Arsenic(As)contamination in groundwater is a major problem in many countries,which causes serious health issues.In this paper,a novel method has been developed for the simultaneous removal of ROX and As(Ⅲ/Ⅴ)using th...Arsenic(As)contamination in groundwater is a major problem in many countries,which causes serious health issues.In this paper,a novel method has been developed for the simultaneous removal of ROX and As(Ⅲ/Ⅴ)using the modified sorghum straw biochar(MSSB).The MSSB was characterized by X-ray diffraction,scanning electron microscopy,Fourier Transform Infrared,and Brunauer–Emmet–Teller(BET)surface area.The removal performance of MSSB for ROX,arsenite[As(Ⅲ)],and arsenate(As(Ⅴ))was investigated using batch experiments.At pH of 5,the arsenic concentration of 1.0 mg/L,adsorbent dose of 1.0 g/L,the maximum adsorptioncapacities of ROX,As(Ⅲ),and As(Ⅴ)were 12.4,5.3,and 23.0 mg/g,respectively.The adsorption behaviors were fit well with the Langmuir and the pseudo-second-order rate model.The results showed that MSSB acted as a highly effective adsorbent to simultaneously remove the composite pollution system consisted of ROX and As(Ⅲ/Ⅴ)in aqueous solutions,providing a promising method in environmental restoration applications.展开更多
Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion...Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion (particularly on the uplands). One possible approach to addressing the soil constraints to rice production both on uplands and lowlands of Sierra Leone is the recycling of rice residues through biochar production and application to soils. A pot experiment was conducted to investigate the effects of application of biochar from rice residues on (i) soil physicochemical properties and (ii) the early growth characteristics of two rice varieties, NERICA L19 and ROK3. The experiment was arranged in a completely randomized design (CRD) with two biochar levels (0 and 15 g/kg soil) and two rice varieties in three replications. For the biochar treated soils (+biochar), 75 g rice straw biochar was applied to 5 kg air-dry soil (15 kg biochar/kg soil), mixed thoroughly and placed into perforated black polythene bags. Seeds of two rice varieties, NERICA L19 and ROK3 were planted on the treated and untreated soils for eight weeks. Application of biochar improved available phosphorus, exchangeable cations and cation exchange capacity in biochar treated soils compared to the control soil without biochar. Plant height, tiller number, and dry biomass weight of both rice varieties grown in soils amended with rice straw biochar were significantly higher than those on untreated soils. The most remarkable increase in plant growth characteristics as a result of biochar addition to soil was reflected in the biomass yield and tiller numbers. Dry shoot biomass for ROK3 rice variety varied significantly from a mean of 3.5 g (control) to 26.2 g (+biochar) while tiller numbers significantly varied from 10 (control) to 29.6 (+biochar). Similarly, for NERICA L19 rice variety, dry shoot biomass increased significantly from 4.5 g (control) to 22.7 g (+biochar) while tiller numbers increased significantly from a mean of 12.3 (control) to 30 (+biochar). Thus converting rice residues to biochar and applying to soil holds promise for improving rice production in Sierra Leone.展开更多
The simultaneous sorption behavior and characteristics of cadmium (Cd) and sulfamethoxazole (SMX) on rice straw biochar were investigated. Isotherms of Cd and SMX were well modeled by the Langmuir equation (R2 >0.9...The simultaneous sorption behavior and characteristics of cadmium (Cd) and sulfamethoxazole (SMX) on rice straw biochar were investigated. Isotherms of Cd and SMX were well modeled by the Langmuir equation (R2 >0.95). The calculated maximum adsorption parameter (Q) of Cd was similar in single and binary systems (34129.69 and 35919.54 mg/kg, respectively). However, the Q of SMX in a binary system (9182.74 mg/kg) was much higher than that in a single system (1827.82 mg/kg). The presence of Cd significantly promoted the sorption of SMX on rice straw biochar. When the pH ranged from 3 to 7.5, the sorption of Cd had the characteristics of a parabola pattern with maximum adsorption at pH 5, while the adsorption quantity of SMX decreased with increasing pH, with maximum adsorption at pH 3. The amount of SMX adsorbed on biochar was positively correlated with the surface area of the biochar, and the maximum adsorption occurred with d 250 biochar (biochar with a diameter of 150-250 μm). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that the removal of Cd and SMX by rice straw biochar may be attributed to precipitation and the formation of surface complexes between Cd or SMX and carboxyl or hydroxyl groups. The results of this study indicate that rice straw biochar has the potential for simultaneous removal of Cd and SMX from co-contaminated water.展开更多
Whether the biochar amendment could affect soil organic matter （SOM） turnover and hence soil carbon （C） stock remains poorly understood. Effects of the addition of ^13C-labelled rice straw or its pyrolysed biochar...Whether the biochar amendment could affect soil organic matter （SOM） turnover and hence soil carbon （C） stock remains poorly understood. Effects of the addition of ^13C-labelled rice straw or its pyrolysed biochar at 250 or 350℃ to a sugarcane soil （Ferrosol） on soil labile C （dissolved organic C, DOC; microbial biomass C, MBC; and mineralizable C, MC） and soil organic C （SOC） were investigated after 112 d of laboratory incubation at 25℃. Four treatments were examined as （1） the control soil without amendment （Soil）; （2） soil plus ^13C-labelled rice straw （Soil＋Straw）; （3） soil plus 250℃ biochar （Soil＋B250） and （4） soil plus 350℃biochar （Soil＋B350）. Compared to un-pyrolysed straw, biochars generally had an increased aryl C, carboxyl C, C and nitrogen concentrations, a decreased O-alkyl C and C：N ratio, but similar alkyl C and δ^13C （1 742- 1 877 %）. Among treatments, significant higher DOC, MBC and MC derived from the new C （straw or biochar） ranked as Soil＋Straw〉Soil＋B250〉Soil＋B350, whilst significant higher SOC from the new C as Soil＋B250〉Soil＋Straw≈Soil＋B350. Compared to Soil, DOC and MBC derived from the native soil were decreased under straw or biochar addition, whilst MC from the native soil was increased under straw addition but decreased under biochar addition. Meanwhile, native SOC was similar among the treatments, irrespective of the straw or biochar addition. Compared to Soil, significant higher total DOC and total MBC were under Soil＋Straw, but not under Soil＋B250 and Soil＋B350, whilst significant higher total MC and total SOC were under straw or biochar addition, except for MC under Soil＋B350. Our results demonstrated that the application of biochar to soil may be an appropriate management practice for increasing soil C storage.展开更多
Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current dev...Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current developments in biochar industry and the production practices prevalent among enterprises in China are critiques.This review analyzes current knowledge gaps,challenges,and opportunities in the industrial application of straw biochar returning.Biochar standards,the quantitative and qualitative analysis methods for biochar,and high-value-added products that are based on biochar are critically examined with goal of providing recommendations for future studies.We propose production and modification of biochar that is application oriented to enhance its fitness for purpose as well as long-term and large-space-scale field study to better understand its impact on soil properties and ecotoxicology.Finally,we make prospects for the future development of SBR,including constructing a standard system about straw biochar returning and promoting self-discipline of biochar industry and the establishment of a biochar-based agricultural production model.展开更多
To better understand the amendment effects and mechanisms of aluminum(Al(Ⅲ))phytotoxicity mitigation by differ-ent regional crop straw biochars,wheat seedling root elongation trials were conducted.The contributions o...To better understand the amendment effects and mechanisms of aluminum(Al(Ⅲ))phytotoxicity mitigation by differ-ent regional crop straw biochars,wheat seedling root elongation trials were conducted.The contributions of liming effect,oxygen-containing surface functional group adsorption,and oxyanions precipitation to Al(Ⅲ)phytotoxicity mitigation by Ca(OH)_(2),pristine and ash-free canola straw biochar were evaluated.The results indicated that biochars derived from canola straw collected from four different regions(Yingtan,Xuancheng,Nanjing,and Huaiyin)caused 22-70%wheat seedling root elongation,which might be linked to liming effect.Incorporation of the corresponding ash-free biochars caused 15-30%elongation,which could be attributed to the surface functional group adsorption.About 0-60%of changes could be explained by Al(Ⅲ)precipitation with inorganic oxyanions.These findings provide new insights into the physicochemical properties,potential applications,efficiencies,and underlying mechanisms of crop straw biochar in alleviating Al(Ⅲ)phytotoxicity,which is dependent on the cultivation soil,and indicate similar application of crop straw biochar for acidic soil amelioration,contaminated soil remediation,and arable soil improvement.展开更多
The purpose of this paper was to study the effects of different C/N ratios on the maturity and microbial quantity of com-posting with sesame meal and rice straw biochar.Rice straw was calcined into biochar as raw mate...The purpose of this paper was to study the effects of different C/N ratios on the maturity and microbial quantity of com-posting with sesame meal and rice straw biochar.Rice straw was calcined into biochar as raw materials composting with sesame meal for 30 days,referring to Chenfu Agricultural Book in Sōuthern Song Dynasty(1127-1279 A.D.).Sesame meal was used to adjust the C/N ratio of compost,and three treatments were designed in the experiment,which were C/N ratios of 15,20 and 30,respectively.The results showed that C/N ratio of 20 was beneficial for promoting the temperature rise,the removal of water,the degradation of organic carbon,and the decrease of microbial quantity.The C/N ratio of 20 was beneficial to the compost maturity(T value was 0.47,final GI was 99.67%).The results of Pearson correlation analysis showed that C/N ratio was positively correlated with moisture content,total organic carbon and negatively correlated with germination index,indicating that high C/N ratio was beneficial to water removal and total organic carbon degradation.Therefore,we suggest that the suitable C/N ratio of rice straw biochar and sesame meal is 20.At the same time,we have proved that the composting method in Southern Song Dynasty is feasible,which is of great significance to understand the development of composting in China.展开更多
Five crop straws (wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210℃, 2.5 MPa and then pyrolyzed at 500℃ for 2 h. Steam explosion (SE) induced 47–95% and 5–16% reduction of hemic...Five crop straws (wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210℃, 2.5 MPa and then pyrolyzed at 500℃ for 2 h. Steam explosion (SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area (SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity (AEC) (6.88–11.44 cmol kg–1) and point of zero net charges (PZNC) (pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.展开更多
The additions of straw and biochar have been suggested to increase soil fertility, carbon sequestration, and crop produc- tivity of agricultural lands. To our knowledge, there is little information on the effects of s...The additions of straw and biochar have been suggested to increase soil fertility, carbon sequestration, and crop produc- tivity of agricultural lands. To our knowledge, there is little information on the effects of straw and biochar addition on soil nitrogen form, carbon storage, and super rice yield in cold waterlogged paddy soils. We performed field trials with four treatments including conventional fertilization system （CK）, straw amendment 6 t ha^-1 （S）, biochar amendment 2 t ha^-1 （C1）, and biochar amendment 40 t ha^-1 （C2）. The super japonica rice variety, Shennong 265, was selected as the test Crop. The results showed that the straw and biochar amendments improved total nitrogen and organic carbon content of the soil, reduced N2O emissions, and had little influence on nitrogen retention, nitrogen density, and CO2 emissions. The S and C1 increased NH4^＋-N content, and C2 increased NO3^--N content. Both S and C1 had little influence on soil organic carbon density （SOCD） and C/N ratio. However, C2 greatly increased SOCD and C/N ratio. C1 and C2 significantly improved the soil carbon sequestration （SCS） by 62.9 and 214.0% （P〈0.05）, respectively, while S had no influence on SCS. C1 and C2 maintained the stability of super rice yield, and significantly reduced CH4 emissions, global warming potential （GWP）, and greenhouse gas intensity （GHGI）, whereas S had the opposite and negative effects. In summary, the biochar amendments in cold waterlogged paddy soils of North China increased soil nitrogen and carbon content, improved soil carbon sequestration, and reduced GHG emission without affecting the yield of super rice.展开更多
The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar,straw,and chemical fertilizers compared with chemical fertilization alone.Five soi...The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar,straw,and chemical fertilizers compared with chemical fertilization alone.Five soil fertilization treatments were evaluated：regular chemical fertilizers（RF）,straw＋regular chemical fertilizers（SRF）,straw biochar＋regular chemical fertilizers（SCRF）,bamboo biochar（BC）＋regular chemical fertilizers（BCRF）,and straw biochar＋70%regular chemical fertilizers（SC＋70%RF）.Their effects were investigated after approximately 1.5 years.The soil p H and cation exchange capacity（CEC）were significantly higher in biochar-treated soils.The soil phosphorous（P）and potassium（K）contents increased with biochar application.The soil Colwell P content was significantly increased with the addition of straw biochar in the treatments of SCRF and SC＋70%RF.The oxygen（O）：carbon（C）ratio doubled in BC picked from the soil.This indicated that BC underwent a significant oxidation process in the soil.The denaturing gradient gel electrophoresis（DGGE）fingerprints of microbial communities differed among the treatments.Soils with added biochar had higher Shannon diversity and species richness indices than soils without biochars.The results suggest that biochar can improve soil fertility.展开更多
Cr（Ⅲ） adsorption by biochars generated from peanut, soybean, canola and rice straws is investigated with batch methods. Adsorption of Cr（Ⅲ） increased as pH rose from 2.5 to 5.0. Adsorption of Cr（Ⅲ） led to pea...Cr（Ⅲ） adsorption by biochars generated from peanut, soybean, canola and rice straws is investigated with batch methods. Adsorption of Cr（Ⅲ） increased as pH rose from 2.5 to 5.0. Adsorption of Cr（Ⅲ） led to peak position shifts in the FFIR-PAS spectra of the biochars and made zeta potential values less negative, suggesting the formation of surface complexes between Cr^3＋ and functional groups on the biochars. The adsorption capacity of Cr（Ⅲ） followed the order： peanut straw char 〉 soybean straw char 〉 canola straw char 〉 rice straw char, which was consistent with the content of acidic functional groups on the biochars. The increase in Cr^3＋ hydrolysis as the pH rose was one of the main reasons for the increased adsorption of Cr（Ⅲ） by the biochars at higher pH values. Cr（llI） can be adsorbed by the biochars through electrostatic attraction between negative surfaces and Cr^3＋, but the relative contribution of electrostatic adsorption was less than 5%. Therefore, Cr（Ⅲ） was mainly adsorbed by the biochars through specific adsorption. The Langumir and Freundlich equations fitted the adsorption isotherms well and can therefore be used to describe the adsorption behavior of Cr（Ⅲ） by the crop straw biochars. The crop straw biochars have great adsorption capacities for Cr（Ⅲ） under acidic conditions and can be used as adsorbents to remove Cr（Ⅲ） from acidic wastewaters.展开更多
Two variable charge soils were incubated with biochars derived from straws of peanut, soybean, canola, and rice to investigate the effect of the biochars on their chemical properties and Pb（II） adsorption using batc...Two variable charge soils were incubated with biochars derived from straws of peanut, soybean, canola, and rice to investigate the effect of the biochars on their chemical properties and Pb（II） adsorption using batch experiments. The results showed soil cation exchange capacity （CEC） and pH significantly increased after 30 d of incubation with the biochars added. The incorporation of the biochars markedly increased the adsorption of Pb（II）, and both the electrostatic and non-electrostatic adsorption mechanisms contributed to Pb（II） adsorption by the variable charge soils. Adsorption isotherms illustrated legume- straw derived biochars more greatly increased Pb（II） adsorption on soils through the non-electrostatic mechanism via the formation of surface complexes between Pb（II） and acid functional groups of the biochars than did non-legume straw biochars. The adsorption capacity of Pb（II） increased, while the desorption amount slightly decreased with the increasing suspension pH for the studied soils, especially in a high suspension pH, indicating that precipitation also plays an important role in immobilizing Pb（II） to the soils.展开更多
We have had little understanding on the effects of different types and quantities of biochar amendment on soil N transformation process and the microbial properties. In this study, various biochars were produced from ...We have had little understanding on the effects of different types and quantities of biochar amendment on soil N transformation process and the microbial properties. In this study, various biochars were produced from straw residues and wood chips, and then added separately to a paddy soil at rates of 0.5, 1 and 2% （w/w）. The effects of biochar application on soil net N mineralization and nitrification processes, chemical and microbial properties were examined in the laboratory experiment. After 135 d of incubation, addition of straw biochars increased soil pH to larger extent than wood biochars. The biochar-amended soils had 37.7, 7.3 and 227.6% more soil organic carbon （SOC）, available P and K contents, respectively, than the control soil. The rates of net N mineralization and nitrification increased significantly as biochars quantity rose, and straw biochars had greater effect on N transformation rate than wood biochars. Soil microbial biomass carbon increased by 14.8, 45.5 and 62.5% relative to the control when 0.5, 1 and 2% biochars （both straw- and wood-derived biochars）, respectively, were added. Moreover, biochars amendments significantly enhanced the concentrations of phospholipid fatty acids （PLFAs）, as the general bacteria abundance increased by 161.0% on average. Multivariate analysis suggested that the three rice straw biochar （RB） application levels induced different changes in soil microbial community structure, but there was no significant difference between RB and masson pine biochar （MB） until the application rate reached 2%. Our results showed that biochars amendment can increase soil nutrient content, affect the N transformation process, and alter soil microbial properties, all of which are biochar type and quantity dependent. Therefore, addition of biochars to soil may be an appropriate way to disposal waste and improve soil quality, while the biochar type and addition rate should be taken into consideration before its large-scale application in agro-ecosystem.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41773136 and41703129)Innovation Talent Support Project of Liaoning (Grant No.LR2017073)+1 种基金the National Key Rand D Program of China (No.2017YFD0800301)the basic research projects of Source-sink transformation of arsenic and roxarsone in sediments (XXLJ2019007)。
文摘Arsenic(As)contamination in groundwater is a major problem in many countries,which causes serious health issues.In this paper,a novel method has been developed for the simultaneous removal of ROX and As(Ⅲ/Ⅴ)using the modified sorghum straw biochar(MSSB).The MSSB was characterized by X-ray diffraction,scanning electron microscopy,Fourier Transform Infrared,and Brunauer–Emmet–Teller(BET)surface area.The removal performance of MSSB for ROX,arsenite[As(Ⅲ)],and arsenate(As(Ⅴ))was investigated using batch experiments.At pH of 5,the arsenic concentration of 1.0 mg/L,adsorbent dose of 1.0 g/L,the maximum adsorptioncapacities of ROX,As(Ⅲ),and As(Ⅴ)were 12.4,5.3,and 23.0 mg/g,respectively.The adsorption behaviors were fit well with the Langmuir and the pseudo-second-order rate model.The results showed that MSSB acted as a highly effective adsorbent to simultaneously remove the composite pollution system consisted of ROX and As(Ⅲ/Ⅴ)in aqueous solutions,providing a promising method in environmental restoration applications.
文摘Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion (particularly on the uplands). One possible approach to addressing the soil constraints to rice production both on uplands and lowlands of Sierra Leone is the recycling of rice residues through biochar production and application to soils. A pot experiment was conducted to investigate the effects of application of biochar from rice residues on (i) soil physicochemical properties and (ii) the early growth characteristics of two rice varieties, NERICA L19 and ROK3. The experiment was arranged in a completely randomized design (CRD) with two biochar levels (0 and 15 g/kg soil) and two rice varieties in three replications. For the biochar treated soils (+biochar), 75 g rice straw biochar was applied to 5 kg air-dry soil (15 kg biochar/kg soil), mixed thoroughly and placed into perforated black polythene bags. Seeds of two rice varieties, NERICA L19 and ROK3 were planted on the treated and untreated soils for eight weeks. Application of biochar improved available phosphorus, exchangeable cations and cation exchange capacity in biochar treated soils compared to the control soil without biochar. Plant height, tiller number, and dry biomass weight of both rice varieties grown in soils amended with rice straw biochar were significantly higher than those on untreated soils. The most remarkable increase in plant growth characteristics as a result of biochar addition to soil was reflected in the biomass yield and tiller numbers. Dry shoot biomass for ROK3 rice variety varied significantly from a mean of 3.5 g (control) to 26.2 g (+biochar) while tiller numbers significantly varied from 10 (control) to 29.6 (+biochar). Similarly, for NERICA L19 rice variety, dry shoot biomass increased significantly from 4.5 g (control) to 22.7 g (+biochar) while tiller numbers increased significantly from a mean of 12.3 (control) to 30 (+biochar). Thus converting rice residues to biochar and applying to soil holds promise for improving rice production in Sierra Leone.
基金supported by the National Key Technology R&D Program of China (No. 2012BAC17B04)the Fundamental Research Funds for the Central Universities, China
文摘The simultaneous sorption behavior and characteristics of cadmium (Cd) and sulfamethoxazole (SMX) on rice straw biochar were investigated. Isotherms of Cd and SMX were well modeled by the Langmuir equation (R2 >0.95). The calculated maximum adsorption parameter (Q) of Cd was similar in single and binary systems (34129.69 and 35919.54 mg/kg, respectively). However, the Q of SMX in a binary system (9182.74 mg/kg) was much higher than that in a single system (1827.82 mg/kg). The presence of Cd significantly promoted the sorption of SMX on rice straw biochar. When the pH ranged from 3 to 7.5, the sorption of Cd had the characteristics of a parabola pattern with maximum adsorption at pH 5, while the adsorption quantity of SMX decreased with increasing pH, with maximum adsorption at pH 3. The amount of SMX adsorbed on biochar was positively correlated with the surface area of the biochar, and the maximum adsorption occurred with d 250 biochar (biochar with a diameter of 150-250 μm). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that the removal of Cd and SMX by rice straw biochar may be attributed to precipitation and the formation of surface complexes between Cd or SMX and carboxyl or hydroxyl groups. The results of this study indicate that rice straw biochar has the potential for simultaneous removal of Cd and SMX from co-contaminated water.
基金supported by the National Natural Science Foundation of China (31070549, 31130013 and 40801087)the Research Project of Ministry of Education, China (213019A)
文摘Whether the biochar amendment could affect soil organic matter （SOM） turnover and hence soil carbon （C） stock remains poorly understood. Effects of the addition of ^13C-labelled rice straw or its pyrolysed biochar at 250 or 350℃ to a sugarcane soil （Ferrosol） on soil labile C （dissolved organic C, DOC; microbial biomass C, MBC; and mineralizable C, MC） and soil organic C （SOC） were investigated after 112 d of laboratory incubation at 25℃. Four treatments were examined as （1） the control soil without amendment （Soil）; （2） soil plus ^13C-labelled rice straw （Soil＋Straw）; （3） soil plus 250℃ biochar （Soil＋B250） and （4） soil plus 350℃biochar （Soil＋B350）. Compared to un-pyrolysed straw, biochars generally had an increased aryl C, carboxyl C, C and nitrogen concentrations, a decreased O-alkyl C and C：N ratio, but similar alkyl C and δ^13C （1 742- 1 877 %）. Among treatments, significant higher DOC, MBC and MC derived from the new C （straw or biochar） ranked as Soil＋Straw〉Soil＋B250〉Soil＋B350, whilst significant higher SOC from the new C as Soil＋B250〉Soil＋Straw≈Soil＋B350. Compared to Soil, DOC and MBC derived from the native soil were decreased under straw or biochar addition, whilst MC from the native soil was increased under straw addition but decreased under biochar addition. Meanwhile, native SOC was similar among the treatments, irrespective of the straw or biochar addition. Compared to Soil, significant higher total DOC and total MBC were under Soil＋Straw, but not under Soil＋B250 and Soil＋B350, whilst significant higher total MC and total SOC were under straw or biochar addition, except for MC under Soil＋B350. Our results demonstrated that the application of biochar to soil may be an appropriate management practice for increasing soil C storage.
基金We gratefully acknowledge the support provided by the:Earmarked Fund for“Modern Agro-industry Technology Research System”(CARS-01-46)National Key R&D Program“Research and Development of Biochar-Based Fertilizer and Microbial Fertilizer”(2017YFD0200800)+2 种基金Innovative Talents Promotion Plan of Ministry of Science and Technology(2017RA2211)Liaoning Revitalization Talents Program(No.XLYC1802094)Shenyang Support Plan for Young&Middle-aged Scientific and Technological Innovation Talents(RC180204).
文摘Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current developments in biochar industry and the production practices prevalent among enterprises in China are critiques.This review analyzes current knowledge gaps,challenges,and opportunities in the industrial application of straw biochar returning.Biochar standards,the quantitative and qualitative analysis methods for biochar,and high-value-added products that are based on biochar are critically examined with goal of providing recommendations for future studies.We propose production and modification of biochar that is application oriented to enhance its fitness for purpose as well as long-term and large-space-scale field study to better understand its impact on soil properties and ecotoxicology.Finally,we make prospects for the future development of SBR,including constructing a standard system about straw biochar returning and promoting self-discipline of biochar industry and the establishment of a biochar-based agricultural production model.
基金National Key R&D Program of China(2019YFC1803403 and 2021YFD1500202)the National Natural Science Foundation of China(41771275).
文摘To better understand the amendment effects and mechanisms of aluminum(Al(Ⅲ))phytotoxicity mitigation by differ-ent regional crop straw biochars,wheat seedling root elongation trials were conducted.The contributions of liming effect,oxygen-containing surface functional group adsorption,and oxyanions precipitation to Al(Ⅲ)phytotoxicity mitigation by Ca(OH)_(2),pristine and ash-free canola straw biochar were evaluated.The results indicated that biochars derived from canola straw collected from four different regions(Yingtan,Xuancheng,Nanjing,and Huaiyin)caused 22-70%wheat seedling root elongation,which might be linked to liming effect.Incorporation of the corresponding ash-free biochars caused 15-30%elongation,which could be attributed to the surface functional group adsorption.About 0-60%of changes could be explained by Al(Ⅲ)precipitation with inorganic oxyanions.These findings provide new insights into the physicochemical properties,potential applications,efficiencies,and underlying mechanisms of crop straw biochar in alleviating Al(Ⅲ)phytotoxicity,which is dependent on the cultivation soil,and indicate similar application of crop straw biochar for acidic soil amelioration,contaminated soil remediation,and arable soil improvement.
基金The project was financially supported by the National key research and development plan“The technology of agricultural waste composting and the research of integrated equipment for composting”(2016YFD0800600).
文摘The purpose of this paper was to study the effects of different C/N ratios on the maturity and microbial quantity of com-posting with sesame meal and rice straw biochar.Rice straw was calcined into biochar as raw materials composting with sesame meal for 30 days,referring to Chenfu Agricultural Book in Sōuthern Song Dynasty(1127-1279 A.D.).Sesame meal was used to adjust the C/N ratio of compost,and three treatments were designed in the experiment,which were C/N ratios of 15,20 and 30,respectively.The results showed that C/N ratio of 20 was beneficial for promoting the temperature rise,the removal of water,the degradation of organic carbon,and the decrease of microbial quantity.The C/N ratio of 20 was beneficial to the compost maturity(T value was 0.47,final GI was 99.67%).The results of Pearson correlation analysis showed that C/N ratio was positively correlated with moisture content,total organic carbon and negatively correlated with germination index,indicating that high C/N ratio was beneficial to water removal and total organic carbon degradation.Therefore,we suggest that the suitable C/N ratio of rice straw biochar and sesame meal is 20.At the same time,we have proved that the composting method in Southern Song Dynasty is feasible,which is of great significance to understand the development of composting in China.
基金funded by the National Key Technology R&D Program of China(2015BAD05B03)
文摘Five crop straws (wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210℃, 2.5 MPa and then pyrolyzed at 500℃ for 2 h. Steam explosion (SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area (SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity (AEC) (6.88–11.44 cmol kg–1) and point of zero net charges (PZNC) (pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.
基金supported by the Science and Technology Consulting Program of Chinese Academy of Engineering(2015-XY-25)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2014BAD02B06-02)+2 种基金the Special Fund for Agro-scientific Research in Public Interest of China(201303095)the Basic Research Foundation of Shenyang Science and Technology Program,China(F16-205-1-38)the Program for Changjiang Scholars and Innovative Research Team in University,China(IRT13079)
文摘The additions of straw and biochar have been suggested to increase soil fertility, carbon sequestration, and crop produc- tivity of agricultural lands. To our knowledge, there is little information on the effects of straw and biochar addition on soil nitrogen form, carbon storage, and super rice yield in cold waterlogged paddy soils. We performed field trials with four treatments including conventional fertilization system （CK）, straw amendment 6 t ha^-1 （S）, biochar amendment 2 t ha^-1 （C1）, and biochar amendment 40 t ha^-1 （C2）. The super japonica rice variety, Shennong 265, was selected as the test Crop. The results showed that the straw and biochar amendments improved total nitrogen and organic carbon content of the soil, reduced N2O emissions, and had little influence on nitrogen retention, nitrogen density, and CO2 emissions. The S and C1 increased NH4^＋-N content, and C2 increased NO3^--N content. Both S and C1 had little influence on soil organic carbon density （SOCD） and C/N ratio. However, C2 greatly increased SOCD and C/N ratio. C1 and C2 significantly improved the soil carbon sequestration （SCS） by 62.9 and 214.0% （P〈0.05）, respectively, while S had no influence on SCS. C1 and C2 maintained the stability of super rice yield, and significantly reduced CH4 emissions, global warming potential （GWP）, and greenhouse gas intensity （GHGI）, whereas S had the opposite and negative effects. In summary, the biochar amendments in cold waterlogged paddy soils of North China increased soil nitrogen and carbon content, improved soil carbon sequestration, and reduced GHG emission without affecting the yield of super rice.
基金financially supported by the National Key Technologies R&D Program of China during the 12th Fiveyear Plan period (2012BAD22B01)
文摘The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar,straw,and chemical fertilizers compared with chemical fertilization alone.Five soil fertilization treatments were evaluated：regular chemical fertilizers（RF）,straw＋regular chemical fertilizers（SRF）,straw biochar＋regular chemical fertilizers（SCRF）,bamboo biochar（BC）＋regular chemical fertilizers（BCRF）,and straw biochar＋70%regular chemical fertilizers（SC＋70%RF）.Their effects were investigated after approximately 1.5 years.The soil p H and cation exchange capacity（CEC）were significantly higher in biochar-treated soils.The soil phosphorous（P）and potassium（K）contents increased with biochar application.The soil Colwell P content was significantly increased with the addition of straw biochar in the treatments of SCRF and SC＋70%RF.The oxygen（O）：carbon（C）ratio doubled in BC picked from the soil.This indicated that BC underwent a significant oxidation process in the soil.The denaturing gradient gel electrophoresis（DGGE）fingerprints of microbial communities differed among the treatments.Soils with added biochar had higher Shannon diversity and species richness indices than soils without biochars.The results suggest that biochar can improve soil fertility.
基金supported by the National Natural Science Foundation of China(No.41230855)the National Key Technology R&D Program of China(No.2012BAJ24B06)
文摘Cr（Ⅲ） adsorption by biochars generated from peanut, soybean, canola and rice straws is investigated with batch methods. Adsorption of Cr（Ⅲ） increased as pH rose from 2.5 to 5.0. Adsorption of Cr（Ⅲ） led to peak position shifts in the FFIR-PAS spectra of the biochars and made zeta potential values less negative, suggesting the formation of surface complexes between Cr^3＋ and functional groups on the biochars. The adsorption capacity of Cr（Ⅲ） followed the order： peanut straw char 〉 soybean straw char 〉 canola straw char 〉 rice straw char, which was consistent with the content of acidic functional groups on the biochars. The increase in Cr^3＋ hydrolysis as the pH rose was one of the main reasons for the increased adsorption of Cr（Ⅲ） by the biochars at higher pH values. Cr（llI） can be adsorbed by the biochars through electrostatic attraction between negative surfaces and Cr^3＋, but the relative contribution of electrostatic adsorption was less than 5%. Therefore, Cr（Ⅲ） was mainly adsorbed by the biochars through specific adsorption. The Langumir and Freundlich equations fitted the adsorption isotherms well and can therefore be used to describe the adsorption behavior of Cr（Ⅲ） by the crop straw biochars. The crop straw biochars have great adsorption capacities for Cr（Ⅲ） under acidic conditions and can be used as adsorbents to remove Cr（Ⅲ） from acidic wastewaters.
基金supported by the Key Technoligies R&D Program of China during the 12th Five-Year Plan period (2012BAJ24B06)the National Natural Science Foundation of China (41230855)
文摘Two variable charge soils were incubated with biochars derived from straws of peanut, soybean, canola, and rice to investigate the effect of the biochars on their chemical properties and Pb（II） adsorption using batch experiments. The results showed soil cation exchange capacity （CEC） and pH significantly increased after 30 d of incubation with the biochars added. The incorporation of the biochars markedly increased the adsorption of Pb（II）, and both the electrostatic and non-electrostatic adsorption mechanisms contributed to Pb（II） adsorption by the variable charge soils. Adsorption isotherms illustrated legume- straw derived biochars more greatly increased Pb（II） adsorption on soils through the non-electrostatic mechanism via the formation of surface complexes between Pb（II） and acid functional groups of the biochars than did non-legume straw biochars. The adsorption capacity of Pb（II） increased, while the desorption amount slightly decreased with the increasing suspension pH for the studied soils, especially in a high suspension pH, indicating that precipitation also plays an important role in immobilizing Pb（II） to the soils.
基金jointly supported by funding from the National Natural Science Foundation of China (41171233)the National Basic Research Program of China (2013CB127401)
文摘We have had little understanding on the effects of different types and quantities of biochar amendment on soil N transformation process and the microbial properties. In this study, various biochars were produced from straw residues and wood chips, and then added separately to a paddy soil at rates of 0.5, 1 and 2% （w/w）. The effects of biochar application on soil net N mineralization and nitrification processes, chemical and microbial properties were examined in the laboratory experiment. After 135 d of incubation, addition of straw biochars increased soil pH to larger extent than wood biochars. The biochar-amended soils had 37.7, 7.3 and 227.6% more soil organic carbon （SOC）, available P and K contents, respectively, than the control soil. The rates of net N mineralization and nitrification increased significantly as biochars quantity rose, and straw biochars had greater effect on N transformation rate than wood biochars. Soil microbial biomass carbon increased by 14.8, 45.5 and 62.5% relative to the control when 0.5, 1 and 2% biochars （both straw- and wood-derived biochars）, respectively, were added. Moreover, biochars amendments significantly enhanced the concentrations of phospholipid fatty acids （PLFAs）, as the general bacteria abundance increased by 161.0% on average. Multivariate analysis suggested that the three rice straw biochar （RB） application levels induced different changes in soil microbial community structure, but there was no significant difference between RB and masson pine biochar （MB） until the application rate reached 2%. Our results showed that biochars amendment can increase soil nutrient content, affect the N transformation process, and alter soil microbial properties, all of which are biochar type and quantity dependent. Therefore, addition of biochars to soil may be an appropriate way to disposal waste and improve soil quality, while the biochar type and addition rate should be taken into consideration before its large-scale application in agro-ecosystem.
