X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of...X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of X-ray diffraction patterns were studied both before and after chemically selective dissolution. It was found that lithiophorite was a common Mn oxide in all examined Fe-Mn nodules. Todorokite, however, was a predominant Mn oxide in Fe-Mn nodules in caf-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules of arp-udic Luvisols in Wuhan and Zaoyang, Hubei Province, contained birnessite and vernadite. Hollandite was found in Fe-Mn nodules of alt-udic Ferrisols of Yizhang, Hunan Province; arp-udic Luvisols of Zaoyang, Hubei Province; and cal-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules in alt-udic Ferrisols of Guiyang, Hunan Province, had a few coronadites. Mineralogy of Mn oxide minerals in soil Fe-Mn nodules was related to soil environment, soil types and quantities of relevant cations.展开更多
Precisely controlling the crystalline phase structure and exposed facets at the atomic level opens up a new avenue for efficient catalyst design.Along this line,we report an unconventional face-centered cubic(fcc)Ru w...Precisely controlling the crystalline phase structure and exposed facets at the atomic level opens up a new avenue for efficient catalyst design.Along this line,we report an unconventional face-centered cubic(fcc)Ru with twinned structure and stacking-fault defects as a competent electrocatalyst towards alkaline hydrogen oxidation reaction(HOR),which is now a major obstacle for the commercialization of anion exchange membrane fuel cells(AEMFC).With conventional hexagonal close packing(hcp)Ru as the counterpart,a novel scope from the phase-engineering is introduced to identify the activity origin and provide fundamental understanding of the sluggish HOR kinetics in alkaline medium.Systematic electrochemical analysis assisted by deconvoluting the hydrogen(H)desorption peaks indicates the superior performance of fcc Ru origins from the structure defects and higher proportion of the most active sites.DFT calculations,together with CO-stripping voltammograns further corroborate the stronger hydroxyl species(OH^(*))affinity lead to the higher activity on these sites.Meanwhile,it also demonstrates the H^(*)adsorption/desorption on polycrystalline Ru among the conventional"hydrogen region"is accompanied by the surface bound OH^(*)in alkaline medium,which is of great significance for subsequent alkaline HOR exploration and catalyst design.展开更多
In this study the antioxidant activity of barley malt rootlet (BMR) extracts w</span><span style="font-family:"">as</span><span style="font-family:""> evaluated in...In this study the antioxidant activity of barley malt rootlet (BMR) extracts w</span><span style="font-family:"">as</span><span style="font-family:""> evaluated in heat treated corn oil up to 5 hours at 185</span><span style="font-family:"">°</span><span style="font-family:"">C frying temperature. The antioxidant activity </span><span style="font-family:"">of </span><span style="font-family:"">BMR extracts was measured at 25, 50, 100 and 150 ppm concentrations. The free and bound antioxidant phenolics were extracted from BMR using three different extraction methods. Conventional solvent extraction (CSE), microwave assisted extraction (MAE) and autoclave assisted pretreated solvent extraction (APSE). In the present experiment, the total phenolic content and antioxidant activity of the various extracts w</span><span style="font-family:"">ere</span><span style="font-family:""> measured. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the ability of the BMR to protect lipid peroxidation in corn oil at 185</span><span style="font-family:"">°</span><span style="font-family:"">C frying temperature. The formation of TBARS at 5 hours of heat treated corn oil ha</span><span style="font-family:"">s</span><span style="font-family:""> shown similar antioxidant levels in 150 ppm butylated hydroxytoluene (BHT) or MAE free phenolic extract added to corn oil. TBARS value for BHT was 1.896 ± 0.013 μg/mL of corn oil and for MAE was 1.896 ± 0.034 μg/mL of corn oil. The highest level of antioxidant activity was found for the free phenolic extracts. The order of inhibition of oxidation was found to be for free phenolics as follows: BHT (100 ppm) > APSE (50 ppm) > MAE (100 ppm) > CSE (100 ppm).展开更多
Fe-Mn oxide modified biochar(FMBC)was produced to explore its potential for remediation of Hg-Cd contaminated paddy soils.The results showed that the application of FMBC decreased the contents of bioavailable Hg and C...Fe-Mn oxide modified biochar(FMBC)was produced to explore its potential for remediation of Hg-Cd contaminated paddy soils.The results showed that the application of FMBC decreased the contents of bioavailable Hg and Cd by 41.49-81.85%and 19.47-33.02%in contrast to CK,while the amount of labile organic carbon(C)fractions and C-pool management index(CPMI)was increased under BC and FMBC treated soils,indicating the enhancement of soil C storage and nutrient cycling function.Dry weight of different parts of Oryza sativa L.was enhanced after the addition of BC and FMBC,and the contents of Fe and Mn in root iron-manganese plaques(IMP)were 1.46-2.06 and 6.72-19.35 times higher than those of the control groups.Hg and Cd contents in brown rice under the FMBC treatments were significantly reduced by 18.32-71.16%and 59.52-72.11%compared with the control.FMBC addition altered the composition and metabolism function of soil bacterial communities,especially increasing the abundance of keystone phyla,including Firmicutes,Proteobacteria and Actinobacteria.Partial least squares path modelling(PLSPM)revealed that the contents of Na_(2)S_(2)O_(3)-Hg,DTPA-Cd and IMP were the key indicators affecting Hg and Cd accumulation in rice grains.These results demonstrate the simultaneous value of FMBC in remediation of Hg and Cd combined pollution and restoring soil fertility and biological productivity.展开更多
The polymer-bound Schiff base ternary manganese complexes [PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ)] have been prepared from the polymer-bound Schiff base ligand, a manganese salt and the second ligand, such as 1,10-phena...The polymer-bound Schiff base ternary manganese complexes [PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ)] have been prepared from the polymer-bound Schiff base ligand, a manganese salt and the second ligand, such as 1,10-phenanthroline(phen), 2,2′-bipyridyl(bipy) and 8-quinolinol(8HQ). The polymer-bound Schiff base ternary manganese complexes were characterized by means of infrared spectrometry and ICP-AES. The catalytic activities of the complexes have been studied in the aerobic epoxidation of long-chain linear aliphatic olefins. It is shown that 1-octene or 1-decene can be directly oxidized by molecular oxygen when catalyzed by PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ), and 1,2-epoxy alkane can be afforded in these reactions.展开更多
Cadmium (Cd) and arsenic (As) are two of the most toxic elements.However,the chemical behaviors of these two elements are different,making it challenging to utilize a single adsorbent with high adsorption capacity for...Cadmium (Cd) and arsenic (As) are two of the most toxic elements.However,the chemical behaviors of these two elements are different,making it challenging to utilize a single adsorbent with high adsorption capacity for both Cd(Ⅱ) and As(Ⅴ) removal.To solve this problem,we synthesized HA/Fe-Mn oxides-loaded biochar (HFMB),a novel ternary material,to perform this task,wherein scanning electron microscopy (SEM) combined with EDS (SEM-EDS) was used to characterize its morphological and physicochemical properties.The maximum adsorption capacity of HFMB was 67.11 mg/g for Cd(Ⅱ) and 35.59 mg/g for As(Ⅴ),which is much higher compared to pristine biochar (11.06 mg/g,0 mg/g for Cd(Ⅱ) and As(Ⅴ),respectively).The adsorption characteristics were investigated by adsorption kinetics and the effects of the ionic strength and pH of solutions.X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) revealed that chelation and deposition were the adsorption mechanisms that bound Cd(Ⅱ) to HFMB,while ligand exchange was the adsorption mechanism that bound As(Ⅴ).展开更多
The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. ...The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. The molar ratio of Fe and Mn in the synthetic Fe-Mn binary oxides was 4 ： 3. The FM-1 and FM-2（prepared at different activation temperatures） having high specific surface areas（358.87 and 128.58 m^2/g, respectively） were amorphous and of nano particle types. The amount of arsenic adsorbed on FM-1 was higher than that adsorbed on FM-2 particles. After adsorption by FM-1, residual arsenic concentration decreased to less than 10 μg/L. The adsorption kinetics data were analyzed using different kinetic models including pseudo first-order model, pseudo second-order model, Elovich model and intraparticle diffusion model. Pseudo second-order kinetic model was the most appropriate model to describe the adsorption kinetics. The adsorption percentage of As（Ⅲ） increased in the p H range of 2–3 while it decreased with the increase of pH（ 3〈pH〈10）. The effects of coexisting anions on As（Ⅲ） removal using FM-1 and FM-2 were also studied and the order of the effects is as follows： NO_3^-, Cl-, F-〈SO_4^（2-）, HCO_3-〈H_2PO_4^-, indicating that H_2PO_4^- is the major competitor with As（Ⅲ） for adsorptive sites on the surface of the adsorbents. The higher adsorption capacity of FM-1 makes it potentially attractive adsorbent for the removal of As（Ⅲ） from groundwater.展开更多
基金Project(No.49771049)supported by the National Natural Science Foundation of China
文摘X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of X-ray diffraction patterns were studied both before and after chemically selective dissolution. It was found that lithiophorite was a common Mn oxide in all examined Fe-Mn nodules. Todorokite, however, was a predominant Mn oxide in Fe-Mn nodules in caf-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules of arp-udic Luvisols in Wuhan and Zaoyang, Hubei Province, contained birnessite and vernadite. Hollandite was found in Fe-Mn nodules of alt-udic Ferrisols of Yizhang, Hunan Province; arp-udic Luvisols of Zaoyang, Hubei Province; and cal-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules in alt-udic Ferrisols of Guiyang, Hunan Province, had a few coronadites. Mineralogy of Mn oxide minerals in soil Fe-Mn nodules was related to soil environment, soil types and quantities of relevant cations.
基金financially supported by the National Natural Science Foundation(91963109)the Fundamental Research Funds for the Central Universities(2019kfyRCPY100)supported by the Analytical and Testing Center of Huazhong University of Science&Technology。
文摘Precisely controlling the crystalline phase structure and exposed facets at the atomic level opens up a new avenue for efficient catalyst design.Along this line,we report an unconventional face-centered cubic(fcc)Ru with twinned structure and stacking-fault defects as a competent electrocatalyst towards alkaline hydrogen oxidation reaction(HOR),which is now a major obstacle for the commercialization of anion exchange membrane fuel cells(AEMFC).With conventional hexagonal close packing(hcp)Ru as the counterpart,a novel scope from the phase-engineering is introduced to identify the activity origin and provide fundamental understanding of the sluggish HOR kinetics in alkaline medium.Systematic electrochemical analysis assisted by deconvoluting the hydrogen(H)desorption peaks indicates the superior performance of fcc Ru origins from the structure defects and higher proportion of the most active sites.DFT calculations,together with CO-stripping voltammograns further corroborate the stronger hydroxyl species(OH^(*))affinity lead to the higher activity on these sites.Meanwhile,it also demonstrates the H^(*)adsorption/desorption on polycrystalline Ru among the conventional"hydrogen region"is accompanied by the surface bound OH^(*)in alkaline medium,which is of great significance for subsequent alkaline HOR exploration and catalyst design.
文摘In this study the antioxidant activity of barley malt rootlet (BMR) extracts w</span><span style="font-family:"">as</span><span style="font-family:""> evaluated in heat treated corn oil up to 5 hours at 185</span><span style="font-family:"">°</span><span style="font-family:"">C frying temperature. The antioxidant activity </span><span style="font-family:"">of </span><span style="font-family:"">BMR extracts was measured at 25, 50, 100 and 150 ppm concentrations. The free and bound antioxidant phenolics were extracted from BMR using three different extraction methods. Conventional solvent extraction (CSE), microwave assisted extraction (MAE) and autoclave assisted pretreated solvent extraction (APSE). In the present experiment, the total phenolic content and antioxidant activity of the various extracts w</span><span style="font-family:"">ere</span><span style="font-family:""> measured. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the ability of the BMR to protect lipid peroxidation in corn oil at 185</span><span style="font-family:"">°</span><span style="font-family:"">C frying temperature. The formation of TBARS at 5 hours of heat treated corn oil ha</span><span style="font-family:"">s</span><span style="font-family:""> shown similar antioxidant levels in 150 ppm butylated hydroxytoluene (BHT) or MAE free phenolic extract added to corn oil. TBARS value for BHT was 1.896 ± 0.013 μg/mL of corn oil and for MAE was 1.896 ± 0.034 μg/mL of corn oil. The highest level of antioxidant activity was found for the free phenolic extracts. The order of inhibition of oxidation was found to be for free phenolics as follows: BHT (100 ppm) > APSE (50 ppm) > MAE (100 ppm) > CSE (100 ppm).
基金National Natural Science Foundation of China,31971525,Yuebing SunThe Innovation Program of Chinese Academy of Agricultural Sciences,CAAS-CSGLCA-202302,Yuebing Sun.
文摘Fe-Mn oxide modified biochar(FMBC)was produced to explore its potential for remediation of Hg-Cd contaminated paddy soils.The results showed that the application of FMBC decreased the contents of bioavailable Hg and Cd by 41.49-81.85%and 19.47-33.02%in contrast to CK,while the amount of labile organic carbon(C)fractions and C-pool management index(CPMI)was increased under BC and FMBC treated soils,indicating the enhancement of soil C storage and nutrient cycling function.Dry weight of different parts of Oryza sativa L.was enhanced after the addition of BC and FMBC,and the contents of Fe and Mn in root iron-manganese plaques(IMP)were 1.46-2.06 and 6.72-19.35 times higher than those of the control groups.Hg and Cd contents in brown rice under the FMBC treatments were significantly reduced by 18.32-71.16%and 59.52-72.11%compared with the control.FMBC addition altered the composition and metabolism function of soil bacterial communities,especially increasing the abundance of keystone phyla,including Firmicutes,Proteobacteria and Actinobacteria.Partial least squares path modelling(PLSPM)revealed that the contents of Na_(2)S_(2)O_(3)-Hg,DTPA-Cd and IMP were the key indicators affecting Hg and Cd accumulation in rice grains.These results demonstrate the simultaneous value of FMBC in remediation of Hg and Cd combined pollution and restoring soil fertility and biological productivity.
基金Supported by the National Natural Science Foundation of China(No.2 99330 5 0,2 95 74 176 ,2 0 2 74 0 34)
文摘The polymer-bound Schiff base ternary manganese complexes [PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ)] have been prepared from the polymer-bound Schiff base ligand, a manganese salt and the second ligand, such as 1,10-phenanthroline(phen), 2,2′-bipyridyl(bipy) and 8-quinolinol(8HQ). The polymer-bound Schiff base ternary manganese complexes were characterized by means of infrared spectrometry and ICP-AES. The catalytic activities of the complexes have been studied in the aerobic epoxidation of long-chain linear aliphatic olefins. It is shown that 1-octene or 1-decene can be directly oxidized by molecular oxygen when catalyzed by PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ), and 1,2-epoxy alkane can be afforded in these reactions.
基金supported by the National Key Research and Development Project of China(No.2016YFD0800706)the Science and Technology Project of Fujian Province of China(No.2018Y0080)the Science and Technology Project of Xiamen(No.3502Z20172026)
文摘Cadmium (Cd) and arsenic (As) are two of the most toxic elements.However,the chemical behaviors of these two elements are different,making it challenging to utilize a single adsorbent with high adsorption capacity for both Cd(Ⅱ) and As(Ⅴ) removal.To solve this problem,we synthesized HA/Fe-Mn oxides-loaded biochar (HFMB),a novel ternary material,to perform this task,wherein scanning electron microscopy (SEM) combined with EDS (SEM-EDS) was used to characterize its morphological and physicochemical properties.The maximum adsorption capacity of HFMB was 67.11 mg/g for Cd(Ⅱ) and 35.59 mg/g for As(Ⅴ),which is much higher compared to pristine biochar (11.06 mg/g,0 mg/g for Cd(Ⅱ) and As(Ⅴ),respectively).The adsorption characteristics were investigated by adsorption kinetics and the effects of the ionic strength and pH of solutions.X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) revealed that chelation and deposition were the adsorption mechanisms that bound Cd(Ⅱ) to HFMB,while ligand exchange was the adsorption mechanism that bound As(Ⅴ).
基金supported by the National Natural Science Foundation of China(No.41120124003)the Ministry of Science and Technology of China(No.2012AA062602)the 111 project and Priority Development Projects of SRFDP of the Ministry of Education of China
文摘The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. The molar ratio of Fe and Mn in the synthetic Fe-Mn binary oxides was 4 ： 3. The FM-1 and FM-2（prepared at different activation temperatures） having high specific surface areas（358.87 and 128.58 m^2/g, respectively） were amorphous and of nano particle types. The amount of arsenic adsorbed on FM-1 was higher than that adsorbed on FM-2 particles. After adsorption by FM-1, residual arsenic concentration decreased to less than 10 μg/L. The adsorption kinetics data were analyzed using different kinetic models including pseudo first-order model, pseudo second-order model, Elovich model and intraparticle diffusion model. Pseudo second-order kinetic model was the most appropriate model to describe the adsorption kinetics. The adsorption percentage of As（Ⅲ） increased in the p H range of 2–3 while it decreased with the increase of pH（ 3〈pH〈10）. The effects of coexisting anions on As（Ⅲ） removal using FM-1 and FM-2 were also studied and the order of the effects is as follows： NO_3^-, Cl-, F-〈SO_4^（2-）, HCO_3-〈H_2PO_4^-, indicating that H_2PO_4^- is the major competitor with As（Ⅲ） for adsorptive sites on the surface of the adsorbents. The higher adsorption capacity of FM-1 makes it potentially attractive adsorbent for the removal of As（Ⅲ） from groundwater.
文摘为了准确评价环境生物中的氚水平,基于高温催化氧化的原理,建立了一套生物中有机结合氚(Organically Bound Tritium,OBT)的制样装置Pyrolyser高温分解熔炉,通过大量的条件实验,优化了OBT的制样条件,并对典型植物中OBT分析的不确定度进行了研究。结果表明,在该装置中OBT制备的最佳条件为通氧量100 m L·min-1、催化氧化温度800°C和氧化燃烧温度600°C,此时,植物样品中OBT的回收率可达85%以上。优化后高温分解熔炉的制样过程更加安全,样品燃烧氧化更加充分,完全满足环境植物中OBT的分析要求,可用于环境生物氚水平测量及评价。
