beginning of November, R1) and ii) sunn hemp harvested at the end of flowering (end of November, R2). In the control (C) double-cropping, sunn hemp was harvested at the beginning of flowering (end of September). Quantitative and qualitative parameters were evaluated for each system across two growing seasons (2019–20 and 2021–22). Sunn hemp biomass and wheat straw residues were determined. The grain qualitative parameters determined for wheat were: grain volume weight (VW), crude protein, wet gluten, starch and Zeleny index (ZI). The R1 and R2 sunn hemp-wheat relay-cropping biomass yield (12.5 Mg d.m. ha−1 y−1) was similar to C (11.3 Mg d.m. ha−1 y−1). In 2019–20, environmental conditions were more favorable, thus, yields were higher than in 2021–22 by 72 %. Wheat grain yields in 2021–22 were higher in R1 (2.9 Mg d.m. ha−1) than C (2.0 Mg d.m. ha−1), with R2 showing intermediate values. In 2019–20, however, the grain quality was higher in R1 than in C for crude protein (+11 %), wet gluten (+15 %), and ZI (+26 %) eventually due to an increased N2-fixation by sunn hemp that reached full flowering. The local availability of low iLUC risk lignocellulosic feedstock for advanced biofuel could be increased through crop intensification with relay-cropping, showing the potential to provide additional biomass and enhance food quality thus complying with the additionality measures set out by the Delegated Regulation of REDIII.

Effect of Pulping Waste Liquid on the Physicochemical Properties and the Prediction Model of Wheat Straw Residue Granular Fuels.

Herein, wheat straw residue and pulping waste liquid were collected from pulping mill and mixed to prepare bio-based granular fuels by using compression molding technology, and to explore the comprehensive utilization of the industrial waste of pulping and papermaking. The effects of pulping waste liquid on granular fuel properties were analyzed systemically. Further study of the function of pulping waste liquid, cellulose and hemicellulose was used to replace wheat straw residue and avoid the interference factors. Therefore, the prediction models of granular fuels were established with influencing factors that included cellulose, hemicellulose and pulping waste liquid. The granular fuels had the best performance with 18.30% solid content of pulping waste liquid. The highest transverse compressive strength of granular fuel was 102.61 MPa, and the activation energy was 81.71 KJ·mol-1. A series of curve fitting prediction models were established to clarify the forming process of granular fuel, and it turned out that the pulping waste liquid could improve the adhesion between solid particles and increase their compression resistance.

Ash Transformation during Fixed-Bed Co-combustion of Sewage Sludge and Agricultural Residues with a Focus on Phosphorus.

This work investigates the ash transformation during fixed-bed co-combustion of sewage sludge mixtures with the agricultural residues wheat straw and sunflower husks, focusing on the fate of phosphorus (P) in the resulting ash fractions. The study aims to determine suitable process parameters for fixed-bed combustion of fuels previously investigated in single-pellet experiments. The pure fuels and fuel mixtures were combusted in a 20 kWth residential pellet burner while monitoring the flue gas composition, temperature, and particulate matter formation. Subsequently, the different ash fractions were collected and characterized by CHN, SEM/EDS, and XRD analysis. The results showed that co-combustion of sewage sludge and agricultural residues reduced the formation of particulate matter as well as the formation of slag. Co-combustion of sewage sludge with either agricultural residue resulted in a change in phosphate speciation, displaying higher shares of Ca and lower shares of Fe and Al in the formed orthophosphates as well as amorphous phases containing higher shares of K. The formation of K-bearing phosphates was hindered by the spatial association of P with Ca and Fe in the sewage sludge, the incorporation of available K in K-Al silicates, and the depletion of K in the P-rich melt phase. Compared to mono-combustion, co-combustion experiments showed the potential for improving the combustion performance and reducing the risk of slag formation. The outcome suggests that co-combustion is a feasible path to integrate waste streams in fixed-bed energy conversion with simultaneous formation of phosphates enabling P recovery.

Carposome productivity of Pleurotus ostreatus and Pleurotus eryngii growing on agro-industrial residues enriched with nitrogen, calcium salts and oils

The suitability of the abundant agro-industrial residues wheat straw (WS; control), barley and oats straw (BOS) and rice husk (RH), supplemented with various sources of oils (sunflower, corn oil), nitrogen (peptone, yeast extract) and calcium salts (CaSO4·2H2O, CaCl2), as novel substrates in solid-state fermentation of selected Pleurotus ostreatus and P. eryngii mushrooms was investigated. The possible effect of different additives on mycelial growth rate, biomass production and endoglucanase, laccase and lipase biosynthesis were evaluated. Moreover, their impact on essential cultivation aspects (earliness, total mushroom yield, biological efficiency) and carposome quality parameters (weight, morphological characteristics) was assessed. Both fungi showed their highest growth rates on BOS substrates and the most positive implementation was CaSO4·2H2O 6 % w/w (Kr = 9.58 mm/ day; P. ostreatus, Kr = 9.42 mm/ day; P. eryngii), while different additives led to enhancement of biomass production. Pleurotus species demonstrated minimal levels of endoglucanase activity, with values ranging from 0.01 to 0.42 U/g of dry weight, regardless of the substrate and the stage of colonization. On the contrary, the maximum values of laccase activity were observed at 50 % of colonization on BOS and RH, while supplementation with nitrogen and calcium sources positively affected its biosynthesis. P. ostreatus and P. eryngii cultivated on BOS supplemented with peptone at 2 and 5 % w/w, synthesized significant laccase amounts, i.e., 12,165.78 and 8,624.55 U/g d.w., respectively. Satisfactory amounts of lipase were produced, especially in substrates supplemented with sunflower 2 % w/w, in quantities up to 1.42 U/g d.w., whereas the highest lipase activity was achieved by P. eryngii on WS supplemented with corn oil at 2 % w/w, with a value of 4.25 U/g d.w. being recorded. Regarding fermentation of Pleurotus species in polypropylene bags, WS and BOS supported faster colonization and shorter earliness period than RH substrates, whereas supplementation did not seem to affect these culture parameters. Furthermore, oils supplementation had a positive effect on BE of both species, with values up to 100 % for P. ostreatus and 80 % for P. eryngii on WS and BOS, whereas on RH the lowest BE values were detected. Morphological characteristics were not significantly affected by the additives. Results indicate the positive impact that certain additives have on mushroom productivity and production of enzymes with great financial and environmental importance.

Wheat straw delignification by Djerkandera adusta (Willd.) P. Karst. 1879: The effect on enzymatic hydrolysis

The use of lignocellulosic materials in the production of biofuels and biochemicals holds a huge prospect since wood and agricultural residues represent the most abundant global source of renewable biomass. However, delignification is an inevitable step in lignocellulose pre-treatment rendering the cellulose and hemicellulose more exposed to enzymatic saccharification. The aim of this study was to assess the potential of different Bjerkandera adusta strains to enhance the efficiency of enzymatic saccharification of wheat straw after solid-state culturing. Three white-rot fungal strains of Bjerkandera adusta (Willd.) P. Karst. 1879, (BEOFB1601, BEOFB1602 and BEOFB1603) were used for partial delignification of wheat straw during solid-state cultivation. Activity of ligninolytic enzymes were measured spectrophotometrically while wheat straw residues were used for determination of hemicelluloses, cellulose and lignin contents. Enzymatic hydrolysis of pre-treated wheat straw was conducted using commercial cellulase in loadings of 60 U g-1 of solid substrate. The content of reducing sugars was measured calorimetrically using 1,4-dinitrosalycilic acid. Enzymes predominantly responsible for lignin degradation by tested fungal strains were peroxidases. The highest rate of lignin degradation was noticed in samples pretreated with the strain BEOFB1601 (42.3 ? 3.7%). The highest reducing sugars yield (8.6 ? 0.3 gGE L-1) was achieved after enzymatic saccharification of samples pre-treated with the strain BEOFB1601, as the most selective lignin degrader. The obtained results suggest that fungal culturing as a bio?logical pre-treatment method can be significantly strain specific. A key mechanism which enhances convertibility of carbohydrates is selective lignin degradation of the biomass.

Wheat Straw Burial Enhances the Root Physiology, Productivity, and Water Utilization Efficiency of Rice under Alternative Wetting and Drying Irrigation

This study evaluated whether the straw burial and alternative wetting and drying (AWD) irrigation could improve the root activity, yield, and water utilization efficiency (WUE) of rice. Accordingly, we conducted a field experiment with three straw burial levels, i.e., with no straw burial (NSB), low straw burial 300 kg.ha−1 (LSB), and dense straw burial 800 kg.ha−1 (DSB), and three irrigation regimes, i.e., alternate wetting/moderate drying (AWMD), alternate wetting/severe drying (AWSD), and alternate wetting/critical drying (AWCD). Results showed that straw burial improved the root activity, rice yield, and WUE under AWD regimes. The combination AWMD×DSB resulted in the greatest values of total dry mass (1764.7 g/m2) and water use (853.1 mm). Conversely, the treatment AWCD × NSB led to the lowest values of total biomass (583.3 g/m2) and water use (321.8 mm). Root dry weight density (1.11 g cm−3) and root active absorption area (31.6 m2 plant−1) were higher in the treatment AWMD × DSB than root dry weight density (0.41 g cm−3) and root active absorption area (21.2 m2 plant−1) were in the treatment AWCD×NSB. The former combined treatment increased root oxidation ability (55.5 mg g−1 FWh−1), the root surface phosphatase activity (1.67 mg g−1 FWh−1) and nitrate reductase activity of root (14.4 μg g−1 h−1) while the latter considerably reduced the values of root oxidation ability (21.4 mg g−1 FWh−1), the root surface phosphatase activity (0.87 mg g−1 FWh−1) and nitrate reductase activity of root (5.8 μg g−1 h−1). The following conclusions can be drawn with regard to water use and biomass yield. (i) The reduction in water consumption was greater than the reduction in yield in the case of AWSD. (ii) The decline in water consumption was less than the decline in biomass yield in the case of AWCD. (iii) The increase in in water consumption was greater than the increase in biomass yield in the case of AWMD. Therefore, the indicators of WUE were recorded in the following order: AWSD > AWMD > AWCD. This study recommends AWD irrigation to improve the root growth traits that contribute to the greater biomass yield of rice. It also suggests that farmers should implement AWD irrigation after leaving wheat straw residues in the field, and followed by deep tillage, to mitigate the negative effect of drought stress caused by AWD irrigation, preserving plant growth without large biomass losses, and thus, addressing the constrains of straw residues and sustaining rice production under limited freshwater resources.

Pore reconstruction mechanism of wheat straw-templated Li4SiO4 pellets for CO2 capture

The traditional Li4SiO4-based CO2 sorbent pellets prepared from mechanical granulation methods usually presented densified microstructures. Hence, wheat straw, an agricultural waste featured with huge production and low cost, was used as porosity creator to improve the microstructures and CO2 capture performance of Li4SiO4 pellets. The results indicated that wheat straw effectively enhanced the cyclic CO2 sorption capacity of the pellets. In particular, 30 wt% wheat straw-templated Li4SiO4 pellets (LA-WS30) exhibited the capacity of ~0.15 g/g that is almost twice as high as that of unmodified pellets. The enriched porosity and improved porous structures resulted from the quick release of burning gases was considered as the main reason for the performance enhancement. In addition, the alkaline (K and Na) salts in wheat straw played a positive role in CO2 sorption of Li4SiO4 pellets due to the reduced diffusion resistance. However, the pore plugging of residual wheat straw ashes after high-temperature treatment decreased the contact areas and, thus, led to the capacity reduction. To conclude, the comprehensive performance of wheat straw-templated Li4SiO4 pellets is the result of the combined effects of porosity creation, alkali doping and pore plugging by ashes.

Technological feasibility and environmental assessment of polylactic acid-nisin-based active packaging

The new consumption patterns based on the “use and throw away” trend has led to an increase in the production of petroleum-based plastics for their application as food packaging films, leading to significant environmental impacts. In the search for alternatives to conventional plastics, polylactic acid (PLA) stands out due to its renewable origin, its mechanical properties and its biodegradability potential. In this regard, this manuscript addresses the large-scale simulation of a bio-technological process for the valorization of wheat straw residues for the co-production of nisin and lactic acid through a batch-type fermentation process. Subsequently, lactic acid will be used for the production of PLA films, to which nisin will be applied to convert them into functional antimicrobial films. To assess the degree of environmental impacts and sustainability of this biotechnological process, Life Cycle Assessment, considering a cradle-to-gate approach, and Greenness Grid methodologies have been applied. The environmental profiles obtained showed that the pre-treatment and downstream stages are the ones leading to the highest impact, being the energy requirements the main hot spots. Moreover, seeking an environmental communication perspective, useful for researchers and stakeholders, the Green Index indicator value obtained leads to the consideration of a potentially sustainable process.

Spontaneous combustion of wheat straw residue at different cooling temperatures: Combined effect of water sorption and air oxidation

Self-heating and spontaneous combustion of torrefied biomass are direct hazards related to the production, storage and transport of torrefied biomass. In this study, we investigated the effect of combined air oxidation and water sorption on self-heating of torrefied agricultural residue biomass at 60, 120 and 180 °C cooling temperatures by measuring weight change and heat flow using thermogravimetric analysis and differential scanning calorimetry (TGA/DSC). Our results showed that the effect of water adsorption predominated at 60 °C. When the gas stream was changed from nitrogen to humid nitrogen, the weight of the torrefied biomass increased rapidly associated with heat generation. Conversely, at 180 °C, the effect of air oxidation predominated and the torrefied biomass decreased rapidly when it was exposed to dry air associated with heat generation. The effect of water adsorption decreased with an increase in the cooling temperature whereas the effect of air oxidation increased with an increase in temperature. The higher torrefaction severity increases the self-heating propensity. The air oxidation and water adsorption may lead to the self-heating of torrefied biomass.

Kinetics and Adsorption Equilibrium in the Removal of Azo-Anionic Dyes by Modified Cellulose

This study introduces a new and bio-friendly adsorbent based on natural and cetyltrimethylammonium chloride (CTAC)-modified adsorbent prepared from wheat straw residues for the removal of Congo red (CR) and tartrazine azo-anionic dyes from aqueous solution. The adsorbent was characterized by thermogravimetric analysis (TGA), calorimetric differential (DSC), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX), and pH point of zero charge (pHPZC) techniques. It was found that decreasing the adsorbent dose and increasing the initial concentration favors the removal of tartrazine and Congo red. Tartrazine adsorption capacities were 2.31 mg/g for the cellulose extracted from wheat residues (WC) and 18.85 mg/g for the modified wheat residue cellulose (MWC) for tartrazine as well as 18.5 mg/g for WC and 19.92 for MWC during Congo red (CR) adsorption, respectively. Increasing the initial and decreasing the adsorbent dose concentration favored the adsorption process. From time effect analysis, it was found that the equilibrium time was reached at 120 min when modified wheat cellulose was used and at 480 min when wheat cellulose was used. The kinetics of adsorption were described by pseudo-second-order in all cases with R2 > 0.95. The obtained data equilibrium from this research was well-fitted by the Freundlich isotherm model.

Site-specific nutrient management: impact on productivity, nutrient uptake and economics of rice-wheat system

A field experiment was conducted on Typic Ustochrept soil at the Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, for two years (2014–15 to 2015–16) to evaluate site specific nutrient management (SSNM) against state recommendation (SR), integration of SSNM and SR with crop residue and farm yard manure. In terms of crop growth yield, nutrient uptake and economics, SSNM had significantly higher growth parameters, viz. number of tillers/m2 and dry matter accumulation as compared to SR in both rice and wheat crops. Different yield attributes, viz. number of grains/panicle or spike, test weight of rice and wheat were also higher with SSNM. SSNM out yielded for rice, wheat and rice-wheat system (RWS) productivity by 10.3%, 14.1% and 11.9%. System N, P and K uptake under SSNM was also higher by 24.36, 9.55 and 36.01 kg/ha, respectively, compared to SR. An additional income of `12953/ha over SR and maximum return/rupee invested (`2.50) was also recorded with SSNM. Recycling of 5 t/ha rice and wheat straw residue along with SSNM had added advantage.

Performance evaluation of AquaCrop model for rice (Oryza sativa) crop in Trans-Gangetic plains

A field experiment was conducted on Typic Ustochrept soil at the Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, for two years (2014–15 to 2015–16) to evaluate site specific nutrient management (SSNM) against state recommendation (SR), integration of SSNM and SR with crop residue and farm yard manure. In terms of crop growth yield, nutrient uptake and economics, SSNM had significantly higher growth parameters, viz. number of tillers/m2 and dry matter accumulation as compared to SR in both rice and wheat crops. Different yield attributes, viz. number of grains/panicle or spike, test weight of rice and wheat were also higher with SSNM. SSNM out yielded for rice, wheat and rice-wheat system (RWS) productivity by 10.3%, 14.1% and 11.9%. System N, P and K uptake under SSNM was also higher by 24.36, 9.55 and 36.01 kg/ha, respectively, compared to SR. An additional income of `12953/ha over SR and maximum return/rupee invested (`2.50) was also recorded with SSNM. Recycling of 5 t/ha rice and wheat straw residue along with SSNM had added advantage.

Cellulose Nanofiber-Based Aerogels from Wheat Straw: Influence of Surface Load and Lignin Content on Their Properties and Dye Removal Capacity.

Water pollution is one of the most serious problems worldwide. Nanocellulose-based aerogels usually show excellent adsorption capacities due to their high aspect ratio, specific surface area and surface charge, making them ideal for water purification. In this work, (ligno)cellulose nanofibers (LCNFs/CNFs) from wheat straw residues were obtained using two types of pre-treatments: mechanical (Mec) and TEMPO-mediated oxidization (TO), to obtain different consistency (0.2, 0.4, 0.6 and 0.8) bioaerogels, and their adsorption capacities as dye removers were further studied. The materials were characterized in terms of density, porosity and mechanical properties. An inversely proportional relationship was observed between the consistencies of the aerogels and their achieved densities. Despite the increase in density, all samples showed porosities above 99%. In terms of mechanical properties, the best results were obtained for the 0.8% consistency LCNF and CNF-Mec aerogels, reaching 67.87 kPa and 64.6 kPa for tensile strength and Young’s modulus, respectively. In contrast, the adsorption capacity of the aerogels was better for TEMPO-oxidized aerogels, reaching removal rates of almost 100% for the CNF-TO5 samples. Furthermore, the residual lignin content in LCNF-Mec aerogels showed a great improvement in the removal capacity, reaching rates higher than 80%, further improving the cost efficiency of the samples due to the reduction in chemical treatments.

Effect of chemical treatment on mechanical properties and water resistance of wheat straw epoxy biocomposites

Biocomposites are becoming popular options for various industrial applications because they are lightweight, renewable, eco-friendly, economical, and sustainable. In this research article, synthetic epoxy resin has been used as a polymer matrix and residual wheat straw has been used as fillers to fabricate a range of biocomposites. The wheat straw fillers were chemically treated to increase adhesion between the fibre surface and the polymer matrix, resulting in improved mechanical properties. Two different loading levels of fillers were taken in the study and they were subjected to either alkali treatment or a combination of silane and alkali treatment. These biocomposites were investigated for water resistance, flexural strength, and flexural modulus. For higher water resistance and flexural qualities, a twofold treatment of wheat straw fillers was found to be more effective than a single treatment.

Lignin-enriched residues from bioethanol production: Chemical characterization, isocyanate functionalization and oil structuring properties

Lignin-enriched waste products from bioethanol production of agriculture residues were tested as structuring agents in castor oil once functionalized with hexamethylene diisocyanate. Cane bagasse, barley and wheat straw were processed through steam explosion, pre-saccharification and simultaneous saccharification and fermentation (PSSF). Alternatively, cane bagasse was submitted to steam explosion and enzymatic hydrolysis (EH). Several Nuclear Magnetic Resonance techniques were used to characterize both residues and NCO-functionalized counterparts. The β-O-4′/resinol/phenylcoumaran content and hydroxyphenyl/guaiacyl/syringyl distribution depend on biomass source, pretreatment, and enzymatic hydrolysis. Total hydroxyl content (from 1.23 for cane bagasse to 1.85 for wheat straw residues), aromatic/aliphatic hydroxyl ratio (0.78 for cane bagasse and 0.61 and 0.49 for barley and wheat straw residues, respectively) and S/G ratio (ranging from 0.25 to 0.86) influence the NCO-functionalization and oleogel rheological response. Oleogels obtained with barley straw residues exhibited the highest values of the storage modulus; around 2 × 105 Pa and 104 Pa for 25% and 20% contents, respectively. PSSF process showed weaker modification, leading to softer viscoelastic response compared to EH. These oleogels exhibited rheological properties similar to lubricating greases of different NLGI grades. Therefore, we herein show an integrative protocol for the valorization of lignin-enriched residues from bioethanol production as potential thickeners of lubricating greases.

Ash transformation during single-pellet gasification of sewage sludge and mixtures with agricultural residues with a focus on phosphorus

The recovery of phosphorus (P) from sewage sludge ashes has been the focus of recent research due to the initiatives for the use of biogenic resources and resource recovery. This study investigates the ash transformation chemistry of P in sewage sludge ash during the co-gasification with the K-Si- and K-rich agricultural residues wheat straw and sunflower husks, respectively, at temperatures relevant for fluidized bed technology, namely 800 °C and 950 °C. The residual ash was analyzed by ICP­AES, SEM/EDS, and XRD, and the results were compared to results of thermochemical equilibrium calculations. More than 90% of P and K in the fuels were retained in the residual ash fraction, and significant interaction phenomena occurred between the P-rich sewage sludge and the K-rich ash fractions. Around 45–65% of P was incorporated in crystalline K-bearing phosphates, i.e., K-whitlockite and CaKPO4, in the residual ashes with 85–90 wt% agricultural residue in the fuel mixture. In residual ashes of sewage sludge and mixtures with 60–70 wt% agricultural residue, P was mainly found in Ca(Mg,Fe)-whitlockites and AlPO4. Up to about 40% of P was in amorphous or unidentified phases. The results show that gasification provides a potential for the formation of K-bearing phosphates similar to combustion processes.

A performance evaluation study of nano-biochar as a potential slow-release nano-fertilizer from wheat straw residue for sustainable agriculture

Agro-Wastes are identified as to manufacture potential valuable organic biochar fertilizer product economically while also managing the waste. Biochar (BC) produced from agriculture waste is helps to improve the soil because of its neutral pH, addition of organic carbon to the soil and lower salt index values. This study focused on the development of nano-biochar into a more enhanced biochar product where it was checked whether the biochar derived from wheat straw can absorb nutrients and then act as support matter for releasing micro-nutrients and macro-nutrients for the plants on slow liberation basis. Wheat biochar (WBC) and wheat nano-biochar (WBNC) were synthesized by pyrolysis at two different temperatures and nutrients were fused into the WBC via impregnation technique. Physical parameters such as Proximate, Ultimate analysis & other were also studied and inspected by standard control procedures. Studies were also carried out on water retention (WR), water absorbance (WA), swelling ratio (SR) and equilibrium water content (EWC) for all samples; data was collected and compared for the better sample. Slow-release studies performed portrayed the release pattern of nutrients for prolonged periods, which are very important for the plant growth, yield and productivity. Overall, the experimental results displayed that BNC produced at 350 °C showed promising features of (SI:0.05, SR: 3.67, WA:64%, EWC:78.6%, FC:53.05% and pH:7.22), is a good substance however the nano-biochar has improved results; environmental friendly & could be utilized as a potential fertilizer on slow release for sustainable and green agriculture application.

Durability of Flame-Retarded, Co-Extruded Profiles Based on High-Density Polyethylene and Wheat Straw Residues.

At present, little information is available in the scientific literature related to the durability (weathering resistance) of fire-retarded wood and natural fiber-reinforced thermoplastics. In this work, thermoplastic profiles for façade applications based on high-density polyethylene, wheat straw particles, and fire-retardants were extruded and their reaction-to-fire performance before and after artificial weathering evaluated. Profile geometries were either solid or hollow-core profiles, and fire-retardants (FR) were added either in the co-extruded layer or in the bulk. Various FR for inclusion in the co-extruded layer were screened based on UL-94 tests. For profile extrusion, two types of FR were chosen: a coated intumescent combination based on ammonium polyphosphate (APP) and an APP coated with melamine and without formaldehyde. Before weathering, the peak heat release rate (pHRR) and the total heat release (THR), which were determined using cone calorimeter measurements, were reduced by up to 64% and 67% due to the FR. However, even before weathering, pHRR of the profiles was relatively high, with best (lowest) values between 230 and 250 kW/m2 under the test conditions. After 28 days of artificial weathering, changes in reaction-to-fire performance and color were evaluated. Use of the APP in the co-extruded layer worsened color change compared to the formulation without APP but the pHRR was not significantly changed. The influence of weathering on the fire behavior was small compared to the difference between fire-retarded and non-fire-retarded materials. Results from the cone calorimeter were analyzed with regard to ETAG 028, which provides requirements related to the durability of fire performance of building products. In many formulations, increase in THR was less than 20% compared to before weathering, which would place some of the profiles in class C or better (EN 13501-1). However, due to the high pHRR, at best, class D was obtained under the conditions of this study. In addition to cone calorimeter measurements, results from the single flame source test, limiting oxygen index determination and thermogravimetric analysis, are shown and discussed. Strength properties, water uptake and swelling of the profiles, thermal conductivity, and energy dispersive X-ray data are also presented.

Structural composition of immobilized fertilizer N associated with decomposed wheat straw residues using advanced nuclear magnetic resonance spectroscopy combined with 13C and 15N labeling

When crop residues are returned to soil, nitrogen (N) from applied chemical fertilizers can be immobilized by microbial growth and incorporated back into the residues themselves to form organic N compounds with poor bioavailability. However, the chemical composition of these compounds has remained poorly understood. Knowledge of the chemical composition of immobilized fertilizer N is crucial for understanding its fate in the field and its associated impacts on fertilizer applications and management. Here, we characterized immobilized fertilizer N by coupling isotopic labeling of wheat straw (13C) and fertilizer N (urea-15N) with two advanced nuclear magnetic resonance (NMR) techniques, (13C{15N} rotational-echo double resonance, REDOR) and two-dimensional (2D) 15N−13C heteronuclear single quantum coherence (HSQC) spectroscopy. We found that the immobilization of N under aerobic conditions was greater than that under anaerobic conditions (52% of fertilizer 15N vs 38% of fertilizer 15N). Under anaerobic conditions, most of the immobilized fertilizer 15N was in the form of protonated amide N. Compared to anaerobic conditions, 15N spectra of aerobic samples showed more diversity amongst N containing functional groups, including peptide-amides (54%), methylated amides (22%), amines (7%), anilides (5%) and heterocyclics (3%). Additionally, from the perspective of its structural composition, 55-80% of the immobilized fertilizer 15N was estimated to be a potentially labile N fraction. Collectively, these results indicate that the immobilization of fertiziler N during aerobic decomposition of straw residues produces organic N functional groups with a strong potential for remineralization available for use by crops when they are released into soil.