Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(...Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.展开更多
Freshwater ecosystems are crucial in the global emissions of greenhouse gases(GHGs)such as CH_(4).Macrophytes are the main organic matter(i.e.,detritus)supplier to the sediment of these systems,thus controlling CH_(4)...Freshwater ecosystems are crucial in the global emissions of greenhouse gases(GHGs)such as CH_(4).Macrophytes are the main organic matter(i.e.,detritus)supplier to the sediment of these systems,thus controlling CH_(4) production.However,species-specific differences(structure and composition)may determine contrasting patterns of detritus transformation into CH_(4).Furthermore,eutrophication can affect the degradation and,consequently,CH_(4) production.We performed a 64-day microcosm experiment with anoxic incubations of detritus from seven phylogenetically different macrophytes(two charophytes,filamentous algae–Spirogyra,Cladophora–,three submerged plants and an amphibious one),under two trophic conditions(oligo-versus eutrophic)and with/without sediment.We assessed the CH_(4) and CO_(2) production and the changes in the detritus quality at the end of the experiment.The ranking in the mean cumulative CH_(4) production was:Chara hispida>Nitella hyalina>Najasmarina≈Teucrium scordium>Stuckenia pectinata≈Myriophyllum spicatum>filamentous algae,and it was related to the detritus quality.GHGs maximumproduction rates were 1.6(N.marina)-1.2(C.hispida)mmol CH_(4)/(g OC·day)and 1.7(N.marina)-1.5(C.hispida)mmol CO_(2)/(g OC·day).The CO_(2):CH_(4) ratiowas biased towards CO_(2) during the first 10 days(average ratio of 200)and fell afterwards to about 1 for all macrophyte species and treatments.The sediment favored detritus decomposition(probably due to the“positive priming effect”),increasing GHGs production.The influence of nutrient enrichment was not evident.Delving into themacrophyte detritus quality-GHGs production relationship is needed to forecast the GHGs emissions in macrophyte-dominated systems.展开更多
Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived...Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate)(PBST)and poly(butylene adipate-co-terephthalate)(PBAT).In this study,quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradationmechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B(CALB).Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism,with the initial two steps being acylation reactions and the subsequent two being hydrolysis reactions.Notably,the first step of the hydrolysis is identified as the rate-determining step.Moreover,by introducing single-point mutations to expand the substrate entrance tunnel,the catalytic distance of the first acylation step decreases.Additionally,energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme’s active site.This study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme’s active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB.展开更多
This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The imp...This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The impact of different Si/Al ratios on the adsorption oxidative performance of Cu_(30)/HZSM-5–85 adsorbents was investigated.According to the performance test results,Cu_(30)/HZSM-5–85 exhibited the highest breakthrough capacity,reaching 231.75 mg H_(2)S/g_(sorbent).Cu/HZSM-5 sorbent maintains a strong ability to remove H_(2)S even under humid conditions and shows excellent water resistance.XRD,BET,and XPS results revealed that CuO is the primary active species,with Cu_(30)/HZSM-5–85 having the largest surface area and highest CuO content,providing more active sites for H_(2)S adsorption.H_(2)-TPR and O_(2)-TPD results confirmed that Cu_(30)/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity,contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process.With notable characteristics such as a large surface area,high desulfurization efficiency,and water resistance,Cu_(30)/HZSM-5–85 sorbents hold significant importance for industrial applications.展开更多
Mercury(Hg),especially methylmercury(MeHg),accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals.In a...Mercury(Hg),especially methylmercury(MeHg),accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals.In addition to being a food staple,rice is widely used as a raw material to produce a vast variety of processed food products.Little is known about Hg levels in snacking rice-food products and potential Hg exposure from consumption of them,besides previous studies on infant rice cereals.Aiming to provide complementary information for a more complete assessment on Hg exposure risk originated from Hgcontaining rice,this study determined total Hg(THg)and MeHg levels in 195 rice-containing and rice-free processed food products covering all major types of snack foods marketed in China and the estimated daily intake(EDI)of dietary Hg from the consumption of these foods.The results clearly showed THg and MeHg contents in rice-containing foods were significantly higher than rice-free products,suggesting the transfer of Hg and MeHg from the rice to the end products,even after manufacturing processes.Moreover,significant positive correlations were observed between THg,MeHg,or MeHg/THg ratio and rice content for samples containing multiple grains as ingredients,further indicating the deciding role of rice for Hg levels in the end food products.Although the EDI of THg and MeHg via ricebased food products were relatively low compared to the reference dose,it should be considered these snacking food products would contribute additive Hg intake outside of the daily regular meals.展开更多
Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range c...Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range can induce very mild cardiac pathological changes.In the present study,we revisited the toxic effect of PM_(2.5)on rat heart by adopting single and multiple exposure durations.FemaleWistar ratswere exposed to PM_(2.5)at a concentration of 250μg/m3 daily for 3 hr for single(1 day)and multiple(7,14,21 days)durations.The major pathological changes noted in 21 days exposed myocardium comprised of an elevated ST segment(the segment between the S wave and the T wave),development of cardiac fibrosis,hypertrophy,cardiac injury,tissue inflammation and declined cardiac function.With 14 days exposed heart,the electrocardiograms(ECG),data showed insignificantly declined heart rate and an increased QT(the time from the start of the Q wave to the end of the T wave)interval along with mild fibrosis,hypertrophy and lesser number of TUNEL positive cells.On the other hand,single-and 7-days exposure to PM_(2.5)did not impart any significant changes in the myocardium.To determine the reversibility potential of PM_(2.5)induced cardiotoxicity,a washout period of 24 hours was adopted and all observed changes in the myocardium were reversed till day 7,but not in 14-and 21-days exposed samples.Based on the above findings we concluded that PM_(2.5)associated cardiac dysfunction is the cumulative outcome of ineffective cardiac adaptive and repair process that accumulate additively over the time due to prolonged exposure durations.展开更多
NH_(2)-MIL-125 and its derivatives are receivingmore attention in various aspects of photocatalytic reactions,especially in the photocatalytic hydrogen peroxide(H_(2)O_(2))production from water(H_(2)O)and oxygen(O_(2)...NH_(2)-MIL-125 and its derivatives are receivingmore attention in various aspects of photocatalytic reactions,especially in the photocatalytic hydrogen peroxide(H_(2)O_(2))production from water(H_(2)O)and oxygen(O_(2)),which is a promising and sustainable strategy.However,the generation of H_(2)O_(2) from NH_(2)-MIL-125 is far from satisfactory due to rapid photo-generated carriers recombination and poor surface electron transfer.In the work,the composite photocatalyst CQDs/TiO_(2)/NH_(2)-MIL-125(C/T/NM)was designed for the first time by one-step hydrothermal method.TiO_(2) was in situ converted from partial NH_(2)-MIL-125(NM)during the successful loaded of Carbon quantum dots(CQDs)by hydrothermal process.The results indicated the typeⅡheterojunction was successfully constructed between the NM and TiO_(2) interface,which could promote the transmission of photo-generated electrons.In addition,the successful loaded of CQDs could effectively transfer and stored the photo-generated electrons to the photocatalyst surface to participate in the reaction,and further avoiding the recombination of photo-generated carriers.The C/T/NM composite photocatalyst achieved a H_(2)O_(2) generation of 455μmol/L for 5 hours under visible light without oxygen bubbling,whichwas 7.1 times superior to that of NM.The H_(2)O_(2) generation rate reached 645.4μM/(g·h),which was in priority in the reported literature under the same conditions.Finally,based on the active species capture experiments,energy band structure analysis and the photoelectrochemicalmeasurements,a possiblemechanism for the efficientH_(2)O_(2) generation through C/T/NM had been proposed.This work provided new ideas for designing NH_(2)-MIL-125 based composite photocatalysts for the production of H_(2)O_(2).展开更多
Integrating photocatalysis technology with peroxymonosulfate oxidation possesses huge potential for degrading stubborn pollutant.Herein,a porous ultra-thin carbon nitride with C-defect O-doping and advanced n-π^(∗)tr...Integrating photocatalysis technology with peroxymonosulfate oxidation possesses huge potential for degrading stubborn pollutant.Herein,a porous ultra-thin carbon nitride with C-defect O-doping and advanced n-π^(∗)transition was customized by one-pot thermalinduced polymerization of molten urea assisted with paraformaldehyde.Via visible-light coupling peroxymonosulfate activation,the DCN-100 can completely photodegrade 2,4-dichlorophenol,and rate constant is 136.6 and 37.9 times that of CN and DCN-100 without peroxymonosulfate.The light-absorption of DCN-100 surpasses 550 nm,specific surface area rises from 45.03 to 98.58m^(2)/g,and charge behaviors are significantly improved.The effects of paraformaldehyde amount,PMS dosage,pH,2,4-dichlorophenol concentration,different water-body,wavelength and recycling times on photodegradation performance were explored in detail.Via capture experiments,ESR,LC-MS,Fukui-function,TEXT toxicity assessment and DFT theoretical calculation,themain active substances,degradation pathway,intermediate toxicity and enhanced activity mechanism of DCN-100 were clarified.The research provides a cost-effective,high-efficiency and environmental-friendly photocatalysts to activate peroxymonosulfate for water remediating.展开更多
The mass production and widespread use of Pharmaceuticals and Personal Care Products(PPCPs)have posed a serious threat to the water environment and public health.In this work,a green metal-based Metal Organic Framewor...The mass production and widespread use of Pharmaceuticals and Personal Care Products(PPCPs)have posed a serious threat to the water environment and public health.In this work,a green metal-based Metal Organic Framework(MOF)Bi-NH_(2)-BDC was prepared and characterized,and the adsorption characteristics of Bi-NH_(2)-BDCwere investigated with typical PPCPs-diclofenac sodium(DCF).It was found that DCF mainly covered the adsorbent surface as a single molecular layer,the adsorption reaction was a spontaneous,entropyincreasing exothermic process and the adsorption mechanisms between Bi-NH_(2)-BDC and DCF were hydrogen bonding,π-πinteractions and electrostatic interactions.In addition,Bi-NH_(2)-BDC also had considerable photocatalytic properties,and its application in adsor-bent desorption treatment effectively solved the problem of secondary pollution,achieving a green and sustainable adsorption desorption cycle.展开更多
Carbon black(CB)is a vital constituent of airborne pollutants,comprising diesel exhaust and fine particulate matter(PM_(2.5)),aswell as a prevalent manufacturingmaterial.CBwas known to cause pulmonary dysfunction and ...Carbon black(CB)is a vital constituent of airborne pollutants,comprising diesel exhaust and fine particulate matter(PM_(2.5)),aswell as a prevalent manufacturingmaterial.CBwas known to cause pulmonary dysfunction and fibrosis.However,the detailedmolecular mechanisms underlying fibrosis development are poorly understood.In this study,18 C57BL/6mice were randomized into two groups and exposed to CB and filtered air(FA)for 28 days,with 6 hr/day and 7 days perweek exposure regimen,respectively.The human normal bronchial epithelial cell line(BEAS-2B)was subjected to CB treatment for 24 h in vitro,with CB concentrations in 0,50,100,and 200μg/mL.Our study indicated that exposure to CB resulted in a reduction in lung function and the development of pulmonary fibrosis in mice.Furthermore,our results showed cytoskeleton rearrangement and epithelial-mesenchymal transition(EMT)phenotype in BEAS-2B cells were happened,after CB exposure.Subsequent studies revealed that elevated expression of THBS2 after CB primarily contributed to the development of pulmonary fibrosis.The research findings from both in vivo and in vitro studies provided evidence that piR-713551 was involved in CB exposure-induced EMT by targeting the THBS2 gene and activating theβ-catenin pathway.Mechanically,piR-713551/PIWIL4 complex activated the THBS2 transcription by recruitment of histone demethyltransferase KDM4A to reduce H3K9me3 modification at the THBS2 gene promoter.Conclusively,our research showed that CB exposure could activate EMT and lead pulmonary fibrosis which was modulated by piR-713551/PIWIL4 targeting THBS2.展开更多
The catalytic diesel particulate filter(CDPF)is the most widely used after-treatment device for controlling diesel engine soot emissions.The development of cost-effective catalysts is crucial for diesel engines to com...The catalytic diesel particulate filter(CDPF)is the most widely used after-treatment device for controlling diesel engine soot emissions.The development of cost-effective catalysts is crucial for diesel engines to comply with future ultra-low emission regulations.This paper studies a new type of Ce/La modified Cs-V non-noble metal CDPF catalyst.Three test catalysts(Cs-V,Cs-V-5%Ce,and Cs-V-5%La)were formulated to explore the physical properties,activity,and sulfur resistance through XRD,SEM,XPS,and TPO tests.And TGA tests with different catalyst-to-soot mass ratios were designed to analyze the reaction kinetics.The results show that the soot oxidation process is divided into three stages:slow oxidation,rapid oxidation,and soot burnout.SEM and XRD results show that,compared with Ce doping,La-doped catalysts have less damage to the microstructure of the first active component,Cs_(2)V_(4)O_(11).XPS results show that the introduction of Ce and La is beneficial to the formation of oxygen vacancies and lattice distortion,increasing the proportion of active oxygen species,thereby improving the soot oxidation activity,among which La-doped active oxygen species have the highest proportion(94%).And the Cs-V-5%La catalyst has the best effect on improving the soot conversion of the three stages.The fresh state has the best low-temperature activity index,the lowest characteristic temperature(T_(50) of 374℃)and activation energy(115.01 kJ/mol),and excellent sulfur resistance.The soot conversion and oxidation speed of the three stages decreases,duration lengthens,and activation energy increases by more than 100 kJ/mol as catalyst-to-soot mass ratios decrease.展开更多
The emission regulations for heavy-duty diesel engines regarding nitrogen oxide(NO_(x))are becoming increasingly stringent,particularly in relation to cold start cycles.While the twostage selective catalytic reduction...The emission regulations for heavy-duty diesel engines regarding nitrogen oxide(NO_(x))are becoming increasingly stringent,particularly in relation to cold start cycles.While the twostage selective catalytic reduction(SCR)has the potential to achieve ultra-low NO_(x) emissions,several challenges remain,including the accurate prediction of ammonia(NH_(3))storage mass and the co-control of the two-stage SCR.The first step in this study involved the establishment of a rapid control prototype platform to facilitate the development and validation of a two-stage SCR control strategy.Secondly,an initial method for predicting the NH_(3) storage based on the mass conservation law was proposed,which was subsequently improved by filling and emptying experiments.The third step involved the development of a two-stage SCR co-control strategy,including obtaining the steady-state NH_(3) storage target value,dynamic correction for NH_(3) storage target value,regulation of NH_(3) storage,and control of the close-coupled SCR urea injector state.Finally,the two-stage SCR urea injection control strategy was certified under the world harmonized transient cycle(WHTC).The results demonstrate that the composite value of engine outlet NO_(x) emissions under cold and hot start WHTC cycles is 13 g/(kW·h).Meanwhile,the composite value of tailpipe NO_(x) emissions under cold and hot start WHTC cycles is 0.065 g/(kW·h),representing only 14%of the EU VI limit value of 0.46 g/(kW·h).Thus,the findings demonstrate that integrating an accurate NH_(3) storage prediction method with the two-stage SCR co-control function is crucial for heavy-duty diesel engines to achieve ultra-low NO_(x) emissions.展开更多
Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,...Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,we report the development of a sorbent tube sampler based on an unmanned aerial vehicle(UAV)platform.Vertical profile measurement of VOCs with a vertical resolution of 25mwas achieved.The sampler consists of five lightweight VOC sorbent tubes and a 5-way solenoid valve,making it available for collecting five atmospheric VOC samples in a single flight with a time response of less than 30min.The samplerweighed∼1.45 kg and had dimensions of 240mm×220mm×100mmwith small penetration loss(<10%)under 4-liter sampling conditions(flow rate of 200 mL/min).Commercialized SUMMA canisters were used as experimental controls to investigate the possible loss of self-made sampler for target compounds in the same sampling process.Comparison experiment on the ground showed that the concentration differences for all VOC species were lower than 0.14μg/m3,proving the good reliability for VOCs measurements using sorbent tube sampler.The UAV platform also incorporated online instruments for meteorological parameters and O_(3) measurement.The sampler was successfully applied to characterize the vertical profiles of VOCs up to 100 m in October 2023 in the Huaihe River Basin of China.The UAV platform and the sorbent tube sampler demonstrate good performance and will be a valuable and reliable tool for vertical VOCs measurement.展开更多
Carbon emissions resulting from energy consumption have become a pressing issue for governments worldwide.Accurate estimation of carbon emissions using satellite remote sensing data has become a crucial research probl...Carbon emissions resulting from energy consumption have become a pressing issue for governments worldwide.Accurate estimation of carbon emissions using satellite remote sensing data has become a crucial research problem.Previous studies relied on statistical regression models that failed to capture the complex nonlinear relationships between carbon emissions and characteristic variables.In this study,we propose a machine learning algorithm for carbon emissions,a Bayesian optimized XGboost regression model,using multi-year energy carbon emission data and nighttime lights(NTL)remote sensing data from Shaanxi Province,China.Our results demonstrate that the XGboost algorithm outperforms linear regression and four other machine learning models,with an R^(2)of 0.906 and RMSE of 5.687.We observe an annual increase in carbon emissions,with high-emission counties primarily concentrated in northern and central Shaanxi Province,displaying a shift from discrete,sporadic points to contiguous,extended spatial distribution.Spatial autocorrelation clustering reveals predominantly high-high and low-low clustering patterns,with economically developed counties showing high-emission clustering and economically relatively backward counties displaying low-emission clustering.Our findings show that the use of NTL data and the XGboost algorithm can estimate and predict carbon emissionsmore accurately and provide a complementary reference for satellite remote sensing image data to serve carbon emission monitoring and assessment.This research provides an important theoretical basis for formulating practical carbon emission reduction policies and contributes to the development of techniques for accurate carbon emission estimation using remote sensing data.展开更多
Siderite tailings is a potentially cost-free iron(Fe)source for arsenic(As)fixation in hazardous arsenic-calcium residues(ACR)as stable scorodite.In this study,a pure siderite reagent was employed to investigate the m...Siderite tailings is a potentially cost-free iron(Fe)source for arsenic(As)fixation in hazardous arsenic-calcium residues(ACR)as stable scorodite.In this study,a pure siderite reagent was employed to investigate the mechanism and optimal conditions for As fixation in ACR via scorodite formation,while the waste siderite tailings were used to further demonstrate the cotreatment method.The cotreatment method starts with an introduction of sulfuric acid to the ACR for As extraction and gypsum precipitation,and is followed by the addition of H_(2)O_(2) to oxidize As(Ⅲ)in the extraction solutions and finalized by adding siderite with continuous air injection for scorodite formation.The dissolution-oxidation of siderite can slowly produce Fe(Ⅲ)to control aqueous As(V)-Fe(Ⅲ)precipitation supersaturation for continuous scorodite crystallization.Chemical analyses show that the extraction efficiency of As from the ACR reaches 94.55%,while the precipitation yield of extracted As via scorodite formation arrives at 99.63% and 99.47%,leading to fixation efficiency of 94.20% and 94.04% in terms of the total As in the ACR by using siderite reagent and tailings,respectively.The final solid products show desirable TCLP stability and long-term stability,meeting the requirement for safe storage(GB 5085.3-2007).XRD,FTIR,and TEM results reveal that such high stability is attributable to the formation of scorodite and the surface adsorption of As on the raw siderite and secondary maghemite.This innovative and economical application of siderite tailings for the treatment of hazardous ACR can be extended to the management of hydrometallurgical wastes.展开更多
Piezoelectric effect,plasma effect and semiconductor heterostructure are important strategies for enhanced photocatalytic performance.Herein,we developed a novel heterostructure piezoelectric photocatalyst,Ag/Ag_(2)S/...Piezoelectric effect,plasma effect and semiconductor heterostructure are important strategies for enhanced photocatalytic performance.Herein,we developed a novel heterostructure piezoelectric photocatalyst,Ag/Ag_(2)S/BiFeO_(3)(AAS/BFO),for photocatalytic degradation of ciprofloxacin from water.Experimental results verified the enhancement of combining heterostructure piezoelectric polarization effect,which promotes efficient migration and separation of photogenerated carriers due to the localized surface plasmon resonance effect of Ag nanoparticles.Additionally,the introduction of Ag_(2)S constructs a new heterostructure,that enhances the electron transport rate and improves the separation efficiency on electron-hole pairs.Under ultrasonic stimulation and visible light irradiation,the degradation efficiencies of 15%-AAS/BFO towards ciprofloxacin,methyl orange and methylene blue are significantly enhanced compared to pure BFO fibers.The demonstrated AAS/BFO material based on the synergistic piezoelectric effect and plasmon heterostructure shows potential in efficient organic pollutants water treatment and transforming mechanical energy into chemical energy.展开更多
Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies,for which the electron donor is an essential one.Propanol is an extraordinarily promising electron d...Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies,for which the electron donor is an essential one.Propanol is an extraordinarily promising electron donor because it can be generated from renewable resources,including lignocellulosic biomass and protein wastes.Here,propanol was proven in detail to be an efficient electron donor,enhancing the production of odd medium-chain carboxylates during chain elongation.By exploring various electron acceptors,reactor conditions,and electron donor/electron acceptor mol ratios,our study highlights that acetate is the most suitable electron acceptor for the production of both odd-and even-chain carboxylates.The optimal conditions for propanol-based chain elongation were 30℃ and pH 6,achieving 82.8%selectivity for odd-chain carboxylates.Another critical insight from our work is that a propanol/acetate mol ratio of 1:1 can minimize the inhibitory effect of propanol and maximize the yield of medium-chain carboxylates,with the highest concentration of n-heptanoate reaching 124.5 mmol C/L.This was further illustrated by 16S rRNA amplicon sequencing,which elucidated that the community composition and keystone species in a propanol-based reactor closely resembled that of the ethanol one.The dominant phylum of the propanol-based reactor,Firmicutes showed a significant positive correlation with the concentrations of n-caproate and n-valerate.Additionally,the co-occurrence of Clostridium sensu stricto 12 and Oscillibacter,known as typical chain elongators,was identified within the propanol-based reactor.These findings enhance our understanding of propanolbased chain elongation,offer guiding principles for reactor microbiota assembly,and support efficient odd medium-chain carboxylate production.展开更多
Phthalic acid esters(PAEs)are widely released into the environment due to industrial and agricultural activities.This poses significant risks,not only to crops grown on contaminated soil but also to humans.PAEs enter ...Phthalic acid esters(PAEs)are widely released into the environment due to industrial and agricultural activities.This poses significant risks,not only to crops grown on contaminated soil but also to humans.PAEs enter the human body through the food chain,causing potential health hazards.Endophytic bacteria have demonstrated a significant potential as effective bioremediation agents,with specialized mechanisms of PAEs degradation.Endophytic bacteria such as Rhodococcus,Pseudomonas and Sphingomona recognize root exudates,adhere to and penetrate root surfaces,and ultimately colonize crops.They form symbiotic relationships with crops,obtaining nutrients and habitats from crops,meanwhile,promoting plant growth and health through hormone production,nutrient regulation,and the suppression of pathogenic microorganisms.Furthermore,endophytic bacteria efficiently degrade PAEs in soil-crop systems through synergistic interactions with indigenous rhizosphere microflora and regulatory effects on enzyme activity in crops.Here,we review the role of endophytic bacteria in the bioremediation of PAEs-contaminated crops and soils.In addition,we discuss the scarcity of endophytic bacterial strains with a confirmed ability to degrade PAEs,and underscore the lack of the research on the mechanisms of PAEs degradation by these bacteria.This review also points out that future study should investigate the molecular mechanisms underlying the interaction between endophytic bacteria and PAEs to offer novel insights and solutions for environmental protection and sustainable agricultural development.展开更多
Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduc...Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduction potential by the Domestic Emission Control Area(DECA)policy and GSC cooperation is still lacking.Here,a series of multi-year high spatiotemporal ship emission inventories around Hainan,a representative island province of China,were developed with the state-of-the-art Shipping Emission Inventory Model.The improved origin-destination identification algorithm allowed emission allocation to port level.The emission reduction potential of the DECA policy and Hainan's joining GSCwas analyzed.In 2022,ship emission intensity in waters 12 Nm from Hainan(Hainan-12Nm)were 6.4%-7.4% of that in waters 12 Nm from China.From 2019 to 2022,Hainan-12Nm emissions dropped by 66.7%-77.8% for SO_(2) and PM2.5.Ideally,with adequate ultra-low-sulfur fuel,DECA can reduce SO_(2) and PM2.5 emissions by 16.6% and 22.4% yearly compared with no-DECA scenario.However,emission reduction would drop markedly if ultra-low-sulfur fuel is short in supply.Emissions of voyages passing through 200 Nm from Hainan took up 1%-4%of international shipping emissions,implying great emission reduction potential for Hainan's establishing GSCs,especially considering the flourishing South-South trade.This study provides a thorough assessment of the current state of shipping emissions around Hainan as well as offers excellent data support for Hainan to further advance the future upgrade of ship emission management policies.展开更多
Arsenic-contaminated groundwater is widely used in agriculture.To meet the increasing demand for safe water in agriculture,an efficient and cost-effective method for As removal from groundwater is urgently needed.We h...Arsenic-contaminated groundwater is widely used in agriculture.To meet the increasing demand for safe water in agriculture,an efficient and cost-effective method for As removal from groundwater is urgently needed.We hypothesized that Fe(oxyhydr)oxide(FeOOH)minerals precipitated in situ from indigenous Fe in groundwater may immobilize As,providing a solution for safely using As-contaminated groundwater in irrigation.To confirm this hypothesis and identify the controlling mechanisms,we comprehensively evaluated the transport,speciation changes,and immobilization of As and Fe in agricultural canals irrigated using As-contaminated groundwater.The efficiently removed As and Fe in the canals accumulated in shallow sediment rather than subsurface sediment.Linear combination fitting(LCF)analysis of X-ray absorption near edge spectroscopy(XANES)indicated that As(Ⅴ)was the dominant As species,followed by As(Ⅲ),and therewas no FeAsO_(4) precipitate.Sequential extraction revealed higher contents of amorphous FeOOH and associated As in shallower sediment than in the subsurface layer.Stoichiometric molar ratio calculations,SEM-EDS,FTIR,and fluorescence spectroscopy collectively demonstrated that the microbial reductive dissolution of amorphous FeOOH proceeded via reactive dissolved organic matter(DOM)consumption in subsurface anoxic porewater environment facilitating high labile As,whereas in surface sediment,the in situ-generated amorphous FeOOH was stable and strongly inhibited As release via adsorption.In summary,groundwater Fe^(2+)can efficiently precipitate in benthic surface sediment as abundant amorphous FeOOH,which immobilizes most of the dissolved As,protecting agricultural soil from contamination.This field research supports the critical roles of the phase and reactivity of in situ-generated FeOOH in As immobilization and provides new insight into the sustainable use of contaminated water.展开更多
基金supported by the National Key Research and Development Project(No.2020YFA0907500)the National Natural Science Foundation of China(No.22476206)+1 种基金the supports from the National Young Top-Notch Talents(No.W03070030)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.
基金supported by Spanish Ministry of Science and Innovation (No.PID2020–116147GB-C22)funded by the European Union (Next Generation UE)+1 种基金funded by the Programa de Posgrado en Ciencias del Mar y Limnología (UNAM)CONAHCYT (CVU:828722).
文摘Freshwater ecosystems are crucial in the global emissions of greenhouse gases(GHGs)such as CH_(4).Macrophytes are the main organic matter(i.e.,detritus)supplier to the sediment of these systems,thus controlling CH_(4) production.However,species-specific differences(structure and composition)may determine contrasting patterns of detritus transformation into CH_(4).Furthermore,eutrophication can affect the degradation and,consequently,CH_(4) production.We performed a 64-day microcosm experiment with anoxic incubations of detritus from seven phylogenetically different macrophytes(two charophytes,filamentous algae–Spirogyra,Cladophora–,three submerged plants and an amphibious one),under two trophic conditions(oligo-versus eutrophic)and with/without sediment.We assessed the CH_(4) and CO_(2) production and the changes in the detritus quality at the end of the experiment.The ranking in the mean cumulative CH_(4) production was:Chara hispida>Nitella hyalina>Najasmarina≈Teucrium scordium>Stuckenia pectinata≈Myriophyllum spicatum>filamentous algae,and it was related to the detritus quality.GHGs maximumproduction rates were 1.6(N.marina)-1.2(C.hispida)mmol CH_(4)/(g OC·day)and 1.7(N.marina)-1.5(C.hispida)mmol CO_(2)/(g OC·day).The CO_(2):CH_(4) ratiowas biased towards CO_(2) during the first 10 days(average ratio of 200)and fell afterwards to about 1 for all macrophyte species and treatments.The sediment favored detritus decomposition(probably due to the“positive priming effect”),increasing GHGs production.The influence of nutrient enrichment was not evident.Delving into themacrophyte detritus quality-GHGs production relationship is needed to forecast the GHGs emissions in macrophyte-dominated systems.
基金supported by the Joint Funds of the National Natural Science Foundation of China(No.U21A20320)the National Natural Science Foundation of China(No.22106102)was also sponsored by the special fund of State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants(No.SEPKLEHIAEC-202203).
文摘Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate)(PBST)and poly(butylene adipate-co-terephthalate)(PBAT).In this study,quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradationmechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B(CALB).Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism,with the initial two steps being acylation reactions and the subsequent two being hydrolysis reactions.Notably,the first step of the hydrolysis is identified as the rate-determining step.Moreover,by introducing single-point mutations to expand the substrate entrance tunnel,the catalytic distance of the first acylation step decreases.Additionally,energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme’s active site.This study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme’s active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB.
基金supported by the National Natural Science Foundation of China(Nos.52270106 and 22266021)Yunnan Major Scientific and Technological Projects(No.202202AG050005)Yunnan Fundamental Research Projects(No.202201AT070116).
文摘This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The impact of different Si/Al ratios on the adsorption oxidative performance of Cu_(30)/HZSM-5–85 adsorbents was investigated.According to the performance test results,Cu_(30)/HZSM-5–85 exhibited the highest breakthrough capacity,reaching 231.75 mg H_(2)S/g_(sorbent).Cu/HZSM-5 sorbent maintains a strong ability to remove H_(2)S even under humid conditions and shows excellent water resistance.XRD,BET,and XPS results revealed that CuO is the primary active species,with Cu_(30)/HZSM-5–85 having the largest surface area and highest CuO content,providing more active sites for H_(2)S adsorption.H_(2)-TPR and O_(2)-TPD results confirmed that Cu_(30)/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity,contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process.With notable characteristics such as a large surface area,high desulfurization efficiency,and water resistance,Cu_(30)/HZSM-5–85 sorbents hold significant importance for industrial applications.
基金supported by the Shandong Provincial Natural Science Foundation (No.ZR2022QB242)the National Natural Science Foundation of China (No.22306111 and 22306108)+1 种基金the Shandong Provincial Natural Science Foundation (No.ZR2020ZD20)the Chinese Postdoctoral Science Foundation (No.2023M732059).
文摘Mercury(Hg),especially methylmercury(MeHg),accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals.In addition to being a food staple,rice is widely used as a raw material to produce a vast variety of processed food products.Little is known about Hg levels in snacking rice-food products and potential Hg exposure from consumption of them,besides previous studies on infant rice cereals.Aiming to provide complementary information for a more complete assessment on Hg exposure risk originated from Hgcontaining rice,this study determined total Hg(THg)and MeHg levels in 195 rice-containing and rice-free processed food products covering all major types of snack foods marketed in China and the estimated daily intake(EDI)of dietary Hg from the consumption of these foods.The results clearly showed THg and MeHg contents in rice-containing foods were significantly higher than rice-free products,suggesting the transfer of Hg and MeHg from the rice to the end products,even after manufacturing processes.Moreover,significant positive correlations were observed between THg,MeHg,or MeHg/THg ratio and rice content for samples containing multiple grains as ingredients,further indicating the deciding role of rice for Hg levels in the end food products.Although the EDI of THg and MeHg via ricebased food products were relatively low compared to the reference dose,it should be considered these snacking food products would contribute additive Hg intake outside of the daily regular meals.
基金the Indian Council of Medical Research(No.3/1/2(22)/Env/2021-NCD-II)Department of science and technology,India(CRG/2021/000227)for funding this research.
文摘Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range can induce very mild cardiac pathological changes.In the present study,we revisited the toxic effect of PM_(2.5)on rat heart by adopting single and multiple exposure durations.FemaleWistar ratswere exposed to PM_(2.5)at a concentration of 250μg/m3 daily for 3 hr for single(1 day)and multiple(7,14,21 days)durations.The major pathological changes noted in 21 days exposed myocardium comprised of an elevated ST segment(the segment between the S wave and the T wave),development of cardiac fibrosis,hypertrophy,cardiac injury,tissue inflammation and declined cardiac function.With 14 days exposed heart,the electrocardiograms(ECG),data showed insignificantly declined heart rate and an increased QT(the time from the start of the Q wave to the end of the T wave)interval along with mild fibrosis,hypertrophy and lesser number of TUNEL positive cells.On the other hand,single-and 7-days exposure to PM_(2.5)did not impart any significant changes in the myocardium.To determine the reversibility potential of PM_(2.5)induced cardiotoxicity,a washout period of 24 hours was adopted and all observed changes in the myocardium were reversed till day 7,but not in 14-and 21-days exposed samples.Based on the above findings we concluded that PM_(2.5)associated cardiac dysfunction is the cumulative outcome of ineffective cardiac adaptive and repair process that accumulate additively over the time due to prolonged exposure durations.
基金supported by the National Natural Science Foundation of China(NSFC)(No.52100101)and the National Scholarship Fund.
文摘NH_(2)-MIL-125 and its derivatives are receivingmore attention in various aspects of photocatalytic reactions,especially in the photocatalytic hydrogen peroxide(H_(2)O_(2))production from water(H_(2)O)and oxygen(O_(2)),which is a promising and sustainable strategy.However,the generation of H_(2)O_(2) from NH_(2)-MIL-125 is far from satisfactory due to rapid photo-generated carriers recombination and poor surface electron transfer.In the work,the composite photocatalyst CQDs/TiO_(2)/NH_(2)-MIL-125(C/T/NM)was designed for the first time by one-step hydrothermal method.TiO_(2) was in situ converted from partial NH_(2)-MIL-125(NM)during the successful loaded of Carbon quantum dots(CQDs)by hydrothermal process.The results indicated the typeⅡheterojunction was successfully constructed between the NM and TiO_(2) interface,which could promote the transmission of photo-generated electrons.In addition,the successful loaded of CQDs could effectively transfer and stored the photo-generated electrons to the photocatalyst surface to participate in the reaction,and further avoiding the recombination of photo-generated carriers.The C/T/NM composite photocatalyst achieved a H_(2)O_(2) generation of 455μmol/L for 5 hours under visible light without oxygen bubbling,whichwas 7.1 times superior to that of NM.The H_(2)O_(2) generation rate reached 645.4μM/(g·h),which was in priority in the reported literature under the same conditions.Finally,based on the active species capture experiments,energy band structure analysis and the photoelectrochemicalmeasurements,a possiblemechanism for the efficientH_(2)O_(2) generation through C/T/NM had been proposed.This work provided new ideas for designing NH_(2)-MIL-125 based composite photocatalysts for the production of H_(2)O_(2).
基金supported by the Natural Science Foundation Project of Jilin Province(Nos.20230101297JC,YDZJ202201ZYTS347,YDZJ202101ZYTS073,20210101117JC,YDZJ202201ZYTS349,YDZJ202102CXJD049)the National Natural Science Foundation(22004047)+4 种基金China Postdoctoral Science Foundation(No.2023M731299)the Project of Jilin Province Development and Reform Commission(Nos.2023C032-5,2023C032-4,2023C032-2)the Project of Human Resources and Social Security Department of Jilin Province(No.2023337)the National College students’innovation and entrepreneurship training program(No.202310203008)the Project of Education Department of Jilin Province(Nos.JJKH20220429KJ,JJKH20210460KJ).
文摘Integrating photocatalysis technology with peroxymonosulfate oxidation possesses huge potential for degrading stubborn pollutant.Herein,a porous ultra-thin carbon nitride with C-defect O-doping and advanced n-π^(∗)transition was customized by one-pot thermalinduced polymerization of molten urea assisted with paraformaldehyde.Via visible-light coupling peroxymonosulfate activation,the DCN-100 can completely photodegrade 2,4-dichlorophenol,and rate constant is 136.6 and 37.9 times that of CN and DCN-100 without peroxymonosulfate.The light-absorption of DCN-100 surpasses 550 nm,specific surface area rises from 45.03 to 98.58m^(2)/g,and charge behaviors are significantly improved.The effects of paraformaldehyde amount,PMS dosage,pH,2,4-dichlorophenol concentration,different water-body,wavelength and recycling times on photodegradation performance were explored in detail.Via capture experiments,ESR,LC-MS,Fukui-function,TEXT toxicity assessment and DFT theoretical calculation,themain active substances,degradation pathway,intermediate toxicity and enhanced activity mechanism of DCN-100 were clarified.The research provides a cost-effective,high-efficiency and environmental-friendly photocatalysts to activate peroxymonosulfate for water remediating.
基金supported by Liaoning Revitalization Talents Program(No.XLYC1907173)the Science and Technology General Project of Liaoning Provincial Education Department(No.LJKMZ20221835)the National Natural Science Foundation of China(Nos.22006073 and 22205027).
文摘The mass production and widespread use of Pharmaceuticals and Personal Care Products(PPCPs)have posed a serious threat to the water environment and public health.In this work,a green metal-based Metal Organic Framework(MOF)Bi-NH_(2)-BDC was prepared and characterized,and the adsorption characteristics of Bi-NH_(2)-BDCwere investigated with typical PPCPs-diclofenac sodium(DCF).It was found that DCF mainly covered the adsorbent surface as a single molecular layer,the adsorption reaction was a spontaneous,entropyincreasing exothermic process and the adsorption mechanisms between Bi-NH_(2)-BDC and DCF were hydrogen bonding,π-πinteractions and electrostatic interactions.In addition,Bi-NH_(2)-BDC also had considerable photocatalytic properties,and its application in adsor-bent desorption treatment effectively solved the problem of secondary pollution,achieving a green and sustainable adsorption desorption cycle.
基金supported by the National Natural Science Foundation of China(Nos.81973074,92043202,82204075,and 82204074).
文摘Carbon black(CB)is a vital constituent of airborne pollutants,comprising diesel exhaust and fine particulate matter(PM_(2.5)),aswell as a prevalent manufacturingmaterial.CBwas known to cause pulmonary dysfunction and fibrosis.However,the detailedmolecular mechanisms underlying fibrosis development are poorly understood.In this study,18 C57BL/6mice were randomized into two groups and exposed to CB and filtered air(FA)for 28 days,with 6 hr/day and 7 days perweek exposure regimen,respectively.The human normal bronchial epithelial cell line(BEAS-2B)was subjected to CB treatment for 24 h in vitro,with CB concentrations in 0,50,100,and 200μg/mL.Our study indicated that exposure to CB resulted in a reduction in lung function and the development of pulmonary fibrosis in mice.Furthermore,our results showed cytoskeleton rearrangement and epithelial-mesenchymal transition(EMT)phenotype in BEAS-2B cells were happened,after CB exposure.Subsequent studies revealed that elevated expression of THBS2 after CB primarily contributed to the development of pulmonary fibrosis.The research findings from both in vivo and in vitro studies provided evidence that piR-713551 was involved in CB exposure-induced EMT by targeting the THBS2 gene and activating theβ-catenin pathway.Mechanically,piR-713551/PIWIL4 complex activated the THBS2 transcription by recruitment of histone demethyltransferase KDM4A to reduce H3K9me3 modification at the THBS2 gene promoter.Conclusively,our research showed that CB exposure could activate EMT and lead pulmonary fibrosis which was modulated by piR-713551/PIWIL4 targeting THBS2.
基金supported by the National Natural Science Foundation of China(No.52206167)the Science and Technology Talents and Platform Program(Academician ExpertWorkstation)(No.202305AF150109)+1 种基金Shanghai Sailing Program(No.21YF1448900)the Introduced and co-builded high-level research and development institutions of Jiangxi Province(No.20212CCH45004).
文摘The catalytic diesel particulate filter(CDPF)is the most widely used after-treatment device for controlling diesel engine soot emissions.The development of cost-effective catalysts is crucial for diesel engines to comply with future ultra-low emission regulations.This paper studies a new type of Ce/La modified Cs-V non-noble metal CDPF catalyst.Three test catalysts(Cs-V,Cs-V-5%Ce,and Cs-V-5%La)were formulated to explore the physical properties,activity,and sulfur resistance through XRD,SEM,XPS,and TPO tests.And TGA tests with different catalyst-to-soot mass ratios were designed to analyze the reaction kinetics.The results show that the soot oxidation process is divided into three stages:slow oxidation,rapid oxidation,and soot burnout.SEM and XRD results show that,compared with Ce doping,La-doped catalysts have less damage to the microstructure of the first active component,Cs_(2)V_(4)O_(11).XPS results show that the introduction of Ce and La is beneficial to the formation of oxygen vacancies and lattice distortion,increasing the proportion of active oxygen species,thereby improving the soot oxidation activity,among which La-doped active oxygen species have the highest proportion(94%).And the Cs-V-5%La catalyst has the best effect on improving the soot conversion of the three stages.The fresh state has the best low-temperature activity index,the lowest characteristic temperature(T_(50) of 374℃)and activation energy(115.01 kJ/mol),and excellent sulfur resistance.The soot conversion and oxidation speed of the three stages decreases,duration lengthens,and activation energy increases by more than 100 kJ/mol as catalyst-to-soot mass ratios decrease.
基金supported by the National Natural Science Foundation of China(No.51921004).
文摘The emission regulations for heavy-duty diesel engines regarding nitrogen oxide(NO_(x))are becoming increasingly stringent,particularly in relation to cold start cycles.While the twostage selective catalytic reduction(SCR)has the potential to achieve ultra-low NO_(x) emissions,several challenges remain,including the accurate prediction of ammonia(NH_(3))storage mass and the co-control of the two-stage SCR.The first step in this study involved the establishment of a rapid control prototype platform to facilitate the development and validation of a two-stage SCR control strategy.Secondly,an initial method for predicting the NH_(3) storage based on the mass conservation law was proposed,which was subsequently improved by filling and emptying experiments.The third step involved the development of a two-stage SCR co-control strategy,including obtaining the steady-state NH_(3) storage target value,dynamic correction for NH_(3) storage target value,regulation of NH_(3) storage,and control of the close-coupled SCR urea injector state.Finally,the two-stage SCR urea injection control strategy was certified under the world harmonized transient cycle(WHTC).The results demonstrate that the composite value of engine outlet NO_(x) emissions under cold and hot start WHTC cycles is 13 g/(kW·h).Meanwhile,the composite value of tailpipe NO_(x) emissions under cold and hot start WHTC cycles is 0.065 g/(kW·h),representing only 14%of the EU VI limit value of 0.46 g/(kW·h).Thus,the findings demonstrate that integrating an accurate NH_(3) storage prediction method with the two-stage SCR co-control function is crucial for heavy-duty diesel engines to achieve ultra-low NO_(x) emissions.
基金supported by the National Natural Science Foundation of China(Nos.42022051,U21A2028,and 42305124)the Youth Innovation Promotion Association CAS(No.Y202089)the HFIPS Director’s Fund(Nos.BJPY2023A02,YZJJ202101,and YZJJ2023QN01).
文摘Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,we report the development of a sorbent tube sampler based on an unmanned aerial vehicle(UAV)platform.Vertical profile measurement of VOCs with a vertical resolution of 25mwas achieved.The sampler consists of five lightweight VOC sorbent tubes and a 5-way solenoid valve,making it available for collecting five atmospheric VOC samples in a single flight with a time response of less than 30min.The samplerweighed∼1.45 kg and had dimensions of 240mm×220mm×100mmwith small penetration loss(<10%)under 4-liter sampling conditions(flow rate of 200 mL/min).Commercialized SUMMA canisters were used as experimental controls to investigate the possible loss of self-made sampler for target compounds in the same sampling process.Comparison experiment on the ground showed that the concentration differences for all VOC species were lower than 0.14μg/m3,proving the good reliability for VOCs measurements using sorbent tube sampler.The UAV platform also incorporated online instruments for meteorological parameters and O_(3) measurement.The sampler was successfully applied to characterize the vertical profiles of VOCs up to 100 m in October 2023 in the Huaihe River Basin of China.The UAV platform and the sorbent tube sampler demonstrate good performance and will be a valuable and reliable tool for vertical VOCs measurement.
基金supported by the Key Research and Development Program in Shaanxi Province,China(No.2022ZDLSF07-05)the Fundamental Research Funds for the Central Universities,CHD(No.300102352901)。
文摘Carbon emissions resulting from energy consumption have become a pressing issue for governments worldwide.Accurate estimation of carbon emissions using satellite remote sensing data has become a crucial research problem.Previous studies relied on statistical regression models that failed to capture the complex nonlinear relationships between carbon emissions and characteristic variables.In this study,we propose a machine learning algorithm for carbon emissions,a Bayesian optimized XGboost regression model,using multi-year energy carbon emission data and nighttime lights(NTL)remote sensing data from Shaanxi Province,China.Our results demonstrate that the XGboost algorithm outperforms linear regression and four other machine learning models,with an R^(2)of 0.906 and RMSE of 5.687.We observe an annual increase in carbon emissions,with high-emission counties primarily concentrated in northern and central Shaanxi Province,displaying a shift from discrete,sporadic points to contiguous,extended spatial distribution.Spatial autocorrelation clustering reveals predominantly high-high and low-low clustering patterns,with economically developed counties showing high-emission clustering and economically relatively backward counties displaying low-emission clustering.Our findings show that the use of NTL data and the XGboost algorithm can estimate and predict carbon emissionsmore accurately and provide a complementary reference for satellite remote sensing image data to serve carbon emission monitoring and assessment.This research provides an important theoretical basis for formulating practical carbon emission reduction policies and contributes to the development of techniques for accurate carbon emission estimation using remote sensing data.
基金supported by the National Natural Science Foundation of China(Nos.42207258 and 52270150)the Liaoning Provincial Natural Science Foundation Program Project(No.2022-BS-312)+1 种基金the Liaoning University of Technology Doctoral Research Start-up Fund Project(No.XB2021013)the Shenyang Youth Science and Technology Project(No.RC210166).
文摘Siderite tailings is a potentially cost-free iron(Fe)source for arsenic(As)fixation in hazardous arsenic-calcium residues(ACR)as stable scorodite.In this study,a pure siderite reagent was employed to investigate the mechanism and optimal conditions for As fixation in ACR via scorodite formation,while the waste siderite tailings were used to further demonstrate the cotreatment method.The cotreatment method starts with an introduction of sulfuric acid to the ACR for As extraction and gypsum precipitation,and is followed by the addition of H_(2)O_(2) to oxidize As(Ⅲ)in the extraction solutions and finalized by adding siderite with continuous air injection for scorodite formation.The dissolution-oxidation of siderite can slowly produce Fe(Ⅲ)to control aqueous As(V)-Fe(Ⅲ)precipitation supersaturation for continuous scorodite crystallization.Chemical analyses show that the extraction efficiency of As from the ACR reaches 94.55%,while the precipitation yield of extracted As via scorodite formation arrives at 99.63% and 99.47%,leading to fixation efficiency of 94.20% and 94.04% in terms of the total As in the ACR by using siderite reagent and tailings,respectively.The final solid products show desirable TCLP stability and long-term stability,meeting the requirement for safe storage(GB 5085.3-2007).XRD,FTIR,and TEM results reveal that such high stability is attributable to the formation of scorodite and the surface adsorption of As on the raw siderite and secondary maghemite.This innovative and economical application of siderite tailings for the treatment of hazardous ACR can be extended to the management of hydrometallurgical wastes.
基金supported by the National Natural Science Foundation of China(Nos.52372090 and 52073177)the National Natural Science Foundation of Guangdong,China(No.2023A1515010947)Shenzhen Basic Research Program(No.JCYJ20220531102207017).
文摘Piezoelectric effect,plasma effect and semiconductor heterostructure are important strategies for enhanced photocatalytic performance.Herein,we developed a novel heterostructure piezoelectric photocatalyst,Ag/Ag_(2)S/BiFeO_(3)(AAS/BFO),for photocatalytic degradation of ciprofloxacin from water.Experimental results verified the enhancement of combining heterostructure piezoelectric polarization effect,which promotes efficient migration and separation of photogenerated carriers due to the localized surface plasmon resonance effect of Ag nanoparticles.Additionally,the introduction of Ag_(2)S constructs a new heterostructure,that enhances the electron transport rate and improves the separation efficiency on electron-hole pairs.Under ultrasonic stimulation and visible light irradiation,the degradation efficiencies of 15%-AAS/BFO towards ciprofloxacin,methyl orange and methylene blue are significantly enhanced compared to pure BFO fibers.The demonstrated AAS/BFO material based on the synergistic piezoelectric effect and plasmon heterostructure shows potential in efficient organic pollutants water treatment and transforming mechanical energy into chemical energy.
基金supported by the National Key R&D Program of China(No.2022YFC2105301)the National Natural Science Foundation of China(No.52270096).
文摘Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies,for which the electron donor is an essential one.Propanol is an extraordinarily promising electron donor because it can be generated from renewable resources,including lignocellulosic biomass and protein wastes.Here,propanol was proven in detail to be an efficient electron donor,enhancing the production of odd medium-chain carboxylates during chain elongation.By exploring various electron acceptors,reactor conditions,and electron donor/electron acceptor mol ratios,our study highlights that acetate is the most suitable electron acceptor for the production of both odd-and even-chain carboxylates.The optimal conditions for propanol-based chain elongation were 30℃ and pH 6,achieving 82.8%selectivity for odd-chain carboxylates.Another critical insight from our work is that a propanol/acetate mol ratio of 1:1 can minimize the inhibitory effect of propanol and maximize the yield of medium-chain carboxylates,with the highest concentration of n-heptanoate reaching 124.5 mmol C/L.This was further illustrated by 16S rRNA amplicon sequencing,which elucidated that the community composition and keystone species in a propanol-based reactor closely resembled that of the ethanol one.The dominant phylum of the propanol-based reactor,Firmicutes showed a significant positive correlation with the concentrations of n-caproate and n-valerate.Additionally,the co-occurrence of Clostridium sensu stricto 12 and Oscillibacter,known as typical chain elongators,was identified within the propanol-based reactor.These findings enhance our understanding of propanolbased chain elongation,offer guiding principles for reactor microbiota assembly,and support efficient odd medium-chain carboxylate production.
基金supported by the National Natural Science Foundation of China(No.22161132011)Jiangsu Provincial Special Fund for S&T Innovation in Carbon Emission Peak and Neutrality(No.20220013)+1 种基金the National Key Research and Development Program of China(Nos.2023YFE0110800 and 2023YFC3708100)the Fundamental Research Funds for the Central Universities(No.QTPY2024001).
文摘Phthalic acid esters(PAEs)are widely released into the environment due to industrial and agricultural activities.This poses significant risks,not only to crops grown on contaminated soil but also to humans.PAEs enter the human body through the food chain,causing potential health hazards.Endophytic bacteria have demonstrated a significant potential as effective bioremediation agents,with specialized mechanisms of PAEs degradation.Endophytic bacteria such as Rhodococcus,Pseudomonas and Sphingomona recognize root exudates,adhere to and penetrate root surfaces,and ultimately colonize crops.They form symbiotic relationships with crops,obtaining nutrients and habitats from crops,meanwhile,promoting plant growth and health through hormone production,nutrient regulation,and the suppression of pathogenic microorganisms.Furthermore,endophytic bacteria efficiently degrade PAEs in soil-crop systems through synergistic interactions with indigenous rhizosphere microflora and regulatory effects on enzyme activity in crops.Here,we review the role of endophytic bacteria in the bioremediation of PAEs-contaminated crops and soils.In addition,we discuss the scarcity of endophytic bacterial strains with a confirmed ability to degrade PAEs,and underscore the lack of the research on the mechanisms of PAEs degradation by these bacteria.This review also points out that future study should investigate the molecular mechanisms underlying the interaction between endophytic bacteria and PAEs to offer novel insights and solutions for environmental protection and sustainable agricultural development.
基金supported by the National Natural Science Foundation of China(No.42325505)the National Key R&D Program of China(No.2022YFC3704200)the Tsinghua University Initiative Scientific Research Program.
文摘Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduction potential by the Domestic Emission Control Area(DECA)policy and GSC cooperation is still lacking.Here,a series of multi-year high spatiotemporal ship emission inventories around Hainan,a representative island province of China,were developed with the state-of-the-art Shipping Emission Inventory Model.The improved origin-destination identification algorithm allowed emission allocation to port level.The emission reduction potential of the DECA policy and Hainan's joining GSCwas analyzed.In 2022,ship emission intensity in waters 12 Nm from Hainan(Hainan-12Nm)were 6.4%-7.4% of that in waters 12 Nm from China.From 2019 to 2022,Hainan-12Nm emissions dropped by 66.7%-77.8% for SO_(2) and PM2.5.Ideally,with adequate ultra-low-sulfur fuel,DECA can reduce SO_(2) and PM2.5 emissions by 16.6% and 22.4% yearly compared with no-DECA scenario.However,emission reduction would drop markedly if ultra-low-sulfur fuel is short in supply.Emissions of voyages passing through 200 Nm from Hainan took up 1%-4%of international shipping emissions,implying great emission reduction potential for Hainan's establishing GSCs,especially considering the flourishing South-South trade.This study provides a thorough assessment of the current state of shipping emissions around Hainan as well as offers excellent data support for Hainan to further advance the future upgrade of ship emission management policies.
基金supported by the National Natural Science Foundation of China(Nos.41830753,42277201,42377242,and 41977286)the Scientific Research Foundation of Guangzhou University(No.YJ2023027)the College Student Innovation and Entrepreneurship Training Program(No.S202311078057).
文摘Arsenic-contaminated groundwater is widely used in agriculture.To meet the increasing demand for safe water in agriculture,an efficient and cost-effective method for As removal from groundwater is urgently needed.We hypothesized that Fe(oxyhydr)oxide(FeOOH)minerals precipitated in situ from indigenous Fe in groundwater may immobilize As,providing a solution for safely using As-contaminated groundwater in irrigation.To confirm this hypothesis and identify the controlling mechanisms,we comprehensively evaluated the transport,speciation changes,and immobilization of As and Fe in agricultural canals irrigated using As-contaminated groundwater.The efficiently removed As and Fe in the canals accumulated in shallow sediment rather than subsurface sediment.Linear combination fitting(LCF)analysis of X-ray absorption near edge spectroscopy(XANES)indicated that As(Ⅴ)was the dominant As species,followed by As(Ⅲ),and therewas no FeAsO_(4) precipitate.Sequential extraction revealed higher contents of amorphous FeOOH and associated As in shallower sediment than in the subsurface layer.Stoichiometric molar ratio calculations,SEM-EDS,FTIR,and fluorescence spectroscopy collectively demonstrated that the microbial reductive dissolution of amorphous FeOOH proceeded via reactive dissolved organic matter(DOM)consumption in subsurface anoxic porewater environment facilitating high labile As,whereas in surface sediment,the in situ-generated amorphous FeOOH was stable and strongly inhibited As release via adsorption.In summary,groundwater Fe^(2+)can efficiently precipitate in benthic surface sediment as abundant amorphous FeOOH,which immobilizes most of the dissolved As,protecting agricultural soil from contamination.This field research supports the critical roles of the phase and reactivity of in situ-generated FeOOH in As immobilization and provides new insight into the sustainable use of contaminated water.
