Recommendations for Using Crop Straws to Produce Organic Fertilizers in Liaoning Province

This paper introduces in detail the current situation of crop straw resources and comprehensive utilization in Liaoning Province and the basic situation of enterprises using crop straw to produce organic fertilizers.In addition,it analyzes in detail the problems existing in the production of organic fertilizers in Liaoning Province,and finally comes up with some recommendations for using crop straw to produce organic fertilizers.

Steam explosion of crop straws improves the characteristics of biochar as a soil amendment

Five crop straws (wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210℃, 2.5 MPa and then pyrolyzed at 500℃ for 2 h. Steam explosion (SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area (SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity (AEC) (6.88–11.44 cmol kg–1) and point of zero net charges (PZNC) (pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.

Effect of four crop straws on transformation of organic matter during sewage sludge composting

A 45-d laboratory experiment was conducted to compare the effect of four crop straws on the transformations of organic matter （OM） during composting of sewage sludge. The four crop straws included rape straw, wheat straw, maize straw and rice straw. The following parameters such as temperature, OM, humic-like substances （HS）, fulvic-like acids （FA） and humic-like acids （HA） were determined. The degradation of OM and the formation of HS and HA could be described well by the first-order kinetic model, while the FA content fluctuated during composting. The maximal degradation rates of OM in the compost piles added with rape straw, wheat straw, maize straw and rice straw were 34.7, 46.9, 54.7 and 52.8%, respectively, and the final contents of HS were 118, 128, 141 and 134 g kg-1, respectively, while the humification indices were higher in the compost piles added with maize straw and wheat straw than in those with rice straw and rape straw. The results indicate that a higher hemicellulose content and a lower C/N ratio in crop straw can result in a higher rate of OM degradation and higher contents of HS, while a higher content of lignin can lead to a higher polymerization degree of humic substances in compost piles. The final compost piles added with maize straw has the highest contents of OM, total nitrogen and humus substance as well as the highest values of polymerization degree, while compost piles with rape straw have the highest potassium content and those with rice straw have the highest pH values.

Decomposition of different crop straws and variation in straw-associated microbial communities in a peach orchard,China

Crop residue is a major source of soil organic matter;therefore,application of crop straw to soil contributes to the sustainable development of organic agriculture.To better understand the transformation of crop straw in orchard soils,we investigated the relationship between the characteristics of straw decomposition and functional diversity of associated microbial communities in a long-term peach orchard,China.Mesh bags,each containing 30 g of corn or bean straw,were buried at a soil depth of 20 cm in a 12-year-old peach orchard for 360 d(October 2011–October 2012).Three treatments were applied,i.e.,fresh corn straw,fresh corn straw with nitrogen fertilizer(urea,10.34 g/kg),and fresh bean straw.Changes in straw residual rate,straw water content and soil conditions were monitored after treatment.The functional diversity of straw-associated microbial communities was analyzed by the Biolog-Eco microplate assay.During the decomposition process,straw residual rates did not vary considerably from 10 d(30.4%–45.4%)to 360 d(19.0%–30.3%).Irrespective of nitrogen addition,corn straw decomposed faster than bean straw.Corn straw with nitrogen fertilizer yielded the highest average well color development(AWCD)values(1.11–1.67),followed by corn straw(1.14–1.68)and bean straw(1.18–1.62).Although the AWCD values did not differ significantly among the three treatments,substantial differences occurred across various time periods of the decomposition process(P<0.01).In terms of carbon source utilization,the dominant microbial groups fed mainly on saccharides.Hard-to-decompose substances gradually accumulated in the middle and late stages of straw decomposition.Of the six categories of carbon sources tested,the utilization rate of aromatics was the lowest with corn straw,whereas that of polymers was the lowest with bean straw.Among different treatments,straw residual rate was negatively correlated to soil available phosphorous,soil available potassium and soil temperature(P<0.05),but not to soil water content.In some cases(corn straw with or without nitrogen fertilizer),straw residual rate was negatively correlated to straw water content,amino acid utilization and carboxylic acid utilization,and positively correlated with microbial species richness and evenness(P<0.05).Microbial community associated with corn and bean straw decomposition in soil was respectively dominated by aromatic-and polymer-metabolizing groups during the middle and late stages of this process,which could reduce the stability of microbial community structure and decrease the rate of straw decomposition in the fruit tree orchard.

Research State of Disposable Nonplastic Straws

The continuous production of disposable plastic straw places a high demand on global petrochemical resources and a significant environmental burden.Biodegradable and eco-friendly straws have therefore been studied and produced worldwide.This article briefly introduces the characteristics of paper straws and polylactic acid(PLA)straws,and focuses on edible straws made using,e.g.,hydrophilic colloids,zein,and starch.Raw-material selection,preparation methods,advantages,and defects of straws are summarized,to provide a reference for the development and research of eco-friendly straws.

An efficient method for the sanitary vitrification of bovine oocytes in straws

Background：At present,vitrification has been widely applied to humans,mice and farm animals.To improve the efficiency of vitrification in straw,bovine oocytes were used to test a new two-step vitrification method in this study.Results：When in vitro matured oocytes were exposed to 20%ethylene glycol（EG20） for 5 min and 40%ethylene glycol（EG40） for 30 s,followed by treatment with 30%glycerol（Gly30）,Gly40 or Gly50,a volume expansion was observed in Gly30 and Gly40 but not Gly50.This indicates that the intracellular osmotic pressure after a 30 s differs between EG40 and ranged between Gly40（approximately 5.6 mol/L） and Gly50（approximately 7.0 mol/L）.Since oocytes are in EG40 just for only a short period of time（30 s） and at a lower temperature（4℃）,we hypothesize that the main function of this step in to induce dehydration.Based on these results,we omitted the EG40 step,before oocytes were pretreated in EG20 for 5 min,exposed to pre-cooled（4℃） Gly50,for 30 s,and then dipped into liquid nitrogen.After warming,81.1%of the oocytes survived,and the surviving oocytes developed into cleavage stage embryos（63.5%） or blastocysts（20.0%） after parthenogenetic activation.Conclusions：These results demonstrate that in a two-step vitrification procedure,the permeability effect in the second step is not necessary.It is possible that the second step is only required to provide adequate osmotic pressure to condense the intracellular concentration of CPAs to a level required for successful vitrification.

Straw return increases crop production by improving soil organic carbon sequestration and soil aggregation in a long-term wheat-cotton cropping system

Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cotton(Gossypium hirsutum L.)cropping system remains uncertain.The objective of this study was to quantify the long-term(10 years)impact of carbon(C)input on SOC sequestration,soil aggregation and crop yields in a wheat-cotton cropping system in the Yangtze River Valley,China.Five treatments were arranged with a single-factor randomized design as follows:no straw return(Control),return of wheat straw only(Wt),return of cotton straw only(Ct),return of 50%wheat and 50%cotton straw(Wh-Ch)and return of 100%wheat and 100%cotton straw(Wt-Ct).In comparison to the Control,the SOC content increased by 8.4 to 20.2%under straw return.A significant linear positive correlation between SOC sequestration and C input(1.42-7.19 Mg ha^(−1)yr^(−1))(P<0.05)was detected.The percentages of aggregates of sizes>2 and 1-2 mm at the 0-20 cm soil depth were also significantly elevated under straw return,with the greatest increase of the aggregate stability in the Wt-Ct treatment(28.1%).The average wheat yields increased by 12.4-36.0%and cotton yields increased by 29.4-73.7%,and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.The average sustainable yield index(SYI)reached a maximum value of 0.69 when the C input was 7.08 Mg ha^(−1)yr^(−1),which was close to the maximum value(SYI of 0.69,C input of 7.19 Mg ha^(−1)yr^(-1))in the Wt-Ct treatment.Overall,the return of both wheat and cotton straw was the best strategy for improving SOC sequestration,soil aggregation,yields and their sustainability in the wheat-cotton rotation system.

Dynamic changes of rumen microbiota and serum metabolome revealed increases in meat quality and growth performances of sheep fed bio‑fermented rice straw

Background Providing high-quality roughage is crucial for improvement of ruminant production because it is an essential component of their feed.Our previous study showed that feeding bio-fermented rice straw(BF)improved the feed intake and weight gain of sheep.However,it remains unclear why feeding BF to sheep increased their feed intake and weight gain.Therefore,the purposes of this research were to investigate how the rumen micro-biota and serum metabolome are dynamically changing after feeding BF,as well as how their changes influence the feed intake,digestibility,nutrient transport,meat quality and growth performances of sheep.Twelve growing Hu sheep were allocated into 3 groups:alfalfa hay fed group(AH:positive control),rice straw fed group(RS:negative control)and BF fed group(BF:treatment).Samples of rumen content,blood,rumen epithelium,muscle,feed offered and refusals were collected for the subsequent analysis.Results Feeding BF changed the microbial community and rumen fermentation,particularly increasing(P<0.05)relative abundance of Prevotella and propionate production,and decreasing(P<0.05)enteric methane yield.The histomorphology(height,width,area and thickness)of rumen papillae and gene expression for carbohydrate trans-port(MCT1),tight junction(claudin-1,claudin-4),and cell proliferation(CDK4,Cyclin A2,Cyclin E1)were improved(P<0.05)in sheep fed BF.Additionally,serum metabolome was also dynamically changed,which led to up-regulating(P<0.05)the primary bile acid biosynthesis and biosynthesis of unsaturated fatty acid in sheep fed BF.As a result,the higher(P<0.05)feed intake,digestibility,growth rate,feed efficiency,meat quality and mono-unsaturated fatty acid concentration in muscle,and the lower(P<0.05)feed cost per kg of live weight were achieved by feeding BF.Conclusions Feeding BF improved the growth performances and meat quality of sheep and reduced their feed cost.Therefore,bio-fermentation of rice straw could be an innovative way for improving ruminant production with mini-mizing production costs.

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

Water is the key factor limiting dryland wheat grain yield.Mulching affects crop yield and yield components by affecting soil moisture.Further research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance analysis.The results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,respectively.The average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) treatment.There were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically signifiant.Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,respectively.The relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in CK.In terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three treatments.Based on the three analysis methods,we found that spike number and ET were positively correlated with grain yield.However,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in CK.Suifcient SWSSF could indirectly increase spike number and ET in the three treatments.Based on these results,mulch can improve yield and soil water storage.The most important factor affecting the grain yield of dryland wheat was spike number under mulching,and ET with CK.These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK.

A combination of straw incorporation and polymer-coated urea offsets soil ammonia and nitrous oxide emissions in winter wheat fields

The combined effects of straw incorporation(SI)and polymer-coated urea(PCU)application on soil ammonia(NH_(3))and nitrous oxide(N_(2)O)emissions from agricultural fields have not been comprehensively evaluated in Northwest China.We conducted a two-year field experiment to assess the effects of combining SI with either uncoated urea(U)or PCU on soil NH_(3)emissions,N_(2)O emissions,winter wheat yields,yield-scaled NH_(3)(/NH_(3)),and yield-scaled N_(2)O(/N_(2)O).Five treatments were investigated,no nitrogen(N)fertilizer(N_(0)),U application at 150 kg N ha-1 with and without SI(SI+U and S_(0)+U),and PCU application at 150 kg N ha^(-1) with and without SI(SI+PCU and S_(0)+PCU).The results showed that the NH_(3);emissions increased by 20.98-34.35%following Sl compared to straw removal,mainly due to increases in soil ammonium(NH_(4)^(+)-N)content and water-flled pore space(WFPS).SI resulted in higher N_(2)O emissions than under the So scenario by 13.31-49.23%due to increases in soil inorganic N(SIN)contents,WFPS,and soil microbial biomass.In contrast,the PCU application reduced the SIN contents compared to the U application,reducing the NH_(3)and N_(2)O emissions by 45.99-58.07 and 18.08-53.04%,respectively.Moreover,no significant positive effects of the SI or PCU applications on the winter wheat yield were observed.The lowest /NH_(3) and /N_(2)O values were observed under the S_(0)+PCU and SI+PCU treatments.Our results suggest that single PCU applications and their combination with straw are the optimal agricultural strategies for mitigating gaseous N emissions and maintaining optimal winter wheat yields in Northwest China.

Common Organic Amendment (Rice Straw) Can Reduce Salinity Effects on Bean (Phaseolus vulgaris) Growth with or without Photoperiod Manipulation

Soil salinity is a major limiting factor for crop production in coastal areas of Bangladesh. Cheap and sustainable management of soil salinity is hence most sought out topics in agricultural research. Conceptualizing that idea in mind, a pot experiment was conducted in the Department of Soil, Water & Environment, University of Dhaka in order to analyze if common organic amendments (rice straw, saw dust) coupled with reduce photoperiod can mitigate salinity effect on the growth of bean (Phaseolus vulgaris). The experiment was set up following completely randomized design (CRD) with nine treatments and three replications containing Tc (Control), T1 (Ambient photoperiod + 110 mM Salinity treatment + Rice straw), T2 (Reduced photoperiod + 110 mM Salinity treatment + Rice straw), T3 (Ambient photoperiod + 220 mM Salinity treatment + Rice straw), T4 (Reduced photoperiod + 220 mM Salinity treatment + Rice straw), T5 (Ambient photoperiod + 110 mM Salinity treatment + Saw dust), T6 (Reduced photoperiod + 110 mM Salinity treatment + Saw dust), T7 (Ambient photoperiod + 220 mM Salinity treatment + Saw dust) and T8 (Reduced photoperiod + 220 mM Salinity treatment + Saw dust). Organic amendments were used separately at the rate of 12 ton/ha. The highest plant height (98.67 cm), root length (12.5 cm), pod number (10.33), leaf area (13.99 cm2), fresh weight (680 kg/ha), dry weight (316.67 kg/ha) were recorded with the treatment T1 while the second-best treatment was treatment T2 (with highest harvest index 0.040) and these results were statistically significant (p < 0.001). In post-harvest soil, pH, EC, OC, OM;available N, P, K, S;total Ca, Mg, Zn, Mn were increased significantly in treatment T1. The overall results illustrated that the best growth and yield performances were achieved in the treatment T1 and T2.

The Advantages of Methane Production by Combined Fermentation of Lignite and Wheat Straw

Biogasification of coal is important for clean utilization of coal. Experiments on the fermentation of single lignite, single straw and their mixture were performed to explore the variation characteristics of gas production potential, microbial community and methanogenic metabolic pathways of mixture. Research has shown that mixed fermentation of lignite and straw significantly promoted biomethane production. The abundance of hydrolytic acidifying functional bacteria genera (Sphaerochaeta, Lentimicrobium) in mixed fermentation was higher than that in the fermentation of single lignite and single straw. The abundance of some key CAZy metabolic enzyme gene sequences in mixed fermentation group was increased, which was favorable to improve methane production. Aceticlastic methanogenesis was the most critical methanogenic pathway and acetic acid pathway was more competitive in methanogenic mode during peak fermentation. Macrogenomics provided theoretical support for the claim that mixed fermentation of coal and straw promoted biomethane metabolism, which was potentially valuable in expanding methanogenesis from mixed fermentation of lignite with different biomasses.

喝些奶饮品!

Are you thirsty?What do you drink?Some people drink milk often.Others never drink it.But it is good for you.It has calcium in it.Calcium makes your bones and your teeth strong.Plain milk is fine for some people.Others like chocolate milk,strawberry milk or banana milk.What kind of milk do you like?

Forensic examination of plastic drinking straws based on their physical characteristics and manufacturing marks

This work highlights the evidential value of examining plastic drinking straws to establish linkages between multiple sources for forensic intelligence,investigative or prosecution pur-poses.Plastic drinking straws are commonly encountered in drug cases,either as inhalational paraphernalia or as packaging material.However,to the best of our knowledge,systematic studies on the evidential value of straws have not previously been carried out.In this study,over 80 packets of clear and colourless straws—most of which were visually similar—were purchased from various commercial outlets in Singapore.Some physical characteristics(viz.,polarizing patterns,thickness,circumference and mass per unit length)and the manufactur-ing marks of these straws were examined to assess their potentials for discriminating straws from different packets.Comparison of polarizing patterns yielded a discrimination of approximately 69%,while thickness,circumference,and mass per unit length measurements resulted in lower discriminations.Comparison microscopy of manufacturing marks was found to be the most discriminating among all techniques employed herein,with a discrimination of about 95%,even among straws with similar polarizing patterns.

Evaluation of different clean heat supply modes based on crop straws in the rural area of Northern China

This study evaluated eight different types of heat supply modes based on crop residues utilization in the rural area of Northern China,including straw densified solid fuel combustion,pyrolysis char combustion,biogas combustion,and pyrolysis gas combustion for single household heating;straw densified solid fuel combustion,baling straw combustion,biogas combustion,and pyrolysis gas combustion for centralized heating;centralized gas supply and centralized pyrolysis gas supply modes.Comprehensively evaluation was the cost of these different eight heat supply modes.The results showed that the cost of straw densified solid fuel combustion,pyrolysis char combustion for single household heating were 2346 RMB/household and 2390 RMB/household.With the heating scale of 200-500 households,the pipe network distance was 8 m/household,and the total annual heating cost was predicted at 2201-2992 RMB/household.Among them,the cost of straw baling combustion for centralized heating was the lowest,the cost of densified solid fuel,biogas,and pyrolysis for centralized heating was the second,and the cost of biogas and pyrolysis gas for centralized gas supply was the highest.For the increase in every 1 m of the pipeline distance,the investment cost will increase by about 645 RMB for each household.This study provides a basis for the implementation of clean heat supply technologies in less-developed areas and guidance of village heat-supply subsidy policies.

The telomere-to-telomere genome of Fragaria vesca reveals the genomic evolution of Fragaria and the origin of cultivated octoploid strawberry

Fragaria vesca,commonly known as wild or woodland strawberry,is the most widely distributed diploid Fragaria species and is native to Europe and Asia.Because of its small plant size,low heterozygosity,and relative ease of genetic transformation,F.vesca has been a model plant for fruit research since the publication of its Illumina-based genome in 2011.However,its genomic contribution to octoploid cultivated strawberry remains a long-standing question.Here,we de novo assembled and annotated a telomere-to-telomere,gap-free genome of F.vesca‘Hawaii 4’,with all seven chromosomes assembled into single contigs,providing the highest completeness and assembly quality to date.The gap-free genome is 220785082 bp in length and encodes 36173 protein-coding gene models,including 1153 newly annotated genes.All 14 telomeres and seven centromeres were annotated within the seven chromosomes.Among the three previously recognized wild diploid strawberry ancestors,F.vesca,F.iinumae,and F.viridis,phylogenomic analysis showed that F.vesca and F.viridis are the ancestors of the cultivated octoploid strawberry F.×ananassa,and F.vesca is its closest relative.Three subgenomes of F.×ananassa belong to the F.vesca group,and one is sister to F.viridis.We anticipate that this high-quality,telomere-to-telomere,gap-free F.vesca genome,combined with our phylogenomic inference of the origin of cultivated strawberry,will provide insight into the genomic evolution of Fragaria and facilitate strawberry genetics and molecular breeding.

High-quality haplotype-resolved genome assembly of cultivated octoploid strawberry

Cultivated strawberry(Fragaria×ananassa),a perennial herb belonging to the family Rosaceae,is a complex octoploid with high heterozygosity at most loci.However,there is no research on the haplotype of the octoploid strawberry genome.Here we aimed to obtain a high-quality genome of the cultivated strawberry cultivar,“Yanli”,using single molecule real-time sequencing and high-throughput chromosome conformation capture technology.The“Yanli”genome was 823 Mb in size,with a long terminal repeat assembly index of 14.99.The genome was phased into two haplotypes,Hap1(825 Mb with contig N50 of 26.70 Mb)and Hap2(808 Mb with contig N50 of 27.51 Mb).Using the combination of Hap1 and Hap2,we obtained for the first time a haplotype-resolved genome with 56 chromosomes for the cultivated octoploid strawberry.We identified a∼10 Mb inversion and translocation on chromosome 2-1.104957 and 102356 protein-coding genes were annotated in Hap1 and Hap2,respectively.Analysis of the genes related to the anthocyanin biosynthesis pathway revealed the structural diversity and complexity in the expression of the alleles in the octoploid F.×ananassa genome.In summary,we obtained a high-quality haplotype-resolved genome assembly of F.×ananassa,which will provide the foundation for investigating gene function and evolution of the genome of cultivated octoploid strawberry.

Inversion tillage with straw incorporation affects the patterns of soil microbial co-occurrence and multi-nutrient cycling in a Hapli-Udic Cambisol

Inversion tillage with straw amendment is widely applied in northeastern China, and it can substantially increase the storage of carbon and improve multiple subsoil functions. Soil microorganisms are believed to be the key to this process,but research into their role in subsoil amelioration is limited. Therefore, a field experiment was conducted in 2018 in a region in northeastern China with Hapli-Udic Cambisol using four treatments: conventional tillage(CT, tillage to a depth of 15 cm with no straw incorporation), straw incorporation with conventional tillage(SCT, tillage to a depth of 15 cm),inversion tillage(IT, tillage to a depth of 35 cm) and straw incorporation with inversion tillage(SIT, tillage to a depth of 35 cm). The soils were managed by inversion to a depth of 15 or 35 cm every year after harvest. The results indicated that SIT improved soil multi-nutrient cycling variables and increased the availability of key nutrients such as soil organic carbon, total nitrogen, available nitrogen, available phosphorus and available potassium in both the topsoil and subsoil.In contrast to CT and SCT, SIT created a looser microbial network structure but with highly centralized clusters by reducing the topological properties of average connectivity and node number, and by increasing the average path length and the modularity. A Random Forest analysis found that the average path length and the clustering coefficient were the main determinants of soil multi-nutrient cycling. These findings suggested that SIT can be an effective option for improving soil multi-nutrient cycling and the structure of microbial networks, and they provide crucial information about the microbial strategies that drive the decomposition of straw in Hapli-Udic Cambisol.

Research and Application Progress of Straw

Straw is a general term for the stem and leaf parts of mature crops,and is a multi-purpose renewable biomass energy resource in the agricultural ecosystem.The prospect of comprehensive utilization of straw has become broad with the development of agricultural production,the advancement of science and technology,and the improvement of the level of agricultural mechanization.The comprehensive utilization of straw plays an important role in enhancing the sustainable development ability of agricultural economy and improving the current situation of comprehensive utilization of agricultural resources in my country.This paper briefly combs the development history of straw and the prospect and current situation of comprehensive utilization,and expounds the separation technology of straw components,straw man-made panels,straw concrete,straw returning technology and oyster mushroom cultivation.It focuses on the description of the component separation technology of straw and the manufacturing process of straw-based panels.The different separation methods and separation effects of cellulose,hemicellulose and lignin were introduced in detail,and the static yield strength(MOR),internal bonding strength(IB)and water absorption thickness of several common straw-based panels were compared and studied(TS).Finally,it summarizes the benefit analysis of the comprehensive utilization of straw by scholars from the perspective of economics,and summarizes the corresponding measures based on their own views.

Preparation of activated carbon from sunflower straw through H_(3)PO_(4) activation and its application for acid fuchsin dye adsorption

With the development circular economy, the use of agricultural waste to prepare biomass materials to remove pollutants has become a research hotspot. In this study, sunflower straw activated carbon (SSAC) was prepared by the one-step activation method, with sunflower straw (SS) used as the raw material and H3PO4 used as the activator. Four types of SSAC were prepared with impregnation ratios (weight of SS to weight of H3PO4) of 1:1, 1:2, 1:3, and 1:5, corresponding to SSAC1, SSAC2, SSAC3, and SSAC4, respectively. The adsorption process of acid fuchsin (AF) in water using the four types of SSAC was studied. The results showed that the impregnation ratio significantly affected the structure of the materials. The increase in the impregnation ratio increased the specific surface area and pore volume of SSAC and improved the adsorption capacity of AF. However, an impregnation ratio that was too large led to a decrease in specific surface area. SSAC3, with an impregnation ratio of 1:3, had the largest specific surface area (1 794.01 m2/g), and SSAC4, with an impregnation ratio of 1:5, exhibited the smallest microporosity (0.052 7 cm3/g) and the largest pore volume (2.549 cm3/g). The adsorption kinetics of AF using the four types of SSAC agreed with the quasi-second-order adsorption kinetic model. The Langmuir isotherm model was suitable to describe SSAC3 and SSAC4, and the Freundlich isotherm model was appropriate to describe SSAC1 and SSAC2. The result of thermodynamics showed that the adsorption process was spontaneous and endothermic. At 303 K, SSAC4 showed a removal rate of 97.73% for 200-mg/L AF with a maximum adsorption capacity of 2 763.36 mg/g, the highest among the four types of SSAC. This study showed that SAAC prepared by the H3PO4-based one-step activation method is a green and efficient carbon material and has significant application potential for the treatment of dye-containing wastewater.