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Particle-bound organic and elemental carbons for source identification of PM<0.1μm from biomass combustion

Journal of Environmental Sciences 2022年第3期34卷 385-393页

作者： Hisam Samae Surajit Tekasakul Perapong Tekasakul Worradorn Phairuang Masami Furuuchi Surapa Hongtieab Department of Chemistry Division of Physical SciencesFaculty of SciencePrince of Songkla UniversityHat YaiSongkhla 90112Thailand Department of Mechanical Engineering Faculty of EngineeringPrince of Songkla UniversityHat YdiSongkhla 90112Thailand Air Pollution and Health Effect Research Center Prince of Songkla UniversityHat YaiSongkhla90112Thailand Faculty of Environmental Management Prince of Songkla UniversityHat YaiSongkhla90112Thailand Faculty of Geoscience and Civil Engineering Institute of Science and EngineeringKanazawa UniversityKakuma-machiKanazawaIshikawa920-1192Japan Department of Geography Faculty of Social SciencesChiang Mai UniversityMuangChiang Mai50200Thailand

Atmospheric nanoparticles(PM50%)with minor contribution from EC(3%-12%).The higher fraction of carbonaceous components was found in the particulates with smaller sizes,and lignin content may relate to concentration of... 详细信息

Atmospheric nanoparticles(PMsources identification of atmospheric particulates is necessary.Combustion of bituminous coal and biomass includ-ing rubber wood,palm kernel,palm fiber,rice stubble,rice straw,maize residue,sugarcane leaves and sugarcane bagasse,which are considered as sources of air quality problems in many countries,was performed.Emissions of particle-bound chemical components includ-ing organic carbon(OC),elemental carbon(EC),water-soluble ions(NH4^(+),Cl^(-),NO_(3)^(-),SO_(4)^(2-)),elements(Ca,K,Mg,Na)and heavy metals(Cd,Cr,Ni,Pb)were investigated.The results re-vealed that PM50%)with minor contribution from EC(3%-12%).The higher fraction of carbonaceous components was found in the particulates with smaller sizes,and lignin content may relate to concentration of pyrolyzed organic carbon(PyOC)resulting in the differences of OC/EC values.PM emit-ted from burning palm fiber and rice stubble showed high values of OC/EC and also high PyOC.Non-carbonaceous components such as Cl^(-),Cr,Ca,Cd,Ni,Na and Mg may be useful as source indicators,but they did not show any correlation with the size of PM.

关键词： PM<0.1 pm Organic carbon Elemental carbon source identification Emission factors

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Exploration of the potential application of plutonium isotopes in source identification of sandstorm in the atmosphere of Beijing

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Chinese Chemical Letters 2022年第7期33卷 3516-3521页

作者： Jie Ouyang Yang Shao Min Luo Jilong Zhang Xiongxin Dai Lingling Ma Diandou Xu Beijing Engineering Research Center of Radiographic Techniques and Equipment Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Institute of Environmental and Health Sciences College of Quality and Safety EngineeringChina Jiliang UniversityHangzhou 310018China State Nuclear Security Technology Center Beijing 102401China China Institute for Radiation Protection Taiyuan 030000China

Plutonium(Pu)is an anthropogenic radionuclide which mainly derived from atmospheric nuclear tests in the environment.In this study,the Pu isotopes(^(239)Pu and^(240)Pu)in aerosol samples collected during the sandstorm and non-sandstorm period were measured by accelerator mass spectrometry(AMS)and the behavior of Pu was studied.The activity concentrations of ^(239)Pu and ^(240)Pu in the aerosol samples of Beijing were ranged from 0.62 nB q/m^(3)to 99.6 n Bq/m^(3)for ^(239)Pu and 3.51 nBq/m^(3)to 60.23 n Bq/m^(3)for ^(240)Pu,respectively.^(239)Pu and ^(240)Pu concentrations exhibited a remarkable seasonal variation trend,with the higher results showed in spring,and the relatively lower concentrations in winter.The observed higher concentration of^(239)Pu and^(240)Pu detected in sandstorm samples further indicated Pu was closely related to the occurrence of sandstorms.The global fallout characteristics of^(240)Pu/^(239)Pu atom ratios(average0.20,ranging from 0.16 to 0.27)in aerosol samples indicating that global fallout was the major source of Pu in the atmosphere.Using aluminum(Al)as an indicator of soil resuspension,significant positive correlation between^(239)Pu and Al(r^(2)=0.934),240Pu and Al(^(r)2=0.525)revealed that soil resuspension was a primary source of atmospheric Pu in Beijing.These results implied that the combination of^(239)Pu,^(240)Pu and Al could be used as the potential tracer of sandstorm.

关键词： Plutonium Atmosphere source identification Sandstorm

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Contrasting compositions of PM_(2.5)in Northern Thailand during La Nina(2017)and El Nino(2019)years

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Journal of Environmental Sciences 2024年第1期135卷 585-599页

作者： Pavidarin Kraisitnitikul Duangduean Thepnuan Sarana Chansuebsri Nuttipon Yabueng Wan Wiriya Supattarachai Saksakulkrai Zongbo Shi Somporn Chantara Environmental Science Research Center Faculty of ScienceChiang Mai UniversityChiang Mai50200Thailand Department of Chemistry Faculty of Science and TechnologyChiang Mai Rajabhat UniversityChiang Mai50300Thailand Chemistry Department Faculty of ScienceChiang Mai UniversityChiang Mai50200Thailand School of Geography Earth and Environmental SciencesUniversity of BirminghamBirminghamB152TTUK

There have been a very limited number of systematic studies on PM_(2.5)compositions and their source contribution in Southeast Asia.This study aims to explore the characteristics of PM_(2.5)composition collected in Chiang Mai(Thailand)during La Nina and El Nino years and to apportion their sources during smoke haze and non-haze periods.The average PM_(2.5)concentration of smoke haze episode in 2019(El Nino)was much higher than in 2017(La Nina).The ratios of organic carbon(OC)to elemental carbon(EC),as well as K(biomass burning(BB)tracer)to PM_(2.5),were higher during smoke haze episodes in 2019 than in 2017 indicating a significant influence from BB.The ratios of secondary organic carbon(SOC)levels to primary organic carbon(POC)levels during smoke haze episodes were higher than those in non-haze period,which indicated greater SOC contributions or more photo-oxidation of precursors in haze episodes with high ambient temperatures.However,the ratios of soil markers(Ca and Mg)during non-haze period were high implying that soil source contributed more to PM_(2.5)concentrations when there less BB occurred.The positive Matrix Factorization(PMF)model revealed that the source of BB,characterized by high K fractions,was the largest contributor during smoke haze episodes accounting for 50%(2017)and 79%(2019).Climate conditions influence meteorological patterns,particularly during incidences of extreme weather such as droughts,which affect the scale and frequency of open burning and thus air pollution levels.

关键词： Climate Air pollution Metals Carbon Biomass burning source identification

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Effect of observation time on source identification of diffusion in complex networks

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Chinese Physics B 2022年第7期31卷 97-103页

作者：史朝义张琦楚天广 College of Engineering Peking UniversityBeijing 100871China School of Information Technology and Management University of International Business and EconomicsBeijing 100105China

This paper examines the effect of the observation time on source identification of a discrete-time susceptible-infectedrecovered diffusion process in a network with snapshot of partial nodes.We formulate the source identification problem as a maximum likelihood(ML)estimator and develop a statistical inference method based on Monte Carlo simulation(MCS)to estimate the source location and the initial time of diffusion.Experimental results in synthetic networks and real-world networks demonstrate evident impact of the observation time as well as the fraction of the observers on the concerned problem.

关键词： complex network source identification statistical inference partial observation

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On Regularization of a source identification Problem in a Parabolic PDE and its Finite Dimensional Analysis

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Journal of Partial Differential Equations 2021年第3期34卷 240-257页

作者： MONDAL Subhankar NAIR M.Thamban Department of Mathematics IIT MadrasChennai 600036India

We consider the inverse problem of identifying a general source term,which is a function of both time variable and the spatial variable,in a parabolic PDE from the knowledge of boundary measurements of the solution on some portion of the lateral boundary.We transform this inverse problem into a problem of solving a compact linear operator equation.For the regularization of the operator equation with noisy data,we employ the standard Tikhonov regularization,and its finite dimensional realization is done using a discretization procedure involving the space L^(2)(0,τ;L^(2)(Ω)).For illustrating the specification of an a priori source condition,we have explicitly obtained the range space of the adjoint of the operator involved in the operator equation.

关键词： Ill-posed source identification Tikhonov regularization weak solution

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Groundwater contaminant source identification based on iterative local update ensemble smoother

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Journal of Groundwater Science and Engineering 2020年第1期8卷 1-9页

作者： YANG Ai-lin JIANG Si-min LIU Jin-bing JIANG Qian-yun ZHOU Ting ZHANG Wen Department of Hydraulic Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Beijing Haidian International School Beijing 100195China Department of Environmental Science and Engineering Fudan UniversityShanghai 200433China

identification of the location and intensity of groundwater pollution source contributes to the effect of pollution remediation,and is called groundwater contaminant source identification.This is a kind of typical groundwater inverse problem,and the solution is usually ill-posed.Especially considering the spatial variability of hydraulic conductivity field,the identification process is more challenging.In this paper,the solution framework of groundwater contaminant source identification is composed with groundwater pollutant transport model(MT3DMS)and a data assimilation method(Iterative local update ensemble smoother,ILUES).In addition,Karhunen-Loève expansion technique is adopted as a PCA method to realize dimension reduction.In practical problems,the geostatistical method is usually used to characterize the hydraulic conductivity field,and only the contaminant source information is inversely calculated in the identification process.In this study,the identification of contaminant source information under Kriging K-field is compared with simultaneous identification of source information and K-field.The results indicate that it is necessary to carry out simultaneous identification under heterogeneous site,and ILUES has good performance in solving high-dimensional parameter inversion problems.

关键词： Groundwater contamination Groundwater inverse problem source identification Ensemble smoother Data assimilation

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Index model equation analysis:A case study of the risk and source of inorganic contaminants in roadside uncontaminated soil of the Egi oil producing area,Niger Delta

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International Journal of Sediment Research 2023年第6期38卷 891-900页

作者： Elechi Owhoeke Asmat Ali Okorondu Justin Nnaemeka Kingsley John Orie Julius Nkeonyeasua Ehiwario Abdur Rashid Department of Industrial Chemistry/Petrochemical Technology School of Science Laboratory TechnologyUniversity of Port Harcourt School of Environmental Studies China University of Geosciences State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Department of Environmental Management Federal University of Technology Owerri Department of Pure and Industrial Chemistry University of Port Harcourt Department of Microbiology Faculty of Life ScienceAmbrose Alli University

This study examined the sources,health risk and pollution status of selected inorganic contaminants such as iron(Fe),nickel(Ni),cadmium(Cd),cobalt(Co),arsenic(As),manganese(Mn),lead(Pb),copper(Cu),zinc(Zn),and chromium(Cr) in representative roadside uncontaminated soil(n=72) from the Egi crude oil mining areas(Oboburu,Obagi,and Ogbogu),Niger Delta,Nigeria,using a combination of multiple models(Principle component analysis(PCA),correlation analysis,geo-accumulation index(Igeo),contamination factor(CF),enrichment factor(EF),pollution load index(PLI),cancer risk(CR),hazard quotient(HQ),and metal daily intake(MDIm)).A random sampling method was applied in the sampling and analysis using inductively coupled plasma mass spectroscopy.The result revealed that the mean(mg/kg) for Oboburu,was the highest for Fe(89.95 ± 28.83) and Mn(26.12 ± 7.642),whereas Obagi,had less Fe(28.90 ± 7.601) and Mn(16.80 ± 5.021),and Ogbogu,Fe(44.67 ± 28.15) and Pb(19.38± 8.731) was the second highest heavy metal.The order of contamination was F> Mn> Zn> Pb> Cu> Cr> Ni> Cd> Co.The Igeo and CF had cadmium as a metal of concern.The contamination level was low from the PLI estimation.The EF revealed anthropogenic sources for all the metals except for Ni,which was biogenic.The correlations at p source control,and integrated environmental management of the study area.

关键词： Carcinogenicity Health risk Soil source identification Variability

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Baseline determination,pollution source and ecological risk of heavy metals in surface sediments of the Amu Darya Basin,Central Asia

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Journal of Geographical Sciences 2022年第11期32卷 2349-2364页

作者： ZHAN Shuie WU Jinglu JIN Miao ZHANG Hongliang State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyCASNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China

Central Asia(CA)is one of the most fragile regions worldwide owing to arid climate and accumulated human activities,and is a global hotspot due to gradually deteriorating ecological environment.The Amu Darya Basin(ADB),as the most economically and demographically important region in CA,is of particular concern.To determine the concentration,source and pollution status of heavy metals(HMs)in surface sediments of the ADB,154samples were collected and analyzed for metals across the basin.Correlation and cluster analysis,and positive matrix factorization model were implemented to understand metals’association and apportion their possible sources.Cumulative frequency distribution and normalization methods were used to determine the geochemical baseline values(GBVs).Then,various pollution indices and ecological risk index were employed to characterize and evaluate the pollution levels and associated risks based on the GBVs.Results indicated that the mean concentrations of HMs showed the following descending order in the surface sediments of ADB:Zn>Cr>Ni>Cu>Pb>Co>Cd.The spatial distribution maps showed that Cr,Ni,and Cu had relatively high enrichment in the irrigated agricultural area;high abundances of Zn,Pb,and Cd were mainly found in the urban areas.Four source factors were identified for these metals,namely natural sources,industrial discharge,agricultural activities,and mixed source of traffic and mining activities,accounting for 33.5%,11.4%,34.2%,and 20.9%of the total contribution,respectively.The GBVs of Cd,Zn,Pb,Cu,Ni,Cr,and Co in the ADB were 0.27,58.9,14.6,20.3,25.8,53.4,and 9.80 mg/kg,respectively,which were similar to the regional background values obtained from lake sediments in the bottom.In general,the assessment results revealed that surface sediments of the ADB were moderately polluted and low ecological risk by HMs.

关键词： heavy metal spatial distribution source identification geochemical baseline value risk assessment Amu Darya Basin

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source identification of Network Diffusion Processes with Partial Observations

Source Identification of Network Diffusion Processes with Pa...

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第36届中国控制会议

作者： Chaoyi Shi Qi Zhang Tianguang Chu College of Engineering Peking University

ISBN: (纸本)9781538629185

In this paper,we study the problem of identifying the source of network diffusion processes by using the contact networks and sampled infections.The dynamic processes are described by the susceptible-infected（SI） model and a maximum likelihood（ML） estimator is formulated for identification of the source.We propose a two-stage method that first locates a set of suspected source nodes and then identifies the infection source from the candidate source nodes by using Markov random field method.Experiments on regular tree and real-world networks verify the effectiveness of our approach.

关键词： source identification Susceptible-infected（SI） model Maximum likelihood Markov random fields

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Soil heavy metal pollution from Pb/Zn smelting regions in China and the remediation potential of biomineralization

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Journal of Environmental Sciences 2023年第3期125卷 662-677页

作者： Xinghua Luo Chuan Wu Yongcheng Lin Waichin Li Min Deng Jingqiang Tan Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China Department of Science and Environmental Studies The Education University of Hong KongTai PoHong Kong 999077China School of Geosciences and Info-physics Central South UniversityChangsha 410083China

Smelting activities pose serious environmental problems due to the local and regional heavy metal pollution in soils they cause. It is therefore important to understand the pollution situation and its source in the contaminated soils. In this paper, data on heavy metal pollution in soils resulting from Pb/Zn smelting(published in the last 10 years) in China was summarized. The heavy metal pollution was analyzed from a macroscopic point of view. The results indicated that Pb, Zn, As and Cd were common contaminants that were present in soils with extremely high concentrations. Because of the extreme carcinogenicity, genotoxicity and neurotoxicity that heavy metals pose, remediation of the soils contaminated by smelting is urgently required. The primary anthropogenic activities contributing to soil pollution in smelting areas and the progressive development of accurate source identification were performed. Due to the advantages of biominerals, the potential of biomineralization for heavy metal contaminated soils was introduced. Furthermore, the prospects of geochemical fraction analysis, combined source identification methods as well as several optimization methods for biomineralization are presented, to provide a reference for pollution investigation and remediation in smelting contaminated soils in the future.

关键词： Heavy metals Smelting contaminated soils source identification Remediation

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