We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momen...We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.展开更多
This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The e...This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The effect of three reaction parameters,i.e.reaction temperature,reaction time and oil-water ratio,is analyzed on the product and their correlation with viscosity.The results show that the flow state of heavy oil is significantly improved with a viscosity reduction of 99.4%in average after the reaction in the supercritical water.Excessively high reaction temperature leads to a higher content of resins and asphaltenes,with significantly increasing production of coke.The optimal temperature ranges in 380–420℃.Prolonged reaction time could continuously increase the yield of light oil,but it will also results in the growth of resins and asphaltenes,with the optimal reaction time of 150 min.Reducing the oil-water ratio helps improve the diffusion environment within the reaction system and reduce the content of resins and asphaltenes,but it will increase the cost of heavy oil treatment.An oil-water ratio of 1︰2 is considered as optimum to balance the quality improvement,viscosity reduction and reaction economics.The correlation of the three reaction parameters relative to the oil sample viscosity is ranked as temperature,time and oil-water ratio.Among the four fractions of heavy oil,the viscosity is dominated by asphaltene content,followed by aromatic content and less affected by resins and saturates contents.展开更多
LiV_(2)O_(4)is a spinel-structured compound that stands out as the first known 3d-electron system exhibiting typical heavy fermion behavior.A central question is how such strong mass renormalization emerges in the abs...LiV_(2)O_(4)is a spinel-structured compound that stands out as the first known 3d-electron system exhibiting typical heavy fermion behavior.A central question is how such strong mass renormalization emerges in the absence of f-electrons.In this work,we investigate the three-dimensional electronic structure of LiV_(2)O_(4)thin films using angle-resolved photoemission spectroscopy.We identify that an electron-like flat band is derived from a_(1g)orbitals,along with a highly dispersive e′_(g)band strongly coupled with phonons.The overall agreement with dynamical mean-field theory calculations highlights the essential role of inter-orbital Hund’s coupling in reducing the a_(1g)bandwidth to 25 meV,approaching a Mott state.Notably,we find that heavy-fermion behavior arises from additional renormalization at the a_(1g)band near the Fermi level,likely driven by many-body interactions at energy scales down to a few meV and potentially linked to geometric frustration inherent to the spinel lattice.These results provide crucial insights into the origin of the heavy fermion behavior in 3d-electron systems.展开更多
Heavy metal pollution in coastal waters is on the rise,presenting serious threats to both ecosystems and human health.Coastal aquaculture zones,such as those in Quang Ninh province,are especially vulnerable due to the...Heavy metal pollution in coastal waters is on the rise,presenting serious threats to both ecosystems and human health.Coastal aquaculture zones,such as those in Quang Ninh province,are especially vulnerable due to the accumulation of heavy metals from multiple sources,including industrial wastewater,land runoff,and maritime activities.This study applies the Heavy Metal Pollution Index(HPI)to assess pollution levels based on the concentrations of nine heavy metals(Cr,Mn,Fe,Cu,Zn,As,Cd,Hg,Pb)found in seawater samples collected from coastal aquaculture areas in Quang Ninh.According to the HPI method,values exceeding 100 indicate polluted water,serving as a benchmark for evaluating heavy metal contamination in the region.A total of 25 seawater samples were collected and analyzed;of these,18 samples(72%)had HPI values above 100,signaling a concerning level of heavy metal pollution,while only 7 samples(28%)fell below the threshold,suggesting no significant contamination.These results underscore the urgent need for enhanced monitoring of water quality and stricter regulation of pollution sources to protect both environmental and public health.展开更多
The synthesis of superheavy nuclei remains a critical area of research in nuclear physics,with the aim of extending the periodic table and deepening our understanding of the properties of nuclei.This review provides a...The synthesis of superheavy nuclei remains a critical area of research in nuclear physics,with the aim of extending the periodic table and deepening our understanding of the properties of nuclei.This review provides a comprehensive overview of the latest advancements in superheavy nuclei synthesis,focusing on both the experimental and theoretical developments.We discuss the primary synthesis methods,including early fusion reactions with light nuclei,cold fusion reactions using lead and bismuth targets,and hot fusion reactions involving48Ca projectiles and actinide targets.In addition,we introduce the major experimental facilities and theoretical models currently employed worldwide.This review also summarizes the experimental plans and theoretical predictions for the synthesis of new superheavy elements.Furthermore,we discuss future directions,including the potential of employing heavier projectiles,radioactive beam-induced reactions,and multi-nucleon transfer reactions,which may offer new pathways for discovering unknown superheavy nuclei.展开更多
Controlling heavy metal pollution in agricultural soil has been a significant challenge.These heavy metals seriously threaten the surrounding ecological environment and human health.The effective assessment and remedi...Controlling heavy metal pollution in agricultural soil has been a significant challenge.These heavy metals seriously threaten the surrounding ecological environment and human health.The effective assessment and remediation of heavy metals in agricultural soils are crucial.These two aspects support each other,forming a close and complete decisionmaking chain.Therefore,this review systematically summarizes the distribution characteristics of soil heavy metal pollution,the correlation between soil and crop heavy metal contents,the presence pattern and migration and transformation mode of heavy metals in the soil-crop system.The advantages and disadvantages of the risk evaluation tools and models of heavy metal pollution in farmland are further outlined,which provides important guidance for an in-depth understanding of the characteristics of heavymetal pollution in farmland soils and the assessment of the environmental risk.Soil remediation strategies involve multiple physical,chemical,biological and even combined technologies,and this paper compares the potential and effect of the above current remediation technologies in heavy metal polluted farmland soils.Finally,the main problems and possible research directions of future heavy metal risk assessment and remediation technologies in agricultural soils are prospected.This review provides new ideas for effective assessment and selection of remediation technologies based on the characterization of soil heavy metals.展开更多
Agricultural soil is related to food security and human health,antibiotics and heavy metals(HMs),as two typical pollutants,possess a high coexistence rate in the environmental medium,which is extremely prone to induci...Agricultural soil is related to food security and human health,antibiotics and heavy metals(HMs),as two typical pollutants,possess a high coexistence rate in the environmental medium,which is extremely prone to inducing antibiotic-HMs combined pollution.Recently,frequent human activities have led to more prominent antibiotics-HMs combined contamination in agricultural soils,especially the production and spread of antibiotic resistance genes(ARGs),heavy metal resistance genes(MRGs),antibiotic resistant bacteria(ARB),and antibiotics-HMs complexes(AMCs),which seriously threaten soil ecology and human health.This review describes the main sources(Intrinsic and manmade sources),composite mechanisms(co-selective resistance,oxidative stress,and Joint toxicity mechanism),environmental fate and the potential risks(soil ecological and human health risks)of antibiotics and HMs in agricultural soils.Finally,the current effective source blocking,transmission control,and attenuation strategies are classified for discussion,such as the application of additives and barrier materials,as well as plant and animal remediation and bioremediation,etc.,pointing out that future research should focus on the whole chain process of“source-processterminal”,intending to provide a theoretical basis and decision-making reference for future research.展开更多
Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution character...Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution characteristics and health risks of HMs in groundwater nearby a typical coking plant.Nine HMs including Fe,Zn,Mo,As,Cu,Ni,Cr,Pb and Cd were analyzed.The average concentration of total HMswas higher in the nearby area(244.27μg/L)than that of remote area away the coking plant(89.15μg/L).The spatial distribution of pollution indices including heavy metal pollution index(HPI),Nemerow index(NI)and contamination degree(CD),all demonstrated higher values at the nearby residential areas,suggesting coking activity could significantly impact the HMs distribution characteristics.Four sources of HMs were identified by Positive Matrix Factorization(PMF)model,which indicated coal washing and coking emission were the dominant sources,accounted for 40.4%,and 31.0%,respectively.Oral ingestionwas found to be the dominant exposure pathway with higher exposure dose to children than adults.Hazard quotient(HQ)values were below 1.0,suggesting negligible non-carcinogenic health risks,while potential carcinogenic risks were from Pb and Ni with cancer risk(CR)values>10−6.Monte Carlo simulation matched well with the calculated results with HMs concentrations to be the most sensitive parameters.This study provides insights into understanding how the industrial coking activities can impact the HMs pollution characteristics in groundwater,thus facilitating the implement of HMs regulation in coking industries.展开更多
Gallium nitride(GaN)-based devices have significant potential for space applications.However,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains unknown.This study inve...Gallium nitride(GaN)-based devices have significant potential for space applications.However,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains unknown.This study investigates the effects of radiation on p-gate AlGaN/GaN high-electron-mobility transistors(HEMTs).Under a high voltage,the HEMT leakage current increased sharply and was accompanied by a rapid increase in power density that caused"thermal burnout"of the devices.In addition,a burnout signature appeared on the surface of the burned devices,proving that a single-event burnout effect occurred.Additionally,degradation,including an increase in the on-resistance and a decrease in the breakdown voltage,was observed in devices irradiated with high-energy heavy ions and without bias.The latent tracks induced by heavy ions penetrated the heterojunction interface and extended into the GaN layer.Moreover,a new type of N_(2)bubble defect was discovered inside the tracks using Fresnel analysis.The accumulation of N_(2)bubbles in the heterojunction and buffer layers is more likely to cause leakage and failure.This study indicates that electrical stress accelerates the failure rate and that improving heat dissipation is an effective reinforcement method for GaN-based devices.展开更多
Soil naturally contains various heavy metals,however,their concentrations have reached toxic levels due to excessive agrochemical use and industrial activities.Heavy metals are persistent and non-biodegradable,causing...Soil naturally contains various heavy metals,however,their concentrations have reached toxic levels due to excessive agrochemical use and industrial activities.Heavy metals are persistent and non-biodegradable,causing environmental disruption and posing significant health hazards.Microbial-mediated remediation is a promising strategy to prevent heavy metal leaching and mobilization,facilitating their extraction and detoxification.Nickel(Ni),being a prevalent heavy metal pollutant,requires specific attention in remediation efforts.Plants have evolved defense mechanisms to cope with environmental stresses,including heavy metal toxicity,but such stress significantly reduces crop productivity.Beneficial microorganisms play a crucial role in enhancing plant yield and mitigating abiotic stress.The impact of heavy metal abiotic stress on plants’growth and productivity requires thorough investigation.Bioremediation using Nickel nanoparticles(Ni NPs)offers an effective approach to mitigating environmental pollution.Microorganisms contribute to nanoparticle bioremediation by immobilizing metals or inducing the synthesis of remediating microbial enzymes.Understanding the interactions between microorganisms,contaminants,and nanoparticles(NPs)is essential for advancing bioremediation strategies.This review focuses on the role of Bacillus subtilis in the bioremediation of nickel nanoparticles to mitigate environmental pollution and associated health risks.Furthermore,sustainable approaches are necessary to minimize metal contamination in seeds.The current review discusses bacterial inoculation in enhancing heavy metal tolerance,plant signal transduction pathways,and the transition from molecular to genomic research in metal stress adaptation.Moreover,the inoculation of advantageous bacteria is crucial for preserving plants under severe mental stress.Different researchers develop a complex,vibrant relationship with plants through a series of events known as plant-microbe interactions.It increases metal stress resistance through the creation of phytohormones.In general,the defensive responses of plants to heavy metal stress,mediated by microbial inoculation require further in-depth research.Further studies should explore the detoxification mechanism of nickel through bioremediation to develop more effective and sustainable remediation strategies.展开更多
The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of den...The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.展开更多
Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of ...Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of the 150 phosphate fertilizers stored at the Institute for Crop and Soil Science in Germany has been conducted,supplemented by previously published data.The elements Cd,Bi,U,Cr,Zn,Tl,As,B,Sb,Ni,and Se are found in higher concentrations in sedimentary derived phosphates compared to igneous derived phosphates.Mineral fertilizers contain more than ten times the amount of U,Cd,B,and As compared to farmyard manure.Principal component analyses(PCA)indicate that U,Cd,Be,and Cr are primarily present in sedimentary derived phosphates and their concentrations are 2 to 10 times higher than those in igneous derived phosphates.Regarding heavy metal contamination,over 1000 potential combinations were identified;36% of these were significant but weak(>0.1).It is estimated that approximately 707 t of uranium enter farmland annually through the application of mineral phosphate fertilizers in European countries.This contribution addresses environmental issues related to the utilization of rock phosphate as well as alternative production methods for cleaner and safer phosphate fertilizers while presenting a roadmap with measures for mitigation.展开更多
Abandoned mines,especially pyrite-rich ones,release acid mine drainage(AMD)with high acidity and excessive amounts of heavy metals,threatening regional ecosystems.Six samples of mine drainage,nine samples of surface w...Abandoned mines,especially pyrite-rich ones,release acid mine drainage(AMD)with high acidity and excessive amounts of heavy metals,threatening regional ecosystems.Six samples of mine drainage,nine samples of surface water,and twelve samples of sediment were analyzed in this case study of the Dashu pyrite mine in southwest China.A comprehensive analysis of the pollution levels,pollution sources,and potential hazards of eight metals(Ni,Cd,Cu,Zn,Fe,Al,Pb,and Mn)that exceeded regulatory standardswas conducted bymonitoring 24 conventional and characteristic indicators.Ultimately,this research evaluated the environmental hazards associated with abandonedmine water using the"pressure-response"model,thereby providing valuable insights for the effective protection of the environment in mining regions.The primary pollutants in mine water were determined to be SO_(4)^(2−),Fe,and Mn,with concentrations of 7700,1450,and 6.78mg/L,respectively.A clear"source-sink"dynamic was observed between themine water and the surrounding water system.surface water was primarily polluted by Ni and Mn,while water system sediments were primarily polluted by Cu and Hg.Ion ratio and Pearson correlation analyses indicated heavy metals in surface water and sediments originated from the same AMD source.The"pressureresponse"model was used to assess the environmental hazards of water from abandoned mines.Mines W1,W2,W5,and W6 were classified as high-risk,while W3 and W4 were medium-risk.This study offers a novel approach and valuable reference for identifying and classifying environmental risks in abandoned mines and targeting AMD treatment.展开更多
Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened.The surface of the bio-Fe/Mn oxides produced by the oxidation...Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened.The surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II)and Mn(II)by Pseudomonas taiwanensis(marked as P4)and Pseudomonas plecoglossicida(marked as G1)contains rich reactive oxygen functional groups,which play critical roles in the removal efficiency and immobilization of heavymetal(loid)s in co-contamination system.The isolated strains P4 and G1 can growwell in the following environments:pH 5-9,NaCl 0-4%,and temperature 20-30℃.The removal efficiencies of Fe,Pb,As,Zn,Cd,Cu,and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system(the initial concentrations of heavy metal(loid)were 1 mg/L),approximately reaching 96%,92%,85%,67%,70%,54%and 15%,respectively.The exchangeable and carbonate bound As,Cd,Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil,thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)s.This research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.展开更多
Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)an...Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.展开更多
The traditional techniques for treating wastewater contaminated by heavy metals mostly involve chemical precipitation,solvent extraction and adsorption,ion-exchange,chemical precipitation,and membrane separation.The m...The traditional techniques for treating wastewater contaminated by heavy metals mostly involve chemical precipitation,solvent extraction and adsorption,ion-exchange,chemical precipitation,and membrane separation.The main shortcomings of traditional procedures are low economic efficiency,lack of environmental friendliness,and poor selectivity.Cyclodextrins are artificial compounds that resemble cages.Through host-vip interaction,pollutants can be adsorbed by its stable inner hydrophobic chamber and exterior hydrophilic surface.It is not only inexpensive and environmentally friendly,but also quite selective.The synthesis and application of materials were reviewed,as well as the primary influencing factors,and the reaction principle of cyclodextrin adsorbent materials for better separation of heavy metal ions.And the future trend of discovery was described.展开更多
Industrial activities have contributed so much to the pollution of water bodies and these pollutions have adversely affected the aquatic ecosystem.This study aimed to investigate the ecological risk evaluation of heav...Industrial activities have contributed so much to the pollution of water bodies and these pollutions have adversely affected the aquatic ecosystem.This study aimed to investigate the ecological risk evaluation of heavy metal accumulation in Aba River bottom sediments:implications for soap and detergent industry wastewater management.Varian AA240 Atomic absorption spectrometer was used to analyse heavy metals.Individual and complex ecological indices were used to evaluate heavy metal contamination in bottom sediments.According to the results,the heavy metal properties of the wastewater indicated that Fe,Pb,Cd,Cr and Cu mean concentration values were higher than the World Health Organization(WHO)and the National Environmental Standards and Regulations Enforcement Agency(NESREA)permissible limits.Heavy metal properties of the surface water in Aba River(dry seasons)showed that Pb,Cd,Cu,Mn,Fe,and Cr,mean concentrations were above the NESREA,WHO and U.S.Environmental Protection Agency(USEPA)permissible limits.Heavy metal properties of the bottom sediments of Aba River(wet and dry season)showed that Pb,Cd,and Fe mean concentrations were significantly higher than the NESREA,WHO and USEPA permissible limits.The heavy metal contamination factor(CF)of sediments obtained from Aba River during the wet and dry season was low and the CFs of each of the assayed heavy metals were less than 1(CD<1).This also signifies the existence of a low contamination in the sediments of the course streams of Aba River during wet and dry season.The pollution load index(PLI)values of Aba River(sediment)indicated that there is no metal pollution at PLI<1 in the sampled sediments.The potential ecological risk index(RI)of Aba River was less than 150(RI<150)indicating a low ecological RI.Abatement of pollutants in the wastewater to permissible concentrations required for natural environment protection is needed.展开更多
The migration/transformation characteristics of heavy metals and polycyclic aromatic hydrocarbons(PAHs) during the co-liquefaction of pig manure and rice straw/wood sawdust were explored in this study.More than 87% of...The migration/transformation characteristics of heavy metals and polycyclic aromatic hydrocarbons(PAHs) during the co-liquefaction of pig manure and rice straw/wood sawdust were explored in this study.More than 87% of the heavy metals in feedstocks were enriched in hydrochars.The decreased proportion of active heavy metals in the hydrochars suggested partial passivation of the heavy metals.The pollution degree and risk of heavy metals were significantly mitigated from high and considerable levels in pig manure to moderate and low levels in hydrochar,respectively.Compared with commercial diesel,bio-oil products still contained an undesirable amount of heavy metals.PAHs were re-synthesized during liquefaction,with a net synthesis amount of 29.65-73.98 mg·kg^(-1).Moreover,the PAHs mainly existed in bio-oils,with a content of 57.32-132.33 mg·kg^(-1) and a toxicity equivalent of3.25-8.19 mg·kg^(-1).Compared to pig manure,the hydrochars presented a lower content of PAHs(1.76-3.53 mg·kg^(-1) versus 3.73 mg·kg^(-1)) and a smaller toxicity equivalent(0.14-0.22 mg·kg^(-1) versus0.26 mg·kg^(-1)).Interestingly,introducing lignocellulose(especially for rice straw) during the liquefaction of pig manure further mitigated the pollution degree/risk of heavy metals and PAHs.Overall,hydrochar reached a safe utilization level,while bio-oil products needed further clarification.展开更多
Urban rivers are one of the main water sources for local residents.However,the rapid industrialization and urbanization caused serious heavy metals pollution in urban rivers,which posed harmful impact on human health ...Urban rivers are one of the main water sources for local residents.However,the rapid industrialization and urbanization caused serious heavy metals pollution in urban rivers,which posed harmful impact on human health and ecosystem.In this study,134 sediment samples were collected fromurban rivers in a typical Economic and Technological Development Zone(ETDZ)to evaluate the contamination status,ecological risk,biotoxicity,and potential source of 8 heavy metals including arsenic(As),cadmium(Cd),chromium(Cr),copper(Cu),mercury(Hg),nickel(Ni),plumbum(Pb),and zinc(Zn).Results showed that the average concentrations of all 8 metals exceeded their corresponding background values and followed the trend:Cr(248.67 mg/kg)>Pb(123.58 mg/kg)>Zn(67.06 mg/kg)>Ni(47.19 mg/kg)>Cu(27.40 mg/kg)>As(16.15 mg/kg)>Cd(0.62mg/kg)>Hg(0.21mg/kg).A high contamination and accumulation tendency of Cd and Cr were found in the sediments.Moreover,Cd and Hg were the main contributors of ecological risk,and posed moderate to high risk.In terms of biotoxicity,all the sediment samples were harmful to benthic organisms.Two possible pollution sources of heavy metals were identified:one is a combined source of industrial and traffic pollution dominated by Cr and Pd,the other is an industrial pollution source consisting of six heavy metals(Ni,Zn,Cd,Hg,As,and Cu).This study provides insights into heavy metals pollution management and risk control in the ETDZ and similar urban rivers worldwide due to intense industrialization.展开更多
Nusantara,the new capital city of Indonesia,and its surrounding areas experienced intense heavy rainfall on 15-16 March 2022,leading to devastating and widespread flooding.However,the factors triggering such intense h...Nusantara,the new capital city of Indonesia,and its surrounding areas experienced intense heavy rainfall on 15-16 March 2022,leading to devastating and widespread flooding.However,the factors triggering such intense heavy rainfall and the underlying physical mechanisms are still not fully understood.Using high-resolution GSMaP(Global Satellite Mapping of Precipitation)data,we show that a mesoscale convective system(MCS)was the primary cause of the heavy rainfall event.The rainfall peak occurred during the MCS's mature stage at 1800 UTC 15 March 2022,and diminished as it entered the dissipation stage.To understand the large-scale environmental factors affecting the MCS event,we analyzed contributions from the MJO,equatorial waves,and low-frequency variability to column water vapor and moisture flux convergence.Results indicate a substantial influence of the MJO and equatorial waves on lower-level(boundary layer)meridional moisture flux convergence during the pre-MCS stage and initiation,with their contributions accounting for up to80%during the growth phase.Moreover,while La Nina and the Asian monsoon had negligible impacts on MCS moisture supply,we find a large contribution from the residual term of the water vapour budget during the maturation and decay phases of the MCS.This suggests that local forcing(such as small-scale convection,local evaporation,land-surface feedback,and topography)also contributed to modulation of the intensity and duration of the MCS.The results of this study can help in our understanding of the potential causes of extreme rainfall in Nusantara and could be leveraged to improve rainstorm forecasting and risk management across the region in the future.展开更多
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant Nos.2020B0301030008 and 2023A1515010416)the National Natural Science Foundation of China(Grant Nos.12375073,12275091,12147128,and 12035007).
文摘We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.
基金Supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China(52421002)General Program of National Natural Science Foundation of China(52474016).
文摘This paper investigates the macroscopic and microscopic characteristics of viscosity reduction and quality improvement of heavy oil in a supercritical water environment through laboratory experiments and testing.The effect of three reaction parameters,i.e.reaction temperature,reaction time and oil-water ratio,is analyzed on the product and their correlation with viscosity.The results show that the flow state of heavy oil is significantly improved with a viscosity reduction of 99.4%in average after the reaction in the supercritical water.Excessively high reaction temperature leads to a higher content of resins and asphaltenes,with significantly increasing production of coke.The optimal temperature ranges in 380–420℃.Prolonged reaction time could continuously increase the yield of light oil,but it will also results in the growth of resins and asphaltenes,with the optimal reaction time of 150 min.Reducing the oil-water ratio helps improve the diffusion environment within the reaction system and reduce the content of resins and asphaltenes,but it will increase the cost of heavy oil treatment.An oil-water ratio of 1︰2 is considered as optimum to balance the quality improvement,viscosity reduction and reaction economics.The correlation of the three reaction parameters relative to the oil sample viscosity is ranked as temperature,time and oil-water ratio.Among the four fractions of heavy oil,the viscosity is dominated by asphaltene content,followed by aromatic content and less affected by resins and saturates contents.
基金support of Dr.Z.T.Liu,Dr.Z.C.Jiang,Dr.Marta Zonno,and Dr.Sergey Gorovikovsupported in part by the National Key R&D Program of the MOST of China(Grant No.2023YFA1406300)+4 种基金the National Natural Science Foundation of China(Grant Nos.12274085,12422404,and 92477206)the New Cornerstone Science Foundation,the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302803)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)The ARPES measurements used Beamlines 09U and 03U of the SSRF and Beamline QMSC of Canadian Light sourcesupported by the ME2 project from the National Natural Science Foundation of China(Contract No.11227902).
文摘LiV_(2)O_(4)is a spinel-structured compound that stands out as the first known 3d-electron system exhibiting typical heavy fermion behavior.A central question is how such strong mass renormalization emerges in the absence of f-electrons.In this work,we investigate the three-dimensional electronic structure of LiV_(2)O_(4)thin films using angle-resolved photoemission spectroscopy.We identify that an electron-like flat band is derived from a_(1g)orbitals,along with a highly dispersive e′_(g)band strongly coupled with phonons.The overall agreement with dynamical mean-field theory calculations highlights the essential role of inter-orbital Hund’s coupling in reducing the a_(1g)bandwidth to 25 meV,approaching a Mott state.Notably,we find that heavy-fermion behavior arises from additional renormalization at the a_(1g)band near the Fermi level,likely driven by many-body interactions at energy scales down to a few meV and potentially linked to geometric frustration inherent to the spinel lattice.These results provide crucial insights into the origin of the heavy fermion behavior in 3d-electron systems.
基金the outcome of project conducted at the Vietnam Academy of Science and Technology(VAST.07.05/24-25).
文摘Heavy metal pollution in coastal waters is on the rise,presenting serious threats to both ecosystems and human health.Coastal aquaculture zones,such as those in Quang Ninh province,are especially vulnerable due to the accumulation of heavy metals from multiple sources,including industrial wastewater,land runoff,and maritime activities.This study applies the Heavy Metal Pollution Index(HPI)to assess pollution levels based on the concentrations of nine heavy metals(Cr,Mn,Fe,Cu,Zn,As,Cd,Hg,Pb)found in seawater samples collected from coastal aquaculture areas in Quang Ninh.According to the HPI method,values exceeding 100 indicate polluted water,serving as a benchmark for evaluating heavy metal contamination in the region.A total of 25 seawater samples were collected and analyzed;of these,18 samples(72%)had HPI values above 100,signaling a concerning level of heavy metal pollution,while only 7 samples(28%)fell below the threshold,suggesting no significant contamination.These results underscore the urgent need for enhanced monitoring of water quality and stricter regulation of pollution sources to protect both environmental and public health.
基金supported by the National Key R&D Program of China(No.2023YFA1606401)the National Key R&D Program of China(Nos.2023YFA1606500,2023YFA1606501,2023YFA1606504)+3 种基金the National Natural Science Foundation of China(Nos.12135004,11635003,11961141004,12375118,and 12435008)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34010000)the Major State Basic Research Development Program of China(2023YFA1606503)the CAS Strategic Priority Research Program(XDB34010000)。
文摘The synthesis of superheavy nuclei remains a critical area of research in nuclear physics,with the aim of extending the periodic table and deepening our understanding of the properties of nuclei.This review provides a comprehensive overview of the latest advancements in superheavy nuclei synthesis,focusing on both the experimental and theoretical developments.We discuss the primary synthesis methods,including early fusion reactions with light nuclei,cold fusion reactions using lead and bismuth targets,and hot fusion reactions involving48Ca projectiles and actinide targets.In addition,we introduce the major experimental facilities and theoretical models currently employed worldwide.This review also summarizes the experimental plans and theoretical predictions for the synthesis of new superheavy elements.Furthermore,we discuss future directions,including the potential of employing heavier projectiles,radioactive beam-induced reactions,and multi-nucleon transfer reactions,which may offer new pathways for discovering unknown superheavy nuclei.
基金supported by the National Natural Science Foundation of China(Nos.52100184,and U22A20617).
文摘Controlling heavy metal pollution in agricultural soil has been a significant challenge.These heavy metals seriously threaten the surrounding ecological environment and human health.The effective assessment and remediation of heavy metals in agricultural soils are crucial.These two aspects support each other,forming a close and complete decisionmaking chain.Therefore,this review systematically summarizes the distribution characteristics of soil heavy metal pollution,the correlation between soil and crop heavy metal contents,the presence pattern and migration and transformation mode of heavy metals in the soil-crop system.The advantages and disadvantages of the risk evaluation tools and models of heavy metal pollution in farmland are further outlined,which provides important guidance for an in-depth understanding of the characteristics of heavymetal pollution in farmland soils and the assessment of the environmental risk.Soil remediation strategies involve multiple physical,chemical,biological and even combined technologies,and this paper compares the potential and effect of the above current remediation technologies in heavy metal polluted farmland soils.Finally,the main problems and possible research directions of future heavy metal risk assessment and remediation technologies in agricultural soils are prospected.This review provides new ideas for effective assessment and selection of remediation technologies based on the characterization of soil heavy metals.
基金supported by the National Natural Science Foundation of China(No.32171615)the National Key R&D Program of China(2019YFC1804102)。
文摘Agricultural soil is related to food security and human health,antibiotics and heavy metals(HMs),as two typical pollutants,possess a high coexistence rate in the environmental medium,which is extremely prone to inducing antibiotic-HMs combined pollution.Recently,frequent human activities have led to more prominent antibiotics-HMs combined contamination in agricultural soils,especially the production and spread of antibiotic resistance genes(ARGs),heavy metal resistance genes(MRGs),antibiotic resistant bacteria(ARB),and antibiotics-HMs complexes(AMCs),which seriously threaten soil ecology and human health.This review describes the main sources(Intrinsic and manmade sources),composite mechanisms(co-selective resistance,oxidative stress,and Joint toxicity mechanism),environmental fate and the potential risks(soil ecological and human health risks)of antibiotics and HMs in agricultural soils.Finally,the current effective source blocking,transmission control,and attenuation strategies are classified for discussion,such as the application of additives and barrier materials,as well as plant and animal remediation and bioremediation,etc.,pointing out that future research should focus on the whole chain process of“source-processterminal”,intending to provide a theoretical basis and decision-making reference for future research.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804501)the National Natural Science Foundation of China(Nos.42122056 and U1901210)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2021B1515020063)the Key Research and Development Program of Guangdong Province(No.2021B1111380003)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032).
文摘Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution characteristics and health risks of HMs in groundwater nearby a typical coking plant.Nine HMs including Fe,Zn,Mo,As,Cu,Ni,Cr,Pb and Cd were analyzed.The average concentration of total HMswas higher in the nearby area(244.27μg/L)than that of remote area away the coking plant(89.15μg/L).The spatial distribution of pollution indices including heavy metal pollution index(HPI),Nemerow index(NI)and contamination degree(CD),all demonstrated higher values at the nearby residential areas,suggesting coking activity could significantly impact the HMs distribution characteristics.Four sources of HMs were identified by Positive Matrix Factorization(PMF)model,which indicated coal washing and coking emission were the dominant sources,accounted for 40.4%,and 31.0%,respectively.Oral ingestionwas found to be the dominant exposure pathway with higher exposure dose to children than adults.Hazard quotient(HQ)values were below 1.0,suggesting negligible non-carcinogenic health risks,while potential carcinogenic risks were from Pb and Ni with cancer risk(CR)values>10−6.Monte Carlo simulation matched well with the calculated results with HMs concentrations to be the most sensitive parameters.This study provides insights into understanding how the industrial coking activities can impact the HMs pollution characteristics in groundwater,thus facilitating the implement of HMs regulation in coking industries.
基金supported by the National Natural Science Foundation of China(Nos.12035019,62234013,12205350,12075290,12175287)the China National Postdoctoral Program for Innovative Talents(BX20200340)+1 种基金the fund of Innovation Center of Radiation Application(No.KFZC2022020601)the Chinese Academy of Sciences(CAS)“Light of West China"Program hosted by Jian Zeng.
文摘Gallium nitride(GaN)-based devices have significant potential for space applications.However,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains unknown.This study investigates the effects of radiation on p-gate AlGaN/GaN high-electron-mobility transistors(HEMTs).Under a high voltage,the HEMT leakage current increased sharply and was accompanied by a rapid increase in power density that caused"thermal burnout"of the devices.In addition,a burnout signature appeared on the surface of the burned devices,proving that a single-event burnout effect occurred.Additionally,degradation,including an increase in the on-resistance and a decrease in the breakdown voltage,was observed in devices irradiated with high-energy heavy ions and without bias.The latent tracks induced by heavy ions penetrated the heterojunction interface and extended into the GaN layer.Moreover,a new type of N_(2)bubble defect was discovered inside the tracks using Fresnel analysis.The accumulation of N_(2)bubbles in the heterojunction and buffer layers is more likely to cause leakage and failure.This study indicates that electrical stress accelerates the failure rate and that improving heat dissipation is an effective reinforcement method for GaN-based devices.
基金supported by the project of Sanya Yazhou Bay Science and Technology City,Grant No.SKJC-2023-02-004Education Department of Hainan Province,Grant No.Hnky2024ZD-27Key R&D Project of Hainan Province(Science and Technology Commissioner):405314040001.
文摘Soil naturally contains various heavy metals,however,their concentrations have reached toxic levels due to excessive agrochemical use and industrial activities.Heavy metals are persistent and non-biodegradable,causing environmental disruption and posing significant health hazards.Microbial-mediated remediation is a promising strategy to prevent heavy metal leaching and mobilization,facilitating their extraction and detoxification.Nickel(Ni),being a prevalent heavy metal pollutant,requires specific attention in remediation efforts.Plants have evolved defense mechanisms to cope with environmental stresses,including heavy metal toxicity,but such stress significantly reduces crop productivity.Beneficial microorganisms play a crucial role in enhancing plant yield and mitigating abiotic stress.The impact of heavy metal abiotic stress on plants’growth and productivity requires thorough investigation.Bioremediation using Nickel nanoparticles(Ni NPs)offers an effective approach to mitigating environmental pollution.Microorganisms contribute to nanoparticle bioremediation by immobilizing metals or inducing the synthesis of remediating microbial enzymes.Understanding the interactions between microorganisms,contaminants,and nanoparticles(NPs)is essential for advancing bioremediation strategies.This review focuses on the role of Bacillus subtilis in the bioremediation of nickel nanoparticles to mitigate environmental pollution and associated health risks.Furthermore,sustainable approaches are necessary to minimize metal contamination in seeds.The current review discusses bacterial inoculation in enhancing heavy metal tolerance,plant signal transduction pathways,and the transition from molecular to genomic research in metal stress adaptation.Moreover,the inoculation of advantageous bacteria is crucial for preserving plants under severe mental stress.Different researchers develop a complex,vibrant relationship with plants through a series of events known as plant-microbe interactions.It increases metal stress resistance through the creation of phytohormones.In general,the defensive responses of plants to heavy metal stress,mediated by microbial inoculation require further in-depth research.Further studies should explore the detoxification mechanism of nickel through bioremediation to develop more effective and sustainable remediation strategies.
基金supported by Open Foundation of the State Key Laboratory of Refractories and Metallurgy(No.G201711)the National Natural Science Foundation of China(Nos.52104317 and 51874001).
文摘The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.
基金funded by the Project of Yunnan Province’s Xingdian Talents Support Program(yfgrc202437)the Project of the International Cooperation Science Program of National Natural Science Foundation of China(42361144885).
文摘Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of the 150 phosphate fertilizers stored at the Institute for Crop and Soil Science in Germany has been conducted,supplemented by previously published data.The elements Cd,Bi,U,Cr,Zn,Tl,As,B,Sb,Ni,and Se are found in higher concentrations in sedimentary derived phosphates compared to igneous derived phosphates.Mineral fertilizers contain more than ten times the amount of U,Cd,B,and As compared to farmyard manure.Principal component analyses(PCA)indicate that U,Cd,Be,and Cr are primarily present in sedimentary derived phosphates and their concentrations are 2 to 10 times higher than those in igneous derived phosphates.Regarding heavy metal contamination,over 1000 potential combinations were identified;36% of these were significant but weak(>0.1).It is estimated that approximately 707 t of uranium enter farmland annually through the application of mineral phosphate fertilizers in European countries.This contribution addresses environmental issues related to the utilization of rock phosphate as well as alternative production methods for cleaner and safer phosphate fertilizers while presenting a roadmap with measures for mitigation.
基金supported by the National Key Research and Development Program of China(No.2023YFC3710000)the National Natural Science Foundation of China(Nos.42277078 and 42307118).
文摘Abandoned mines,especially pyrite-rich ones,release acid mine drainage(AMD)with high acidity and excessive amounts of heavy metals,threatening regional ecosystems.Six samples of mine drainage,nine samples of surface water,and twelve samples of sediment were analyzed in this case study of the Dashu pyrite mine in southwest China.A comprehensive analysis of the pollution levels,pollution sources,and potential hazards of eight metals(Ni,Cd,Cu,Zn,Fe,Al,Pb,and Mn)that exceeded regulatory standardswas conducted bymonitoring 24 conventional and characteristic indicators.Ultimately,this research evaluated the environmental hazards associated with abandonedmine water using the"pressure-response"model,thereby providing valuable insights for the effective protection of the environment in mining regions.The primary pollutants in mine water were determined to be SO_(4)^(2−),Fe,and Mn,with concentrations of 7700,1450,and 6.78mg/L,respectively.A clear"source-sink"dynamic was observed between themine water and the surrounding water system.surface water was primarily polluted by Ni and Mn,while water system sediments were primarily polluted by Cu and Hg.Ion ratio and Pearson correlation analyses indicated heavy metals in surface water and sediments originated from the same AMD source.The"pressureresponse"model was used to assess the environmental hazards of water from abandoned mines.Mines W1,W2,W5,and W6 were classified as high-risk,while W3 and W4 were medium-risk.This study offers a novel approach and valuable reference for identifying and classifying environmental risks in abandoned mines and targeting AMD treatment.
基金supported d by the National Key Research and Development Program of China(No.2018YFC1802905).
文摘Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened.The surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II)and Mn(II)by Pseudomonas taiwanensis(marked as P4)and Pseudomonas plecoglossicida(marked as G1)contains rich reactive oxygen functional groups,which play critical roles in the removal efficiency and immobilization of heavymetal(loid)s in co-contamination system.The isolated strains P4 and G1 can growwell in the following environments:pH 5-9,NaCl 0-4%,and temperature 20-30℃.The removal efficiencies of Fe,Pb,As,Zn,Cd,Cu,and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system(the initial concentrations of heavy metal(loid)were 1 mg/L),approximately reaching 96%,92%,85%,67%,70%,54%and 15%,respectively.The exchangeable and carbonate bound As,Cd,Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil,thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)s.This research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.
文摘Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.
基金National Natural Science Foundation of China(52074031)Key Research and Development Program of Shandong Province(ZR2021MB051,ZR2020ME256)。
文摘The traditional techniques for treating wastewater contaminated by heavy metals mostly involve chemical precipitation,solvent extraction and adsorption,ion-exchange,chemical precipitation,and membrane separation.The main shortcomings of traditional procedures are low economic efficiency,lack of environmental friendliness,and poor selectivity.Cyclodextrins are artificial compounds that resemble cages.Through host-vip interaction,pollutants can be adsorbed by its stable inner hydrophobic chamber and exterior hydrophilic surface.It is not only inexpensive and environmentally friendly,but also quite selective.The synthesis and application of materials were reviewed,as well as the primary influencing factors,and the reaction principle of cyclodextrin adsorbent materials for better separation of heavy metal ions.And the future trend of discovery was described.
文摘Industrial activities have contributed so much to the pollution of water bodies and these pollutions have adversely affected the aquatic ecosystem.This study aimed to investigate the ecological risk evaluation of heavy metal accumulation in Aba River bottom sediments:implications for soap and detergent industry wastewater management.Varian AA240 Atomic absorption spectrometer was used to analyse heavy metals.Individual and complex ecological indices were used to evaluate heavy metal contamination in bottom sediments.According to the results,the heavy metal properties of the wastewater indicated that Fe,Pb,Cd,Cr and Cu mean concentration values were higher than the World Health Organization(WHO)and the National Environmental Standards and Regulations Enforcement Agency(NESREA)permissible limits.Heavy metal properties of the surface water in Aba River(dry seasons)showed that Pb,Cd,Cu,Mn,Fe,and Cr,mean concentrations were above the NESREA,WHO and U.S.Environmental Protection Agency(USEPA)permissible limits.Heavy metal properties of the bottom sediments of Aba River(wet and dry season)showed that Pb,Cd,and Fe mean concentrations were significantly higher than the NESREA,WHO and USEPA permissible limits.The heavy metal contamination factor(CF)of sediments obtained from Aba River during the wet and dry season was low and the CFs of each of the assayed heavy metals were less than 1(CD<1).This also signifies the existence of a low contamination in the sediments of the course streams of Aba River during wet and dry season.The pollution load index(PLI)values of Aba River(sediment)indicated that there is no metal pollution at PLI<1 in the sampled sediments.The potential ecological risk index(RI)of Aba River was less than 150(RI<150)indicating a low ecological RI.Abatement of pollutants in the wastewater to permissible concentrations required for natural environment protection is needed.
基金supported by the National Natural Science Foundation of China(21707056)the Natural Science Foundation of Jiangxi Province,China(20192BAB203019)the Jiangxi Province Graduate Innovation Special Fund Project(YC2022-S412)。
文摘The migration/transformation characteristics of heavy metals and polycyclic aromatic hydrocarbons(PAHs) during the co-liquefaction of pig manure and rice straw/wood sawdust were explored in this study.More than 87% of the heavy metals in feedstocks were enriched in hydrochars.The decreased proportion of active heavy metals in the hydrochars suggested partial passivation of the heavy metals.The pollution degree and risk of heavy metals were significantly mitigated from high and considerable levels in pig manure to moderate and low levels in hydrochar,respectively.Compared with commercial diesel,bio-oil products still contained an undesirable amount of heavy metals.PAHs were re-synthesized during liquefaction,with a net synthesis amount of 29.65-73.98 mg·kg^(-1).Moreover,the PAHs mainly existed in bio-oils,with a content of 57.32-132.33 mg·kg^(-1) and a toxicity equivalent of3.25-8.19 mg·kg^(-1).Compared to pig manure,the hydrochars presented a lower content of PAHs(1.76-3.53 mg·kg^(-1) versus 3.73 mg·kg^(-1)) and a smaller toxicity equivalent(0.14-0.22 mg·kg^(-1) versus0.26 mg·kg^(-1)).Interestingly,introducing lignocellulose(especially for rice straw) during the liquefaction of pig manure further mitigated the pollution degree/risk of heavy metals and PAHs.Overall,hydrochar reached a safe utilization level,while bio-oil products needed further clarification.
基金supported by the National Key Research and Development Plan of China(No.2022YFE0197200)the National Natural Science Foundation of China(No.42277055).
文摘Urban rivers are one of the main water sources for local residents.However,the rapid industrialization and urbanization caused serious heavy metals pollution in urban rivers,which posed harmful impact on human health and ecosystem.In this study,134 sediment samples were collected fromurban rivers in a typical Economic and Technological Development Zone(ETDZ)to evaluate the contamination status,ecological risk,biotoxicity,and potential source of 8 heavy metals including arsenic(As),cadmium(Cd),chromium(Cr),copper(Cu),mercury(Hg),nickel(Ni),plumbum(Pb),and zinc(Zn).Results showed that the average concentrations of all 8 metals exceeded their corresponding background values and followed the trend:Cr(248.67 mg/kg)>Pb(123.58 mg/kg)>Zn(67.06 mg/kg)>Ni(47.19 mg/kg)>Cu(27.40 mg/kg)>As(16.15 mg/kg)>Cd(0.62mg/kg)>Hg(0.21mg/kg).A high contamination and accumulation tendency of Cd and Cr were found in the sediments.Moreover,Cd and Hg were the main contributors of ecological risk,and posed moderate to high risk.In terms of biotoxicity,all the sediment samples were harmful to benthic organisms.Two possible pollution sources of heavy metals were identified:one is a combined source of industrial and traffic pollution dominated by Cr and Pd,the other is an industrial pollution source consisting of six heavy metals(Ni,Zn,Cd,Hg,As,and Cu).This study provides insights into heavy metals pollution management and risk control in the ETDZ and similar urban rivers worldwide due to intense industrialization.
基金supported by the Budget Execution(Allotment)Document,National Research and Innovation Agency(BRIN)in 2022(Grant No.SP DIPA-124.01.1.690504/2022)。
文摘Nusantara,the new capital city of Indonesia,and its surrounding areas experienced intense heavy rainfall on 15-16 March 2022,leading to devastating and widespread flooding.However,the factors triggering such intense heavy rainfall and the underlying physical mechanisms are still not fully understood.Using high-resolution GSMaP(Global Satellite Mapping of Precipitation)data,we show that a mesoscale convective system(MCS)was the primary cause of the heavy rainfall event.The rainfall peak occurred during the MCS's mature stage at 1800 UTC 15 March 2022,and diminished as it entered the dissipation stage.To understand the large-scale environmental factors affecting the MCS event,we analyzed contributions from the MJO,equatorial waves,and low-frequency variability to column water vapor and moisture flux convergence.Results indicate a substantial influence of the MJO and equatorial waves on lower-level(boundary layer)meridional moisture flux convergence during the pre-MCS stage and initiation,with their contributions accounting for up to80%during the growth phase.Moreover,while La Nina and the Asian monsoon had negligible impacts on MCS moisture supply,we find a large contribution from the residual term of the water vapour budget during the maturation and decay phases of the MCS.This suggests that local forcing(such as small-scale convection,local evaporation,land-surface feedback,and topography)also contributed to modulation of the intensity and duration of the MCS.The results of this study can help in our understanding of the potential causes of extreme rainfall in Nusantara and could be leveraged to improve rainstorm forecasting and risk management across the region in the future.
