Atmospheric pollution in an urban environment by tree bark biomonitoring--part I: trace element analysis

Tree bark has been shown to be a useful biomonitor of past air quality because it accumulates atmospheric particulate matter (PM) in its outermost structure. Trace element concentrations of tree bark of more than 73 trees allow to elucidate the impact of past atmospheric pollution on the urban environment of the cities of Strasbourg and Kehl in the Rhine Valley. Compared to the upper continental crust (UCC) tree barks are strongly enriched in Mn, Ni, Cu, Zn, Cd and Pb. To assess the degree of pollution of the different sites in the cities, a geoaccumulation index I_geo was applied. Global pollution by V, Ni, Cr, Sb, Sn and Pb was observed in barks sampled close to traffic axes. Cr, Mo, Cd pollution principally occurred in the industrial area. A total geoaccumulation index I_GEO-tot was defined; it is based on the total of the investigated elements and allows to evaluate the global pollution of the studied environment by assembling the I_geo indices on a pollution map.     

监测数据反推下PM_(2.5)扩散模型及突发情况模拟

建立了PM2.5扩散模型和应急污染扩散评估方法。模型考虑了风向、风速、温度等影响,根据监测点位置和PM2.5浓度信息反推虚拟污染源位置及浓度信息;采用高斯扩散模型,得到稳定风向、风速、温度下的任意时间、接收点的PM2.5扩散衰减模型;突发情况下,用时间变量替换速度项,得到该地区时态变化的PM2.5变化规律。根据西北某城市PM2.5监测数据,建立了其四季PM2.5扩散衰减模型,并对其空气质量进行分级表征,同时对某监测点突发情况下PM2.5时空变化进行了预测评估。结果表明,该模型合理可行。     

西安大气气相中的多环芳烃

利用PUF被动采样器于2008年8月—2009年7月采集了西安大气样品,研究了大气气相中多环芳烃（PAHs）的含量和季节分布特征。结果表明,西安大气气相中16种美国EPA优控的PAHs（Σ16PAHs）质量浓度为10.9-489.6 ng/m3（平均为143.4 ng/m3）,四季具有明显的季节差异,依次为夏季（62.5 ng/m3）〈春季（80.1 ng/m3）〈秋季（175.8 ng/m3）〈冬季（255.2 ng/m3）。气相中PAHs主要以3-4环为主,占总量的86.5%-94.1%。利用主成分分析法判断四季气相中PAHs的污染来源类型,主要为燃煤和机动车尾气及生物质燃烧的复合源。     

A chemometric approach to the evaluation of atmospheric and fluvial pollutant inputs in aquatic systems: the Guadalquivir River estuary as a case study

To establish the quality of waters it is necessary to identify both point and non-point pollution sources. In this work, we propose the combination of clean analytical methodologies and chemometric tools to study discrete and diffuse pollution caused in a river by tributaries and precipitations, respectively.During a two-year period, water samples were taken in the Guadalquivir river (selected as a case study) and its main tributaries before and after precipitations. Samples were characterized by analysing nutrients, pH, dissolved oxygen, total and volatile suspended solids, carbon species, and heavy metals. Results were used to estimate fluvial and atmospheric inputs and as tracers for anthropic activities.Multivariate analysis was used to estimate the background pollution, and to identify pollution inputs. Principal Component Analysis and Cluster Analysis were used as data exploratory tools, while box-whiskers plots and Linear Discriminant Analysis were used to analyse and distinguish the different types of water samples.     

Identification of pollution sources in rivers using a hydrodynamic diffusion wave model and improved Bayesian-Markov chain Monte Carlo algorithm

● A hydrodynamic-Bayesian inference model was developed for water pollution tracking. ● Model is not stuck in local optimal solutions for high-dimensional problem. ● Model can estimate source parameters accurately with known river water levels. ● Both sudden spill incident and normal sewage inputs into the river can be tracked. ● Model is superior to the traditional approaches based on the test cases. Water quality restoration in rivers requires identification of the locations and discharges of pollution sources, and a reliable mathematical model to accomplish this identification is essential. In this paper, an innovative framework is presented to inversely estimate pollution sources for both accident preparedness and normal management of the allowable pollutant discharge. The proposed model integrates the concepts of the hydrodynamic diffusion wave equation and an improved Bayesian-Markov chain Monte Carlo method (MCMC). The methodological framework is tested using a designed case of a sudden wastewater spill incident (i.e., source location, flow rate, and starting and ending times of the discharge) and a real case of multiple sewage inputs into a river (i.e., locations and daily flows of sewage sources). The proposed modeling based on the improved Bayesian-MCMC method can effectively solve high-dimensional search and optimization problems according to known river water levels at pre-set monitoring sites. It can adequately provide accurate source estimation parameters using only one simulation through exploration of the full parameter space. In comparison, the inverse models based on the popular random walk Metropolis (RWM) algorithm and microbial genetic algorithm (MGA) do not produce reliable estimates for the two scenarios even after multiple simulation runs, and they fall into locally optimal solutions. Since much more water level data are available than water quality data, the proposed approach also provides a cost-effective solution for identifying pollution sources in rivers with the support of high-frequency water level data, especially for rivers receiving significant sewage discharges.     

2022年青岛市沿海区域臭氧污染特征及传输影响分析

基于2022年1—12月青岛市沿海区域臭氧（O₃）自动监测数据和气象观测资料,对O₃污染变化特征及影响因素进行了分析,结合后向轨迹聚类与潜在源区分析等方法,对O₃外来输送通道及潜在源分布情况进行分析研究。结果表明：青岛市沿海区域O₃污染主要集中在4—10月份,日变化特征呈单峰单谷趋势,峰值出现在15：00—16：00;气象因素中,地面短波辐射对O₃浓度变化的相对贡献最大,偏南风易导致O₃污染;受二氧化氮（NO₂）滴定作用以及海陆风转换影响,沿海区域O₃峰值与谷值均滞后青岛城区1 h左右;O₃生成整体处于VOCs控制区,1-丁烯、正丁烷与异戊烷是O₃污染期间导致O₃浓度上升的关键组分;O₃污染的主要潜在源区为长三角北部和黄海近岸海域,以及山东中南部地区。     

Urban soil quality of Raipur,Chhattisgarh, India

Soil quality in urban areas in India is degraded due to multiple anthropogenic activities. The objectives of this work are to determine the concentration variations, toxicity, and sources of carbons, metals, and ions in the surface soil of Raipur, the industrialized capital city of Chhattisgarh state, India. High concentrations of Al, K, Ca, Ti, Fe, and elemental carbon (EC) were registered. Relatively lower concentrations of V, Cr, Mn, Ni, Cu, Zn, Sr, Ba, Pb, organic carbon (OC), and carbonate carbon (CC), as well as ions (viz. F^–, Cl^–, NO₃^–, SO₄^2–, Na⁺, K⁺, Mg²⁺, and Ca²⁺), were also recorded. EC was found to be one of the major pollutants, although enrichment factors pointed to high contamination with SO₄^2–, K⁺, Mg²⁺_, Cr, Mn, and Pb; and extreme contamination with NO₃^– and Ca²⁺. The spatial and temporal variations, enrichment factors, toxicity, and sources of the chemical species detected in the soil are discussed.     

雅鲁藏布江上游夏季水化学特征及来源解析

为探究雅鲁藏布江上游干支流的无机水化学特征,于2020年8月在雅鲁藏布江上游河源和河流段采集干支流水样,分析了水体主要离子的化学组成和空间变化规律,并对离子来源进行了解析.结果表明,雅鲁藏布江上游干支流水体中的阴离子以HCO3、SO42为主,分别占阴离子总量的71.11％、23.16％;优势阳离子为Ca2+、Na+,分...     

用我国各地实测资料拟合的高架源大气扩散参数

采用Ｂｒｉｇｇｓ大气扩散参数的一般式（σ＝ａｘ（１＋βｘ）＾－１／２）将国内一些实测大气扩散参数组织拟合,求出高架源大气扩散参数。拟合大气扩散参数经与ＧＢ３８４０－９１和Ｂｒｉｇｇｓ大气扩散参数比较结果合理,一般适用于１００ｍ 以上的高架源扩散情况。因此在大气扩散计算中有实用价值。     

Genotoxicity evaluation and a primary risk assessment of organic pollutants in the drinking water sources of Nanjing, China

An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In this study, the comet assay was conducted to investigate the genotoxicity to human body caused by organic concentrates in the drinking water sources of Nanjing City from Yangtze River of China, and health and ecology risk due to expose to these organic pollutants were evaluated with the multimedia environmental assessment system （MEAS）. For all the water samples, they were collected from four different locations in the drinking water sourcr samples, es of Nanjing City. The results of the comet assay showed that all the organic concentrates from the water samples could induce different levels DNA damages on human peripheral blood lymphocytes, and a statistically significant difference （p〈0.01） was observed compared with the solvent control, which demonstrated the genotoxicity was in existence. According to the ambient severity （AS） of individual compound, we had sorted out the main organic pollutants in the drinking water source of the four waterworks, and the results showed that there was some potential hazard to human body for all the source water, namely the total ambient severity （TAS） of health for each water source was more than 1. However, the TAS of ecology for each water source was less than 1, which indicated that it was safe to ecology. The results of this investigation demonstrate the application of the comet assay and the MEAS in aquatic environmental monitoring studies, and the comet assay found to be fast, sensitive, and suitable for genotoxicity monitoring programs of drinking water source.