Fine particulate matter(PM_(2.5))and ozone(O_(3))pollutions are prevalent air quality issues in China.Volatile organic compounds(VOCs)have significant impact on the formation of O_(3)and secondary organic aerosols(SOA...Fine particulate matter(PM_(2.5))and ozone(O_(3))pollutions are prevalent air quality issues in China.Volatile organic compounds(VOCs)have significant impact on the formation of O_(3)and secondary organic aerosols(SOA)contributing PM_(2.5).Herein,we investigated 54 VOCs,O_(3)and SOA in Tianjin from June 2017 to May 2019 to explore the non-linear relationship among O_(3),SOA and VOCs.The monthly patterns of VOCs and SOA concentrations were characterized by peak values during October to March and reached a minimum from April to September,but the observed O_(3)was exactly the opposite.Machine learning methods resolved the importance of individual VOCs on O_(3)and SOA that alkenes(mainly ethylene,propylene,and isoprene)have the highest importance to O_(3)formation;alkanes(C_(n),n≥6)and aromatics were the main source of SOA formation.Machine learning methods revealed and emphasized the importance of photochemical consumptions of VOCs to O_(3)and SOA formation.Ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)calculated by consumed VOCs quantitatively indicated that more than 80%of the consumed VOCs were alkenes which dominated the O_(3)formation,and the importance of consumed aromatics and alkenes to SOAFP were 40.84%and 56.65%,respectively.Therein,isoprene contributed the most to OFP at 41.45%regardless of the season,while aromatics(58.27%)contributed the most to SOAFP in winter.Collectively,our findings can provide scientific evidence on policymaking for VOCs controls on seasonal scales to achieve effective reduction in both SOA and O_(3).展开更多
Data assimilation algorithm depends on the basic assumption of unbiased observation error,so bias correction is one of the important steps in satellite data processing.In this paper,using the geostationary interferome...Data assimilation algorithm depends on the basic assumption of unbiased observation error,so bias correction is one of the important steps in satellite data processing.In this paper,using the geostationary interferometric infrared sounder(GIIRS)of FengYun-4 A(FY-4 A)observation and simulated brightness temperature based on background field,the brightness temperature bias correction of GIIRS channel is carried out based on random forest(RF)and extreme gradient boosting(XGBoost)machine learning.Based on the case data of Typhoon"Haishen",the correction effect of machine learning method is compared with Harris and Kelly’s"off-line"method,and the importance of different predictors to the bias correction is further discussed.The experimental results show that the systematic bias is effectively corrected,and the following conclusions are obtained:the correction effect is improved by adding geographic information(longitude and latitude)into the predictors;under the given combination of predictors,the correction effect of XGBoost is the best,followed by random forest,and finally offline method,but the three methods can correct the bias effectively;compared with long wave data of FY-4 A/GIIRS,machine learning may be more feasible for medium wave data bias correction.展开更多
Plant polyphenol-based coordination polymers(CPs) with ultra-small particle size and tailorable compositions are highly desired in biomedical applicatio ns,but their synthesis is still challenging due to the sophistic...Plant polyphenol-based coordination polymers(CPs) with ultra-small particle size and tailorable compositions are highly desired in biomedical applicatio ns,but their synthesis is still challenging due to the sophisticated coordination assembly process and unavoidable self-oxidation polymerization of polyphenol. He rein,a general ligand covalent-modification mediated coordination assembly strategy is proposed for the synthesis of water-dispersible CPs with tunable metal species(e.g., Gd,Cu,Ni,Zn,Fe)and ultra-small diameter(8.6-37.8 nm) using nontoxic plant polyphenol(e.g..tannic acid,gallic acid) as a polymerizable ligand.Polyphenol molecules react with formaldehyde firstly,which can effectively retard the oxidation induced self-polymerization of polyphenol and lead to the formation of metal ions containing CPs colloidal nanoparticles.These ultrafine nanoparticles with stably chelated metal io ns are highly water dispersible and thus advantageous for bioimaging.As an example,ultra-small Gd contained CPs exhibit higher longitudinal relaxivity(r_(1)=25.5 L mmol^(-1) s^(-1)) value with low r2/r1(1.19) than clinically used Magnevist(Gd-DTPA,r1=3.7 L mmol^(-1) s^(-1)) .Due to the enhanced permeability and retention effect,they can be further used as a positive contrast agent for T1-weighted MR imaging of tumour.展开更多
In persulfate-based advanced oxidation process(PS-AOPs),fixing nanosized metal oxide on processable substrates is highly desirable to avoid the aggregation and loss of nanocatalysts during the practical application.Ho...In persulfate-based advanced oxidation process(PS-AOPs),fixing nanosized metal oxide on processable substrates is highly desirable to avoid the aggregation and loss of nanocatalysts during the practical application.However,it is still challenging to develop a versatile strategy for the deposition of metal oxide nanocatalysts on various substrates with different physicochemical properties.Herein,polyphenols are utilized as a“molecular glue”and reductant to mediate the interfacial deposition of MnO_(2) nanocatalysts on different substrates.MnO_(2) nanocatalysts were in-situ grown on macroscope mineral substrates(e.g.,airstone)via an interfacial redox strategy between tannic acid(TA)and oxidized KMnO4,and then employed as a fixed catalyst of peroxymonosulfate(PMS)activation for treating pharmaceutical and personal care products(PPCPs)in water.The fixed MnO_(2) exhibited superior catalytic performance toward different PPCPS via a singlet oxygen(^(1)O_(2))-dominated nonradical oxidation pathway.PPCPs in the secondary effluent of wastewater treatment plants could be effectively removed by a fixed-bed column of the fixed MnO_(2) with long term stability.Redox cycle of Mn^(4+)/Mn^(3+)and surface hydroxyl group of the fixed MnO_(2) was proved to be responsible for the activation of PMS.This work provides a new avenue for developing fixed metal oxides for sustainable water treatment.展开更多
Tiller number and grain size are important agronomic traits that determine grain yield in rice.Here,we demonstrate that DEFECTIVE TILLER GROWTH 1(DTG1),a member of the casein kinase 1 protein family,exerts a co-regula...Tiller number and grain size are important agronomic traits that determine grain yield in rice.Here,we demonstrate that DEFECTIVE TILLER GROWTH 1(DTG1),a member of the casein kinase 1 protein family,exerts a co-regulatory effect on tiller number and grain size.We identified a single amino acid substitution in DTG1(I357K)that caused a decrease in tiller number and an increase in grain size in NIL-dtg1.Genetic analyses revealed that DTG1 plays a pivotal role in regulation of tillering and grain size.The DTG1^(I357K) allelic variant exhibited robust functionality in suppressing tillering.We show that DTG1 is preferentially expressed in tiller buds and young panicles,and negatively regulates grain size by restricting cell proliferation in spikelet hulls.We further confirm that DTG1 functioned in grain size regulation by directly interacting with Grain Width 2(GW2),a critical grain size regulator in rice.The CRISPR/Cas9-mediated elimination of DTG1 significantly enhanced tiller number and grain size,thereby increasing rice grain yield under field conditions,thus highlighting potential value of DTG1 in rice breeding.展开更多
The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically.A standard kturbulence model is used in synergy with an Eulerian-Lagrangian approach.The results s...The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically.A standard kturbulence model is used in synergy with an Eulerian-Lagrangian approach.The results show that the wind pressure on the windward side of the U-shaped ring is the highest,a negative pressure zone appears on both sides of the U-shaped ring,while a Kármán Vortex Street is created on its leeward side.There are three possible regimes of motion for the sand grains in the wind field.Sand grains with size below 0.125 mm can follow the airflow directly into the contact area of two U-shaped rings.When the sand size is about 0.1 mm,the number of sand grains that are blown into the contact area attains a maximum.Through the simulation of U-shaped rings in the wind-sand field,the dynamics of such processes are explained in detail,thereby providing relevant information for the subsequent protection and design of connecting hardware used for power transmission.展开更多
The Tibetan Plateau ecosystem is fragile and sensitive to climate change.Understanding the relationships between modern pollen and the vegetation and climate of the region is critical for the evaluation of ecological ...The Tibetan Plateau ecosystem is fragile and sensitive to climate change.Understanding the relationships between modern pollen and the vegetation and climate of the region is critical for the evaluation of ecological processes.Here,we explore modern pollen assemblages of typical land-cover types at a large spatial scale by analyzing 36surface samples from the southeastern Tibetan Plateau,supplemented by typical desert,desert-steppe,and steppe meadow transition data selected from the Chinese Surface Pollen Database,giving a total of 75 samples.We used redundancy analysis(RDA)to explore the responses of vegetation in the assemblages to regional climate.Our results show that pollen assemblages generally reflect the vegetation composition:assemblages from alpine meadow samples are dominated by Cyperaceae,Asteraceae,Rosaceae,and Polygonaceae;alpine shrublands mainly comprise Fabaceae,Rosaceae,Ericaceae,and Quercus(Q.spinosa);and coniferous forest surface samples mainly comprise Picea,Abies,Pinus,and Betulaceae.Our RDA shows that mean annual precipitation(MAP)is the main meteorological factor affecting the pollen assemblage and vegetation type;MAP positively correlates with percentages of Cyperaceae,Poaceae,Rosaceae,and Asteraceae,and negatively correlates with percentages of Chenopodiaceae,Ephedraceae,Nitraria,and Tamaricaceae.The ratio of Artemisia to Chenopodiaceae is a useful indicator to distinguish temperate desert from other land-cover types on the Tibetan Plateau,while the ratio of Cyperaceae+Asteraceae to Artemisia+Chenopodiaceae can be used to distinguish arid desert from other landcover types,and may provide a useful altitude index for the eastern Tibetan Plateau.展开更多
Cell sheet-based scaffold-free technology holds promise for tissue engineering applications and has been extensively explored during the past decades.However,efficient harvest and handling of cell sheets remain challe...Cell sheet-based scaffold-free technology holds promise for tissue engineering applications and has been extensively explored during the past decades.However,efficient harvest and handling of cell sheets remain challenging,including insufficient extracellular matrix content and poor mechanical strength.Mechanical loading has been widely used to enhance extracellular matrix production in a variety of cell types.However,currently,there are no effective ways to apply mechanical loading to cell sheets.In this study,we prepared thermo-responsive elastomer substrates by grafting poly(N-isopropyl acrylamide)(PNIPAAm)to poly(dimethylsiloxane)(PDMS)surfaces.The effect of PNIPAAm grafting yields on cell behaviours was investigated to optimize surfaces suitable for cell sheet culturing and harvesting.Subsequently,MC3T3-E1 cells were cultured on the PDMS-g-PNIPAAm substrates under mechanical stimulation by cyclically stretching the substrates.Upon maturation,the cell sheets were harvested by lowering the temperature.We found that the extracellular matrix content and thickness of cell sheet were markedly elevated upon appropriate mechanical conditioning.Reverse transcription quantitative polymerase chain reaction and Western blot analyses further confirmed that the expression of osteogenic-specific genes and major matrix components were up-regulated.After implantation into the critical-sized calvarial defects of mice,the mechanically conditioned cell sheets significantly promoted new bone formation.Findings from this study reveal that thermo-responsive elastomer,together with mechanical conditioning,can potentially be applied to prepare high-quality cell sheets for bone tissue engineering.展开更多
The emissions of volatile sulfur compounds(VSCs)from wastewater treatment plants(WWTPs)pose odor nuisances and health risks to workers and surrounding residents,thus becoming a major environmental concern for these fa...The emissions of volatile sulfur compounds(VSCs)from wastewater treatment plants(WWTPs)pose odor nuisances and health risks to workers and surrounding residents,thus becoming a major environmental concern for these facilities.This study investigated the long-term monitoring of emissions of VSCs from an anaerobic/oxic(A/O)WWTP and employed the AERMOD model to simulate the dispersion of VSCs within an area of 5×5 km^(2) for assessing the impact of these emissions on odor and health risks.The obtained results indicated that the emissions of VSCs from the WWTP decreased in the order of summer>autumn>spring>winter.The pretreatment unit accounted for 90.72%of the total VSCs emissions.The dispersion of VSCs was significantly influenced by the direction and speed of wind,with the largest dispersion range observed in autumn and the smallest one in spring.Dimethyl disulfide(DMDS),dimethyl sulfide(DMS),and hydrogen sulfide(H_(2)S)were identified as the primary VSCs contributing to odor impacts.The source tracing analysis revealed that the fugitive emissions of VSCs from the grill and sand-water separation unit(SWSU)contributed most significantly to their dispersion,odor pollution,and health risks,accounting for 74.87%and 11.33%,respectively.Enclosure of the grill and SWSU with covers,adjustment of the position of the exhaust pipe of the deodorizing facility,and increment in the height of the exhaust pipe are expected to be effective measures in mitigating the negative impacts of VSCs.These measures would provide new insights into dispersion modelling,risk prediction,and emission control of gaseous pollutant emitted from other factories.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2018 YFE0106900)supported by National Natural Science Foundation of China(Nos.42077191,41775149)+2 种基金Fundamental Research Funds for the Central Universities(No.63213072)National Research Program for Key Issues in Air Pollution Control(No.DQGG-05-30)the Blue Sky Foundation
文摘Fine particulate matter(PM_(2.5))and ozone(O_(3))pollutions are prevalent air quality issues in China.Volatile organic compounds(VOCs)have significant impact on the formation of O_(3)and secondary organic aerosols(SOA)contributing PM_(2.5).Herein,we investigated 54 VOCs,O_(3)and SOA in Tianjin from June 2017 to May 2019 to explore the non-linear relationship among O_(3),SOA and VOCs.The monthly patterns of VOCs and SOA concentrations were characterized by peak values during October to March and reached a minimum from April to September,but the observed O_(3)was exactly the opposite.Machine learning methods resolved the importance of individual VOCs on O_(3)and SOA that alkenes(mainly ethylene,propylene,and isoprene)have the highest importance to O_(3)formation;alkanes(C_(n),n≥6)and aromatics were the main source of SOA formation.Machine learning methods revealed and emphasized the importance of photochemical consumptions of VOCs to O_(3)and SOA formation.Ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)calculated by consumed VOCs quantitatively indicated that more than 80%of the consumed VOCs were alkenes which dominated the O_(3)formation,and the importance of consumed aromatics and alkenes to SOAFP were 40.84%and 56.65%,respectively.Therein,isoprene contributed the most to OFP at 41.45%regardless of the season,while aromatics(58.27%)contributed the most to SOAFP in winter.Collectively,our findings can provide scientific evidence on policymaking for VOCs controls on seasonal scales to achieve effective reduction in both SOA and O_(3).
基金Supported by the National Natural Science Foundation of China(41805080)Special Project for Innovation and Development of Anhui Meteorological Bureau(CXB202101)Central Asian Fund for Atmospheric Science Research(CAAS202003)。
文摘Data assimilation algorithm depends on the basic assumption of unbiased observation error,so bias correction is one of the important steps in satellite data processing.In this paper,using the geostationary interferometric infrared sounder(GIIRS)of FengYun-4 A(FY-4 A)observation and simulated brightness temperature based on background field,the brightness temperature bias correction of GIIRS channel is carried out based on random forest(RF)and extreme gradient boosting(XGBoost)machine learning.Based on the case data of Typhoon"Haishen",the correction effect of machine learning method is compared with Harris and Kelly’s"off-line"method,and the importance of different predictors to the bias correction is further discussed.The experimental results show that the systematic bias is effectively corrected,and the following conclusions are obtained:the correction effect is improved by adding geographic information(longitude and latitude)into the predictors;under the given combination of predictors,the correction effect of XGBoost is the best,followed by random forest,and finally offline method,but the three methods can correct the bias effectively;compared with long wave data of FY-4 A/GIIRS,machine learning may be more feasible for medium wave data bias correction.
基金financially supported by the National Natural Science Foundation of China (Nos.21701130 and 311343)the Fundamental Research Funds for the Central Universities+1 种基金“Young Talent Support Plan” of Xi’an Jiaotong UniversityResearch Supporting Project number (No.RSP-2019/155),King Saud University, Riyadh,Saudi Arabia。
文摘Plant polyphenol-based coordination polymers(CPs) with ultra-small particle size and tailorable compositions are highly desired in biomedical applicatio ns,but their synthesis is still challenging due to the sophisticated coordination assembly process and unavoidable self-oxidation polymerization of polyphenol. He rein,a general ligand covalent-modification mediated coordination assembly strategy is proposed for the synthesis of water-dispersible CPs with tunable metal species(e.g., Gd,Cu,Ni,Zn,Fe)and ultra-small diameter(8.6-37.8 nm) using nontoxic plant polyphenol(e.g..tannic acid,gallic acid) as a polymerizable ligand.Polyphenol molecules react with formaldehyde firstly,which can effectively retard the oxidation induced self-polymerization of polyphenol and lead to the formation of metal ions containing CPs colloidal nanoparticles.These ultrafine nanoparticles with stably chelated metal io ns are highly water dispersible and thus advantageous for bioimaging.As an example,ultra-small Gd contained CPs exhibit higher longitudinal relaxivity(r_(1)=25.5 L mmol^(-1) s^(-1)) value with low r2/r1(1.19) than clinically used Magnevist(Gd-DTPA,r1=3.7 L mmol^(-1) s^(-1)) .Due to the enhanced permeability and retention effect,they can be further used as a positive contrast agent for T1-weighted MR imaging of tumour.
基金financially supported by the National Key Research and Development Program(No.2022YFE0100400)National Natural Science Foundation of China(No.21701130)+2 种基金Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.20JC1415300)State Key Laboratory of Transducer Technology of China(No.SKT2207)Key Research and Development Program of Shaanxi(No.2021GY-225)。
文摘In persulfate-based advanced oxidation process(PS-AOPs),fixing nanosized metal oxide on processable substrates is highly desirable to avoid the aggregation and loss of nanocatalysts during the practical application.However,it is still challenging to develop a versatile strategy for the deposition of metal oxide nanocatalysts on various substrates with different physicochemical properties.Herein,polyphenols are utilized as a“molecular glue”and reductant to mediate the interfacial deposition of MnO_(2) nanocatalysts on different substrates.MnO_(2) nanocatalysts were in-situ grown on macroscope mineral substrates(e.g.,airstone)via an interfacial redox strategy between tannic acid(TA)and oxidized KMnO4,and then employed as a fixed catalyst of peroxymonosulfate(PMS)activation for treating pharmaceutical and personal care products(PPCPs)in water.The fixed MnO_(2) exhibited superior catalytic performance toward different PPCPS via a singlet oxygen(^(1)O_(2))-dominated nonradical oxidation pathway.PPCPs in the secondary effluent of wastewater treatment plants could be effectively removed by a fixed-bed column of the fixed MnO_(2) with long term stability.Redox cycle of Mn^(4+)/Mn^(3+)and surface hydroxyl group of the fixed MnO_(2) was proved to be responsible for the activation of PMS.This work provides a new avenue for developing fixed metal oxides for sustainable water treatment.
基金supported by the Sichuan Science and Technology Support Project (2022ZDZX0012,2021YFYZ0016,2023YFN0007,2021YFYZ0027)the National Natural Science Foundation of China (32171966,U23A20180).
文摘Tiller number and grain size are important agronomic traits that determine grain yield in rice.Here,we demonstrate that DEFECTIVE TILLER GROWTH 1(DTG1),a member of the casein kinase 1 protein family,exerts a co-regulatory effect on tiller number and grain size.We identified a single amino acid substitution in DTG1(I357K)that caused a decrease in tiller number and an increase in grain size in NIL-dtg1.Genetic analyses revealed that DTG1 plays a pivotal role in regulation of tillering and grain size.The DTG1^(I357K) allelic variant exhibited robust functionality in suppressing tillering.We show that DTG1 is preferentially expressed in tiller buds and young panicles,and negatively regulates grain size by restricting cell proliferation in spikelet hulls.We further confirm that DTG1 functioned in grain size regulation by directly interacting with Grain Width 2(GW2),a critical grain size regulator in rice.The CRISPR/Cas9-mediated elimination of DTG1 significantly enhanced tiller number and grain size,thereby increasing rice grain yield under field conditions,thus highlighting potential value of DTG1 in rice breeding.
基金National Natural Science Foundation of China(51865055)Tianshan Talents Plan of Xinjiang Autonomous Region of China(201720025)。
文摘The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically.A standard kturbulence model is used in synergy with an Eulerian-Lagrangian approach.The results show that the wind pressure on the windward side of the U-shaped ring is the highest,a negative pressure zone appears on both sides of the U-shaped ring,while a Kármán Vortex Street is created on its leeward side.There are three possible regimes of motion for the sand grains in the wind field.Sand grains with size below 0.125 mm can follow the airflow directly into the contact area of two U-shaped rings.When the sand size is about 0.1 mm,the number of sand grains that are blown into the contact area attains a maximum.Through the simulation of U-shaped rings in the wind-sand field,the dynamics of such processes are explained in detail,thereby providing relevant information for the subsequent protection and design of connecting hardware used for power transmission.
基金supported by the NSFC(42161144012,42030505,42271176,and 41972020)the Western Light Project of CAS(xbzgzdsys-202204)Youth Innovation Promotion Association of CAS(2022439)
文摘The Tibetan Plateau ecosystem is fragile and sensitive to climate change.Understanding the relationships between modern pollen and the vegetation and climate of the region is critical for the evaluation of ecological processes.Here,we explore modern pollen assemblages of typical land-cover types at a large spatial scale by analyzing 36surface samples from the southeastern Tibetan Plateau,supplemented by typical desert,desert-steppe,and steppe meadow transition data selected from the Chinese Surface Pollen Database,giving a total of 75 samples.We used redundancy analysis(RDA)to explore the responses of vegetation in the assemblages to regional climate.Our results show that pollen assemblages generally reflect the vegetation composition:assemblages from alpine meadow samples are dominated by Cyperaceae,Asteraceae,Rosaceae,and Polygonaceae;alpine shrublands mainly comprise Fabaceae,Rosaceae,Ericaceae,and Quercus(Q.spinosa);and coniferous forest surface samples mainly comprise Picea,Abies,Pinus,and Betulaceae.Our RDA shows that mean annual precipitation(MAP)is the main meteorological factor affecting the pollen assemblage and vegetation type;MAP positively correlates with percentages of Cyperaceae,Poaceae,Rosaceae,and Asteraceae,and negatively correlates with percentages of Chenopodiaceae,Ephedraceae,Nitraria,and Tamaricaceae.The ratio of Artemisia to Chenopodiaceae is a useful indicator to distinguish temperate desert from other land-cover types on the Tibetan Plateau,while the ratio of Cyperaceae+Asteraceae to Artemisia+Chenopodiaceae can be used to distinguish arid desert from other landcover types,and may provide a useful altitude index for the eastern Tibetan Plateau.
基金National Natural Science Foundation of China(No.81925027)Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Cell sheet-based scaffold-free technology holds promise for tissue engineering applications and has been extensively explored during the past decades.However,efficient harvest and handling of cell sheets remain challenging,including insufficient extracellular matrix content and poor mechanical strength.Mechanical loading has been widely used to enhance extracellular matrix production in a variety of cell types.However,currently,there are no effective ways to apply mechanical loading to cell sheets.In this study,we prepared thermo-responsive elastomer substrates by grafting poly(N-isopropyl acrylamide)(PNIPAAm)to poly(dimethylsiloxane)(PDMS)surfaces.The effect of PNIPAAm grafting yields on cell behaviours was investigated to optimize surfaces suitable for cell sheet culturing and harvesting.Subsequently,MC3T3-E1 cells were cultured on the PDMS-g-PNIPAAm substrates under mechanical stimulation by cyclically stretching the substrates.Upon maturation,the cell sheets were harvested by lowering the temperature.We found that the extracellular matrix content and thickness of cell sheet were markedly elevated upon appropriate mechanical conditioning.Reverse transcription quantitative polymerase chain reaction and Western blot analyses further confirmed that the expression of osteogenic-specific genes and major matrix components were up-regulated.After implantation into the critical-sized calvarial defects of mice,the mechanically conditioned cell sheets significantly promoted new bone formation.Findings from this study reveal that thermo-responsive elastomer,together with mechanical conditioning,can potentially be applied to prepare high-quality cell sheets for bone tissue engineering.
基金supported by the National Natural Science Foundation of China(Nos.52170017 and 62021003)the Beijing Nova Program(No.20240484694)the Key Laboratory of Odor Pollution Control in Ministry of Ecology and Environment(No.20230803).
文摘The emissions of volatile sulfur compounds(VSCs)from wastewater treatment plants(WWTPs)pose odor nuisances and health risks to workers and surrounding residents,thus becoming a major environmental concern for these facilities.This study investigated the long-term monitoring of emissions of VSCs from an anaerobic/oxic(A/O)WWTP and employed the AERMOD model to simulate the dispersion of VSCs within an area of 5×5 km^(2) for assessing the impact of these emissions on odor and health risks.The obtained results indicated that the emissions of VSCs from the WWTP decreased in the order of summer>autumn>spring>winter.The pretreatment unit accounted for 90.72%of the total VSCs emissions.The dispersion of VSCs was significantly influenced by the direction and speed of wind,with the largest dispersion range observed in autumn and the smallest one in spring.Dimethyl disulfide(DMDS),dimethyl sulfide(DMS),and hydrogen sulfide(H_(2)S)were identified as the primary VSCs contributing to odor impacts.The source tracing analysis revealed that the fugitive emissions of VSCs from the grill and sand-water separation unit(SWSU)contributed most significantly to their dispersion,odor pollution,and health risks,accounting for 74.87%and 11.33%,respectively.Enclosure of the grill and SWSU with covers,adjustment of the position of the exhaust pipe of the deodorizing facility,and increment in the height of the exhaust pipe are expected to be effective measures in mitigating the negative impacts of VSCs.These measures would provide new insights into dispersion modelling,risk prediction,and emission control of gaseous pollutant emitted from other factories.
