Iron-plating technology used for restoration of axis parts was applied to the manufacture of diamond bits in this paper.The technology for electroplating diamond bit of iron matrix was mastered through repeated experi...Iron-plating technology used for restoration of axis parts was applied to the manufacture of diamond bits in this paper.The technology for electroplating diamond bit of iron matrix was mastered through repeated experiments and research.The productive practice indicated that the DC-electroplated iron matrix of diamond bit has high hardness and good diamond exposure ability;the drilling rate of electroplated iron-based diamond bit was 2 m/h when drilling in grade 9 granite and bit life can reach 44 m,which can satisfy the drilling production requirements.展开更多
The glass formation was intensively studied for Fe-based alloys. Parameters defining kinetics and thermodynamic behavior of crystallization were calculated using calorimetric measurements and physical properties of co...The glass formation was intensively studied for Fe-based alloys. Parameters defining kinetics and thermodynamic behavior of crystallization were calculated using calorimetric measurements and physical properties of constituent elements. It is found that the critical cooling rate Rc estimated by combining kinetic and thermodynamic parameters highly correlates with measured Rc found in literatures with correlation coefficient R2=0.944, and alloy compositions with high melting enthalpy AHm can easily form glass even without high undercooling and high value of the ,β-parameter of Tumbull＇s theory, revealing that the glass formation in this group of alloys is mostly controlled by growth limitation. This combination of kinetic and thermodynamic parameters can be used to determine alloy composition with good glass forming ability in Fe-based alloys just using physical properties of alloying elements and calorimetric measurements.展开更多
In order to reduce powder temperature to lower than 100℃ in warm compaction by changing polymer lubricant design, powder flowability, warm compacting behavior, lubricating mode as well as ultimate tensile strength af...In order to reduce powder temperature to lower than 100℃ in warm compaction by changing polymer lubricant design, powder flowability, warm compacting behavior, lubricating mode as well as ultimate tensile strength after sinter-hardening and tempering were investigated systematically. By means of low temperature warm pressing and sintered hardening technique, samples with the sintered densities of 7.407.45g/cm3 and the strengths of 950 1390MPa are achieved as the early compacting pressure is 686735MPa.展开更多
The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace K...The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.展开更多
In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon ...In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.展开更多
Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influenc...Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms.展开更多
Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms ...Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.展开更多
Four sewage sludge(SS)feedstocks with distinct properties were converted into biochars by pyrolysis at 300−700℃,in order to clarify the effects of the composition difference of SS feedstocks.The yields of biochars pr...Four sewage sludge(SS)feedstocks with distinct properties were converted into biochars by pyrolysis at 300−700℃,in order to clarify the effects of the composition difference of SS feedstocks.The yields of biochars present a positive correlation with the contents of ash in SS.Notedly,the contents of organic matter(OM)in SS largely determine the quality of biochars.SS feedstocks with high content of OM are more likely to form stable biochars with higher aromaticity/carbonization degree,and the formed biochars possess higher calorific values.The contents of residual OM in biochars derived from SS feedstocks with low content of OM likely fail to meet the needs of soil improvement(10 wt.%).Most of heavy metals(HMs)existing in raw SS are remained in biochars after pyrolysis.The biochar produced from SS feedstocks with high content of HMs usually contains higher contents of HMs.Surprisingly,the leachability of HMs in biochars is all weakened to some extent compared to raw SS.In addition,the biochars show higher thermal stability and pH values,and P/K nutrients are enriched in biochars.The biochars prepared from four SS feedstocks exhibit different adsorption ability of methylene blue,especially at low dosage of biochar.展开更多
Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice sy...Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.展开更多
Biochar is a carbon-rich(】60%)organic material derived from incomplete combustion of fossil fuels and biomass.It consists of a continuum ranging from slightly charred material through char and charcoal to soot,and is...Biochar is a carbon-rich(】60%)organic material derived from incomplete combustion of fossil fuels and biomass.It consists of a continuum ranging from slightly charred material through char and charcoal to soot,and is ubiquitous in the atmosphere,marine sediment,soil and water.Moreover,】80%of biochar produced ends up in soils,where it resides for hundreds to thousands of years.Because of its resistance to biological and chemical breakdown, biochar can serve as a pool of C with long residence time in the soil.As a result,there has been increasing attention given to the potential of biochar to sequestrate carbon and counteract展开更多
A batch experiment was conducted to investigate the adsorption of trivalent chromium （Cr（Ⅲ）） from aqueous solutions by sugarcane pulp residue （SPR） and biochar. The results show that Cr（Ⅲ） adsorption by SPR ...A batch experiment was conducted to investigate the adsorption of trivalent chromium （Cr（Ⅲ）） from aqueous solutions by sugarcane pulp residue （SPR） and biochar. The results show that Cr（Ⅲ） adsorption by SPR and biochar is highly pH-dependent and Cr（Ⅲ） adsorption amount increases with the increase of pH. The adsorption kinetics of Cr（Ⅲ） fits well with the pseudo-second-order model. The maximum Cr（Ⅲ） adsorption capacities of 15.85 mg/g and 3.43 mg/g for biochar and SPR were calculated by Langmuir model. This indicates that biochar has a larger ability for Cr（Ⅲ） adsorption than SPR. The free energy change value （AG） reveals a spontaneous sorption process of Cr（Ⅲ） onto SPR and non-spontaneous sorption process onto biochar. The entropy change （AS） and enthalpy change （AH） are found to be 66.27 J/（mol＇K） and 17.13 kJ/mol for SPR and 91.59 J/（mol-K） and 30.875 kJ/mol for biochar which further reflect an affinity of Cr（Ⅲ） onto SPR and biochar. It is suggested that biochar has potential to be an efficient adsorbent in the removal of Cr（Ⅲ） from industrial wastewater.展开更多
The effects of biochar(BC),arbuscular mycorrhizal fungi(AM),nitrogen(N)and their composite treatments(BC+N,AM+N,BC+AM and BC+AM+N)application on Cichorium intybus L.(C.intybus L.)nutrient uptake,soil properties and ca...The effects of biochar(BC),arbuscular mycorrhizal fungi(AM),nitrogen(N)and their composite treatments(BC+N,AM+N,BC+AM and BC+AM+N)application on Cichorium intybus L.(C.intybus L.)nutrient uptake,soil properties and cadmium(Cd)accumulation were investigated in Cd contaminated soil(0.11 mg·kg^(-1)).The results showed that the addition of BC increased the rate of mycorrhizal infection.However,the addition of N slightly inhibited mycorrhizal colonization,and the shoot and root bioaccumulation of chicory was positively influenced by BC and N when inoculated with AM fungi.Compared with the single component treatment(AM,BC or N)or two-component treatment(BC+N,AM+N or BC+AM),the three-component composite treatment(BC+AM+N)had the highest shoot bioaccumulation,whereas BC+AM treatment was considered the best for root biomass bioaccumulation.Compared with the control treatment,the single component treatment(AM,BC or N)and the composite treatment resulted in an overall improvement of the chicory shoot,root related nutrient uptake(N,P,K,Mg,Ca,Mn and Fe)and some soil physicochemical properties;in addition,these treatments showed better results than BC+AM+N and BC+AM treatments.Among the Cd-related indexes,Cd concentrations in the shoot,root and soil of C.intybus L.were reduced through treatment with AM and BC.However,a lower bioconcentration coefficient(BCF)and a higher transfer coefficient(TF)were observed in both treatments,and the most desirable effect was observed following the combination treatment(BC+AM).Compared with other single management,the shoot and root Cd concentrations of C.intybus L.after the management of N alone were higher,and the value of BCF(2.63%)was higher,but the value of TF(1.05%)was lower.Indexes related to Cd improved concurrently following the application of N in combination with BC or AM.Therefore,in Cd contaminated soils,single or combined application of BC,AM and N could promote chicory growth and nutrient uptake and improve some soil physicochemical properties.However,N should not be applied alone and needed to be combined with AM and BC;furthermore,it was evident that the treatment with the three composites(BC+AM+N)was optimal from an application point of view.展开更多
A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar)...A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar),C1(0.6 t•hm-2 biochar),C2(0.6 t•hm-2 wood vinegar),C3(1.2 t•hm-2 wood vinegar),C4(1.8 t•hm-2 wood vinegar),C5(0.6 t•hm-2 biochar+0.6 t•hm-2 wood vinegar),C6(0.6 t•hm-2 biochar+1.2 t•hm-2 wood vinegar),and C7(0.6 t•hm-2 biochar+1.8 t•hm-2 wood vinegar).The results showed that biochar without wood vinegar and the co-application of biochar and wood vinegar significantly increased soil total phosphorus content.Meanwhile,compared with CK,all of treatments increased resin phosphorus and sodium bicarbonate-extracted inorganic phosphorus(NaHCO3-Pi)contents in saline-alkali soil.Especially,the contents of resin phosphorus and NaHCO3-Pi under C5,C6,and C7 treatments were higher than those of C2,C3,and C4 treatments,respectively,indicating that the increases of labile phosphorus contents under the co-application of biochar and wood vinegar were better than those of the alone application of biochar and wood vinegar.Each treatment increased the proportion of labile phosphorus pool in saline-alkali soil and the proportion of labile phosphorus pool increased with the increase of the amount of wood vinegar.In addition,the application of biochar and wood vinegar increased the 100-grain weight of rice,and C6 treatment had the best effect,increasing the 100-grain weight by 134.35%.Therefore,the application of biochar and wood vinegar in saline-alkali soil could improve the soil phosphorus availability,increase the weight of rice grains,thereby realizing the resource utilization of agricultural waste and the sustainable development of agriculture.展开更多
Long term tillage in mollisol of Northeast China has led to an inhomogeneous distribution of soil organic matter content.Biochar,a carbon material,changes the soil carbon pool and physical-chemical characteristics aft...Long term tillage in mollisol of Northeast China has led to an inhomogeneous distribution of soil organic matter content.Biochar,a carbon material,changes the soil carbon pool and physical-chemical characteristics after adding to the soil.However,the mechanism remains unclear for the relation between the soil organic matter level and biochar amount.So,the soil physical and chemical properties and soybean growth in a two-year pot experiment were detected at three levels of soil organic matter and three biochar additions(0,1%and 10%).The difference was found in two biochar application rates.The 1%biochar addition had no positive effect on the soil chemical properties based the two-year experiment.However,10%biochar application significantly increased the soil water content(8.0%-39.7%),the total porosity(9.7%-21.3%),pH(0.26-0.84 unit),organic matter content(89.0%-261.2%),and the available potassium content(29.0%-109.1%).The biomass of soybean increased by 19.4%-78.1%after biochar addition,yet,the soil bulk density reduced at the range of 12.6%-26.0%by 10%biochar addition.Only the 100-grain weight was correlated to the interaction of biochar and the native soil organic matter.All the indicators showed that the interaction between biochar and soil organic matter level was weak in mollisol.The effects of biochar on the physical-chemical properties relied on its amount.When biochar is applied to the soil,the amount of biochar should be considered rather than the native soil organic matter level.展开更多
Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between phy...Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between physical properties and LOC fractions. A field positioning experiment was performed in Mollisols region of Northeast China to evaluate the influence of maize stalk biochar on the spatial distribution and temporal changes of physical properties and LOC fractions. Maize stalk biochar treatments included C1(1.5 kg·hm^(-2)), C2(3 kg·hm^(-2)), C3(15 kg·hm^(-2)), C4(30 kg·hm^(-2)), and CK(0). The results showed that maize stalk biochar increased soil water contents(SWC) and soil porosity(SP), but reduced bulk density(BD). Maize stalk biochar reduced dissolved organic carbon(DOC) contents in the 0-20 cm soil layer, ranging from 0.25 g·kg^(-1) to 0.31 g·kg^(-1) in harvest period, while increased in the 20-40 cm soil layer. In addition, the application of biochar had a significant impact on the spatial distribution and temporal change of SWC, BD, SP, DOC, hot-water extractable carbon(HWC), acid hydrolyzed organic carbon(AHC Ⅰ, Ⅱ), and readily oxidized organic carbon(ROC). High amounts of maize stalk biochar up-regulated the contents of soil organic carbon SOC, HWC, AHC Ⅰ, AHC Ⅱ, and ROC. In addition, SWC and SP were the key physical factors to affect LOC fractions. In conclusions, maize stalk biochar could improve physical properties, and then influence LOC fractions, and maize stalk biochar could be used as an organic amendment for restoring degraded soils governed by their rates of addition.展开更多
文摘Iron-plating technology used for restoration of axis parts was applied to the manufacture of diamond bits in this paper.The technology for electroplating diamond bit of iron matrix was mastered through repeated experiments and research.The productive practice indicated that the DC-electroplated iron matrix of diamond bit has high hardness and good diamond exposure ability;the drilling rate of electroplated iron-based diamond bit was 2 m/h when drilling in grade 9 granite and bit life can reach 44 m,which can satisfy the drilling production requirements.
基金Projects(51174094, 51101059) supported by the National Natural Science Foundation of China
文摘The glass formation was intensively studied for Fe-based alloys. Parameters defining kinetics and thermodynamic behavior of crystallization were calculated using calorimetric measurements and physical properties of constituent elements. It is found that the critical cooling rate Rc estimated by combining kinetic and thermodynamic parameters highly correlates with measured Rc found in literatures with correlation coefficient R2=0.944, and alloy compositions with high melting enthalpy AHm can easily form glass even without high undercooling and high value of the ,β-parameter of Tumbull＇s theory, revealing that the glass formation in this group of alloys is mostly controlled by growth limitation. This combination of kinetic and thermodynamic parameters can be used to determine alloy composition with good glass forming ability in Fe-based alloys just using physical properties of alloying elements and calorimetric measurements.
文摘In order to reduce powder temperature to lower than 100℃ in warm compaction by changing polymer lubricant design, powder flowability, warm compacting behavior, lubricating mode as well as ultimate tensile strength after sinter-hardening and tempering were investigated systematically. By means of low temperature warm pressing and sintered hardening technique, samples with the sintered densities of 7.407.45g/cm3 and the strengths of 950 1390MPa are achieved as the early compacting pressure is 686735MPa.
基金supported by the National Natural Science Foundation of China(52376103,542B2081).
文摘The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.
基金Project(2020YFC1908802)supported by the National Key Research and Development Project of China。
文摘Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms.
基金Projects(2019NY-200,2020ZDLNY06-06,2020ZDLNY07-10)supported by the Key Research and Development Program of Shaanxi Province,ChinaProject(2019YFC1803604)supported by the National Key Research and Development Program of China。
文摘Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.
基金Project(21707056)supported by the National Natural Science Foundation of ChinaProject(20192BAB203019)supported by the Natural Science Foundation of Jiangxi Province,China。
文摘Four sewage sludge(SS)feedstocks with distinct properties were converted into biochars by pyrolysis at 300−700℃,in order to clarify the effects of the composition difference of SS feedstocks.The yields of biochars present a positive correlation with the contents of ash in SS.Notedly,the contents of organic matter(OM)in SS largely determine the quality of biochars.SS feedstocks with high content of OM are more likely to form stable biochars with higher aromaticity/carbonization degree,and the formed biochars possess higher calorific values.The contents of residual OM in biochars derived from SS feedstocks with low content of OM likely fail to meet the needs of soil improvement(10 wt.%).Most of heavy metals(HMs)existing in raw SS are remained in biochars after pyrolysis.The biochar produced from SS feedstocks with high content of HMs usually contains higher contents of HMs.Surprisingly,the leachability of HMs in biochars is all weakened to some extent compared to raw SS.In addition,the biochars show higher thermal stability and pH values,and P/K nutrients are enriched in biochars.The biochars prepared from four SS feedstocks exhibit different adsorption ability of methylene blue,especially at low dosage of biochar.
基金Project(2019YFC1803601)supported by the National Key Research and Development Program of ChinaProject(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China。
文摘Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.
文摘Biochar is a carbon-rich(】60%)organic material derived from incomplete combustion of fossil fuels and biomass.It consists of a continuum ranging from slightly charred material through char and charcoal to soot,and is ubiquitous in the atmosphere,marine sediment,soil and water.Moreover,】80%of biochar produced ends up in soils,where it resides for hundreds to thousands of years.Because of its resistance to biological and chemical breakdown, biochar can serve as a pool of C with long residence time in the soil.As a result,there has been increasing attention given to the potential of biochar to sequestrate carbon and counteract
基金Project(50925417) supported by the National Funds for Distinguished Young Scientist,ChinaProject(50830301) supported by the Key Program of National Natural Science Foundation of ChinaProject(51074191) supported by the National Natural Science Foundation of China
文摘A batch experiment was conducted to investigate the adsorption of trivalent chromium （Cr（Ⅲ）） from aqueous solutions by sugarcane pulp residue （SPR） and biochar. The results show that Cr（Ⅲ） adsorption by SPR and biochar is highly pH-dependent and Cr（Ⅲ） adsorption amount increases with the increase of pH. The adsorption kinetics of Cr（Ⅲ） fits well with the pseudo-second-order model. The maximum Cr（Ⅲ） adsorption capacities of 15.85 mg/g and 3.43 mg/g for biochar and SPR were calculated by Langmuir model. This indicates that biochar has a larger ability for Cr（Ⅲ） adsorption than SPR. The free energy change value （AG） reveals a spontaneous sorption process of Cr（Ⅲ） onto SPR and non-spontaneous sorption process onto biochar. The entropy change （AS） and enthalpy change （AH） are found to be 66.27 J/（mol＇K） and 17.13 kJ/mol for SPR and 91.59 J/（mol-K） and 30.875 kJ/mol for biochar which further reflect an affinity of Cr（Ⅲ） onto SPR and biochar. It is suggested that biochar has potential to be an efficient adsorbent in the removal of Cr（Ⅲ） from industrial wastewater.
文摘The effects of biochar(BC),arbuscular mycorrhizal fungi(AM),nitrogen(N)and their composite treatments(BC+N,AM+N,BC+AM and BC+AM+N)application on Cichorium intybus L.(C.intybus L.)nutrient uptake,soil properties and cadmium(Cd)accumulation were investigated in Cd contaminated soil(0.11 mg·kg^(-1)).The results showed that the addition of BC increased the rate of mycorrhizal infection.However,the addition of N slightly inhibited mycorrhizal colonization,and the shoot and root bioaccumulation of chicory was positively influenced by BC and N when inoculated with AM fungi.Compared with the single component treatment(AM,BC or N)or two-component treatment(BC+N,AM+N or BC+AM),the three-component composite treatment(BC+AM+N)had the highest shoot bioaccumulation,whereas BC+AM treatment was considered the best for root biomass bioaccumulation.Compared with the control treatment,the single component treatment(AM,BC or N)and the composite treatment resulted in an overall improvement of the chicory shoot,root related nutrient uptake(N,P,K,Mg,Ca,Mn and Fe)and some soil physicochemical properties;in addition,these treatments showed better results than BC+AM+N and BC+AM treatments.Among the Cd-related indexes,Cd concentrations in the shoot,root and soil of C.intybus L.were reduced through treatment with AM and BC.However,a lower bioconcentration coefficient(BCF)and a higher transfer coefficient(TF)were observed in both treatments,and the most desirable effect was observed following the combination treatment(BC+AM).Compared with other single management,the shoot and root Cd concentrations of C.intybus L.after the management of N alone were higher,and the value of BCF(2.63%)was higher,but the value of TF(1.05%)was lower.Indexes related to Cd improved concurrently following the application of N in combination with BC or AM.Therefore,in Cd contaminated soils,single or combined application of BC,AM and N could promote chicory growth and nutrient uptake and improve some soil physicochemical properties.However,N should not be applied alone and needed to be combined with AM and BC;furthermore,it was evident that the treatment with the three composites(BC+AM+N)was optimal from an application point of view.
基金Supported by Funding from Harbin Science and Technology Bureau(2017RAXXJ023)。
文摘A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar),C1(0.6 t•hm-2 biochar),C2(0.6 t•hm-2 wood vinegar),C3(1.2 t•hm-2 wood vinegar),C4(1.8 t•hm-2 wood vinegar),C5(0.6 t•hm-2 biochar+0.6 t•hm-2 wood vinegar),C6(0.6 t•hm-2 biochar+1.2 t•hm-2 wood vinegar),and C7(0.6 t•hm-2 biochar+1.8 t•hm-2 wood vinegar).The results showed that biochar without wood vinegar and the co-application of biochar and wood vinegar significantly increased soil total phosphorus content.Meanwhile,compared with CK,all of treatments increased resin phosphorus and sodium bicarbonate-extracted inorganic phosphorus(NaHCO3-Pi)contents in saline-alkali soil.Especially,the contents of resin phosphorus and NaHCO3-Pi under C5,C6,and C7 treatments were higher than those of C2,C3,and C4 treatments,respectively,indicating that the increases of labile phosphorus contents under the co-application of biochar and wood vinegar were better than those of the alone application of biochar and wood vinegar.Each treatment increased the proportion of labile phosphorus pool in saline-alkali soil and the proportion of labile phosphorus pool increased with the increase of the amount of wood vinegar.In addition,the application of biochar and wood vinegar increased the 100-grain weight of rice,and C6 treatment had the best effect,increasing the 100-grain weight by 134.35%.Therefore,the application of biochar and wood vinegar in saline-alkali soil could improve the soil phosphorus availability,increase the weight of rice grains,thereby realizing the resource utilization of agricultural waste and the sustainable development of agriculture.
基金Supported by the National Natural Science Fund(41301316,32172072)the Project of Nature Scientific Foundation of Heilongjiang Province(LH2021C025)Open Project of Key Laboratory for Germplasm Innovation and Physiological Ecology of Food Crops in Cold Regions of the Ministry of Education(CXSTOP2021008)。
文摘Long term tillage in mollisol of Northeast China has led to an inhomogeneous distribution of soil organic matter content.Biochar,a carbon material,changes the soil carbon pool and physical-chemical characteristics after adding to the soil.However,the mechanism remains unclear for the relation between the soil organic matter level and biochar amount.So,the soil physical and chemical properties and soybean growth in a two-year pot experiment were detected at three levels of soil organic matter and three biochar additions(0,1%and 10%).The difference was found in two biochar application rates.The 1%biochar addition had no positive effect on the soil chemical properties based the two-year experiment.However,10%biochar application significantly increased the soil water content(8.0%-39.7%),the total porosity(9.7%-21.3%),pH(0.26-0.84 unit),organic matter content(89.0%-261.2%),and the available potassium content(29.0%-109.1%).The biomass of soybean increased by 19.4%-78.1%after biochar addition,yet,the soil bulk density reduced at the range of 12.6%-26.0%by 10%biochar addition.Only the 100-grain weight was correlated to the interaction of biochar and the native soil organic matter.All the indicators showed that the interaction between biochar and soil organic matter level was weak in mollisol.The effects of biochar on the physical-chemical properties relied on its amount.When biochar is applied to the soil,the amount of biochar should be considered rather than the native soil organic matter level.
基金Supported by the National Natural Science Foundation of China Project(31770582)。
文摘Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between physical properties and LOC fractions. A field positioning experiment was performed in Mollisols region of Northeast China to evaluate the influence of maize stalk biochar on the spatial distribution and temporal changes of physical properties and LOC fractions. Maize stalk biochar treatments included C1(1.5 kg·hm^(-2)), C2(3 kg·hm^(-2)), C3(15 kg·hm^(-2)), C4(30 kg·hm^(-2)), and CK(0). The results showed that maize stalk biochar increased soil water contents(SWC) and soil porosity(SP), but reduced bulk density(BD). Maize stalk biochar reduced dissolved organic carbon(DOC) contents in the 0-20 cm soil layer, ranging from 0.25 g·kg^(-1) to 0.31 g·kg^(-1) in harvest period, while increased in the 20-40 cm soil layer. In addition, the application of biochar had a significant impact on the spatial distribution and temporal change of SWC, BD, SP, DOC, hot-water extractable carbon(HWC), acid hydrolyzed organic carbon(AHC Ⅰ, Ⅱ), and readily oxidized organic carbon(ROC). High amounts of maize stalk biochar up-regulated the contents of soil organic carbon SOC, HWC, AHC Ⅰ, AHC Ⅱ, and ROC. In addition, SWC and SP were the key physical factors to affect LOC fractions. In conclusions, maize stalk biochar could improve physical properties, and then influence LOC fractions, and maize stalk biochar could be used as an organic amendment for restoring degraded soils governed by their rates of addition.
