Formic acid(FA)has come to be considered a potential candidate for hydrogen storage,and the development of efficient catalysts for H2releasing is crucial for realizing the sustainable process from FA.Herein,we have de...Formic acid(FA)has come to be considered a potential candidate for hydrogen storage,and the development of efficient catalysts for H2releasing is crucial for realizing the sustainable process from FA.Herein,we have developed the ultrafine Pd nanoparticle(NPs)with amine-functionalized carbon as a support,which was found to show an excellent catalytic activity in H_(2)generation from FA dehydrogenation.The synergetic mechanism between amine-group and Pd active site was demonstrated to facilitate H2generation byβ-hydride elimination.Moreover,the texture of support for Pd NPs also plays an important role in determining the reactivity of FA,since the diffusion of gaseous products makes the kinetics of diffusion as a challenge in this high performance Pd catalysts.As a result,the as-prepared Pd/NH_(2)-TPC catalyst with the small sized Pd nanoparticles and the hierarchically porous structures shows a turnover of frequency(TOF)value of 4312 h^(-1)for the additive-free FA dehydrogenation at room temperature,which is comparable to the most promising heterogeneous catalysts.Our results demonstrated that the intrinsic catalytic activities of active site as well as the porous structure of support are both important factors in determining catalytic performances in H2generation from FA dehydrogenation,which is also helpful to develop high-activity catalysts for other advanced gas-liquid-solid reactions systems.展开更多
Silver carp mediated biological control techniques are often advocated for controlling cyanobacteria blooms in eutrophic water,which are often enriched with arsenic(As).How-ever,the transfer and fate of As during the ...Silver carp mediated biological control techniques are often advocated for controlling cyanobacteria blooms in eutrophic water,which are often enriched with arsenic(As).How-ever,the transfer and fate of As during the biological control of cyanobacteria blooms by silver carp in As-rich eutrophic water remain unclear.Based on the simulated ecosystem experiment,the accumulation of As in silver carp and the transfer and fate of As in the water-algae-silver carp system during Microcystis aeruginosa blooms controlled by silver carp were investigated.Microcystis aeruginosa showed high tolerance to As(V).The accumulation of As in different tissues of silver carp was different,as follows:intestine>liver>gill>skin>muscle.After silver carp ingested As-rich Microcystis aeruginosa,As accumulation in the intestine,liver,gill,and skin of silver carp was enhanced under the action of digestion and skin contact.Compared with the system without algal,As accumulation in the intestine,liver,gill,and skin of silver carp increased by 1.1,3.3,3.3,and 9.6 times,respectively,after incubation for 30 days in the system with Microcystis aeruginosa,while the accumulation of As in the muscle was only slightly increased by 0.56 mg/kg.This work revealed the transfer and fate of As during algal control by silver carp,elucidated the accumulation mechanism of As in water-algae-silver carp system,enriched our understanding of As bioaccumulation and transformation in As-rich eutrophication water,and provided a scientific basis for as-sessing and predicting As migration and enrichment in water-algae-silver carp system.展开更多
The conversion of rapeseed straw into biochar not only effectively mitigates pollution from traditional straw burning but also aligns with China’s sustainable agricultural development goals. A significant quantity of...The conversion of rapeseed straw into biochar not only effectively mitigates pollution from traditional straw burning but also aligns with China’s sustainable agricultural development goals. A significant quantity of rapeseed stalks is frequently burned in fields, leading to severe air pollution characterized by black smoke and residue, resulting in a substantial waste of straw resources. To address this issue, rapeseed straw form Nanchi Village, Puzhen Town, Hanzhong City, Shaanxi Province, was utilized as a precursor and KOH was employed as an activator to produce porous activated carbon by pyrolysis. Scanning electron microscopy (SEM), elemental analyzer, infrared spectroscopy, specific surface area analysis, and other instruments were employed to characterize the porous activated carbon produced under various temperature gradients and activator concentrations. The microelement composition, structure, specific surface area, and pore size of biochar produced under varying conditions were analyzed to determine the optimal preparation parameters. Furthermore, the adsorption efficiency for tetracycline in wastewater was evaluated using a three-factor, three-level orthogonal experimental design. The results showed that the interior of the activated carbon was porous, while the exterior contained oxygenated functional groups that facilitated the adsorption of nitrogen, phosphorus, and other elements. The optimal carbonization temperature and KOH concentration for activated carbon were determined to be 400°C and 0.5, respectively. The optimal adsorption conditions were identified as pH value of 7, an initial tetracycline concentration of 30 mg/L, a biochar dosage of 0.2 g, an adsorption time of 60 min, and a removal rate of 98.53%. The factors influencing the adsorption of tetracycline onto rapeseed straw biochar were ranked as initial tetracycline concentration>adsorption reaction time>biochar dasage. The findings will provide valuable references for research on biochar performance and the treatment of tetracycline contamination in water.展开更多
Optimization of water and fertilizer coupling management approaches could not only increase apple yield and quality,but also reduce the potential negative impacts of such management activities on the environment.The a...Optimization of water and fertilizer coupling management approaches could not only increase apple yield and quality,but also reduce the potential negative impacts of such management activities on the environment.The aim of the present study was to determine the optimal water-nitrogen(WN)coupling management strategy in an apple orchard in the Weibei Dryland,Shaanxi Province,China,under limited irrigation.A randomized complete block design was adopted to test the effects of three drip irrigation levels(W1,300 m^(3)/hm^(2);W2,600 m^(3)/hm^(2);W3,900 m^(3)/hm^(2))and four N application levels(N0,0 kg/hm^(2);N1,200 kg/hm^(2);N2,400 kg/hm^(2);and N3,600 kg/hm^(2))on N distribution in the 0-100 cm soil profile.Apple yield and economic benefits under different treatments were also evaluated over a three-year period(2012-2014).Compared with the N0W1 treatment,soil N contents were higher and exhibited distinct trends in the soil profile under other treatments.Overall,total N contents exhibited a downward trend from the surface to the subsurface layers(0.11-2.34 g/kg);however,the total N contents of the lower soil layer increased with an increase in irrigation amount.NO_(3)-N contents were the lowest in the 40-60 cm soil layer and then increased with an increase in soil depth.The highest NO_(3)-N contents of different soil layers were observed under the N3W3 treatment,ranging from 124.7 mg/kg(0-20 cm)to 90.9 mg/kg(80-100 cm).NH_(4)^(+)-N contents were low(<10 mg/kg),mainly accumulating in the surface layer and decreasing toward the deeper layers>20 cm.Different water-N coupling treatments also increased apple yield by 7.30%-41.62%when compared with the N0W1 treatment.The highest apple yield(three-year mean:41.01 t/hm^(2))was observed under the N2W2 treatment,with an output value of 237900 RMB yuan/hm^(2) and a net income of 232000 RMB yuan/hm^(2).Considering fruit yield,partial productivity of N fertilizer,and economic and environmental benefits,the N2W2 treatment is the optimal water-N fertilizer coupling drip irrigation scheme for apple production in the study area and other similar dryland areas.展开更多
Accumulation of heavy metals in agricultural soils tends to increase crop uptake of heavy metals,and can adversely impact human health through food chains.This study assessed the heavy metal pollution status and the p...Accumulation of heavy metals in agricultural soils tends to increase crop uptake of heavy metals,and can adversely impact human health through food chains.This study assessed the heavy metal pollution status and the potential ecological risk of tea plantation soils in southern Shaanxi Province,China.A total of 330 topsoil samples were collected to analyze the concentrations of seven heavy metals(Pb,Zn,Cu,Cr,Hg,As and Cd)and the pH level.The Hakanson potential ecological risk index was used based on the background levels of soil heavy metals in Shaanxi.Results showed that the averaged concentrations of soil Pb,Zn,Cu,Cr,Hg,As,and Cd were 10.0,87.6,16.4,12.4,0.2,6.9 and 0.1 mg/kg,respectively.Cd and Hg concentrations exceeded level II of China’s Soil Environment Quality Standard(GB 15618-2009)in 9.3%and 7.0%of the total samples,respectively.The coefficient of variation ranged from 29.2%to 52.2%for different elements,and was 49.3%for Cd and 48.6%for Hg.The averaged comprehensive potential ecological risk index was 95.4,and the overall potential ecological risk was low,with 82.4%of the total samples at a low level of potential ecological risk.Cd and Hg contributed most to the potential ecological risk(35.5%and 46.5%,respectively),and the risks associated with other elements were relatively minor.This study suggested that soil Cd and Hg pollution should be controlled to ensure the safe production of tea in the study area.展开更多
基金funded by the Natural Science Basic Research Program of Shaanxi(2021JCW-20)the Key Research and Development Program of Shaanxi(2020ZDLGY11-06)+1 种基金the Scientific Research Plan Projects of Shaanxi Education Department(20JS014)the Scientific Research Project of City-University Co-construction of Shaanxi Province(SXC-2108)。
文摘Formic acid(FA)has come to be considered a potential candidate for hydrogen storage,and the development of efficient catalysts for H2releasing is crucial for realizing the sustainable process from FA.Herein,we have developed the ultrafine Pd nanoparticle(NPs)with amine-functionalized carbon as a support,which was found to show an excellent catalytic activity in H_(2)generation from FA dehydrogenation.The synergetic mechanism between amine-group and Pd active site was demonstrated to facilitate H2generation byβ-hydride elimination.Moreover,the texture of support for Pd NPs also plays an important role in determining the reactivity of FA,since the diffusion of gaseous products makes the kinetics of diffusion as a challenge in this high performance Pd catalysts.As a result,the as-prepared Pd/NH_(2)-TPC catalyst with the small sized Pd nanoparticles and the hierarchically porous structures shows a turnover of frequency(TOF)value of 4312 h^(-1)for the additive-free FA dehydrogenation at room temperature,which is comparable to the most promising heterogeneous catalysts.Our results demonstrated that the intrinsic catalytic activities of active site as well as the porous structure of support are both important factors in determining catalytic performances in H2generation from FA dehydrogenation,which is also helpful to develop high-activity catalysts for other advanced gas-liquid-solid reactions systems.
基金supported by the National Natural Science Foundation of China(Nos.41572230 and 41172219)the Grant for Innovative Research Groups of the National Natural Sci-ence Foundation of China(No.41521001)+1 种基金the Special Scien-tific Research Project of Hanzhong City-Shaanxi University of Technology Co-construction State Key Laboratory(No.SXJ-2106)the Scientific Research Foundation of State Key Laboratory of Qinba Bio-Resource and Ecological Environment(No.SXC-2105).
文摘Silver carp mediated biological control techniques are often advocated for controlling cyanobacteria blooms in eutrophic water,which are often enriched with arsenic(As).How-ever,the transfer and fate of As during the biological control of cyanobacteria blooms by silver carp in As-rich eutrophic water remain unclear.Based on the simulated ecosystem experiment,the accumulation of As in silver carp and the transfer and fate of As in the water-algae-silver carp system during Microcystis aeruginosa blooms controlled by silver carp were investigated.Microcystis aeruginosa showed high tolerance to As(V).The accumulation of As in different tissues of silver carp was different,as follows:intestine>liver>gill>skin>muscle.After silver carp ingested As-rich Microcystis aeruginosa,As accumulation in the intestine,liver,gill,and skin of silver carp was enhanced under the action of digestion and skin contact.Compared with the system without algal,As accumulation in the intestine,liver,gill,and skin of silver carp increased by 1.1,3.3,3.3,and 9.6 times,respectively,after incubation for 30 days in the system with Microcystis aeruginosa,while the accumulation of As in the muscle was only slightly increased by 0.56 mg/kg.This work revealed the transfer and fate of As during algal control by silver carp,elucidated the accumulation mechanism of As in water-algae-silver carp system,enriched our understanding of As bioaccumulation and transformation in As-rich eutrophication water,and provided a scientific basis for as-sessing and predicting As migration and enrichment in water-algae-silver carp system.
基金supported by the Key Research and Development Program of Shaanxi Province,China(Grant No.2024NC-YBXM-258,2023-YBNY-272)the Scientific Research Project of City-University Co-construction of Shaanxi Province for State Key Laboratory of Qinba Bio-Resource and Ecological Environment(Grant No.SXC-2108,SXJ-2304).
文摘The conversion of rapeseed straw into biochar not only effectively mitigates pollution from traditional straw burning but also aligns with China’s sustainable agricultural development goals. A significant quantity of rapeseed stalks is frequently burned in fields, leading to severe air pollution characterized by black smoke and residue, resulting in a substantial waste of straw resources. To address this issue, rapeseed straw form Nanchi Village, Puzhen Town, Hanzhong City, Shaanxi Province, was utilized as a precursor and KOH was employed as an activator to produce porous activated carbon by pyrolysis. Scanning electron microscopy (SEM), elemental analyzer, infrared spectroscopy, specific surface area analysis, and other instruments were employed to characterize the porous activated carbon produced under various temperature gradients and activator concentrations. The microelement composition, structure, specific surface area, and pore size of biochar produced under varying conditions were analyzed to determine the optimal preparation parameters. Furthermore, the adsorption efficiency for tetracycline in wastewater was evaluated using a three-factor, three-level orthogonal experimental design. The results showed that the interior of the activated carbon was porous, while the exterior contained oxygenated functional groups that facilitated the adsorption of nitrogen, phosphorus, and other elements. The optimal carbonization temperature and KOH concentration for activated carbon were determined to be 400°C and 0.5, respectively. The optimal adsorption conditions were identified as pH value of 7, an initial tetracycline concentration of 30 mg/L, a biochar dosage of 0.2 g, an adsorption time of 60 min, and a removal rate of 98.53%. The factors influencing the adsorption of tetracycline onto rapeseed straw biochar were ranked as initial tetracycline concentration>adsorption reaction time>biochar dasage. The findings will provide valuable references for research on biochar performance and the treatment of tetracycline contamination in water.
基金financially supported by the Key Research and Development Program of Shaanxi Province,China(Grant No.2019NY-202)the Research Foundation of Education Bureau of Shaanxi Province,China(Grant No.19JS012)the Scientific Research Project of City-University Co-construction of Shaanxi Province for State Key Laboratory of Qinba Bio-Resource and Ecological Environment(SXC-2108).
文摘Optimization of water and fertilizer coupling management approaches could not only increase apple yield and quality,but also reduce the potential negative impacts of such management activities on the environment.The aim of the present study was to determine the optimal water-nitrogen(WN)coupling management strategy in an apple orchard in the Weibei Dryland,Shaanxi Province,China,under limited irrigation.A randomized complete block design was adopted to test the effects of three drip irrigation levels(W1,300 m^(3)/hm^(2);W2,600 m^(3)/hm^(2);W3,900 m^(3)/hm^(2))and four N application levels(N0,0 kg/hm^(2);N1,200 kg/hm^(2);N2,400 kg/hm^(2);and N3,600 kg/hm^(2))on N distribution in the 0-100 cm soil profile.Apple yield and economic benefits under different treatments were also evaluated over a three-year period(2012-2014).Compared with the N0W1 treatment,soil N contents were higher and exhibited distinct trends in the soil profile under other treatments.Overall,total N contents exhibited a downward trend from the surface to the subsurface layers(0.11-2.34 g/kg);however,the total N contents of the lower soil layer increased with an increase in irrigation amount.NO_(3)-N contents were the lowest in the 40-60 cm soil layer and then increased with an increase in soil depth.The highest NO_(3)-N contents of different soil layers were observed under the N3W3 treatment,ranging from 124.7 mg/kg(0-20 cm)to 90.9 mg/kg(80-100 cm).NH_(4)^(+)-N contents were low(<10 mg/kg),mainly accumulating in the surface layer and decreasing toward the deeper layers>20 cm.Different water-N coupling treatments also increased apple yield by 7.30%-41.62%when compared with the N0W1 treatment.The highest apple yield(three-year mean:41.01 t/hm^(2))was observed under the N2W2 treatment,with an output value of 237900 RMB yuan/hm^(2) and a net income of 232000 RMB yuan/hm^(2).Considering fruit yield,partial productivity of N fertilizer,and economic and environmental benefits,the N2W2 treatment is the optimal water-N fertilizer coupling drip irrigation scheme for apple production in the study area and other similar dryland areas.
基金This work was financially supported by Key Research and Development Program of Shaanxi Province,China(No.2019NY-202)the Key Laboratory for Agricultural Environment,Ministry of Agriculture Open Foundation(No.2015)+1 种基金Research Foundation of Education Bureau of Shaanxi Province,China(No.19JS012)the Shaanxi Province Key Laboratory of Bio-resources(2015SZS-15-04/09).
文摘Accumulation of heavy metals in agricultural soils tends to increase crop uptake of heavy metals,and can adversely impact human health through food chains.This study assessed the heavy metal pollution status and the potential ecological risk of tea plantation soils in southern Shaanxi Province,China.A total of 330 topsoil samples were collected to analyze the concentrations of seven heavy metals(Pb,Zn,Cu,Cr,Hg,As and Cd)and the pH level.The Hakanson potential ecological risk index was used based on the background levels of soil heavy metals in Shaanxi.Results showed that the averaged concentrations of soil Pb,Zn,Cu,Cr,Hg,As,and Cd were 10.0,87.6,16.4,12.4,0.2,6.9 and 0.1 mg/kg,respectively.Cd and Hg concentrations exceeded level II of China’s Soil Environment Quality Standard(GB 15618-2009)in 9.3%and 7.0%of the total samples,respectively.The coefficient of variation ranged from 29.2%to 52.2%for different elements,and was 49.3%for Cd and 48.6%for Hg.The averaged comprehensive potential ecological risk index was 95.4,and the overall potential ecological risk was low,with 82.4%of the total samples at a low level of potential ecological risk.Cd and Hg contributed most to the potential ecological risk(35.5%and 46.5%,respectively),and the risks associated with other elements were relatively minor.This study suggested that soil Cd and Hg pollution should be controlled to ensure the safe production of tea in the study area.
