Ruminants play a critical role in our food system by converting plant biomass that humans cannot or choose not to consume into edible high-quality food.However,ruminant excreta is a significant source of nitrous oxide...Ruminants play a critical role in our food system by converting plant biomass that humans cannot or choose not to consume into edible high-quality food.However,ruminant excreta is a significant source of nitrous oxide(N_(2)O),a potent greenhouse gas with a long-term global warming potential 298 times that of carbon dioxide.Natural phytochemicals or forages containing phytochemicals have shown the potential to improve the efficiency of nitrogen(N)utilization and decrease N_(2)O emissions from the excreta of ruminants.Dietary inclusion of tannins can shift more of the excreted N to the feces,alter the urinary N composition and consequently reduce N_(2)O emissions from excreta.Essential oils or saponins could inhibit rumen ammonia production and decrease urinary N excretion.In grazed pastures,large amounts of glucosinolates or aucubin can be introduced into pasture soils when animals consume plants rich in these compounds and then excrete them or their metabolites in the urine or feces.If inhibitory compounds are excreted in the urine,they would be directly applied to the urine patch to reduce nitrification and subsequent N_(2)O emissions.The phytochemicals’role in sustainable ruminant production is undeniable,but much uncertainty remains.Inconsistency,transient effects,and adverse effects limit the effectiveness of these phytochemicals for reducing N losses.In this review,we will identify some current phytochemicals found in feed that have the potential to manipulate ruminant N excretion or mitigate N_(2)O production and deliberate the challenges and opportunities associated with using phytochemicals or forages rich in phytochemicals as dietary strategies for reducing N excretion and excreta-derived N_(2)O emissions.展开更多
To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was...To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch (OD), where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification (SND) rate (rSND) was put forward to quantify SND. The results indicate that: (1) high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen (TN) and total phosphate (TP) removal rates were 80% and 85%, respectively; (2) when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; (3) the natural logarithm of the ratio of NOx to NH4^+ in the effluent had a linear correlation to oxidation-reduction potential (ORP); (4) when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; (5) denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.展开更多
Dielectric barrier discharge (DBD) plasma was utilized to oxidize NO contained in the exhaust gas to NO2, ultimately improve the selective catalytic reduction of nitrogen oxides (NOx). In the one case, DBD was cre...Dielectric barrier discharge (DBD) plasma was utilized to oxidize NO contained in the exhaust gas to NO2, ultimately improve the selective catalytic reduction of nitrogen oxides (NOx). In the one case, DBD was created directly in the exhaust gas (direct application), and in the an other case, ozone produced by DBD was injected into the exhaust gas (indirect application). A comparative study between such direct and indirect applications of DBD plasma was made in terms of the NOx removal efficiency and the energy consumption. The NO2 content in the exhaust gas was changed by the voltage applied to the DBD device (for direct application) or by the amount of ozone added to the exhaust gas (for indirect application). In both cases, NO was easily oxidized to NO2, and the change in NO2 content largely affected the NOx removal performance of the catalytic reactor placed downstream, where both NO and NO2 were reduced to N2 in the presence of ammonia as the reducing agent. The experiments were primarily concerned with the effect of reaction temperature on the catalytic NOx reduction at various NO2 contents. The direct and indirect applications of DBD were found to remarkably improve the catalytic NOx reduction, especially at low temperatures.展开更多
A single-stage plasma-catalytic reactor in which catalytic materials werepacked was used to remove nitrogen oxides. The packing material was scoria being made of variousmetal oxides including Al_2O_3, MgO, TiO_2, etc....A single-stage plasma-catalytic reactor in which catalytic materials werepacked was used to remove nitrogen oxides. The packing material was scoria being made of variousmetal oxides including Al_2O_3, MgO, TiO_2, etc. Scoria was able to act not only as dielectricpellets but also as a catalyst in the presence of reducing agent such as ethylene and ammonia.Without plasma discharge, scoria did not work well as a catalyst in the temperature range of 100 ℃to 200 ℃, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range.展开更多
The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that ...The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that more than 85% of nitric oxide was removed from synthetic combustion gas-streams which contained 20% oxygen and 350 μL/L NO, with a residence time of 60 seconds. In the process, it was found that the existing of oxygen showed no evident negative effect on the efficiency of nitrogen removal.展开更多
This paper reports the studies conducted on removal of oxides ofnitrogen (NOx) from diesel engine exhaust using electrical dischargeplasma combined with adsorbing materials such as molecular sieves.This study is being...This paper reports the studies conducted on removal of oxides ofnitrogen (NOx) from diesel engine exhaust using electrical dischargeplasma combined with adsorbing materials such as molecular sieves.This study is being reported for the first time. The exhaust is takenfrom a diesel engine of 6 kW under no load conditions. Thecharacteristic behavior of a pulse energized dielectric barrierdischarge reactor in the diesel exhaust treatment is reported. TheNOx removal was not significant (36/100) when the reactor without anypacking was used.展开更多
We evaluate nitrogen oxides pollution in Takamatsu and Utazu area in Kagawa prefecture, Japan. Annually observations for nitrogen oxides (nitrogen dioxide;NO2, nitric oxide;NO) (1990-2007) were obtained from data base...We evaluate nitrogen oxides pollution in Takamatsu and Utazu area in Kagawa prefecture, Japan. Annually observations for nitrogen oxides (nitrogen dioxide;NO2, nitric oxide;NO) (1990-2007) were obtained from data base of Kagawa prefecture, Japan. Changes in NO2 and NO in Takamatsu and Utazu area were evaluated and compared. In 2007, NO2, NO and NO2 + NO (ppm) in Takamatsu area were higher than those in Utazu area. However, NO2 /NO + NO2 in Takamatsu area was lower than that in Utazu area. From 1990 to 2007, mean of NO2 in a day over the level of 0.06 ppm was 30 days in Takamatsu area and only one day in Utazu area. Mean of NO2, NO and NO2 + NO was significantly higher and NO2/NO + NO2 was lower in Takamatsu area than that in Utazu area. In addition, NO2, NO and NO2 + NO were negatively correlated and NO2/NO + NO2 was positively correlated with years (1990-2007) in Takamatsu area. The level of nitrogen oxides pollution in Utazu area was lower than Takamatsu area. Further observation is required for preventing nitrogen oxides pollution in Kagawa prefecture, Japan.展开更多
V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy ...V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS) and catalytic removal of ethanol, acetaldehyde and nitrogen oxides at low temperature (〈300 ?C) were used to assess the properties of the catalysts. The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol, acetaldehyde and nitrogen oxides. The conversions of ethanol, acetaldehyde and nitrogen oxides at 250 ?C were 100%, 74.4% and 98.7%, respectively. V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface, and possessed a larger mole fraction of V4+ species and unique PdO species on the surface, which can be attributed to the strong synergistic effect among palladium, vanadium and the carriers. The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4+ and Pd2+ species on the surface, which might be favorable for the formation of active sites.展开更多
Total dissolved nitrogen(TDN) is an important parameter for assessing the nutrient cycling and status of natural waters.The accurate determination of TDN in natural waters is essential for assessing its contents and d...Total dissolved nitrogen(TDN) is an important parameter for assessing the nutrient cycling and status of natural waters.The accurate determination of TDN in natural waters is essential for assessing its contents and distinguishing different forms of nitrogen in the water.The TDN in various systems has been largely documented,and the concentrations of TDN are usually obtained using high-temperature catalytic(HTC) or persulfate oxidation(PO).However,the accuracy of these methods and their suitability for all types of natural waters are still unclear.To explore both methods in-depth,assorted samples were tested,including eight solutions composed of nitrogen-containing compounds(3 dissolved inorganic nitrogen fractions:NO_(3)^(-),NO_(2)^(-)and NH_(4)^(+);5 organic compounds:EDTA-2Na,vitamin B1,vitamin B12,amino acids,and urea) and 105 natural waters which were collected from an open ocean(Northwest Pacific Ocean,28),a marginal sea(Yellow Sea,34),an estuary(Huanghe River mouth,31),rivers(Huanghe River,4;Licun River,4),and precipitations(4 samples).The results showed that heterocycles and molecular dimensions had certain effects on the oxidation efficiency of the PO method but had little effect on HTC.There was no significant difference between the two methods for natural waters,but HTC was more suitable for deep-sea samples with low TDN concentrations(less than 10 μmol/L) and low organic activity.Overall,HTC has a relatively simple measurement process,a high degree of automation,and low error.Therefore,HTC can be recommended to determine the TDN of samples in freshwater and seawater.展开更多
Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive prote...Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive proteins on a proteome level remains elusive.In order to gain a deep insight into the proteins responding to nitrogen stress in rapeseed(Brassica napus L.),comparative proteomic analysis was performed to investigate changes of protein expression profiles from the root,stem and leaf under different N concentrations,respectively.More than 200 differential abundance proteins(DAPs)were detected and categorized into groups according to annotations,including“binding and catalytic activity”,“involved in primary metabolism and cellular processes”,“stress-response”and so on.Variation in chlorophyll(Chl)content and antioxidant activities further revealed that oxidative stress raised with the increase of N concentration.Bioinformatics analysis based on the expression level of total proteins suggested these DAPs might play important roles in adaptation to N-stress conditions.Generally,these results provides a new aspect into N-stress responding proteins in Brassica plants.展开更多
基金supported by Beijing Captial Agribusiness&Food Group Co.,Ltd.‘Integrated Innovation and Industrial Application of"Green Digital Intelligence"Technology in the Whole Dairy Industry Chain’(SNSPKJ2022)National Natural Science Foundation of China(32302767).
文摘Ruminants play a critical role in our food system by converting plant biomass that humans cannot or choose not to consume into edible high-quality food.However,ruminant excreta is a significant source of nitrous oxide(N_(2)O),a potent greenhouse gas with a long-term global warming potential 298 times that of carbon dioxide.Natural phytochemicals or forages containing phytochemicals have shown the potential to improve the efficiency of nitrogen(N)utilization and decrease N_(2)O emissions from the excreta of ruminants.Dietary inclusion of tannins can shift more of the excreted N to the feces,alter the urinary N composition and consequently reduce N_(2)O emissions from excreta.Essential oils or saponins could inhibit rumen ammonia production and decrease urinary N excretion.In grazed pastures,large amounts of glucosinolates or aucubin can be introduced into pasture soils when animals consume plants rich in these compounds and then excrete them or their metabolites in the urine or feces.If inhibitory compounds are excreted in the urine,they would be directly applied to the urine patch to reduce nitrification and subsequent N_(2)O emissions.The phytochemicals’role in sustainable ruminant production is undeniable,but much uncertainty remains.Inconsistency,transient effects,and adverse effects limit the effectiveness of these phytochemicals for reducing N losses.In this review,we will identify some current phytochemicals found in feed that have the potential to manipulate ruminant N excretion or mitigate N_(2)O production and deliberate the challenges and opportunities associated with using phytochemicals or forages rich in phytochemicals as dietary strategies for reducing N excretion and excreta-derived N_(2)O emissions.
文摘To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch (OD), where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification (SND) rate (rSND) was put forward to quantify SND. The results indicate that: (1) high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen (TN) and total phosphate (TP) removal rates were 80% and 85%, respectively; (2) when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; (3) the natural logarithm of the ratio of NOx to NH4^+ in the effluent had a linear correlation to oxidation-reduction potential (ORP); (4) when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; (5) denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.
文摘Dielectric barrier discharge (DBD) plasma was utilized to oxidize NO contained in the exhaust gas to NO2, ultimately improve the selective catalytic reduction of nitrogen oxides (NOx). In the one case, DBD was created directly in the exhaust gas (direct application), and in the an other case, ozone produced by DBD was injected into the exhaust gas (indirect application). A comparative study between such direct and indirect applications of DBD plasma was made in terms of the NOx removal efficiency and the energy consumption. The NO2 content in the exhaust gas was changed by the voltage applied to the DBD device (for direct application) or by the amount of ozone added to the exhaust gas (for indirect application). In both cases, NO was easily oxidized to NO2, and the change in NO2 content largely affected the NOx removal performance of the catalytic reactor placed downstream, where both NO and NO2 were reduced to N2 in the presence of ammonia as the reducing agent. The experiments were primarily concerned with the effect of reaction temperature on the catalytic NOx reduction at various NO2 contents. The direct and indirect applications of DBD were found to remarkably improve the catalytic NOx reduction, especially at low temperatures.
基金The project supported by the Basic Research Program of the Korea Science & Engineering Foundation (KOSEF) (No. R05-2001-000-01247-0)
文摘A single-stage plasma-catalytic reactor in which catalytic materials werepacked was used to remove nitrogen oxides. The packing material was scoria being made of variousmetal oxides including Al_2O_3, MgO, TiO_2, etc. Scoria was able to act not only as dielectricpellets but also as a catalyst in the presence of reducing agent such as ethylene and ammonia.Without plasma discharge, scoria did not work well as a catalyst in the temperature range of 100 ℃to 200 ℃, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range.
基金supported by the National Natural Science Foundation of China(Grants No.20277009)
文摘The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that more than 85% of nitric oxide was removed from synthetic combustion gas-streams which contained 20% oxygen and 350 μL/L NO, with a residence time of 60 seconds. In the process, it was found that the existing of oxygen showed no evident negative effect on the efficiency of nitrogen removal.
文摘This paper reports the studies conducted on removal of oxides ofnitrogen (NOx) from diesel engine exhaust using electrical dischargeplasma combined with adsorbing materials such as molecular sieves.This study is being reported for the first time. The exhaust is takenfrom a diesel engine of 6 kW under no load conditions. Thecharacteristic behavior of a pulse energized dielectric barrierdischarge reactor in the diesel exhaust treatment is reported. TheNOx removal was not significant (36/100) when the reactor without anypacking was used.
文摘We evaluate nitrogen oxides pollution in Takamatsu and Utazu area in Kagawa prefecture, Japan. Annually observations for nitrogen oxides (nitrogen dioxide;NO2, nitric oxide;NO) (1990-2007) were obtained from data base of Kagawa prefecture, Japan. Changes in NO2 and NO in Takamatsu and Utazu area were evaluated and compared. In 2007, NO2, NO and NO2 + NO (ppm) in Takamatsu area were higher than those in Utazu area. However, NO2 /NO + NO2 in Takamatsu area was lower than that in Utazu area. From 1990 to 2007, mean of NO2 in a day over the level of 0.06 ppm was 30 days in Takamatsu area and only one day in Utazu area. Mean of NO2, NO and NO2 + NO was significantly higher and NO2/NO + NO2 was lower in Takamatsu area than that in Utazu area. In addition, NO2, NO and NO2 + NO were negatively correlated and NO2/NO + NO2 was positively correlated with years (1990-2007) in Takamatsu area. The level of nitrogen oxides pollution in Utazu area was lower than Takamatsu area. Further observation is required for preventing nitrogen oxides pollution in Kagawa prefecture, Japan.
基金supported by the National Natural Science Foundation of China (No. 21073131)the Shanxi Natural Science Foundation(No. 2009011011-3)
文摘V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS) and catalytic removal of ethanol, acetaldehyde and nitrogen oxides at low temperature (〈300 ?C) were used to assess the properties of the catalysts. The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol, acetaldehyde and nitrogen oxides. The conversions of ethanol, acetaldehyde and nitrogen oxides at 250 ?C were 100%, 74.4% and 98.7%, respectively. V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface, and possessed a larger mole fraction of V4+ species and unique PdO species on the surface, which can be attributed to the strong synergistic effect among palladium, vanadium and the carriers. The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4+ and Pd2+ species on the surface, which might be favorable for the formation of active sites.
基金The National Key Research and Development Project of China under contract No.2019YFC1407802the Fund of State Environmental Protection Key Laboratory of Coastal Ecosystem under contract No.202112+3 种基金the Open Fund of Key Laboratory of Marine Ecological Environment Science and EngineeringMinistry of Natural Resources under contract No.MESE-2019-06the National Natural Science Foundation of China under contract No.41876078the Shandong Provincial Natural Science Foundation of China under contract No.ZR2018MD016。
文摘Total dissolved nitrogen(TDN) is an important parameter for assessing the nutrient cycling and status of natural waters.The accurate determination of TDN in natural waters is essential for assessing its contents and distinguishing different forms of nitrogen in the water.The TDN in various systems has been largely documented,and the concentrations of TDN are usually obtained using high-temperature catalytic(HTC) or persulfate oxidation(PO).However,the accuracy of these methods and their suitability for all types of natural waters are still unclear.To explore both methods in-depth,assorted samples were tested,including eight solutions composed of nitrogen-containing compounds(3 dissolved inorganic nitrogen fractions:NO_(3)^(-),NO_(2)^(-)and NH_(4)^(+);5 organic compounds:EDTA-2Na,vitamin B1,vitamin B12,amino acids,and urea) and 105 natural waters which were collected from an open ocean(Northwest Pacific Ocean,28),a marginal sea(Yellow Sea,34),an estuary(Huanghe River mouth,31),rivers(Huanghe River,4;Licun River,4),and precipitations(4 samples).The results showed that heterocycles and molecular dimensions had certain effects on the oxidation efficiency of the PO method but had little effect on HTC.There was no significant difference between the two methods for natural waters,but HTC was more suitable for deep-sea samples with low TDN concentrations(less than 10 μmol/L) and low organic activity.Overall,HTC has a relatively simple measurement process,a high degree of automation,and low error.Therefore,HTC can be recommended to determine the TDN of samples in freshwater and seawater.
基金funded by Modern Agro-Industry Technology Research System of China(CARS-12)Independent Innovation Project of SAAS(2022ZZCX004)+5 种基金1+9 Open Competition Project of SAAS(1+9KJGG002,1+9KJGG001)the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance DepartmentSichuan Science and Technology Program(2022ZDZX0015)Sichuan Crop Breeding Community(2021YFYZ0018)Disciplinary Construction Project for Modern Agriculture in SAAS(2021XKJS003)Chengdu Science and Technology Project(2021-YF09-00062-SN).
文摘Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive proteins on a proteome level remains elusive.In order to gain a deep insight into the proteins responding to nitrogen stress in rapeseed(Brassica napus L.),comparative proteomic analysis was performed to investigate changes of protein expression profiles from the root,stem and leaf under different N concentrations,respectively.More than 200 differential abundance proteins(DAPs)were detected and categorized into groups according to annotations,including“binding and catalytic activity”,“involved in primary metabolism and cellular processes”,“stress-response”and so on.Variation in chlorophyll(Chl)content and antioxidant activities further revealed that oxidative stress raised with the increase of N concentration.Bioinformatics analysis based on the expression level of total proteins suggested these DAPs might play important roles in adaptation to N-stress conditions.Generally,these results provides a new aspect into N-stress responding proteins in Brassica plants.