Graphdiyne(GDY)and its derivatives have been considered ideal supporting materials for nanoscale active particles because of their unique atomic and electronic structure.An efficient bi-metal Cu-Pd catalyst was added ...Graphdiyne(GDY)and its derivatives have been considered ideal supporting materials for nanoscale active particles because of their unique atomic and electronic structure.An efficient bi-metal Cu-Pd catalyst was added to produce the uniform deposition of Pd nano-clusters with an average size of~0.95 nm on hydrogen-substituted GDY(HGDY)nanosheets.With the assistance of NaBH4,the resulting Pd/H-GDY was very effective in the degradation of 4-nitrophenol(4-NP),whose conversion was sharply increased to 97.21%in 100 s with a rate constant per unit mass(k`)of 8.97×10^(5)min−1 g^(−1).Additionally,dyes such as methyl orange(MO)and Congo red(CR)were completely degraded within 180 and 90 s,respectively.The Pd/H-GDY maintained this activity after 5 reduction cycles.These results highlight the promising performance of Pd/H-GDY in catalyzing the degradation of various pollutants,which is attributed to the combined effect of the largeπ-conjugated structure of the H-GDY nanosheets and the evenly distributed Pd nanoclusters.展开更多
Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium ...Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.展开更多
Buckypapers(BPs)consist of carbon nanotube(CNT)membranes with good mechanical,thermal and elec-trical properties.We report the modification of CNT buckypapers by the surface deposition of a thin layer of ti-tanium dio...Buckypapers(BPs)consist of carbon nanotube(CNT)membranes with good mechanical,thermal and elec-trical properties.We report the modification of CNT buckypapers by the surface deposition of a thin layer of ti-tanium dioxide and their subsequent photocatalytic use for the removal of three wastewater pollutants:diclofenac(DF),carbofuran(CB)and methylene blue(MB).The results show the following decreases(RE)in the initial concentrations of these pollutants,REDF=99.5%,REMB=96%and RECB=90%after 90 min of exposure to UV-Vis radiation using~0.6 mg of photocatalyst.Experiments also showed that the degradation rate of diclofenac(k=0.1028 min^(−1))is respectively 3.5 and 6 times faster than the values for CB(k=0.0298 min^(−1))and MB(k=0.0174 min^(−1)),probably due to the easier bond cleavage in DF.UV-Vis irradiated solutions of these pollutants were then analyzed by mass spectrometry to identify the species formed during photocatalysis and suggest possible degradation paths for MB,DF,and CB.Data showed that the degradation of DF involves the formation of a photocyclization product through loss of HCl molecule,clearly consuming less energy than that needed for the opening of the central aromatic ring in MB,or the loss of the N-methyl amide functional group for CB.展开更多
Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influenc...Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms.展开更多
The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou-Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results...The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou-Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results show that As, Cd, Pb and Zn are major contaminants in sediments, and average concentrations of these elements significantly exceed both the Control Standards for Pollutants in Sludge of China (GB4284-84) for agricultural use in acidic soils and the effect range median (ERM) values. The average concentrations of As, Cd and Pb in the river water slightly exceed the limit of Surface Water Environment Quality Standard (GB3838-2002). The concentrations of As and Cr in depth profiles extensively change, but slight changes are observed in Pb and Zn. Cd and Zn in most sediment samples can easily enter the food-chain and bring possible ecotoxicological risk to organisms living in sediments according to the risk assessment code.展开更多
Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numer...Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.展开更多
Effects of butanol isomers on characteristics of combustion and emission were studied on PFI SI engine. Experiments were operated under the condition of 3 and 5 bar brake mean effective pressure (BMEP) engine loads an...Effects of butanol isomers on characteristics of combustion and emission were studied on PFI SI engine. Experiments were operated under the condition of 3 and 5 bar brake mean effective pressure (BMEP) engine loads and different equivalence ratios (φ=0.83-1.25) with engine speed of 1200 r/min using blends made of 70 vol.% gasoline and 30 vol.% butanol isomers (N30, S30, I30 and T30). The results indicated that compared with gasoline, all butanol isomer blends have higher cylinder pressure. N30 has the highest and most advanced peak pressure, and T30 shows a higher brake specific fuel consumption (BSFC) and lower brake thermal efficiency (BTE). N30 presents a lower UHC emissions and I30 has slightly higher CO emissions than other blends. For unregulated emissions, compared with gasoline, butanol isomer blends have higher acetaldehyde, and N30 produces a higher emission of 1,3-butadiene than other blends. A reduction in benzene, toluene, ethylbenzene and xylene (BTEX) has been found with butanol isomer blends.展开更多
A knowledge-based network for Section Yidong Bridge,Dongyang River,one tributary of Qiantang River,Zhejiang Province,China,is established in order to model water quality in areas under small data.Then,based on normal ...A knowledge-based network for Section Yidong Bridge,Dongyang River,one tributary of Qiantang River,Zhejiang Province,China,is established in order to model water quality in areas under small data.Then,based on normal transformation of variables with routine monitoring data and normal assumption of variables without routine monitoring data,a conditional linear Gaussian Bayesian network is constructed.A "two-constraint selection" procedure is proposed to estimate potential parameter values under small data.Among all potential parameter values,the ones that are most probable are selected as the "representatives".Finally,the risks of pollutant concentration exceeding national water quality standards are calculated and pollution reduction decisions for decision-making reference are proposed.The final results show that conditional linear Gaussian Bayesian network and "two-constraint selection" procedure are very useful in evaluating risks when there is limited data and can help managers to make sound decisions under small data.展开更多
Oxygen fuels have broad application prospects and great potential for realizing efficient and clean combustion,and hence this study applies diesel/n-butanol blends to explore the influence of split-injection strategy ...Oxygen fuels have broad application prospects and great potential for realizing efficient and clean combustion,and hence this study applies diesel/n-butanol blends to explore the influence of split-injection strategy on combustion and emission characteristics.Simultaneously,changing the way of exhaust gas recirculation(EGR)gas introduction forms uneven in-cylinder components distribution,and utilizing EGR stratification optimizes the combustion process and allows better emission results.The results show that the split-injection strategy can reduce the NO_(x)emissions and keep smoke opacity low compared with the single injection,but the rise in accumulation mode particles is noticeable.NO_(x)emissions show an upward trend as the injection interval expands,while soot emissions are significantly reduced.The increase in pre-injection proportion causes the apparent low-temperature heat release,and the two-stage heat release can be observed during the process of main combustion heat release.More pre-injection mass makes NO_(x)gradually increase,but smoke opacity reaches the lowest point at 15%pre-injection proportion.EGR stratification can optimize the emission results under the split injection strategy,especially the considerable suppression of accumulation mode particulate emissions.Above all,fuel stratification coupled with EGR stratification is beneficial for further realizing the in-cylinder purification of pollutants.展开更多
The features of organic pollutants degradation mainly characterized by bio-flocculation for step-A of adsorption-biodegredation（AB） process were studied. By investigating the relationship of extracellular polymeric ...The features of organic pollutants degradation mainly characterized by bio-flocculation for step-A of adsorption-biodegredation（AB） process were studied. By investigating the relationship of extracellular polymeric substances（EPS） with bioflocculation and introducing kinetic model of organic pollutant degradation into EPS, the kinetic model of organic pollutant degradation for step-A hioflocculation was deducted. And through the experiments, the kinetic constants were calculated as follows： k1 =0. 005 3; kc1 =1 710.7 and vmax1=10 min^-1.展开更多
Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed...Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed biomass in ethylene glycol system with sulfuric acid as catalyst for the precursors of polyurethane compounds was studied.The results show that giant reed biomass from metal-contaminated soil is potentially liquefied and significantly affected by solvent/solid ratio,liquefaction temperature and liquefaction time （P〈0.05）.The liquefaction rate of biomass in acidified ethylene glycol system can reach 85.2% with optimized conditions of 60 min,170 ℃,3% sulfuric acid and solvent/biomass ratio of 5：1.The hydroxyl value of liquefied products is of 481 mg KOH/g while reactive hydroxyl groups of them are abundant,which is promised as potential precursors for polyurethane compounds.The solvent liquefaction is a potential method to dispose the metal-contaminated biomass,however,the containing-metal liquefied products should be studied deeply in order to get the suitable precursors in future.展开更多
The purification efficiency in the treatment of the mine drainage generated by the mineral processing industry in Mengzi,Yunnan Project, China, was investigated, and the influences of the treated drainage on the miner...The purification efficiency in the treatment of the mine drainage generated by the mineral processing industry in Mengzi,Yunnan Project, China, was investigated, and the influences of the treated drainage on the mineral electrodes' electrochemical behaviors were tested. Experiments with different doses of polyacrylamide(PAM) and polymeric ferric sulfate(PFS) at different pH values were carried out, and the advanced purification by activated carbon(AC) was conducted. Compared with PFS, the better coagulant for removal efficiency is PAM, under the optimal conditions, the removals of Pb2+, Zn2+, Cu2+ and COD reduction from solution were 94.8%, 79.9%, 87.6% and 85%, respectively. In the advanced purification, the particle size of activated carbon and agitation time played important roles in the removal efficiency. Each pollute concentration could meet the emission standard of pollutants for lead and zinc industry(GB25466—2010). The wastewater without treatment affected galena and sphalerite electrochemical behaviors greatly, after treatment by the technology, the effects disappeared, which proved the reliability of the technology for wastewater treatment.展开更多
Fungi Z4 and Z8, isolated from the heavy metal polluted soil, have strong resistance to Cd and Pb. The strains were identified on the base of their morphology and internal transcribed spacers(ITS) region. Pot experime...Fungi Z4 and Z8, isolated from the heavy metal polluted soil, have strong resistance to Cd and Pb. The strains were identified on the base of their morphology and internal transcribed spacers(ITS) region. Pot experiments were conducted to study the effect of two strains(Z4 and Z8) on the growth and accumulation of Cd and Pb of Guizhou oilseed rape. The results show that strains Z4 and Z8 belong to Mucor circinelloides and Mucor racemosus, respectively. The heights of Guizhou oilseed rape inoculated with strain Z8 increase by 47.90% than the control. The highest fresh mass is found in the plant with Z4/Z8, which is enhanced by160.81%. Pot experiments show that Z4/Z8 inoculums can accelerate accumulation of heavy metals in the plant. The contents of Cd and Pb are increased by 117.60% and 63.48%, respectively. Meanwhile, the heavy metal concentrations in potting soil with the two strains are found to be lower than those of the control, and the concentrations of Cd and Pb are decreased by 60.57% and 27.12%,respectively.展开更多
The ability of a wet swale,constructed in an area of poor soil permeability,to manage runoff from a roadway was monitored through 27 storm events over a period of 8 months.During the monitoring period,the wet swale re...The ability of a wet swale,constructed in an area of poor soil permeability,to manage runoff from a roadway was monitored through 27 storm events over a period of 8 months.During the monitoring period,the wet swale reduced the total runoff volume by 50.4%through exfiltration and evapotranspiration.The wet swale significantly decreased the influent pollutant concentrations,and the effluent mean concentrations of total suspended solids,total phosphorus,chemical oxygen demand,ammonium,oxidized nitrogen,and total nitrogen in the effluent were 31 mg/L,0.10 mg/L,29 mg/L,0.52 mg/L,0.35 mg/L and1.28 mg/L,respectively.Pollutant loads were also substantially reduced from 70%to 85%.Plant uptake played an important role in nutrient removal in the wet swale.Approximately half of the nitrogen(53.8%)and phosphorus(51.5%)that entered the wet swale was incorporated in above-ground plants.It is shown that wet swales are useful for managing runoff from roads in areas of poor soil permeability.展开更多
基金National Natural Science Foundation of China(52072336,51902285)Zhejiang Provincial Natural Science Foundation(LR23E020002)+1 种基金Fundamental Research Funds for the Central Universities(226-2023-00064,226-2024-00146)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2022SZ-FR001)。
文摘Graphdiyne(GDY)and its derivatives have been considered ideal supporting materials for nanoscale active particles because of their unique atomic and electronic structure.An efficient bi-metal Cu-Pd catalyst was added to produce the uniform deposition of Pd nano-clusters with an average size of~0.95 nm on hydrogen-substituted GDY(HGDY)nanosheets.With the assistance of NaBH4,the resulting Pd/H-GDY was very effective in the degradation of 4-nitrophenol(4-NP),whose conversion was sharply increased to 97.21%in 100 s with a rate constant per unit mass(k`)of 8.97×10^(5)min−1 g^(−1).Additionally,dyes such as methyl orange(MO)and Congo red(CR)were completely degraded within 180 and 90 s,respectively.The Pd/H-GDY maintained this activity after 5 reduction cycles.These results highlight the promising performance of Pd/H-GDY in catalyzing the degradation of various pollutants,which is attributed to the combined effect of the largeπ-conjugated structure of the H-GDY nanosheets and the evenly distributed Pd nanoclusters.
基金Project(22376221)supported by the National Natural Science Foundation of ChinaProject(2024JJ2074)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST。
文摘Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.
基金MIUR,Italian Ministry for University and Research(EX-60%/2024)。
文摘Buckypapers(BPs)consist of carbon nanotube(CNT)membranes with good mechanical,thermal and elec-trical properties.We report the modification of CNT buckypapers by the surface deposition of a thin layer of ti-tanium dioxide and their subsequent photocatalytic use for the removal of three wastewater pollutants:diclofenac(DF),carbofuran(CB)and methylene blue(MB).The results show the following decreases(RE)in the initial concentrations of these pollutants,REDF=99.5%,REMB=96%and RECB=90%after 90 min of exposure to UV-Vis radiation using~0.6 mg of photocatalyst.Experiments also showed that the degradation rate of diclofenac(k=0.1028 min^(−1))is respectively 3.5 and 6 times faster than the values for CB(k=0.0298 min^(−1))and MB(k=0.0174 min^(−1)),probably due to the easier bond cleavage in DF.UV-Vis irradiated solutions of these pollutants were then analyzed by mass spectrometry to identify the species formed during photocatalysis and suggest possible degradation paths for MB,DF,and CB.Data showed that the degradation of DF involves the formation of a photocyclization product through loss of HCl molecule,clearly consuming less energy than that needed for the opening of the central aromatic ring in MB,or the loss of the N-methyl amide functional group for CB.
基金Project(2020YFC1908802)supported by the National Key Research and Development Project of China。
文摘Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms.
基金Project (20507022) supported by the National Natural Science Foundation of ChinaProject (EREH050303) supported by the Foundation of Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health
文摘The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou-Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results show that As, Cd, Pb and Zn are major contaminants in sediments, and average concentrations of these elements significantly exceed both the Control Standards for Pollutants in Sludge of China (GB4284-84) for agricultural use in acidic soils and the effect range median (ERM) values. The average concentrations of As, Cd and Pb in the river water slightly exceed the limit of Surface Water Environment Quality Standard (GB3838-2002). The concentrations of As and Cr in depth profiles extensively change, but slight changes are observed in Pb and Zn. Cd and Zn in most sediment samples can easily enter the food-chain and bring possible ecotoxicological risk to organisms living in sediments according to the risk assessment code.
基金Project(2011BAJ03B07)supported by National Twelve Five-year Science and Technology Support Program of ChinaProject supported by the China Scholarship Council+1 种基金Project(51276057,51376198)supported by the National Natural Science Foundation of ChinaProject(CX2014B064)supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.
基金Projects(51776016,51606006) supported by the National Natural Science Foundation of ChinaProjects(3172025,3182030) supported by Beijing Natural Science Foundation,China+4 种基金Project(2017YFB0103401) supported by National Key Research and Development ProgramProject(NELMS2017A10) funded by the National Engineering Laboratory for Mobile Source Emission Control Technology,ChinaProject(2018RC017) supported by the Talents Foundation of Beijing Jiaotong University,ChinaProject(DE-EE0006864) supported by the Department of EnergyProject(201507090044) supported by China Scholarship Council
文摘Effects of butanol isomers on characteristics of combustion and emission were studied on PFI SI engine. Experiments were operated under the condition of 3 and 5 bar brake mean effective pressure (BMEP) engine loads and different equivalence ratios (φ=0.83-1.25) with engine speed of 1200 r/min using blends made of 70 vol.% gasoline and 30 vol.% butanol isomers (N30, S30, I30 and T30). The results indicated that compared with gasoline, all butanol isomer blends have higher cylinder pressure. N30 has the highest and most advanced peak pressure, and T30 shows a higher brake specific fuel consumption (BSFC) and lower brake thermal efficiency (BTE). N30 presents a lower UHC emissions and I30 has slightly higher CO emissions than other blends. For unregulated emissions, compared with gasoline, butanol isomer blends have higher acetaldehyde, and N30 produces a higher emission of 1,3-butadiene than other blends. A reduction in benzene, toluene, ethylbenzene and xylene (BTEX) has been found with butanol isomer blends.
基金Project(50809058)supported by the National Natural Science Foundation of China
文摘A knowledge-based network for Section Yidong Bridge,Dongyang River,one tributary of Qiantang River,Zhejiang Province,China,is established in order to model water quality in areas under small data.Then,based on normal transformation of variables with routine monitoring data and normal assumption of variables without routine monitoring data,a conditional linear Gaussian Bayesian network is constructed.A "two-constraint selection" procedure is proposed to estimate potential parameter values under small data.Among all potential parameter values,the ones that are most probable are selected as the "representatives".Finally,the risks of pollutant concentration exceeding national water quality standards are calculated and pollution reduction decisions for decision-making reference are proposed.The final results show that conditional linear Gaussian Bayesian network and "two-constraint selection" procedure are very useful in evaluating risks when there is limited data and can help managers to make sound decisions under small data.
基金Projects(51476069,51676084)supported by the National Natural Science Foundation of ChinaProject(2019C058-3)supported by the Jilin Provincial Industrial Innovation Special Guidance Fund Project,China+1 种基金Project(20180101059JC)supported by the Jilin Provincial Science and Technology Development Plan Project,ChinaProject(2020C025-2)supported by the Jilin Provincial Specific Project of Industrial Technology Research&Development,China。
文摘Oxygen fuels have broad application prospects and great potential for realizing efficient and clean combustion,and hence this study applies diesel/n-butanol blends to explore the influence of split-injection strategy on combustion and emission characteristics.Simultaneously,changing the way of exhaust gas recirculation(EGR)gas introduction forms uneven in-cylinder components distribution,and utilizing EGR stratification optimizes the combustion process and allows better emission results.The results show that the split-injection strategy can reduce the NO_(x)emissions and keep smoke opacity low compared with the single injection,but the rise in accumulation mode particles is noticeable.NO_(x)emissions show an upward trend as the injection interval expands,while soot emissions are significantly reduced.The increase in pre-injection proportion causes the apparent low-temperature heat release,and the two-stage heat release can be observed during the process of main combustion heat release.More pre-injection mass makes NO_(x)gradually increase,but smoke opacity reaches the lowest point at 15%pre-injection proportion.EGR stratification can optimize the emission results under the split injection strategy,especially the considerable suppression of accumulation mode particulate emissions.Above all,fuel stratification coupled with EGR stratification is beneficial for further realizing the in-cylinder purification of pollutants.
基金project (2004B4604A01-01) supported by the Mega-projects of Science Research for the 10th Five-Year Plan
文摘The features of organic pollutants degradation mainly characterized by bio-flocculation for step-A of adsorption-biodegredation（AB） process were studied. By investigating the relationship of extracellular polymeric substances（EPS） with bioflocculation and introducing kinetic model of organic pollutant degradation into EPS, the kinetic model of organic pollutant degradation for step-A hioflocculation was deducted. And through the experiments, the kinetic constants were calculated as follows： k1 =0. 005 3; kc1 =1 710.7 and vmax1=10 min^-1.
基金Project(41271330)supported by the National Natural Science Foundation of ChinaProject(2012BAC09B04)supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of ChinaProject(2012FJ1010)supported by the Science and Technology Major Program of Hunan Province,China
文摘Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed biomass in ethylene glycol system with sulfuric acid as catalyst for the precursors of polyurethane compounds was studied.The results show that giant reed biomass from metal-contaminated soil is potentially liquefied and significantly affected by solvent/solid ratio,liquefaction temperature and liquefaction time （P〈0.05）.The liquefaction rate of biomass in acidified ethylene glycol system can reach 85.2% with optimized conditions of 60 min,170 ℃,3% sulfuric acid and solvent/biomass ratio of 5：1.The hydroxyl value of liquefied products is of 481 mg KOH/g while reactive hydroxyl groups of them are abundant,which is promised as potential precursors for polyurethane compounds.The solvent liquefaction is a potential method to dispose the metal-contaminated biomass,however,the containing-metal liquefied products should be studied deeply in order to get the suitable precursors in future.
基金Project(2010CB630905)supported by the National Basic Research Program of China
文摘The purification efficiency in the treatment of the mine drainage generated by the mineral processing industry in Mengzi,Yunnan Project, China, was investigated, and the influences of the treated drainage on the mineral electrodes' electrochemical behaviors were tested. Experiments with different doses of polyacrylamide(PAM) and polymeric ferric sulfate(PFS) at different pH values were carried out, and the advanced purification by activated carbon(AC) was conducted. Compared with PFS, the better coagulant for removal efficiency is PAM, under the optimal conditions, the removals of Pb2+, Zn2+, Cu2+ and COD reduction from solution were 94.8%, 79.9%, 87.6% and 85%, respectively. In the advanced purification, the particle size of activated carbon and agitation time played important roles in the removal efficiency. Each pollute concentration could meet the emission standard of pollutants for lead and zinc industry(GB25466—2010). The wastewater without treatment affected galena and sphalerite electrochemical behaviors greatly, after treatment by the technology, the effects disappeared, which proved the reliability of the technology for wastewater treatment.
基金Projects(31100082,60871007,61171061)supported by the National Natural Science Foundation of ChinaProject(2012SK4028)supported by the Science and Technology Agency of Hunan Province,China+1 种基金Project(2013M530358)supported by the Post-doctoral Program of ChinaProjects(12JJ4032,12JJ4082)supported by the Natural Science Foundation of Hunan Province,China
文摘Fungi Z4 and Z8, isolated from the heavy metal polluted soil, have strong resistance to Cd and Pb. The strains were identified on the base of their morphology and internal transcribed spacers(ITS) region. Pot experiments were conducted to study the effect of two strains(Z4 and Z8) on the growth and accumulation of Cd and Pb of Guizhou oilseed rape. The results show that strains Z4 and Z8 belong to Mucor circinelloides and Mucor racemosus, respectively. The heights of Guizhou oilseed rape inoculated with strain Z8 increase by 47.90% than the control. The highest fresh mass is found in the plant with Z4/Z8, which is enhanced by160.81%. Pot experiments show that Z4/Z8 inoculums can accelerate accumulation of heavy metals in the plant. The contents of Cd and Pb are increased by 117.60% and 63.48%, respectively. Meanwhile, the heavy metal concentrations in potting soil with the two strains are found to be lower than those of the control, and the concentrations of Cd and Pb are decreased by 60.57% and 27.12%,respectively.
基金Project(2011ZX07303-002) supported by National Water Pollution Control and Management Technology Major Projects,China
文摘The ability of a wet swale,constructed in an area of poor soil permeability,to manage runoff from a roadway was monitored through 27 storm events over a period of 8 months.During the monitoring period,the wet swale reduced the total runoff volume by 50.4%through exfiltration and evapotranspiration.The wet swale significantly decreased the influent pollutant concentrations,and the effluent mean concentrations of total suspended solids,total phosphorus,chemical oxygen demand,ammonium,oxidized nitrogen,and total nitrogen in the effluent were 31 mg/L,0.10 mg/L,29 mg/L,0.52 mg/L,0.35 mg/L and1.28 mg/L,respectively.Pollutant loads were also substantially reduced from 70%to 85%.Plant uptake played an important role in nutrient removal in the wet swale.Approximately half of the nitrogen(53.8%)and phosphorus(51.5%)that entered the wet swale was incorporated in above-ground plants.It is shown that wet swales are useful for managing runoff from roads in areas of poor soil permeability.
