Global climate change,growing population,and environmental pollution underscore the need for a greater focus on providing advanced water treatment technologies.Although electrochemical basedprocesses are becoming prom...Global climate change,growing population,and environmental pollution underscore the need for a greater focus on providing advanced water treatment technologies.Although electrochemical basedprocesses are becoming promising solutions,they still face challenges owing to mass transport and upscaling which hinder the exploitation of this technology.Electrode design and reactor configuration are key factors for achieving operational improvements.The electroactive membrane has proven to be a breakthrough technology integrating electrochemistry and membrane separation with an enhanced mass transport by convection.In this review article,we discuss recent progress in environmental applications of electroactive membranes with particular focus on those composed of carbon nanotubes(CNT)due to their intriguing physicochemical prope rties.Their applications in degradation of refractory contaminants,detoxification and sequestration of toxic heavy metal ions,and membrane fouling alleviations are systematically reviewed.We then discuss the existing limitations and opportunities for future research.The development of advanced electroactive systems depends on interdisciplinary collaborations in the areas of materials,electrochemistry,membrane development,and environmental sciences.展开更多
Leaching method is usually used to extract rare earth(RE)elements from ion adsorbed RE ores.In the leaching process,some impurities such as aluminum(Al)enter the leaching solution.The separation of Al from RE by carbo...Leaching method is usually used to extract rare earth(RE)elements from ion adsorbed RE ores.In the leaching process,some impurities such as aluminum(Al)enter the leaching solution.The separation of Al from RE by carboxylic acid extractant 4-octyloxybenzoic acid(POOA)was studied in this article.By changing the pH value,temperature,solvent,saponification degree and other parameters,the extraction and separation performance of POOA in chloride system was systematically studied.Through specific extraction experiments and slope analysis,it can be seen that the stoichiometric ratio of POOA to Al is 3:1during the extraction process.The separation factor of Al^(3+)and Pr^(3+)can reach about 160.00.Compared with easily emulsified naphthenic acid,POOA achieves better phase separation.The above results show that saponified POOA(S-POOA)has a good separation effect on Al and RE.Under the condition of low concentration stripping acid of 0.60 mol/L HCl,the developed extraction system can be almost completely stripped,and the stripping rate reaches 97.52%.The regenerated POOA can be directly used for the recycling extraction.展开更多
Reactive oxygen species(ROSs)in Fenton process are of great importance in treating contaminants in wastewater.It is crucial to understand their chemical properties,formation,and reaction mechanisms with contaminants.T...Reactive oxygen species(ROSs)in Fenton process are of great importance in treating contaminants in wastewater.It is crucial to understand their chemical properties,formation,and reaction mechanisms with contaminants.This review summarizes the reactive oxygen species in Fenton process,including hydroxyl radical(·OH),superoxide radical(O_(2)·-),singlet oxygen(1O_(2)),hydroperoxyl radical(HO_(2)·),and high-valent iron.·OH shows a trend to react with chemistry groups with abundant electrons through H-atom abstraction,radical adduct formation and single electron transfer.Electron transfer is discovered to be an important pathway when1O_(2)degrades organic pollutants.Ring-opening andβ-scission are proposed to be the possible ways of1O_(2)to certain contaminants.Proton abstraction,nucleophilic substitution,and single electron transfer are proposed to explain how O_(2)·-degrade pollutants.As the conjugated acid of O_(2)·-,radical adduct formation and H-atom abstraction are reported for the reaction mechanisms of hydroperoxyl radical.High-valent iron in Fenton,namely Fe(IV),reacts with certain pollutants via single-or two-electron transfer.This review is important for researchers to understand the ROSs produced in Fenton and how they react with pollutants.展开更多
Emissions of carbonyl compounds from agricultural machines cannot be ignored.Carbonyl compounds can cause the formation of ozone(O3)and secondary organic aerosols,which can cause photochemical smog to form.In this stu...Emissions of carbonyl compounds from agricultural machines cannot be ignored.Carbonyl compounds can cause the formation of ozone(O3)and secondary organic aerosols,which can cause photochemical smog to form.In this study,20 agricultural machines were tested using portable emission measurement system(PEMS)under real-world tillage processes.The exhaust gases were sampled using 2,4-dinitrophenylhydrazine cartridges,and 15 carbonyl compounds were analyzed by high-performance liquid chromatography.Carbonyl compound emission factors for agricultural machines were 51.14–3315.62 mg/(kg-fuel),and were 2.58±2.05,0.86±1.07 and 0.29±0.20 g/(kg-fuel)for China 0,China II and China III emission standards,respectively.Carbonyl compound emission factor for sowing seeds of China 0 agricultural machines was 3.32±1.73 g/(kg-fuel).Formaldehyde,acetaldehyde and acrolein were the dominant carbonyl compounds emitted.Differences in emission standards and tillage processes impact ozone formation potential(OFP).The mean OFP was 20.15±16.15 g O3/(kg-fuel)for the China 0 emission standard.The OFP values decreased by 66.9% from China 0 to China II,and 67.4%from China II to China III.The mean OFP for sowing seeds of China 0 agricultural machines was 25.92±13.84 g O3/(kg-fuel).Between 1.75 and 24.22 times more ozone was found to be formed during sowing seeds than during other processes for China 0 and China II agricultural machines.Total carbonyl compound emissions from agricultural machines in China was 19.23 Gg in 2019.The results improve our understanding of carbonyl compound emissions from agricultural machines in China.展开更多
Frequent occurrence of harmful algal blooms has already threatened aquatic life and human health.In the present study,floating BiOCl_(0.6)I_(0.4)/ZnO photocatalyst was synthesized in situ by water bath method,and and ...Frequent occurrence of harmful algal blooms has already threatened aquatic life and human health.In the present study,floating BiOCl_(0.6)I_(0.4)/ZnO photocatalyst was synthesized in situ by water bath method,and and applied in inactivation of Microcystis aeruginosa under visible light.The composition,morphology,chemical states,optical properties of the photocatalyst were also characterized.The results showed that BiOCl_(0.6)I_(0.4)exhibited laminated nanosheet structure with regular shape,and the light response range of the composite BZ/EP-3 (BiOCl_(0.6)I_(0.4)/ZnO/EP-3) was tuned from 582 to 638 nm.The results of photocatalytic experiments indicated that BZ/EP-3 composite had stronger photocatalytic activity than a single BiOCl_(0.6)I_(0.4)and ZnO,and the removal rate of chlorophyll a was 89.28%after 6 hr of photocatalytic reaction.The photosynthetic system was destroyed and cell membrane of algae ruptured under photocatalysis,resulting in the decrease of phycobiliprotein components and the release of a large number of ions (K^(+),Ca^(2+)and Mg^(2+)).Furthermore,active species trapping experiment determined that holes (h+) and superoxide radicals (·O_(2)-) were the main active substance for the inactivation of algae,and the p-n mechanism of photocatalyst was proposed.Overall,BZ/EP-3 showed excellent algal removal ability under visible light,providing fundamental theories for practical algae pollution control.展开更多
Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and control.In this study,the impact of different precursors,pH,bromide concentration,and algae-derived or...Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and control.In this study,the impact of different precursors,pH,bromide concentration,and algae-derived organic matters on the formation of HBQs and the removal efficiency by activated carbon were investigated.It was found that the chlorination of bisphenol A produced the most 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ),reaching 14.86μg/L at 1 hr,followed by tyrosine,2-chlorophenol,P-hydroxybenzoic acid,trichlorophenol,and N-methylaniline.The production of 2,6-DCBQ increased first and then decreased from 0 to 36 hr(chlorination doses 0-20 mg/L),indicating that HBQs were unstable in water.Trihalomethanes(THMs)were detected during chlorination,and the concentration increased with prolongation of reaction time.2,6-DCBQ production decreased and 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ)production increased with increment bromide concentration and the bromide promoted the formation of tribromomethane.The production of 2,6-DCBQ decreased with increase of pH,and the maximum production was 141.38μg/L at pH of 5.Microcystis aeruginosa,Chlorella algae cells,and intracellular organic matters(IOM)could be chlorinated as potential precursors for HBQs.The most amount of 2,6-DCBQ was generated from algae cells of Microcystis aeruginosa,followed by Chlorella algae cells,Microcystis aeruginosa IOM,and Chlorella IOM.This study compared the removal efficiency of HBQs by granular activated carbon(GAC)and columnar activated carbon(CAC)under different carbon doses and initial concentrations of HBQs.It was found that the removal efficiency by GAC(80.1%)was higher than that by CAC(51.8%),indicating that GAC has better control for HBQs.展开更多
A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air.Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near th...A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air.Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near the exhaust nozzle.The variation characteristics of fine particle matter(PM_(2.5)) and its components in diesel vehicle exhaust plumes were analyzed.The PM_(2.5) emissions gradually increased with increasing distance from the nozzle in the plume.Elemental carbon emissions remained basically unchanged, organic carbon and total carbon(TC) increased with increasing distance.The concentrations of SO_(4)^(2-),NO_(3)^(-) and NH_(4)^(+) (SNA) directly emitted by the vehicles were very low but increased rapidly in the exhaust plume.The selective catalytic reduction(SCR) reduced 42.7% TC, 40% NO_(3)^(-) emissions, but increased 104% SO_(4)^(2-) and 36% NH_(4)^(+) emissions, respectively.In summary,the SCR reduced 29% primary PM_(2.5) emissions for the tested diesel vehicles.The NH_(4)NO_(3) particle formation maybe more important in the plume, and there maybe other forms of formation of NH_(4)^(+) (eg.NH4Cl).The generation of secondary organic carbon(SOC) plays a leading role in the generation of secondary PM_(2.5).The SCR enhanced the formation of SOC and SNA in the plume, but comprehensive analysis shows that the SCR more enhanced the SNA formation in the plume, which is mainly new particles formation process.The inconsistency between secondary organic aerosol(SOA) and primary organic aerosol definitions is one of the important reasons for the difference between SOA simulation and observation.展开更多
Tertiary amino alkali lignin( TA-AL) was successfully synthesized by a two-step approach; its application as an adsorbent for nitrate and phosphate ions in effluents was investigated. TA-AL was characterized by FT-IR,...Tertiary amino alkali lignin( TA-AL) was successfully synthesized by a two-step approach; its application as an adsorbent for nitrate and phosphate ions in effluents was investigated. TA-AL was characterized by FT-IR,zeta potential,SEM,and elemental analysis. Kinetic and equilibrium adsorption isotherms were determined to investigate the adsorption capacity of TAAL. The results revealed that TA-AL had a very strong adsorption capacity towards anions; the value of p HPZC( PZC,point of zero charge) was about 9. 2.The adsorption of nitrate and phosphate ions was related to effluent p H and initial anion concentration. The maximum absorption of nitrate and phosphate ions was about 26. 9 and 18. 4 mg / g when the initial concentration of the ions was 50 mg / L. The adsorption kinetics conformed to the pseudo-second-order kinetic equation,and the equilibrium data were suitably expressed by the Freundlich model. The regeneration studies confirmed that the lignin-based material was a promising adsorbent for nitrate and phosphate ions in water.展开更多
In the process of extracting ion-absorbed rare earth ore(IREO),the production of radioactive waste is a major environmental concern.To address this issue,MoS_(2) was used to modify ion-absorbed rare earth tailings(RET...In the process of extracting ion-absorbed rare earth ore(IREO),the production of radioactive waste is a major environmental concern.To address this issue,MoS_(2) was used to modify ion-absorbed rare earth tailings(RET) to synthesize a novel MoS_(2)@RET composite material for the effective handling of radioactive waste generated in IREO separation industry.The composite material was thoroughly characterized using various analytical techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),thermogravimetry(TG),Fourier-transform infrared(FTIR),scanning electron microscopy(SEM),Brunaue r-Emmett-Teller(BET) and energy dispersive spectroscopy(EDS).By optimizing the operating parameters,the optimal experimental conditions were determined to be pH=3,contact time=60 min,liquid-solid ratio=6 g/L,and initial concentration=150 mg/L.The adsorption data fitted well with the pseudo second-order rate model.The thermodynamic parameters concerning the adsorption of Th(Ⅳ) were analyzed and computed.Langmuir isotherm model is a more fitting choice for the adsorption process compared to the Freundlich isotherm model.MoS_(2)@RET was used in the acid leachate of IREO waste residue,achieving the separation of Th and rare earth successfully.The mechanism of Th(Ⅳ) adsorption by MoS_(2)@RET was investigated,revealing that the adsorption process involves electrostatic interactions,chemical bonding,and redox reactions.The above research results indicate that MoS_(2)@RET composite materials have application potential in the sustainable treatment of IREO radioactive waste.展开更多
Regulating the orbital spin-electron filling of metal centers via interatomic electron transfer in transition metal oxides is one promising approach to enhancing their electrocatalytic oxygen evolution reaction(OER)pe...Regulating the orbital spin-electron filling of metal centers via interatomic electron transfer in transition metal oxides is one promising approach to enhancing their electrocatalytic oxygen evolution reaction(OER)performances,while it is still a challenge due to lacking of efficient strategy and deep understanding.In this work,a facile strategy containing electrochemical deposition and annealing in air atmosphere has been proposed to introduce monodispersed neodymium(Nd)atoms into spinel Co_(3)O_(4)nanosheets to trigger the electron transfer.Accordingly,the as-prepared Nd doped Co_(3)O_(4)nanosheets(Nd/Co_(3)O_(4))on nickel foam or carbon cloth showed greatly enhanced OER performances,with low overpotential of 284 and 396 mV at 10 m A cm^(-2),small Tafel slope of 95 and 119 mV dec^(-1)in 1.0 M KOH and 0.5 M H_(2)SO_(4),respectively.The experimental and density function theory results coherently indicate that the charge transfer in the Nd-O-Co asymmetric configuration not only enhances the conductivity of Co_(3)O_(4),but also regulates the filling degree of egorbitals of Co,leading to higher spin states,optimized adsorption ability,and accelerated H_(2)O dissociation process,thus achieving boosted OER activity.展开更多
Bioethanol, as a clean and renewable fuel, has gained increasing attention due to its major environmental benefits. Pervaporation(PV) is a promising and competitive technique for the recovery of ethanol from bioethano...Bioethanol, as a clean and renewable fuel, has gained increasing attention due to its major environmental benefits. Pervaporation(PV) is a promising and competitive technique for the recovery of ethanol from bioethanol fermentation systems due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentation process. The main challenge for the industrial application of ethanol perm-selective membranes is to break the trade-off effect between permeability and selectivity. As membrane is the heart of the pervaporation separation process, this article attempts to provide a comprehensive survey on the breakthroughs of ethanol perm-selective PV membranes from the perspectives of tailoring membrane materials to enhance PV separation performance. The research and development of polymeric and organic/inorganic hybrid membranes are reviewed to explore the fundamental structure-property-performance relationships. It is found that mixed matrix membranes with welldesigned membrane structures offer the hope of better control overphysi-/chemical microenvironment and cavity/pore size as well as size distribution, which may provide both high permeability and membrane selectivity to break the trade-off effect. The tentative perspective on the possible future directions of ethanol perm-selective membranes is also briefly discussed, which may provide some insights in developing a new generation of high-performance PV membranes for ethanol recovery.展开更多
To enhance hydrogen production efficiency and energy recovery,a sequential dark fermentation and microbial electrochemical cell(MEC)process was evaluated for hydrogen production from food waste.The hydrogen production...To enhance hydrogen production efficiency and energy recovery,a sequential dark fermentation and microbial electrochemical cell(MEC)process was evaluated for hydrogen production from food waste.The hydrogen production,electrochemical performance and microbial community dynamics were investigated during startup of the MEC that was inoculated with different sludges.Results suggest that biogas production rates and hydrogen proportions were 0.83 L/L d and 92.58%,respectively,using anaerobic digested sludge,which is higher than that of the anaerobic granular sludge(0.55 L/L d and 86.21%).The microbial community were predominated by bacterial genus Acetobacterium,Geobacter,Desulfovibrio,and archaeal genus Methanobrevibacter in electrode biofilms and the community structure was relatively stable both in anode and cathode.The sequential system obtained a 53.8% energy recovery rate and enhanced soluble chemical oxygen demand(sCOD)removal rate of 44.3%.This research demonstrated an important approach to utilize dark fermentation effluent to maximize the conversion of fermentation byproducts into hydrogen.展开更多
Bacterial cellulose doped with P and Cu was used as a catalyst for a microbial fuel cell(MFC) cathode,which was then used to treat ethanol fermentation stillage from food waste.Corresponding output power,coulombic eff...Bacterial cellulose doped with P and Cu was used as a catalyst for a microbial fuel cell(MFC) cathode,which was then used to treat ethanol fermentation stillage from food waste.Corresponding output power,coulombic efficiency(CE),and biological toxicity were detected.Through a series of characterization experiments,the addition of the cathode catalyst was found to improve catalytic activity and accelerate the consumption of the substrate.The resulting maximum output power was 572.16 mW·m^(-2).CE and the removal rate of chemical oxygen demand(COD) in the fermentation stillage by P-Cu-BC reached 26% and 64.5%,respectively.The rate of biotoxicity removal by MFC treatment reached 84.7%.The aim of this study was apply a novel catalyst for MFC and optimize the treatment efficiency of fermentation stillage.展开更多
The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)system.Also,we ...The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)system.Also,we through molecular ecological networks(MENs)discussed the bacterial interactions.At last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removaT in an AS system.The results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS system.The relative abundance of denitrifying and phosphorus removal microorganisms,such as Denitratisoma,Thauera,Dechloromonas,and Defluviicoccus,increased significantly.Candidatus Accumulibacter,well-known as polyphosphate-accumulating organisms(PAOs),increased significantly;the relative abundance of Candidatus Competibacter,known as glycogen-accumulating organisms(GAOs),decreased significantly.Furthermore,metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased,according to the quantities of denitrifying and phosphorus genes,and the corresponding transcription likewise greatly increased.Lastly,MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs,the microbial connections among members related to nitrogen and phosphorus removal were enhanced.The abundance increases of denitrifiers and PAOs,and their increased transcription of functional genes,together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.展开更多
基金the Natural Science Foundation of Shanghai,China(No.18ZR1401000)the Shanghai Pujiang Program(No.18PJ1400400)Donghua University for the start-up grant(No.113-07-005710)。
文摘Global climate change,growing population,and environmental pollution underscore the need for a greater focus on providing advanced water treatment technologies.Although electrochemical basedprocesses are becoming promising solutions,they still face challenges owing to mass transport and upscaling which hinder the exploitation of this technology.Electrode design and reactor configuration are key factors for achieving operational improvements.The electroactive membrane has proven to be a breakthrough technology integrating electrochemistry and membrane separation with an enhanced mass transport by convection.In this review article,we discuss recent progress in environmental applications of electroactive membranes with particular focus on those composed of carbon nanotubes(CNT)due to their intriguing physicochemical prope rties.Their applications in degradation of refractory contaminants,detoxification and sequestration of toxic heavy metal ions,and membrane fouling alleviations are systematically reviewed.We then discuss the existing limitations and opportunities for future research.The development of advanced electroactive systems depends on interdisciplinary collaborations in the areas of materials,electrochemistry,membrane development,and environmental sciences.
基金Project supported by the National Key R&D Program of China(2017YFE0106900)Fujian Program for High-Level Entrepreneurial and Innovative Talents Introduction+1 种基金Key R&D Program of Jiangxi Province(S2020ZPYFG0029)Key Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3-1)。
文摘Leaching method is usually used to extract rare earth(RE)elements from ion adsorbed RE ores.In the leaching process,some impurities such as aluminum(Al)enter the leaching solution.The separation of Al from RE by carboxylic acid extractant 4-octyloxybenzoic acid(POOA)was studied in this article.By changing the pH value,temperature,solvent,saponification degree and other parameters,the extraction and separation performance of POOA in chloride system was systematically studied.Through specific extraction experiments and slope analysis,it can be seen that the stoichiometric ratio of POOA to Al is 3:1during the extraction process.The separation factor of Al^(3+)and Pr^(3+)can reach about 160.00.Compared with easily emulsified naphthenic acid,POOA achieves better phase separation.The above results show that saponified POOA(S-POOA)has a good separation effect on Al and RE.Under the condition of low concentration stripping acid of 0.60 mol/L HCl,the developed extraction system can be almost completely stripped,and the stripping rate reaches 97.52%.The regenerated POOA can be directly used for the recycling extraction.
基金supported by the National Natural Science Foundation of China(Nos.22176102 and 21806081)Natural Science Foundation of Tianjin(No.19JCQNJC07900)+2 种基金Fundamental Research Funds for the Central UniversitiesNatural Science Foundation of Jiangsu Province in China(No.BK20230410)Natural Science Research of Jiangsu Higher Education Institution of China(No.23KJB610010)。
文摘Reactive oxygen species(ROSs)in Fenton process are of great importance in treating contaminants in wastewater.It is crucial to understand their chemical properties,formation,and reaction mechanisms with contaminants.This review summarizes the reactive oxygen species in Fenton process,including hydroxyl radical(·OH),superoxide radical(O_(2)·-),singlet oxygen(1O_(2)),hydroperoxyl radical(HO_(2)·),and high-valent iron.·OH shows a trend to react with chemistry groups with abundant electrons through H-atom abstraction,radical adduct formation and single electron transfer.Electron transfer is discovered to be an important pathway when1O_(2)degrades organic pollutants.Ring-opening andβ-scission are proposed to be the possible ways of1O_(2)to certain contaminants.Proton abstraction,nucleophilic substitution,and single electron transfer are proposed to explain how O_(2)·-degrade pollutants.As the conjugated acid of O_(2)·-,radical adduct formation and H-atom abstraction are reported for the reaction mechanisms of hydroperoxyl radical.High-valent iron in Fenton,namely Fe(IV),reacts with certain pollutants via single-or two-electron transfer.This review is important for researchers to understand the ROSs produced in Fenton and how they react with pollutants.
基金supported by the National Natural Science Foundation of China (Nos. 41775126, 41605095)the Beijing Natural Science Foundation (No. JQ19030)+1 种基金the School Level Cultivation Fund of Beijing Technology and Business University for Distinguished and Excellent Yong Scholars (No. BTBUYP2020)the 2021 Graduate Research Capacity Enhancement Program.
文摘Emissions of carbonyl compounds from agricultural machines cannot be ignored.Carbonyl compounds can cause the formation of ozone(O3)and secondary organic aerosols,which can cause photochemical smog to form.In this study,20 agricultural machines were tested using portable emission measurement system(PEMS)under real-world tillage processes.The exhaust gases were sampled using 2,4-dinitrophenylhydrazine cartridges,and 15 carbonyl compounds were analyzed by high-performance liquid chromatography.Carbonyl compound emission factors for agricultural machines were 51.14–3315.62 mg/(kg-fuel),and were 2.58±2.05,0.86±1.07 and 0.29±0.20 g/(kg-fuel)for China 0,China II and China III emission standards,respectively.Carbonyl compound emission factor for sowing seeds of China 0 agricultural machines was 3.32±1.73 g/(kg-fuel).Formaldehyde,acetaldehyde and acrolein were the dominant carbonyl compounds emitted.Differences in emission standards and tillage processes impact ozone formation potential(OFP).The mean OFP was 20.15±16.15 g O3/(kg-fuel)for the China 0 emission standard.The OFP values decreased by 66.9% from China 0 to China II,and 67.4%from China II to China III.The mean OFP for sowing seeds of China 0 agricultural machines was 25.92±13.84 g O3/(kg-fuel).Between 1.75 and 24.22 times more ozone was found to be formed during sowing seeds than during other processes for China 0 and China II agricultural machines.Total carbonyl compound emissions from agricultural machines in China was 19.23 Gg in 2019.The results improve our understanding of carbonyl compound emissions from agricultural machines in China.
基金supported by the National Natural Science Foundation of China (Nos.51708381, 52100071)the Natural Science Foundation of Jiangsu Province (No.BK20181466)the People’s Livelihood Projects of Suzhou Science and Technology Bureau (No.SS2019028)。
文摘Frequent occurrence of harmful algal blooms has already threatened aquatic life and human health.In the present study,floating BiOCl_(0.6)I_(0.4)/ZnO photocatalyst was synthesized in situ by water bath method,and and applied in inactivation of Microcystis aeruginosa under visible light.The composition,morphology,chemical states,optical properties of the photocatalyst were also characterized.The results showed that BiOCl_(0.6)I_(0.4)exhibited laminated nanosheet structure with regular shape,and the light response range of the composite BZ/EP-3 (BiOCl_(0.6)I_(0.4)/ZnO/EP-3) was tuned from 582 to 638 nm.The results of photocatalytic experiments indicated that BZ/EP-3 composite had stronger photocatalytic activity than a single BiOCl_(0.6)I_(0.4)and ZnO,and the removal rate of chlorophyll a was 89.28%after 6 hr of photocatalytic reaction.The photosynthetic system was destroyed and cell membrane of algae ruptured under photocatalysis,resulting in the decrease of phycobiliprotein components and the release of a large number of ions (K^(+),Ca^(2+)and Mg^(2+)).Furthermore,active species trapping experiment determined that holes (h+) and superoxide radicals (·O_(2)-) were the main active substance for the inactivation of algae,and the p-n mechanism of photocatalyst was proposed.Overall,BZ/EP-3 showed excellent algal removal ability under visible light,providing fundamental theories for practical algae pollution control.
基金supported by the National Natural Science Foundation of China (Nos.51608011 and 42007350)the National Key Research and Development program of China (Nos.2019YFC1906303,2019YFC1906000-4,and 2019YFD1100304)the Natural Science Foundation of Beijing Municipal (No.8202010)。
文摘Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and control.In this study,the impact of different precursors,pH,bromide concentration,and algae-derived organic matters on the formation of HBQs and the removal efficiency by activated carbon were investigated.It was found that the chlorination of bisphenol A produced the most 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ),reaching 14.86μg/L at 1 hr,followed by tyrosine,2-chlorophenol,P-hydroxybenzoic acid,trichlorophenol,and N-methylaniline.The production of 2,6-DCBQ increased first and then decreased from 0 to 36 hr(chlorination doses 0-20 mg/L),indicating that HBQs were unstable in water.Trihalomethanes(THMs)were detected during chlorination,and the concentration increased with prolongation of reaction time.2,6-DCBQ production decreased and 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ)production increased with increment bromide concentration and the bromide promoted the formation of tribromomethane.The production of 2,6-DCBQ decreased with increase of pH,and the maximum production was 141.38μg/L at pH of 5.Microcystis aeruginosa,Chlorella algae cells,and intracellular organic matters(IOM)could be chlorinated as potential precursors for HBQs.The most amount of 2,6-DCBQ was generated from algae cells of Microcystis aeruginosa,followed by Chlorella algae cells,Microcystis aeruginosa IOM,and Chlorella IOM.This study compared the removal efficiency of HBQs by granular activated carbon(GAC)and columnar activated carbon(CAC)under different carbon doses and initial concentrations of HBQs.It was found that the removal efficiency by GAC(80.1%)was higher than that by CAC(51.8%),indicating that GAC has better control for HBQs.
基金supported by the National Natural Science Foundation of China (No.41605095)the Beijing Natural Science Foundation (No.JQ19030)+1 种基金the Beijing Municipal Commission of Education (No.PXM2019014213000007)the School Level Cultivation Fund of Beijing Technology and Business University for Distinguished and Excellent Young Scholars (No.BTBUYP2020)。
文摘A rapid reaction occurs near the exhaust nozzle when vehicle emissions contact the air.Twenty diesel vehicles were studied using a new multipoint sampling system that is suitable for studying the exhaust plume near the exhaust nozzle.The variation characteristics of fine particle matter(PM_(2.5)) and its components in diesel vehicle exhaust plumes were analyzed.The PM_(2.5) emissions gradually increased with increasing distance from the nozzle in the plume.Elemental carbon emissions remained basically unchanged, organic carbon and total carbon(TC) increased with increasing distance.The concentrations of SO_(4)^(2-),NO_(3)^(-) and NH_(4)^(+) (SNA) directly emitted by the vehicles were very low but increased rapidly in the exhaust plume.The selective catalytic reduction(SCR) reduced 42.7% TC, 40% NO_(3)^(-) emissions, but increased 104% SO_(4)^(2-) and 36% NH_(4)^(+) emissions, respectively.In summary,the SCR reduced 29% primary PM_(2.5) emissions for the tested diesel vehicles.The NH_(4)NO_(3) particle formation maybe more important in the plume, and there maybe other forms of formation of NH_(4)^(+) (eg.NH4Cl).The generation of secondary organic carbon(SOC) plays a leading role in the generation of secondary PM_(2.5).The SCR enhanced the formation of SOC and SNA in the plume, but comprehensive analysis shows that the SCR more enhanced the SNA formation in the plume, which is mainly new particles formation process.The inconsistency between secondary organic aerosol(SOA) and primary organic aerosol definitions is one of the important reasons for the difference between SOA simulation and observation.
基金the financial support from the provincial scientific and technological project(2011GGB01165)the"Independent Innovation Project of Colleges and Universities"fund by Ji'nan city,Shandong province(No.201004035-2)+1 种基金the national twelfth five-year science and technology support program(No.2014BAC13B04)the"Major Projects for Analysis and Breakthrough of Several Significant Environmental Bottleneck Issues of Economic and Social Development in Shandong Province"(SDHBPJ-ZB-06)
文摘Tertiary amino alkali lignin( TA-AL) was successfully synthesized by a two-step approach; its application as an adsorbent for nitrate and phosphate ions in effluents was investigated. TA-AL was characterized by FT-IR,zeta potential,SEM,and elemental analysis. Kinetic and equilibrium adsorption isotherms were determined to investigate the adsorption capacity of TAAL. The results revealed that TA-AL had a very strong adsorption capacity towards anions; the value of p HPZC( PZC,point of zero charge) was about 9. 2.The adsorption of nitrate and phosphate ions was related to effluent p H and initial anion concentration. The maximum absorption of nitrate and phosphate ions was about 26. 9 and 18. 4 mg / g when the initial concentration of the ions was 50 mg / L. The adsorption kinetics conformed to the pseudo-second-order kinetic equation,and the equilibrium data were suitably expressed by the Freundlich model. The regeneration studies confirmed that the lignin-based material was a promising adsorbent for nitrate and phosphate ions in water.
基金Project supported by the National Key R&D Program of China (2017YFE0106900)Key R&D Program of Jiangxi Province(20203BBG72W013)Fujian Program for High-Level Entrepreneurial and Innovative Talents Introduction。
文摘In the process of extracting ion-absorbed rare earth ore(IREO),the production of radioactive waste is a major environmental concern.To address this issue,MoS_(2) was used to modify ion-absorbed rare earth tailings(RET) to synthesize a novel MoS_(2)@RET composite material for the effective handling of radioactive waste generated in IREO separation industry.The composite material was thoroughly characterized using various analytical techniques,including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),thermogravimetry(TG),Fourier-transform infrared(FTIR),scanning electron microscopy(SEM),Brunaue r-Emmett-Teller(BET) and energy dispersive spectroscopy(EDS).By optimizing the operating parameters,the optimal experimental conditions were determined to be pH=3,contact time=60 min,liquid-solid ratio=6 g/L,and initial concentration=150 mg/L.The adsorption data fitted well with the pseudo second-order rate model.The thermodynamic parameters concerning the adsorption of Th(Ⅳ) were analyzed and computed.Langmuir isotherm model is a more fitting choice for the adsorption process compared to the Freundlich isotherm model.MoS_(2)@RET was used in the acid leachate of IREO waste residue,achieving the separation of Th and rare earth successfully.The mechanism of Th(Ⅳ) adsorption by MoS_(2)@RET was investigated,revealing that the adsorption process involves electrostatic interactions,chemical bonding,and redox reactions.The above research results indicate that MoS_(2)@RET composite materials have application potential in the sustainable treatment of IREO radioactive waste.
基金support from the Natural Science Foundation and Overseas Talent Projects of Jiangxi Province(20242BAB25217,20232BAB214025,20232BCJ25044)the Jiangxi Provincial Natural Science Foundation(20232BAB204088)the National Natural Science Foundation of China(52402132)。
文摘Regulating the orbital spin-electron filling of metal centers via interatomic electron transfer in transition metal oxides is one promising approach to enhancing their electrocatalytic oxygen evolution reaction(OER)performances,while it is still a challenge due to lacking of efficient strategy and deep understanding.In this work,a facile strategy containing electrochemical deposition and annealing in air atmosphere has been proposed to introduce monodispersed neodymium(Nd)atoms into spinel Co_(3)O_(4)nanosheets to trigger the electron transfer.Accordingly,the as-prepared Nd doped Co_(3)O_(4)nanosheets(Nd/Co_(3)O_(4))on nickel foam or carbon cloth showed greatly enhanced OER performances,with low overpotential of 284 and 396 mV at 10 m A cm^(-2),small Tafel slope of 95 and 119 mV dec^(-1)in 1.0 M KOH and 0.5 M H_(2)SO_(4),respectively.The experimental and density function theory results coherently indicate that the charge transfer in the Nd-O-Co asymmetric configuration not only enhances the conductivity of Co_(3)O_(4),but also regulates the filling degree of egorbitals of Co,leading to higher spin states,optimized adsorption ability,and accelerated H_(2)O dissociation process,thus achieving boosted OER activity.
基金financial support of Beijing Natural Science Foundation Commission-Beijing Municipal Education Commission Joint Foundation,China(KZ201910011012)National Natural Science Foundation of China(21736001,21776153,21206001)+1 种基金Open Research Fund Program of Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry(CP-2020-YB7)College Students Scientific Research and Undertaking Starting Action Project,China。
文摘Bioethanol, as a clean and renewable fuel, has gained increasing attention due to its major environmental benefits. Pervaporation(PV) is a promising and competitive technique for the recovery of ethanol from bioethanol fermentation systems due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentation process. The main challenge for the industrial application of ethanol perm-selective membranes is to break the trade-off effect between permeability and selectivity. As membrane is the heart of the pervaporation separation process, this article attempts to provide a comprehensive survey on the breakthroughs of ethanol perm-selective PV membranes from the perspectives of tailoring membrane materials to enhance PV separation performance. The research and development of polymeric and organic/inorganic hybrid membranes are reviewed to explore the fundamental structure-property-performance relationships. It is found that mixed matrix membranes with welldesigned membrane structures offer the hope of better control overphysi-/chemical microenvironment and cavity/pore size as well as size distribution, which may provide both high permeability and membrane selectivity to break the trade-off effect. The tentative perspective on the possible future directions of ethanol perm-selective membranes is also briefly discussed, which may provide some insights in developing a new generation of high-performance PV membranes for ethanol recovery.
基金supported by the National Natural Science Foundation of China(grant numbers 21406213 and 51408572).
文摘To enhance hydrogen production efficiency and energy recovery,a sequential dark fermentation and microbial electrochemical cell(MEC)process was evaluated for hydrogen production from food waste.The hydrogen production,electrochemical performance and microbial community dynamics were investigated during startup of the MEC that was inoculated with different sludges.Results suggest that biogas production rates and hydrogen proportions were 0.83 L/L d and 92.58%,respectively,using anaerobic digested sludge,which is higher than that of the anaerobic granular sludge(0.55 L/L d and 86.21%).The microbial community were predominated by bacterial genus Acetobacterium,Geobacter,Desulfovibrio,and archaeal genus Methanobrevibacter in electrode biofilms and the community structure was relatively stable both in anode and cathode.The sequential system obtained a 53.8% energy recovery rate and enhanced soluble chemical oxygen demand(sCOD)removal rate of 44.3%.This research demonstrated an important approach to utilize dark fermentation effluent to maximize the conversion of fermentation byproducts into hydrogen.
基金supported by the Open Research Fund Program of Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry (CP-2019-YB7)support by Fundamental Research Funds for the Central Universities (TW2019014)support from Sino-US-Japan Joint Laboratory on Organic Solid Waste Resource and Energy Technology of USTB。
文摘Bacterial cellulose doped with P and Cu was used as a catalyst for a microbial fuel cell(MFC) cathode,which was then used to treat ethanol fermentation stillage from food waste.Corresponding output power,coulombic efficiency(CE),and biological toxicity were detected.Through a series of characterization experiments,the addition of the cathode catalyst was found to improve catalytic activity and accelerate the consumption of the substrate.The resulting maximum output power was 572.16 mW·m^(-2).CE and the removal rate of chemical oxygen demand(COD) in the fermentation stillage by P-Cu-BC reached 26% and 64.5%,respectively.The rate of biotoxicity removal by MFC treatment reached 84.7%.The aim of this study was apply a novel catalyst for MFC and optimize the treatment efficiency of fermentation stillage.
基金This work has received funding from the Major Science and Technology Project of Water Pollution Control and Treatment(No.2018ZX07111003)the Open Research Fund Program of Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry(No.CP-2019-YB8)+1 种基金Beijing Municipal Science and Technology Project(No.Z181100002418017)the Fundamental Research Funds for the Central Universities(No.JD1901).
文摘The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)system.Also,we through molecular ecological networks(MENs)discussed the bacterial interactions.At last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removaT in an AS system.The results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS system.The relative abundance of denitrifying and phosphorus removal microorganisms,such as Denitratisoma,Thauera,Dechloromonas,and Defluviicoccus,increased significantly.Candidatus Accumulibacter,well-known as polyphosphate-accumulating organisms(PAOs),increased significantly;the relative abundance of Candidatus Competibacter,known as glycogen-accumulating organisms(GAOs),decreased significantly.Furthermore,metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased,according to the quantities of denitrifying and phosphorus genes,and the corresponding transcription likewise greatly increased.Lastly,MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs,the microbial connections among members related to nitrogen and phosphorus removal were enhanced.The abundance increases of denitrifiers and PAOs,and their increased transcription of functional genes,together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.
