Article
Environmental Sciences
Jihyeun Jung, Junyoung Park, Yongju Choi, Jong Kwon Choe, Jinsung An, Kyoungphile Nam
Summary: The upstream of Nakdong River in South Korea is polluted by heavy metals such as Cd, Cu, Zn, As, and Pb, suspected to be leached from mine tailings and a refinery. Receptor models (APCS and PMF) were used to identify the contamination sources, and source markers were determined through correlation analysis. The categorization of sources into two factors was validated statistically, and the reliability of the model prediction and initial concentration of contaminants were confirmed through regression analysis and sediment sample testing. GIS analysis revealed the distribution and source contribution of heavy metal contaminated zones influenced by precipitation.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Xu Wang, Meng Zhang, Lili Liu, Zhiping Wang, Kuangfei Lin
Summary: This study collected surface water samples from Taihu Lake Basin and used multivariate statistical analysis to determine the optimal water quality parameters for the receptor models. Through the analysis of dissolved organic matter (DOM) and Pearson correlation analysis, the potential pollution sources in surface water, including agricultural activities, domestic sewage, phytoplankton growth/terrestrial input, and industrial sources, were successfully identified. Quantification of pollution sources was conducted using principal component analysis (PCA) combined with absolute principal component score-multiple linear regression (APCS-MLR) and positive matrix factorization (PMF) models. The results showed that agricultural activities and domestic sewage were the dominant pollution sources of surface water in the study area.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Dawen Yao, Xiaopu Lyu, Haoxian Lu, Lewei Zeng, Tengyu Liu, Chak K. Chan, Hai Guo
Summary: The study conducted a sampling campaign at an urban roadside site in Hong Kong to monitor compositions of non-refractory sub-micron particulate matter (NR-PM1) and gaseous pollutants. Results showed that cooking activities are a significant source of organic aerosols in Hong Kong, even at a busy road. Control measures should focus on both cooking and traffic emissions in Hong Kong.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Environmental Sciences
Gahye Lee, Minkyeong Kim, Duckshin Park, Changkyoo Yoo
Summary: Effective management and regulation of PM2.5 is crucial in South Korea due to high concentrations. This study measured PM2.5 and analyzed its chemical composition in Bucheon City. Using a PMF model, the sources of PM2.5 pollution were identified and their contributions quantified.
Article
Engineering, Environmental
Laura Hyesung Yang, David H. Hagan, Jean C. Rivera-Rios, Makoto M. Kelp, Eben S. Cross, Yuyang Peng, Jennifer Kaiser, Leah R. Williams, Philip L. Croteau, John T. Jayne, Nga Lee Ng
Summary: Advances in low-cost sensors (LCS) have provided opportunities to characterize air quality in finer spatial and temporal resolutions. In this study, LCS were deployed in Atlanta, GA, alongside research-grade instruments to investigate air pollution sources using non-negative matrix factorization (NMF). Results show that both normalized and non-normalized LCS datasets can resolve primary organic aerosol (POA) factors, while normalization can provide factors with more diverse compositions and resolve secondary organic aerosol (SOA) as well.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Environmental Sciences
Yue'e Li, Bin Zhu, Yali Lei, Changping Li, Hongli Wang, Cheng Huang, Minfeng Zhou, Qing Miao, Heng Wei, Yezheng Wu, Xiaohua Zhang, Huangda Ding, Qian Yang, Qiang Zou, Dandan Huang, Xinlei Ge, Junfeng Wang
Summary: This study investigates the seasonal characteristics, formation, and sources of PM2.5 in Suzhou, Yangtze River Delta, China in 2020. Organic matter is found to be the dominant component of PM2.5, with the highest average value in spring. In summer, PM2.5 is mainly produced by the oxidation of volatile organic compounds.
ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
T. K. Mandal, Pooja Yadav, Mukesh Kumar, Shyam Lal, Kirti Soni, Lokesh Yadav, Ummed Singh Saharan, S. K. Sharma
Summary: This study presents measurements of 25 volatile organic carbon compounds (VOCs) in the ambient air of an urban location in Delhi, India. The concentrations of alkenes gradually increase from morning to day time, while alkanes and aromatic compounds show a decrease. There is a strong seasonal cycle for VOCs, with alkanes and alkenes being the most dominant compounds.
Article
Engineering, Environmental
Favour Epuna, Samuel W. Shaheen, Tao Wen
Summary: This study used statistical and geospatial tools to analyze the groundwater quality in rural northern Appalachia. The results showed that salts in the groundwater mainly come from the Appalachian Basin Brine, while road salts also contribute to a significant portion of chloride. However, the study did not find a regional impact of unconventional oil and gas development (UOGD) on groundwater quality, suggesting limited effects of UOGD on groundwater.
Article
Environmental Sciences
Hongling Chen, Dandan Wu, Qiao Wang, Lihu Fang, Yanan Wang, Changlin Zhan, Jiaquan Zhang, Shici Zhang, Junji Cao, Shihua Qi, Shan Liu
Summary: The sources of heavy metals in different types of fugitive dust in mining and metallurgy areas were identified using a method combining principal component analysis and a positive matrix factorization model. The results showed contributions from natural geological processes, transport pathways, mining-related activities, and traffic-related emissions to the accumulation of heavy metals. The findings can assist the government in developing targeted control strategies for heavy metal dispersion efficiency.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Engineering, Electrical & Electronic
Cristian Rusu, Lorenzo Rosasco
Summary: Orthogonal projections are a common technique for dimensionality reduction in machine learning applications. This study focuses on approximating orthogonal matrices to achieve fast and accurate numerical computation. By solving an optimization problem over a set of structured matrices called extended orthogonal Givens transformations, which includes Givens rotations as a special case, an approximation is obtained. An efficient greedy algorithm is proposed to solve the problem, striking a balance between approximation accuracy and computation speed. The approach is relevant to spectral methods and is applied to PCA.
Article
Operations Research & Management Science
Qingsong Wang, Deren Han, Wenxing Zhang
Summary: This paper presents a customized nonconvex optimization algorithm for SVD-free RPCA models. The proposed algorithm reduces computational efforts by partially linearizing data fidelity and increases efficiency by leveraging inertial techniques. Numerical simulations on synthetic and real datasets demonstrate the compelling performance of the proposed algorithm.
Article
Quantum Science & Technology
Max Hunter Gordon, M. Cerezo, Lukasz Cincio, Patrick J. Coles
Summary: Principal component analysis (PCA) is a dimensionality reduction method that involves diagonalizing the covariance matrix of a dataset. Recently, quantum algorithms for PCA based on diagonalizing a density matrix have been proposed. However, a concrete protocol for encoding the covariance matrix as a density matrix has been lacking. In this study, we address this gap by providing a simple means for preparing the covariance matrix for arbitrary quantum datasets or centered classical datasets. We also propose a method for uncentered classical datasets, which we interpret as PCA on a symmetrized dataset. We demonstrate the effectiveness of our method through numerical experiments on the MNIST handwritten digit dataset and molecular ground-state datasets.
Article
Computer Science, Artificial Intelligence
Xixi Jia, Xiangchu Feng, Weiwei Wang, Lei Zhang
Summary: Spectral regularization is a commonly used approach for low-rank matrix recovery, but existing LRMR solvers are computationally expensive. A generalized unitarily invariant gauge function is proposed for LRMR, offering a bilinear variational problem that can be efficiently solved without SVD computation. The GUIG model is shown to be more accurate and faster than state-of-the-art algorithms, especially for large-scale problems.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Zhi-Yong Wang, Hing Cheung So, Abdelhak M. Zoubir
Summary: The correntropy criterion or Welsch function, widely used to resist outliers, has been recently applied to robust matrix recovery. However, it affects all observations, including uncontaminated data. Additionally, its implicit regularizer cannot achieve sparsity, which is desirable in many practical scenarios. To address these issues, a novel M-estimator called hybrid ordinary-Welsch (HOW) function is developed, which only affects the outlier-contaminated data and generates a regularizer that guarantees sparsity. Experimental results demonstrate that the proposed approach outperforms state-of-the-art methods in terms of recovery accuracy and runtime.
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2023)
Article
Environmental Sciences
Ye Tao, Yuan Yuan, Yaojia Cui, Longwei Zhu, Zhuzi Zhao, Shuaishuai Ma, Zhaolian Ye, Xinlei Ge
Summary: This study conducted a comparison of PM2.5 and its chemical components in an industrial site and a suburban site in Changzhou, China, revealing higher PM2.5 concentration in the industrial area. Water-soluble inorganic ions were identified as the major contributors to PM2.5, alongside significant fractions of carbonaceous components. Various analytical techniques such as SP-AMS and PMF were employed to characterize the chemical composition and sources of PM2.5, showing contributions from multiple sources including secondary aerosols, biomass burning, and industrial emissions.
ATMOSPHERIC POLLUTION RESEARCH
(2021)
Article
Environmental Sciences
Pedro Trechera, Meritxell Garcia-Marles, Xiansheng Liu, Cristina Reche, Noemi Perez, Marjan Savadkoohi, David Beddows, Imre Salma, Mate Vorosmarty, Andrea Casans, Juan Andres Casquero-Vera, Christoph Hueglin, Nicolas Marchand, Benjamin Chazeau, Gregory Gille, Panayiotis Kalkavouras, Nikos Mihalopoulos, Jakub Ondracek, Nadia Zikova, Jarkko V. Niemi, Hanna E. Manninen, David C. Green, Anja H. Tremper, Michael Norman, Stergios Vratolis, Konstantinos Eleftheriadis, Francisco J. Gomez-Moreno, Elisabeth Alonso-Blanco, Holger Gerwig, Alfred Wiedensohler, Kay Weinhold, Maik Merkel, Susanne Bastian, Jean-Eudes Petit, Olivier Favez, Suzanne Crumeyrolle, Nicolas Ferlay, Sebastiao Martins Dos Santos, Jean-Philippe Putaud, Hilkka Timonen, Janne Lampilahti, Christof Asbach, Carmen Wolf, Heinz Kaminski, Hicran Altug, Barbara Hoffmann, David Q. Rich, Marco Pandolfi, Roy M. Harrison, Philip K. Hopke, Tuukka Petaja, Andres Alastuey, Xavier Querol
Summary: This study evaluated the hourly particle number size distributions (PNSD) from 26 sites in Europe and 1 in the US, focusing on urban background (UB) and traffic (TR) sites. The objective was to describe the characteristics of urban ultrafine particles (UFP) in Europe. The results showed variations in PNC and BC across different regions and site types, with traffic emissions being a major contributor. The study emphasized the need for specific monitoring of PNSD and measurements of <10 nm PNC for assessing the health effects of nanoparticles.
ENVIRONMENT INTERNATIONAL
(2023)
Article
Geology
Jing Li, Yang Lin, Xuanphu Nguyen, Xinguo Zhuang, Baoqing Li, Xavier Querol, Natalia Moreno, Patricia Cordoba
Summary: This paper investigates the mineralogical and geochemical characteristics of the Upper Triassic coal from the Nui Hong open-pit mine in Vietnam, and focuses on the enrichment of strategic metals in coal. The study finds significant enrichment of Mo, U, Ge, and Cs in the Nui Hong coal, which suggests the economic potential for extracting these metals from the coal. The Ge enrichment in the Nui Hong coal provides new insights for prospecting coal-hosted Ge deposits in high-rank coal.
ORE GEOLOGY REVIEWS
(2023)
Article
Environmental Sciences
Marten in't Veld, M. Pandolfi, F. Amato, N. Perez, C. Reche, P. Dominutti, J. Jaffrezo, A. Alastuey, X. Querol, G. Uzu
Summary: This study investigated the oxidative potential (OP) of ambient particulate matter (PM) in Barcelona and Montseny in Spain. The results showed that the OP of PM10 in Barcelona was much higher than that of PM2.5 and PM1, while in Montseny, the OP of all PM sizes was in the same range but significantly lower. The OP of PM in Barcelona was mainly driven by anthropogenic sources, while in Montseny, no clear drivers were identified.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Chemistry, Physical
Alon Khabra, Haim Cohen, Gad A. Pinhasi, Xavier Querol, Patricia Cordoba Sola, Tomer Zidki
Summary: Sulfur and nitrogen oxides (SOX/NOX) emissions from fuel combustion are major air toxic gas pollutants. Existing technologies for reducing SOX/NOX content are costly and require high operating temperatures. This study proposes SiO2/Co(OH)(2) nanocomposites as potential catalysts for SOX/NOX oxidation at lower temperatures using atmospheric oxygen as the oxidant, replacing expensive and hazardous oxidants. The nanocomposites exhibited excellent catalytic properties, suggesting their potential for simultaneous scrubbing of polluting gases in flue gases.
Article
Environmental Sciences
Jordi Massague, Miguel Escudero, Andres Alastuey, Enrique Mantilla, Eliseo Monfort, Gotzon Gangoiti, Carlos Perez Garcia-Pando, Xavier Querol
Summary: This study evaluates the spatial variation and trends of ground-level ozone (O3) in Spain to support the country's Ozone Mitigation Plan. The results show that O3 spatial variation depends on the part of the O3 distribution being analyzed. The study proposes a classification of atmospheric regions in Spain based on O3 pollution patterns, highlighting priority areas for O3 mitigation. The trends assessment reveals varying O3 trends among different hotspots, emphasizing the importance of designing local/regional mitigation measures.
ENVIRONMENT INTERNATIONAL
(2023)
Review
Environmental Sciences
Kaung Suu Lwin, Aurelio Tobias, Paul Lester Chua, Lei Yuan, Ramita Thawonmas, Sophearen Ith, Zin Wai Htay, Lin Szu Yu, Lisa Yamasaki, Marta Roque, Xavier Querol, Julia C. Fussell, Kari Christine Nadeau, Massimo Stafoggia, Najat A. Saliba, Chris Fook Sheng Ng, Masahiro Hashizume
Summary: This scoping review aims to identify the most likely health effects of desert dust and sandstorms and the methods used to characterize desert dust exposure. Over half of the studies reported significant associations between desert dust and adverse health effects, mainly for respiratory and cardiovascular mortality and morbidity causes. However, there are significant limitations in exposure measurement and statistical analysis in the existing epidemiological studies, potentially contributing to inconsistencies in determining the effect of desert dust on human health.
Article
Environmental Sciences
Marta Via, Jesus Yus-Diez, Francesco Canonaco, Jean-Eudes Petit, Philip Hopke, Cristina Reche, Marco Pandolfi, Matic Ivancic, Martin Rigler, Andre S. H. Prevot, Xavier Querol, Andres Alastuey, Maria Cruz Minguillon
Summary: In this study, the multi-time resolution (MTR) Positive Matrix Factorization (PMF) technique was applied to identify eight PM1 pollution sources in Barcelona, Spain, by combining high and low time resolution data. This approach proved to be more accurate and effective compared to conventional methods.
ENVIRONMENT INTERNATIONAL
(2023)
Article
Environmental Sciences
Xiansheng Liu, Hadiatullah Hadiatullah, Xun Zhang, Pedro Trechera, Marjan Savadkoohi, Meritxell Garcia-Marles, Cristina Reche, Noemi Perez, David C. S. Beddows, Imre Salma, Wanda Then, Panayiotis Kalkavouras, Nikos Mihalopoulos, Christoph Hueglin, David C. Green, Anja H. Tremper, Benjamin Chazeau, Gregory Gille, Nicolas Marchand, Jarkko Niemi, Hanna E. Manninen, Harri Portin, Nadezda Zikova, Jakub Ondracek, Michael Norman, Holger Gerwig, Susanne Bastian, Maik Merkel, Kay Weinhold, Andrea Casans, Juan Andres Casquero-Vera, Francisco J. Gomez-Moreno, Begona Artinano, Maria Gini, Evangelia Diapouli, Suzanne Crumeyrolle, Veronique Riffault, Jean-Eudes Petit, Olivier Favez, Jean-Philippe Putaud, Sebastiao Martins Dos Santos, Hilkka Timonen, Pasi P. Aalto, Tareq Hussein, Janne Lampilahti, Philip K. Hopke, Alfred Wiedensohler, Roy M. Harrison, Tuukka Petaja, Marco Pandolfi, Andres Alastuey, Xavier Querol
Summary: This study aims to analyze the phenomenology of urban ambient total lung deposited surface area (LDSA) based on multiple path particle dosimetry (MPPD) model. The study collected data from monitoring sites in Europe and USA during 2017-2019 period. The spatial-temporal distribution characteristics of LDSA deposition were analyzed, and the relationship between LDSA and other air quality metrics was investigated. The study provides valuable information for epidemiological studies and presents total LDSA in various European urban environments for the first time.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Marten in't Veld, Peeyush Khare, Yufang Hao, Cristina Reche, Noemi Perez, Andres Alastuey, Jesus Yus-Diez, Nicolas Marchand, Andre S. H. Prevot, Xavier Querol, Kaspar R. Daellenbach
Summary: This study found that organic aerosols (OA) are the dominant contributor to the oxidative potential of airborne particulate matter in northeastern Spain. The chemical composition of PM10 was analyzed at two sampling stations in Barcelona city and Montseny Natural Park, and it was found that Barcelona had significantly higher concentrations of water-soluble OA compared to Montseny due to the anthropogenic emissions in the city.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Review
Environmental Sciences
Dikaia E. Saraga, Xavier Querol, Regina M. B. O. Duarte, Noel J. Aquilina, Nuno Canha, Elena Gomez Alvarez, Milena Jovasevic-Stojanovic, Gabriel Beko, Steigvile Bycenkiene, Renata Kovacevic, Kristina Plauskaite, Nicola Carslaw
Summary: Source apportionment for indoor air pollution is challenging due to the complexity and variability of indoor sources, as well as the interconnectedness with the outdoor environment. This paper reviews the current understanding of source apportionment techniques, targeted pollutants, and identified sources, while highlighting limitations and knowledge gaps in this research field.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Cristina Gonzalez-Florez, Martina Klose, Andres Alastuey, Sylvain Dupont, Jeronimo Escribano, Vicken Etyemezian, Adolfo Gonzalez-Romero, Yue Huang, Konrad Kandler, George Nikolich, Agnesh Panta, Xavier Querol, Cristina Reche, Jesus Yus-Diez, Carlos Perez Garcia-Pando
Summary: The particle size distribution (PSD) of emitted mineral dust is dependent on factors such as friction velocity, wind direction, and event type. Dry deposition is identified as a potential cause for the variability in PSD. Dry deposition could represent a large proportion of the emission of both super-coarse particles and smaller particles. The differences in PSDs between regular events and haboob events may be due to differences in dust source fetch and resistance of soil aggregates to fragmentation.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Agnesh Panta, Konrad Kandler, Andres Alastuey, Cristina Gonzalez-Florez, Adolfo Gonzalez-Romero, Martina Klose, Xavier Querol, Cristina Reche, Jesus Yus-Diez, Carlos Perez Garcia-Pando
Summary: The chemical and morphological properties of mineral dust aerosols emitted by wind erosion from arid and semi-arid regions are crucial for understanding climate, ecosystems, air quality, and socio-economic sectors. In this study, we analyzed individual dust particles collected during a field campaign in the Moroccan Sahara to gain insights into their elemental composition and morphology. We identified eight major particle types and found that clay minerals and quartz were the dominant constituents. We also analyzed the mixing state and size distribution of iron-rich and feldspar particles, which are important for understanding the effects of dust on radiation and clouds.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Herve Petetin, Marc Guevara, Roger Garatachea, Franco Lopez, Kevin Oliveira, Santiago Enciso, Oriol Jorba, Xavier Querol, Jordi Massague, Andres Alastuey, Carlos Perez Garcia-Pando
Summary: Tropospheric ozone is a serious air pollutant that affects human health, vegetation, and climate in countries like Spain. A study conducted to support the Spanish O3 Mitigation Plan found that road transport and maritime traffic are the main contributors to ozone pollution. Although emission scenarios can reduce ozone concentrations, exceedances of air quality thresholds will still occur.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)