Groundwater quality assessment and pollution source apportionment in an intensely exploited region of northern China

Deterioration in groundwater quality has attracted wide social interest in China. In this study, groundwater quality was monitored during December 2014 at 115 sites in the Hutuo River alluvial-pluvial fan region of northern China. Results showed that 21.7% of NO₃ ^? and 51.3% of total hardness samples exceeded grade III of the national quality standards for Chinese groundwater. In addition, results of gray relationship analysis (GRA) show that 64.3, 10.4, 21.7, and 3.6% of samples were within the I, II, IV, and V grades of groundwater in the Hutuo River region, respectively. The poor water quality in the study region is due to intense anthropogenic activities as well as aquifer vulnerability to contamination. Results of principal component analysis (PCA) revealed three major factors: (1) domestic wastewater and agricultural runoff pollution (anthropogenic activities), (2) water-rock interactions (natural processes), and (3) industrial wastewater pollution (anthropogenic activities). Using PCA and absolute principal component scores-multivariate linear regression (APCS-MLR), results show that domestic wastewater and agricultural runoff are the main sources of groundwater pollution in the Hutuo River alluvial-pluvial fan area. Thus, the most appropriate methods to prevent groundwater quality degradation are to improve capacities for wastewater treatment and to optimize fertilization strategies.     

Combined source apportionment,using positive matrix factorization–chemical mass balance and principal component analysis/multiple linear regression–chemical mass balance models

The methods of positive matrix factorization–chemical mass balance and principal component analysis/multiple linear regression–chemical mass balance were studied in this paper, for combined source apportionment. Due to the high similarity among the source profiles, several problems would raised when only one receptor model was applied. For example, the collinearity problem would result in the negative contributions when applying CMB model; certain sources would not to be separated out when applying PCA or PMF model. In this study, PCA/MLR–CMB model and PMF–CMB were attempted to resolve the problem, where the combined models were applied to study the synthetic and ambient datasets. In synthetic dataset, there were seven sources (six actual sources from real world, and one unknown source). The results obtained by the combined models show that the combined source apportionment technique is feasible. In addition, an ambient dataset from a northern city in China was analyzed by PCA/MLR–CMB model and PMF–CMB model, and these two models got the similar results. The results show that coal combustion contributed the largest fraction to the total mass.     

Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at the University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed.     

Composition analysis of PM2.5 at multiple sites in Zhengzhou,China: implications for characterization and source apportionment at different pollution levels

Environmental Science and Pollution Research - Zhengzhou is one of the most heavily polluted cities in China. This study collected samples of PM2.5 (atmospheric fine particulate matter with...     

Source apportionment of ambient non-methane hydrocarbons in Hong Kong: application of a principal component analysis/absolute principal component scores (PCA/APCS) receptor model

Receptor-oriented source apportionment models are often used to identify sources of ambient air pollutants and to estimate source contributions to air pollutant concentrations. In this study, a PCA/APCS model was applied to the data on non-methane hydrocarbons (NMHCs) measured from January to December 2001 at two sampling sites: Tsuen Wan (TW) and Central & Western (CW) Toxic Air Pollutants Monitoring Stations in Hong Kong. This multivariate method enables the identification of major air pollution sources along with the quantitative apportionment of each source to pollutant species. The PCA analysis identified four major pollution sources at TW site and five major sources at CW site. The extracted pollution sources included vehicular internal engine combustion with unburned fuel emissions, use of solvent particularly paints, liquefied petroleum gas (LPG) or natural gas leakage, and industrial, commercial and domestic sources such as solvents, decoration, fuel combustion, chemical factories and power plants. The results of APCS receptor model indicated that 39% and 48% of the total NMHCs mass concentrations measured at CW and TW were originated from vehicle emissions, respectively. 32% and 36.4% of the total NMHCs were emitted from the use of solvent and 11% and 19.4% were apportioned to the LPG or natural gas leakage, respectively. 5.2% and 9% of the total NMHCs mass concentrations were attributed to other industrial, commercial and domestic sources, respectively. It was also found that vehicle emissions and LPG or natural gas leakage were the main sources of C(3)-C(5) alkanes and C(3)-C(5) alkenes while aromatics were predominantly released from paints. Comparison of source contributions to ambient NMHCs at the two sites indicated that the contribution of LPG or natural gas at CW site was almost twice that at TW site. High correlation coefficients (R(2) > 0.8) between the measured and predicted values suggested that the PCA/APCS model was applicable for estimation of sources of NMHCs in ambient air.     

成都市冬季重污染过程中挥发性有机物污染特征及来源解析

采用大气挥发性有机物(VOCs)在线监测系统对成都市冬季重污染过程的VOCs进行了连续在线观测,用正交矩阵因子分解(PMF)模型开展了VOCs源解析工作,并对重污染成因进行了分析。结果表明:观测期间成都市总VOCs(TVOCs)体积分数为21.83×10~(-9)～183.59×10~(-9),平均值为54.17×10~(-9),TVOCs中烷烃浓度最高,其次为炔烃、烯烃、芳香烃和卤代烃;成都市主要VOCs污染源为机动车排放源、液化石油气燃烧排放源、工业源、生物质燃烧源和溶剂使用源,贡献率分别为34.15%、21.57%、19.08%、15.19%、10.02%;边界层压缩和静风条件可能是导致VOCs和PM2.5浓度增加的主要原因。     

GIS-based source identification and apportionment of diffuse water pollution: perfluorinated compound pollution in the Tokyo Bay basin

To efficiently reduce perfluorinated compound (PFC) pollution, it is important to have an understanding of PFC sources and their contribution to the pollution. In this study, source identification of diffuse water pollution by PFCs was conducted using a GIS-based approach. Major components of the source identification were collection of the monitoring data and preparation of the corresponding geographic information that was extracted from a constructed GIS database. The spatially distributed pollution factors were then explored by multiple linear regression analysis, after which they were visually expressed using GIS. Among the 35 PFC homologues measured in a survey of the Tokyo Bay basin, 18 homologues were analyzed. Pollution by perfluorooctane sulfonate (PFOS) was explained well by the percentage of arterial traffic area in the basin, and the 84% variance of the measured PFOS concentration was explained by two geographic variables, arterial traffic area and population. Source apportionment between point and nonpoint sources was conducted based on the results of the analysis. The contribution of PFOS from nonpoint sources was comparable to that from point sources in several major rivers flowing into Tokyo Bay. Source identification and apportionment using the GIS-based approach was shown to be effective, especially for ubiquitous types of pollution, such as PFC pollution.     

Hydrochemical appraisal of groundwater quality and pollution source analysis of oil field area: a case study in Daqing City,China

Environmental Science and Pollution Research - Serious groundwater pollution not only affects the development of enterprises but also threatens the life and health of residents. To explore the...     

Characteristics and source apportionment of VOCs measured in Shanghai,China

Volatile organic compounds (VOCs) were measured from 2007 to 2010 at the center of Shanghai, China. Because VOCs are important precursors for ozone photochemical formation, detailed information of VOC sources needs to be investigated. The results show that the measured VOC concentrations in Shanghai are dominated by alkanes (43%) and aromatics (30%), following by halo-hydrocarbons (14%) and alkenes (6%). Based on the measured VOC concentrations, a receptor model (PMF; positive matrix factorization) coupled with the information related to VOC sources (the distribution of major industrial complex, meteorological conditions, etc.) is applied to identify the major VOC sources in Shanghai. The result shows that seven major VOC sources are identified by the PMF method, including (1) vehicle related source which contributes to 25% of the measured VOC concentrations, (2) solvent based industrial source to 17%, (3) fuel evaporation to 15%, (4) paint solvent usage to 15%, (5) steel related industrial production to 12%, (6) biomass/biofuel burning to 9%, and (7) coal burning to 7%. Furthermore, ozone formation potential related to VOC sources is calculated by the MIR (maximum incremental reactivity) technique. The most significant VOC source for ozone formation potential is solvent based industrial sources (27%), paint solvent usage (24%), vehicle related emissions (17%), steel related industrial productions (14%), fuel evaporations (9%), coal burning (6%), and biomass/biofuel burning (3%). The weekend effect on the VOC concentrations shows that VOC concentrations are generally higher in the weekdays than in the weekends at the sampling site, suggesting that traffic conditions and human activities have important impacts on the VOC emissions in Shanghai.     

Source apportionment analysis of atmospheric particulates in an industrialised urban site in southwestern Spain

A detailed physical and chemical characterisation of total suspended particles (TSP) in the highly industrialised city of Huelva (southwestern Spain) was carried out. The results evidenced a coarse grain-size prevalence (PM₁₀ accounting for only 40% of TSP mass, 37 and 91 μg/m³, respectively). PM₁₀ levels are in the usual range for urban background sites in Spain. The crustal, anthropogenic and marine components accounted for a mean of a 40%, 24% and 5% of bulk TSP, respectively. As expected from the industrial activities, relatively high PO₄³⁻ and As levels for an urban site were detected. In addition to the crustal and marine components, source apportionment analysis revealed three additional emission sources influencing the levels and composition of TSP: (a) a petrochemical source, (b) a mixed metallurgical-phosphate source, (c) and an unknown source (Sb and NO₃⁻).Due to the high local emissions, the mean TSP anthropogenic contribution (mostly PM₁₀) obtained for all possible air mass transport scenarios reached 18–29 μg/m³. The 2010 annual EU PM₁₀ limit value (20 μg/m³) would be exceeded by the anthropogenic load recorded for all the air mass transport scenarios, with the exception of the North Atlantic transport (only 15% of the sampling days). Under African air mass transport scenarios (20% of sampling days), the TSP crustal contribution reached near three times the local crustal contribution. It must be pointed out that this crustal input should diminish when sampling PM₁₀ due to the dominant coarse size distribution of this type of particles.     

Seasonal variations and source apportionment of atmospheric PM2.5-bound polycyclic aromatic hydrocarbons in a mixed multi-function area of Hangzhou,China

Environmental Science and Pollution Research - To reveal the seasonal variations and sources of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) during haze and non-haze episodes, daily PM2.5...     

Spatial distribution and source apportionment of water pollution in different administrative zones of Wen-Rui-Tang (WRT) river watershed, China

Water quality degradation in river systems has caused great concerns all over the world. Identifying the spatial distribution and sources of water pollutants is the very first step for efficient water quality management. A set of water samples collected bimonthly at 12 monitoring sites in 2009 and 2010 were analyzed to determine the spatial distribution of critical parameters and to apportion the sources of pollutants in Wen-Rui-Tang (WRT) river watershed, near the East China Sea. The 12 monitoring sites were divided into three administrative zones of urban, suburban, and rural zones considering differences in land use and population density. Multivariate statistical methods [one-way analysis of variance, principal component analysis (PCA), and absolute principal component score—multiple linear regression (APCS-MLR) methods] were used to investigate the spatial distribution of water quality and to apportion the pollution sources. Results showed that most water quality parameters had no significant difference between the urban and suburban zones, whereas these two zones showed worse water quality than the rural zone. Based on PCA and APCS-MLR analysis, urban domestic sewage and commercial/service pollution, suburban domestic sewage along with fluorine point source pollution, and agricultural nonpoint source pollution with rural domestic sewage pollution were identified to the main pollution sources in urban, suburban, and rural zones, respectively. Understanding the water pollution characteristics of different administrative zones could put insights into effective water management policy-making especially in the area across various administrative zones.     

Fine particulate source apportionment using data from the USEPA speciation trends network in Chicago,Illinois: Comparison of two source apportionment models

Data from two of the United States Environmental Protection Agency's speciation trends network fine particulate matter sites within Chicago, Illinois were analyzed using the chemical mass balance (CMB) and positive matrix factorization (PMF) models to determine source contributions to the ambient fine particulate concentrations. The results from the two models were compared to determine the similarities and differences in the source contributions. This included examining the differences in the magnitude of the individual source contributions as well as the correlation between the contribution values from the two methods. The results showed that both models predicted sulfates, nitrates and motor vehicles as the three highest fine particle contributors for the two sites accounting for approximately 80% of the total. The PMF model attributed a slightly greater amount of fine particulate to the road salt, steel and soil sources while vegetative burning contributed more in the CMB results. Correlations between the contribution results from the two models were high for sulfates, nitrates and road salt with very good correlations existing for motor vehicles and petroleum refineries. The predicted PMF profiles agreed well with measured source profiles for the major species associated with each source.     

太原市降水化学特征及来源分析

本研究采集了2012年3—11月间35场太原降水样品,探讨了pH值、电导率和水溶性化学组成特征.结果表明,降水pH加权平均值为5.27;电导率平均值为98.8 μS/cm,表明大气污染显著;SO42-(471.8 μeq/L)、NO3-(93.6 μeq/L)、Ca2+(477.4 μeq/L)和NH4+(133.4 μeq/L)是太原降水的主导离子,4种离子占总离子浓度的85%.SO42-/NO3-当量浓度比为4.38,比太原市1986年的比值(19.02)下降了77%.太原降水的酸性仍以SO42-主导,但NO3-比例大幅上升.降水离子相关性分析和气团后向轨迹表明太原市大气污染物主要来自自身排污企业(热电厂、钢铁厂等)污染物的扩散以及省内焦化企业污染物的输送等小尺度区域内.太原市硫的湿沉降量为1.93 t/(km2·a);氮湿沉降量为1.54 t/(km2·a),其中铵态氮和硝态氮分别为1.28 t/(km2·a)和0.26 t/(km2·a);钙为5.87 t/(km2·a).     

Nonpoint source pollution of urban stormwater runoff: a methodology for source analysis

The characterization and control of runoff pollution from nonpoint sources in urban areas are a major issue for the protection of aquatic environments. We propose a methodology to quantify the sources of pollutants in an urban catchment and to analyze the associated uncertainties. After describing the methodology, we illustrate it through an application to the sources of Cu, Pb, Zn, and polycyclic aromatic hydrocarbons (PAH) from a residential catchment (228 ha) in the Paris region. In this application, we suggest several procedures that can be applied for the analysis of other pollutants in different catchments, including an estimation of the total extent of roof accessories (gutters and downspouts, watertight joints and valleys) in a catchment. These accessories result as the major source of Pb and as an important source of Zn in the example catchment, while activity-related sources (traffic, heating) are dominant for Cu (brake pad wear) and PAH (tire wear, atmospheric deposition).     

浙东沿海城市大气颗粒物污染特征及来源解析研究

对2009年夏季浙东沿海地区环境空气质量进行监测,监测大气颗粒物(TSP、PM10、PM2.5、PM1.0)浓度,分析颗粒物污染特征、水溶性离子及无机元素组成,运用化学质量平衡受体模型(CMB模型)对浙东沿海地区大气TSP来源进行解析.结果表明,浙东沿海地区的大气颗粒物主要以细颗粒物为主,颗粒物中主要的水溶性离子为SO2-4、NH+4、Ca2+,土壤尘是该地区大气TSP的主要来源,北仑、乐清和奉化TSP中土壤尘的分担率分别达到55.49%、42.52%、40.70%,各监测点TSP来源具有一定的地域特征.     

Absolute principal component analysis of atmospheric aerosols in Mexico city

A receptor model is presented based on absolute principal component analysis (APCA) of elemental concentrations in atmospheric aerosols from Mexico City during the Summer of 1995. Elemental contents on samples collected with a Stacking Filter Unit of the Davis design was carried out using Particle Induced X-ray Emission (PIXE). The sampling device allowed the separation of particles with mean aerodynamic diameters ranging from 2.5 μm to 15 μm (coarse fraction) and smaller than 2.5 μm (fine fraction). Sampling was divided into morning, afternoon and night periods, with higher concentrations being found during the morning. Seasonal variation is observed when comparisons with other studies are carried out. The application of APCA allowed identification of four sources for each fraction, with a soil-derived dust predominance in the coarse one. The influence of meteorological parameters is studied using cluster analysis, showing that during the morning there is a transport of pollutants from the west towards the sampling site, while the night transport corresponds to soil-derived dust from the north.     

Chemical composition and source apportionment of PM2.5 particles in the Sihwa area, Korea

To investigate the chemical characteristics of fine particles in the Sihwa area, Korea, atmospheric aerosol samples were collected using a dichotomous PM10 sampler and two URG PM2.5 cyclone samplers during five intensive sampling periods between February 1998 and February 1999. The Inductively Coupled Plasma (ICP)-Atomic Emission Spectrometry (AES)/ICP-Mass Spectrometry (MS), ion chromatograph (IC), and thermal manganese dioxide oxidation (TMO) methods were used to analyze the trace elements, ionic species, and carbonaceous species, respectively. Backward trajectory analysis, factor analysis, and a chemical mass balance (CMB) model were used to estimate quantitatively source contributions to PM2.5 particles collected in the Sihwa area. The results of PM2.5 source apportionment using the CMB7 receptor model showed that (NH4)2SO4 was, on average, the major contributor to PM2.5 particles, followed by nontraffic organic carbon (OC) emission, NH4NO3, agricultural waste burning, motor vehicle emission, road dust, waste incineration, marine aerosol, and others. Here, the nontraffic OC sources include primary anthropogenic OC emitted from the industrial complex zone, secondary OC, and organic species from distant sources. The source impact of waste incineration emission became significant when the dominant wind directions were from southwest and west sectors during the sampling periods. It was found that PM2.5 particles in the Sihwa area were influenced mainly by both anthropogenic local sources and long-range transport and transformation of air pollutants.     

重庆主城区大气重污染形势的激光雷达探测与分析

2013年1月12日-26日,利用大气超级站ALS300型激光雷达对重庆主城区大气进行了连续探测,分析了重污染形势期间的大气扩散条件及大气颗粒物时空分布等探测结果。分析表明,大气层结持续稳定,扩散条件差使得大气颗粒物浓度居高不下,大气能见度持续恶化;大气重污染期间PBL高度较低,平均为320～350m;大气颗粒物污染带处于100～400m高度范围;全国范围内异常的大气环流形势和重庆主城区独特的地形、气候特征是造成持续大气重污染形势的原因。     

Characterization and source apportionment of wintertime aerosol in a wood-burning community

The continuing upsurge in residential wood combustion has raised questions about potential adverse effects on ambient air quality. A study to investigate the effects of wood-burning emissions on ambient aerosol concentrations was conducted in Waterbury, Vermont, from January to March 1982. Data on total, inhalable and respirable particles (24-h averages) were collected at a central monitoring site and augmented with similar measurements at two auxiliary stations. Mass concentrations were determined gravimetrically and selected samples were analyzed for elemental composition (XRF), polycyclic aromatic hydrocarbons (GC/MS, HPLC), and organic and elemental carbon (thermal-optical method). In addition, continuous data from an integrating nephelometer and a meteorological data acquisition system were collected at the central site. This paper presents results of organic and elemental characterization of wintertime aerosol and examines several different source-apportionment methods, focusing on the contribution of residential wood combustion to measured ambient concentrations.