Effects of residues produced by agricultural wastes fermentation(AWF)on low grade copper sulfide ores bioleaching,copper recovery,and microbial community were investigated.The results indicated that adding appropriate...Effects of residues produced by agricultural wastes fermentation(AWF)on low grade copper sulfide ores bioleaching,copper recovery,and microbial community were investigated.The results indicated that adding appropriate bulk of AWF made contributions to low grade copper sulfide ores bioleaching,which may be mainly realized through reducing the passivation layer formed by Fe3+hydrolysis.Improved copper recovery(78.35%)and bacteria concentration(9.56×10^(7)cells·mL^(−1))were yielded in the presence of 5 g·L^(−1)AWF.The result of 16S rDNA analysis demonstrated that microbial community was differentiated by adding AWF.Bacteria proportion,such as Acidithiobacillus ferrooxidans,Moraxella osloensis,and Lactobacillus acetotolerans changed distinctly.Great difference between samples was showed according to beta diversity index,and the maximum value reached 0.375.Acidithiobacillus ferrooxidans accounted for the highest proportion throughout the bioleaching process,and that of sample in the presence of 5 g·L^(−) AWF reached 28.63%.The results should show reference to application of agricultural wastes and low grade copper sulfide ores.展开更多
Agricultural waste straw is the renewable resource with the highest annual yield in the world.In value-added applications of agricultural waste,dicarboxyl cellulose nanocrystals(DCCs)are prepared from rice,wheat,and c...Agricultural waste straw is the renewable resource with the highest annual yield in the world.In value-added applications of agricultural waste,dicarboxyl cellulose nanocrystals(DCCs)are prepared from rice,wheat,and corn straw by sequential periodate-chlorite oxidation.In this study,DCCs from rice,wheat,and corn straw were characterized by transmission electron microscopy(TEM),Fourier transform infrared spectrometer,X-ray diffractometer(XRD),and thermal gravimetric analysis(TGA).The carboxyl content of the DCCs was also investigated.XRD results show that the crystallinity index decreased after sequential periodate-chlorite oxidation;however,the cellulose I structure was maintained.TEM results show that rod-shaped DCCs with an average length and width of 287.0 nm and 9.9 nm,respectively,were successfully prepared by sequential periodate-chlorite oxidation.The carboxyl content of the DCCs was around 3.9 mmol/g,and not affected by the type of straw.Experiments to study the removal of copper ions in aqueous medium were performed with the prepared DCCs.The adsorption capacities of copper ions were 131,162,and 144 mg/g for DCCs prepared from rice,wheat,and corn straws,respectively.The results show that DCCs prepared from rice,wheat,and corn straws by sequential periodatechlorite oxidation have potential for the removal of copper ions from aqueous medium.展开更多
Hydrogen production from food waste,cattle manure,potato pulp and pig manure was optimized through using mixture design in this study.The synergic and antagonistic effects of the four substrates on hydrogen yield,subs...Hydrogen production from food waste,cattle manure,potato pulp and pig manure was optimized through using mixture design in this study.The synergic and antagonistic effects of the four substrates on hydrogen yield,substrate conversion efficiency and pH were evaluated.The results showed that the optimal proportion of food waste,cattle manure,potato pulp and pig manure were 61.6%,38.4%,0,and 0,respectively.Under the optimal condition,hydrogen yield of 21.0 mL/g VS with VS reduction of 29.4%and pH of 5 could be obtained.The interaction between food waste and cattle manure had strongest synergistic effects.Hydrogen was mainly produced by acetic-butyric metabolic pathway,and ammonification of protein played an important role in the maintenance of pH.展开更多
Lignocellulosic biomass can be circulated to produce many materials and products,including biochar.This study analyzed five different types of biochar produced from agricultural wastes and wood residues.The raw materi...Lignocellulosic biomass can be circulated to produce many materials and products,including biochar.This study analyzed five different types of biochar produced from agricultural wastes and wood residues.The raw materials included three agricultural by-products:corncob,cassava rhizome,rice husk,and two types of wood residues:rain tree(Samanea saman(Jacq.)Merr.)and krachid(Streblus ilicifolius(Vidal)Corner.).The biochar were made in patented retorts with locally-appropriated technology at a temper-ature range of 450e500C.This research focuses on the primary physicochemical properties and biochar components,allowing biochar to become a vital material to support sustainable agriculture and the environment.Biochar properties used for agriculture consist of specific surface area,total pore volume,average pore diameter,pH,electrical conductivity(EC),and cation exchange capacity(CEC).The prop-erties that benefit the environmental purposes are the element:carbon(C),hydrogen(H),nitrogen(N),oxygen(O),and the molar ratio of H/C,O/C,and C/N.The study found that all five types of biochar contained suitable properties for soil amendment and carbon sequestration.However,significant dif-ferences were shown in specific surface area,average pore diameter,pH,CEC,and EC of various biochar.Based on O/C and H/C ratios,all five types of biochar persisted in soil from 100 to over 1,000 years.展开更多
Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to...Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one another展开更多
In China, the heating energy consumption patterns of rural housing are changing due to economic development. This study investigated domestic heating in rural areas of Dalian, a city in northeast China. In rural areas...In China, the heating energy consumption patterns of rural housing are changing due to economic development. This study investigated domestic heating in rural areas of Dalian, a city in northeast China. In rural areas of the country, heating devices such as coal boiler, radiator, and/ or air-conditioner are typically used. The Kang, as the main heating system, has been used together with other heating methods for a long time in detached houses, one-story buildings, and quadrangles. Use of the Kang in collective housing is no longer observed. In addition to coal, agricultural wastes have been used to fuel the Kang; the associated CO2 emissions with agricultural fuels are lower than from other heating equipment. Even when a combination of the Kang and other equipment is used, with agricultural waste as fuel, CO2 emissions remain relatively low.展开更多
Owing to its subtropical or tropical environment and climate,South China is home to unique agricultural crops such as sugar cane,pineapple,banana,cassava,and rice,which generate a large amount of lignocellulosic agric...Owing to its subtropical or tropical environment and climate,South China is home to unique agricultural crops such as sugar cane,pineapple,banana,cassava,and rice,which generate a large amount of lignocellulosic agricultural wastes during agricultural as well as associated industrial processing.The efficient utilization of these wastes will have a significant impact on the economy and sustainable development of South China.This paper reviews the research investigations conducted both in China and elsewhere on the conversion of wastes from these subtropical or tropical agricultural crops into useful chemicals,energy,and biomaterials.The goal of this paper is to promote and summarize the extensive investigations on these agricultural wastes for the development of biorefinery.展开更多
Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out...Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out to study the adsorption kinetics mechanism of Cr(Ⅵ) effect of adsorbent dosage, pH, contact time, and temperature. The best results are obtained at 15g/L adsorbent concentration, 60min contact time, 298K temperature, and 50mg/L adsorbate initial concentration at pH 2. The adsorption isotherms, using initial concentrations of Cr(Ⅵ) between 10 and 500mg/L for the Cr(Ⅵ) removal, show the maximum metal uptake capacities of adsorbent were 10.48, 6.71, and 8.54mg/g for WS, RH, and PH, respectively. And the adsorption data fitted well to the Langmuir adsorption isotherm for WS, RH, and PH with correlation coefficients of 0.9862, 0.9723, and 0.9714, respectively. Moreover, the FTIR analysis of WS, RH, and PH before and after adsorption of Cr(Ⅵ) suggested that Cr ions were combined to some functional groups of compounds contained in these materials.展开更多
With the increase of global proportion of soil pollution and the number of areas at risk,researchers have sought to develop various pathways to repair or relieve the pollutants in soil.Among them,biochar represents on...With the increase of global proportion of soil pollution and the number of areas at risk,researchers have sought to develop various pathways to repair or relieve the pollutants in soil.Among them,biochar represents one multi-dimensional soil amendment which has got great deal of attention on its physicochemical properties towards the removal or mitigation of contaminants in soil.A variety of agricultural wastes like straw and manure prepared from different torrefaction process have been employed as feedstock for the production of biochar,which can be applied to the contaminated soil to facilitate the growing environment for crops,and to improve soil fertility and microbial environment.In addition,the utilization of biochar for soil remediation is also considered as a pro-cess of carbon sequestration.The purpose of this review is to summarize the latest research progress in torrefac-tion processes and mechanism of agricultural waste,the effects of different torrefaction methods on the formation and properties of biochar were explained,coupled with the effects of process parameters.Especially,the conver-sion and mechanisms of biochar prepared from agricultural wastes composed mainly with lignocellulosic material were discussed,and the characteristics of biochar prepared for improving soil physical and chemical character-istics,microbial community characteristics,nutrients,and the stability and relief of soil pollutants,especially heavy metals,are compared.Finally,this work discussed the application and future technical challenges of soil remediation based on agricultural waste derived biochar.展开更多
Energy utilization is high-value use pattern of agricultural waste, and is main development direction of agricultural biomass energy industry in China. Planting and breeding industry in Hubei Province occupies importa...Energy utilization is high-value use pattern of agricultural waste, and is main development direction of agricultural biomass energy industry in China. Planting and breeding industry in Hubei Province occupies important position in whole country. Agricultural waste resources are rich, and it has huge potential for developing agriculturel biomass energy. By statistical data during 2000 -2011, we analyzed current situation and problem for energy utilization of agricultural waste in Hubei Province, and put forward several countermeasures and suggestions, vigorously promoting energy utilization of agricultural waste.展开更多
Biomethane potential production from cashew nut hulls, an agricultural waste, was carried out using old and fresh hulls as substrates. Samples were taken from old hulls (around 8 years old) and fresh hulls produced in...Biomethane potential production from cashew nut hulls, an agricultural waste, was carried out using old and fresh hulls as substrates. Samples were taken from old hulls (around 8 years old) and fresh hulls produced in cashew scale transformation units at Bobo Dioulasso/Burkina Faso. Physicochemical parameters showed that cashew hulls can be </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">good candidate for anaerobic digestion. But high acidity, total phenols and lignin tenor could be a constraint for anaerobic bacteria. Theoretical biochemical methane potential showed high value of 666</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">937 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 526</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">206 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> for crushed fresh and powdered old hulls, respectively. Experimental biochemical methane potential showed significantly low potential of</span> <span style="font-family:Verdana;">1.982 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 46.840 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> for </span><span style="font-family:Verdana;">fresh </span><span style="font-family:Verdana;">and hold hulls</span><span style="font-family:Verdana;">, respectively</span><span style="font-family:Verdana;">. Pretreatment for optimization, chemical composition and co-digestion system must be expected for a better anaerobic digestion performance.展开更多
This article returns to the topic of sustainability. West Texas, mainly known for its cotton and cattle production, is facing problems related to the dispensation of agricultural waste produced by these operations. Th...This article returns to the topic of sustainability. West Texas, mainly known for its cotton and cattle production, is facing problems related to the dispensation of agricultural waste produced by these operations. The article looks at the ways of handling agricultural waste and the opportunities of dispensing it in West Texas. Since between 30 - 40 percent of food produced in the US is not consumed, reduction of food waste is another sustainability problem that, when solved, would lead to the reduction of agricultural production and, in turn, the reduction of agricultural waste. Waste reduction management practices of large food chain stores in West Texas are discussed, with a final goal of bringing waste to a zero level. Public sources of sustainable agricultural and non-agricultural waste handling are also mentioned. This research adds to the previous knowledge on sustainability by discussing agricultural waste practices of a specific local area, i.e. West Texas.展开更多
A calculation model of stress field in laser additive manufacturing of walnut shell composite powder(walnut shell/Co-PES powder)was established.The DFLUX subroutine was used to implement the moveable application of a ...A calculation model of stress field in laser additive manufacturing of walnut shell composite powder(walnut shell/Co-PES powder)was established.The DFLUX subroutine was used to implement the moveable application of a double ellipsoid heat source by considering the mechanical properties varying with temperature.The stress field was simulated by the sequential coupling method,and the experimental results were in good accordance with the simulation results.In addition,the distribution and variation of stress and strain field were obtained in the process of laser additive manufacturing of walnut shell composite powder.The displacement of laser additive manufacturing walnut shell composite parts gradually decreased with increasing preheating temperature,decreasing laser power and increasing scanning speed.During the cooling process,the displacement of laser additive manufacturing of walnut shell composite parts gradually increased with the increasing preheating temperature,decreasing scanning speed and increasing laser power.展开更多
Agricultural plastics play a pivotal role in agricultural production.However,due to expensive costs,agricultural plastic waste management(APWM)encounters a vast funding gap.As one of the crucial stakeholders,the publi...Agricultural plastics play a pivotal role in agricultural production.However,due to expensive costs,agricultural plastic waste management(APWM)encounters a vast funding gap.As one of the crucial stakeholders,the public deserves to make appropriate efforts for APWM.Accordingly,identifying whether the public is willing to pay for APWM and clarifying the decisions’driving pathways to explore initiatives for promoting their payment intentions are essential to address the dilemma confronting APWM.To this end,by applying the extended theory of planned behavior(TPB),the study conducted an empirical analysis based on 1,288 residents from four provinces(autonomous regions)of northern China.Results illustrate that:1)respondents hold generally positive and relatively strong payment willingness towards APWM;2)respondents’attitude(AT),subjective norm(SN),and perceived behavioral control(PBC)are positively correlated with their payment intentions(INT);3)environmental cognition(EC)and environmental emotion(EE)positively moderate the relationships between AT and INT,and between SN and INT,posing significant indirect impacts on INT.The study’s implications extend to informing government policies,suggesting that multi-entity cooperation,specifically public payment for APWM,can enhance agricultural non-point waste management.展开更多
This article presents a study on the resistance to chloride penetration, corrosion, porosity, and strength of mortar containing fine fly ash (FA), ground rice husk-bark ash (RB), and ground bagasse ash (BA). Ord...This article presents a study on the resistance to chloride penetration, corrosion, porosity, and strength of mortar containing fine fly ash (FA), ground rice husk-bark ash (RB), and ground bagasse ash (BA). Ordinary Portland cement (CT) was blended with a single pozzolan and two pozzolans. Strength, porosity, rapid chloride penetration, immersion, and corrosion tests were performed to characterize the mortar. Test results showed that the use of ternary blends of CT, FA, and RB or BA decreased the porosity of the mortar, as compared with binary blended mortar containing CT and RB or BA. The resistance to chloride penetration of the mortar improved substantially with partial replacement of CT with FA, RB, and BA. The use of ternary blends of CT, FA and RB or BA produced the mortar with good strength and resistance to chloride penetration. The resistance to chloride penetration was higher with an increase in the replacement level due to the reduced calcium hydroxide.展开更多
Peanut shells from Burkina Faso were characterized using mineralogical, microstructural and chemical methods to perform its possibility to be used as reinforce in adobe bricks. It consists of cellulose (48 wt%), hemic...Peanut shells from Burkina Faso were characterized using mineralogical, microstructural and chemical methods to perform its possibility to be used as reinforce in adobe bricks. It consists of cellulose (48 wt%), hemicellulose (3 wt%) and lignin (28 wt%). The peanut shells were characterized by high porosity and showed water absorption around 198% at 72 hours. Its chemical composition is essentially composed of silica, iron oxides, alumina and calcium oxide. Its microstructure showed that the peanut shells were a compilation of microfibers with high porous of borders. In watery solution, the peanut shells released polyphenols. Thermal conductivity of peanut at 25 °C was <span>0.155 ± 0.021 W/mK. The physico-chemical characteristics of peanut shells were similar to those found with agricultural by-products used in adobe reinforce.</span>展开更多
Date palm fiber(DPF)derived from agrowaste was utilized as a new precursor for the optimized synthesis of a costeffective,nanostructured,powderactivated carbon(nPAC)for aluminum(Al3+)removal from aqueous solutions usi...Date palm fiber(DPF)derived from agrowaste was utilized as a new precursor for the optimized synthesis of a costeffective,nanostructured,powderactivated carbon(nPAC)for aluminum(Al3+)removal from aqueous solutions using carbonization,KOH activation,response surface methodology(RSM)and central composite design(CCD).The optimum synthesis condition,activation temperature,time and impregnation ratio were found to be 650℃,1.09 hour and 1:1,respectively.Furthermore,the optimum conditions for removal were 99.5%and 9.958 mgg 1 in regard to uptake capacity.The optimum conditions of nPAC was analyzed and characterized using XRD,FTIR,FESEM,BET,TGA and Zeta potential.Moreover,the adsorption of the Al3+conditions was optimized with an integrated RSMCCD experimental design.Regression results revealed that the adsorption kinetics data was well fitted by the pseudosecond order model,whereas the adsorption isotherm data was best represented by the Freundlich isotherm model.Optimum activated carbon indicated that DPF can serve as a costeffective precursor adsorbent for Al^(3+)removal.展开更多
Returning biochar to soil is a heavily researched topic because biochar functions well for soil improvement. There is a significant loss of nutrients, which occurs during biochar preparation before biochar is returned...Returning biochar to soil is a heavily researched topic because biochar functions well for soil improvement. There is a significant loss of nutrients, which occurs during biochar preparation before biochar is returned to soil,thereby seriously undermining biochar's efficacy. Therefore, the transformation mechanisms of biochar p H,mass, nutrients and metals during pyrolysis under different atmospheres and temperatures were studied such that the best method for biochar preparation could be developed. Several conclusions can be reached:(1) a CO_2 atmosphere is better than a N_2 atmosphere for biochar preparation, although preparation in a CO_2 atmosphere is not a common practice for biochar producers;(2) 350 °C is the best temperature for biochar preparation because the amount of nutrient loss is notably low based on the premise of straw transferred into biochar; and(3) transforming mechanisms of pH, N, P and K are also involved in the biochar preparation process.展开更多
As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This ...As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.展开更多
Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are underutilized.Lignocellulosic biomass especially crop residues’potential to green energy development has b...Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are underutilized.Lignocellulosic biomass especially crop residues’potential to green energy development has been investigated.Material conditions as process variable was made a centerpiece of investigation in the present study since several parameters in the feedstock mixture come into interplay during pelletization.Moisture,binders,blending ratio,particle size,and principle feedstock material were the parameters of our interest in finding their effect on physical and thermochemical characteristics.It is also an endeavor to investigate low cost binder options in producing composite pellets of high quality.A Taguchi L9 orthogonal array experimental design was employed and Taguchi based Grey relational analysis was performed to determine the best combinatorial optimization of factor levels settings for producing best pellets.The optimal parameter level settings for pelletization was determined to be 3.18 mm wheat feedstock material blended with pine shavings at 60/40 ratio.An analysis of variance(ANOVA)was conducted to identify the contribution of each parameter.The magnitude of the significant impacts of parameters on performance characteristics were in the order of binder>blend ratio>grind>feedstock material.Results also showed that the physico-chemical characteristics of the pellets were concomitant with the proportion of ingredients or recipes in a blend.展开更多
基金financially supported by the Key Program of National Natural Science Foundation of China (Nos. 52034001 and 51734001)the Innovation Team in Key Fields of Ministry of Science and Technology of the People’s Republic of China (No. 2018RA400)+2 种基金the 111 Project (No. B20041)the Fundamental Research Funds for the Central Universities (No. FRF-TP-18-003C1)China Scholarship Council (No. 202006460037)
文摘Effects of residues produced by agricultural wastes fermentation(AWF)on low grade copper sulfide ores bioleaching,copper recovery,and microbial community were investigated.The results indicated that adding appropriate bulk of AWF made contributions to low grade copper sulfide ores bioleaching,which may be mainly realized through reducing the passivation layer formed by Fe3+hydrolysis.Improved copper recovery(78.35%)and bacteria concentration(9.56×10^(7)cells·mL^(−1))were yielded in the presence of 5 g·L^(−1)AWF.The result of 16S rDNA analysis demonstrated that microbial community was differentiated by adding AWF.Bacteria proportion,such as Acidithiobacillus ferrooxidans,Moraxella osloensis,and Lactobacillus acetotolerans changed distinctly.Great difference between samples was showed according to beta diversity index,and the maximum value reached 0.375.Acidithiobacillus ferrooxidans accounted for the highest proportion throughout the bioleaching process,and that of sample in the presence of 5 g·L^(−) AWF reached 28.63%.The results should show reference to application of agricultural wastes and low grade copper sulfide ores.
文摘Agricultural waste straw is the renewable resource with the highest annual yield in the world.In value-added applications of agricultural waste,dicarboxyl cellulose nanocrystals(DCCs)are prepared from rice,wheat,and corn straw by sequential periodate-chlorite oxidation.In this study,DCCs from rice,wheat,and corn straw were characterized by transmission electron microscopy(TEM),Fourier transform infrared spectrometer,X-ray diffractometer(XRD),and thermal gravimetric analysis(TGA).The carboxyl content of the DCCs was also investigated.XRD results show that the crystallinity index decreased after sequential periodate-chlorite oxidation;however,the cellulose I structure was maintained.TEM results show that rod-shaped DCCs with an average length and width of 287.0 nm and 9.9 nm,respectively,were successfully prepared by sequential periodate-chlorite oxidation.The carboxyl content of the DCCs was around 3.9 mmol/g,and not affected by the type of straw.Experiments to study the removal of copper ions in aqueous medium were performed with the prepared DCCs.The adsorption capacities of copper ions were 131,162,and 144 mg/g for DCCs prepared from rice,wheat,and corn straws,respectively.The results show that DCCs prepared from rice,wheat,and corn straws by sequential periodatechlorite oxidation have potential for the removal of copper ions from aqueous medium.
基金National Natural Science Foundation of China(Grant No.51506027)”Young Talents”Project of Northeast Agricultural University(Grant No.16QC18).
文摘Hydrogen production from food waste,cattle manure,potato pulp and pig manure was optimized through using mixture design in this study.The synergic and antagonistic effects of the four substrates on hydrogen yield,substrate conversion efficiency and pH were evaluated.The results showed that the optimal proportion of food waste,cattle manure,potato pulp and pig manure were 61.6%,38.4%,0,and 0,respectively.Under the optimal condition,hydrogen yield of 21.0 mL/g VS with VS reduction of 29.4%and pH of 5 could be obtained.The interaction between food waste and cattle manure had strongest synergistic effects.Hydrogen was mainly produced by acetic-butyric metabolic pathway,and ammonification of protein played an important role in the maintenance of pH.
基金the project"innovation in Increasing the Organic Carbon in Soil for Sustainable Agricultural Purpose in Saline Soil Areas:First-Year Pilot Project at the Lam Takong Watershed"Ratchadaphisek Somphot Endowment Fund(2014),Chulalongkorn University(CU-57-090-CC).
文摘Lignocellulosic biomass can be circulated to produce many materials and products,including biochar.This study analyzed five different types of biochar produced from agricultural wastes and wood residues.The raw materials included three agricultural by-products:corncob,cassava rhizome,rice husk,and two types of wood residues:rain tree(Samanea saman(Jacq.)Merr.)and krachid(Streblus ilicifolius(Vidal)Corner.).The biochar were made in patented retorts with locally-appropriated technology at a temper-ature range of 450e500C.This research focuses on the primary physicochemical properties and biochar components,allowing biochar to become a vital material to support sustainable agriculture and the environment.Biochar properties used for agriculture consist of specific surface area,total pore volume,average pore diameter,pH,electrical conductivity(EC),and cation exchange capacity(CEC).The prop-erties that benefit the environmental purposes are the element:carbon(C),hydrogen(H),nitrogen(N),oxygen(O),and the molar ratio of H/C,O/C,and C/N.The study found that all five types of biochar contained suitable properties for soil amendment and carbon sequestration.However,significant dif-ferences were shown in specific surface area,average pore diameter,pH,CEC,and EC of various biochar.Based on O/C and H/C ratios,all five types of biochar persisted in soil from 100 to over 1,000 years.
文摘Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one another
基金Supported by the Grant-in-Aid for Scientific Research(JSPS KAKENHI(B),22300247)
文摘In China, the heating energy consumption patterns of rural housing are changing due to economic development. This study investigated domestic heating in rural areas of Dalian, a city in northeast China. In rural areas of the country, heating devices such as coal boiler, radiator, and/ or air-conditioner are typically used. The Kang, as the main heating system, has been used together with other heating methods for a long time in detached houses, one-story buildings, and quadrangles. Use of the Kang in collective housing is no longer observed. In addition to coal, agricultural wastes have been used to fuel the Kang; the associated CO2 emissions with agricultural fuels are lower than from other heating equipment. Even when a combination of the Kang and other equipment is used, with agricultural waste as fuel, CO2 emissions remain relatively low.
基金support from China Postdoctoral Science Foundation(2016M590783)the Foundation of Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education of China(KF2015013)
文摘Owing to its subtropical or tropical environment and climate,South China is home to unique agricultural crops such as sugar cane,pineapple,banana,cassava,and rice,which generate a large amount of lignocellulosic agricultural wastes during agricultural as well as associated industrial processing.The efficient utilization of these wastes will have a significant impact on the economy and sustainable development of South China.This paper reviews the research investigations conducted both in China and elsewhere on the conversion of wastes from these subtropical or tropical agricultural crops into useful chemicals,energy,and biomaterials.The goal of this paper is to promote and summarize the extensive investigations on these agricultural wastes for the development of biorefinery.
基金National Natural Science Foundations of China(No.40771185,No.51004053)Li Shang-da Scientific Research Foundation of Jimei University,China(No.ZC2011015)
文摘Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out to study the adsorption kinetics mechanism of Cr(Ⅵ) effect of adsorbent dosage, pH, contact time, and temperature. The best results are obtained at 15g/L adsorbent concentration, 60min contact time, 298K temperature, and 50mg/L adsorbate initial concentration at pH 2. The adsorption isotherms, using initial concentrations of Cr(Ⅵ) between 10 and 500mg/L for the Cr(Ⅵ) removal, show the maximum metal uptake capacities of adsorbent were 10.48, 6.71, and 8.54mg/g for WS, RH, and PH, respectively. And the adsorption data fitted well to the Langmuir adsorption isotherm for WS, RH, and PH with correlation coefficients of 0.9862, 0.9723, and 0.9714, respectively. Moreover, the FTIR analysis of WS, RH, and PH before and after adsorption of Cr(Ⅵ) suggested that Cr ions were combined to some functional groups of compounds contained in these materials.
基金This study is supported by Sichuan Science and Technology Program(2021YFS0284,2018SZDZX0026,2021YFS0289)the Opening Project of Key Laboratory of Theoretical Chemistry of Environment(South China Normal University),Ministry of Education(20200103).
文摘With the increase of global proportion of soil pollution and the number of areas at risk,researchers have sought to develop various pathways to repair or relieve the pollutants in soil.Among them,biochar represents one multi-dimensional soil amendment which has got great deal of attention on its physicochemical properties towards the removal or mitigation of contaminants in soil.A variety of agricultural wastes like straw and manure prepared from different torrefaction process have been employed as feedstock for the production of biochar,which can be applied to the contaminated soil to facilitate the growing environment for crops,and to improve soil fertility and microbial environment.In addition,the utilization of biochar for soil remediation is also considered as a pro-cess of carbon sequestration.The purpose of this review is to summarize the latest research progress in torrefac-tion processes and mechanism of agricultural waste,the effects of different torrefaction methods on the formation and properties of biochar were explained,coupled with the effects of process parameters.Especially,the conver-sion and mechanisms of biochar prepared from agricultural wastes composed mainly with lignocellulosic material were discussed,and the characteristics of biochar prepared for improving soil physical and chemical character-istics,microbial community characteristics,nutrients,and the stability and relief of soil pollutants,especially heavy metals,are compared.Finally,this work discussed the application and future technical challenges of soil remediation based on agricultural waste derived biochar.
基金Supported by Science and Technology Research Item of Hubei Provincial Department of Education,China(B20121208)
文摘Energy utilization is high-value use pattern of agricultural waste, and is main development direction of agricultural biomass energy industry in China. Planting and breeding industry in Hubei Province occupies important position in whole country. Agricultural waste resources are rich, and it has huge potential for developing agriculturel biomass energy. By statistical data during 2000 -2011, we analyzed current situation and problem for energy utilization of agricultural waste in Hubei Province, and put forward several countermeasures and suggestions, vigorously promoting energy utilization of agricultural waste.
文摘Biomethane potential production from cashew nut hulls, an agricultural waste, was carried out using old and fresh hulls as substrates. Samples were taken from old hulls (around 8 years old) and fresh hulls produced in cashew scale transformation units at Bobo Dioulasso/Burkina Faso. Physicochemical parameters showed that cashew hulls can be </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">good candidate for anaerobic digestion. But high acidity, total phenols and lignin tenor could be a constraint for anaerobic bacteria. Theoretical biochemical methane potential showed high value of 666</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">937 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 526</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">206 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VS)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> for crushed fresh and powdered old hulls, respectively. Experimental biochemical methane potential showed significantly low potential of</span> <span style="font-family:Verdana;">1.982 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> and 46.840 CH</span><sub><span style="font-family:Verdana;">4</span></sub><span style="font-family:Verdana;"> L. (Kg VM)</span><sup><span style="color:#4F4F4F;font-family:Verdana;">-</span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;"> for </span><span style="font-family:Verdana;">fresh </span><span style="font-family:Verdana;">and hold hulls</span><span style="font-family:Verdana;">, respectively</span><span style="font-family:Verdana;">. Pretreatment for optimization, chemical composition and co-digestion system must be expected for a better anaerobic digestion performance.
文摘This article returns to the topic of sustainability. West Texas, mainly known for its cotton and cattle production, is facing problems related to the dispensation of agricultural waste produced by these operations. The article looks at the ways of handling agricultural waste and the opportunities of dispensing it in West Texas. Since between 30 - 40 percent of food produced in the US is not consumed, reduction of food waste is another sustainability problem that, when solved, would lead to the reduction of agricultural production and, in turn, the reduction of agricultural waste. Waste reduction management practices of large food chain stores in West Texas are discussed, with a final goal of bringing waste to a zero level. Public sources of sustainable agricultural and non-agricultural waste handling are also mentioned. This research adds to the previous knowledge on sustainability by discussing agricultural waste practices of a specific local area, i.e. West Texas.
基金Supported by the Scientific Research Start-Up Fund Project of Northeast Petroleum University(2019KQ67 and 2021KQ09)the Guiding Innovation Fund Project of Northeast Petroleum University(2021YDL-13)+1 种基金National Natural Science Foundation of China(52075090)Supported by the National Key R&D Program of China(2017YFD0601004).
文摘A calculation model of stress field in laser additive manufacturing of walnut shell composite powder(walnut shell/Co-PES powder)was established.The DFLUX subroutine was used to implement the moveable application of a double ellipsoid heat source by considering the mechanical properties varying with temperature.The stress field was simulated by the sequential coupling method,and the experimental results were in good accordance with the simulation results.In addition,the distribution and variation of stress and strain field were obtained in the process of laser additive manufacturing of walnut shell composite powder.The displacement of laser additive manufacturing walnut shell composite parts gradually decreased with increasing preheating temperature,decreasing laser power and increasing scanning speed.During the cooling process,the displacement of laser additive manufacturing of walnut shell composite parts gradually increased with the increasing preheating temperature,decreasing scanning speed and increasing laser power.
基金supported by the Major Program of the National Social Science Foundation of China(18ZDA048).
文摘Agricultural plastics play a pivotal role in agricultural production.However,due to expensive costs,agricultural plastic waste management(APWM)encounters a vast funding gap.As one of the crucial stakeholders,the public deserves to make appropriate efforts for APWM.Accordingly,identifying whether the public is willing to pay for APWM and clarifying the decisions’driving pathways to explore initiatives for promoting their payment intentions are essential to address the dilemma confronting APWM.To this end,by applying the extended theory of planned behavior(TPB),the study conducted an empirical analysis based on 1,288 residents from four provinces(autonomous regions)of northern China.Results illustrate that:1)respondents hold generally positive and relatively strong payment willingness towards APWM;2)respondents’attitude(AT),subjective norm(SN),and perceived behavioral control(PBC)are positively correlated with their payment intentions(INT);3)environmental cognition(EC)and environmental emotion(EE)positively moderate the relationships between AT and INT,and between SN and INT,posing significant indirect impacts on INT.The study’s implications extend to informing government policies,suggesting that multi-entity cooperation,specifically public payment for APWM,can enhance agricultural non-point waste management.
基金financially supported by the Office of the National Research Council of Thailand (NRCT)Higher Education Research Promotion and National Research University Project of Thailand+2 种基金Office of the Higher Education Commission,through the Advanced Functional Materials Cluster of Khon Kaen Universitythe Thailand Research Fund (TRF) under the TRF Senior Research Scholar Contract No. RTA5480004Rajamangala University of Technology Phra Nakhon (RMUTP)
文摘This article presents a study on the resistance to chloride penetration, corrosion, porosity, and strength of mortar containing fine fly ash (FA), ground rice husk-bark ash (RB), and ground bagasse ash (BA). Ordinary Portland cement (CT) was blended with a single pozzolan and two pozzolans. Strength, porosity, rapid chloride penetration, immersion, and corrosion tests were performed to characterize the mortar. Test results showed that the use of ternary blends of CT, FA, and RB or BA decreased the porosity of the mortar, as compared with binary blended mortar containing CT and RB or BA. The resistance to chloride penetration of the mortar improved substantially with partial replacement of CT with FA, RB, and BA. The use of ternary blends of CT, FA and RB or BA produced the mortar with good strength and resistance to chloride penetration. The resistance to chloride penetration was higher with an increase in the replacement level due to the reduced calcium hydroxide.
文摘Peanut shells from Burkina Faso were characterized using mineralogical, microstructural and chemical methods to perform its possibility to be used as reinforce in adobe bricks. It consists of cellulose (48 wt%), hemicellulose (3 wt%) and lignin (28 wt%). The peanut shells were characterized by high porosity and showed water absorption around 198% at 72 hours. Its chemical composition is essentially composed of silica, iron oxides, alumina and calcium oxide. Its microstructure showed that the peanut shells were a compilation of microfibers with high porous of borders. In watery solution, the peanut shells released polyphenols. Thermal conductivity of peanut at 25 °C was <span>0.155 ± 0.021 W/mK. The physico-chemical characteristics of peanut shells were similar to those found with agricultural by-products used in adobe reinforce.</span>
文摘Date palm fiber(DPF)derived from agrowaste was utilized as a new precursor for the optimized synthesis of a costeffective,nanostructured,powderactivated carbon(nPAC)for aluminum(Al3+)removal from aqueous solutions using carbonization,KOH activation,response surface methodology(RSM)and central composite design(CCD).The optimum synthesis condition,activation temperature,time and impregnation ratio were found to be 650℃,1.09 hour and 1:1,respectively.Furthermore,the optimum conditions for removal were 99.5%and 9.958 mgg 1 in regard to uptake capacity.The optimum conditions of nPAC was analyzed and characterized using XRD,FTIR,FESEM,BET,TGA and Zeta potential.Moreover,the adsorption of the Al3+conditions was optimized with an integrated RSMCCD experimental design.Regression results revealed that the adsorption kinetics data was well fitted by the pseudosecond order model,whereas the adsorption isotherm data was best represented by the Freundlich isotherm model.Optimum activated carbon indicated that DPF can serve as a costeffective precursor adsorbent for Al^(3+)removal.
基金Supported by the National Natural Science Foundation of China(No.41571283)
文摘Returning biochar to soil is a heavily researched topic because biochar functions well for soil improvement. There is a significant loss of nutrients, which occurs during biochar preparation before biochar is returned to soil,thereby seriously undermining biochar's efficacy. Therefore, the transformation mechanisms of biochar p H,mass, nutrients and metals during pyrolysis under different atmospheres and temperatures were studied such that the best method for biochar preparation could be developed. Several conclusions can be reached:(1) a CO_2 atmosphere is better than a N_2 atmosphere for biochar preparation, although preparation in a CO_2 atmosphere is not a common practice for biochar producers;(2) 350 °C is the best temperature for biochar preparation because the amount of nutrient loss is notably low based on the premise of straw transferred into biochar; and(3) transforming mechanisms of pH, N, P and K are also involved in the biochar preparation process.
文摘As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.
文摘Agricultural and agro-processing sector produces large stream of by-products that are either discarded or are underutilized.Lignocellulosic biomass especially crop residues’potential to green energy development has been investigated.Material conditions as process variable was made a centerpiece of investigation in the present study since several parameters in the feedstock mixture come into interplay during pelletization.Moisture,binders,blending ratio,particle size,and principle feedstock material were the parameters of our interest in finding their effect on physical and thermochemical characteristics.It is also an endeavor to investigate low cost binder options in producing composite pellets of high quality.A Taguchi L9 orthogonal array experimental design was employed and Taguchi based Grey relational analysis was performed to determine the best combinatorial optimization of factor levels settings for producing best pellets.The optimal parameter level settings for pelletization was determined to be 3.18 mm wheat feedstock material blended with pine shavings at 60/40 ratio.An analysis of variance(ANOVA)was conducted to identify the contribution of each parameter.The magnitude of the significant impacts of parameters on performance characteristics were in the order of binder>blend ratio>grind>feedstock material.Results also showed that the physico-chemical characteristics of the pellets were concomitant with the proportion of ingredients or recipes in a blend.