Year-round observation of atmospheric inorganic aerosols in urban Beijing: Size distribution, source analysis, and reduction mechanism

To investigate particle characteristics and find an effective measure to control severe particle pollution, year-round observation of size-segregated inorganic aerosols was conducted in Beijing from January to December, 2016. The sampled atmospheric particles all presented bimodal size distribution at four pollution levels (clear, slight pollution, moderate pollution and severe pollution), and peak values appeared at the size range of 0.7-2.1 μm and >9.0 μm, respectively. As dominant particle compositions, NO₃⁻, SO₄²⁻, and NH₄⁺ in four pollution levels all showed significant peaks in fine mode, especially at the size range of 1.1-2.1 μm. Secondary inorganic aerosols accounted for about 67.6% (36.3% (secondary sulfates) + 31.3% (secondary nitrates)) of the total sources of fine particles in urban Beijing. Severe pollution of fine particles was mainly caused by the air masses transported from nearby western and southern areas, which are industrial and densely populated region, respectively. Sensitivity tests further revealed that the control measures focusing on ammonium emission reduction was the most effective for particle pollution mitigation, and fine particles all showed nonlinear responses after reducing ammonium, nitrate, and sulfate concentrations, with the fitting curves of y = -120.8x - 306.1x² + 290.2x³, y = -43.5x - 67.8x², and y = -25.8x - 110.4x² + 7.6x³, respectively (y and x present fine particle mass variation (μg/m³) and concentration reduction ratio (CRR)/100 (dimensionless)). Overall, our study presents useful information for understanding the characteristics of atmospheric inorganic aerosols in urban Beijing, as well as offers policy makers with effective measure for mitigating particle pollution.     

Investigation of PM2.5 pollution during COVID-19 pandemic in Guangzhou, China

The COVID-19 pandemic has raised awareness about various environmental issues, including PM_2.5 pollution. Here, PM_2.5 pollution during the COVID-19 lockdown was traced and analyzed to clarify the sources and factors influencing PM_2.5 in Guangzhou, with an emphasis on heavy pollution. The lockdown led to large reductions in industrial and traffic emissions, which significantly reduced PM_2.5 concentrations in Guangzhou. Interestingly, the trend of PM_2.5 concentrations was not consistent with traffic and industrial emissions, as minimum concentrations were observed in the fourth period (3/01-3/31, 22.45 μg/m³) of the lockdown. However, the concentrations of other gaseous pollutants, e.g., SO₂, NO₂ and CO, were correlated with industrial and traffic emissions, and the lowest values were noticed in the second period (1/24-2/03) of the lockdown. Meteorological correlation analysis revealed that the decreased PM_2.5 concentrations during COVID-19 can be mainly attributed to decreased industrial and traffic emissions rather than meteorological conditions. When meteorological factors were included in the PM_2.5 composition and backward trajectory analyses, we found that long-distance transportation and secondary pollution offset the reduction of primary emissions in the second and third stages of the pandemic. Notably, industrial PM_2.5 emissions from western, southern and southeastern Guangzhou play an important role in the formation of heavy pollution events. Our results not only verify the importance of controlling traffic and industrial emissions, but also provide targets for further improvements in PM_2.5 pollution.     

Identification of unknown disinfection byproducts in drinking water produced from Taihu Lake source water

Although disinfection byproducts(DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry(LC-QTOF MS) to identify the unknown disinfection byproducts(DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surroundi...     

卢氏县集中式饮用水水源保护区划分研究

划分水源地保护区是保障饮用水资源可持续利用的重要措施。在卢氏县集中式饮用水水源保护区的划分工作中,根据《饮用水水源保护区划分技术规范》(HJ/T338-2007),采用现场调研和卫星遥感技术相结合的方法,结合饮用水水源保护区的地形、地标、地物的特点,科学地对卢氏县地下水型、河流型、湖泊型水源地进行保护区划分,并提出卢氏县饮用水水源保护区范围、面积及目标,为卢氏县饮用水源保护规划奠定了理论基础。针对卢氏县饮用水源的特点,提出可行的建议和措施,为下一步饮用水源的保护提供科学依据。     

Occurrence, source diagnosis, and biological effect assessment of DDT and its metabolites in various environmental compartments of the Pearl River Delta, South China: A review

This review summarizes and analyzes available data in the literature (mostly after 2000) on the occurrence of dichlorodiphenyltrichloroethane (DDT) and its main metabolites, dichlorodiphenyldichloroethane (DDD) and chlorodiphenyldichloroethylene (DDE), in the environment of the Pearl River Delta (PRD), South China. Generally, the concentration levels of the sum of DDT, DDD, and DDE, designated as DDTs thereafter, have not significantly declined since 1983. However, the composition of DDTs residues has changed with time. DDTs in soil, freshwater sediment and freshwater fish species were mainly residues from chronological use. There is evidence that new point sources, such as dicofol and anti-fouling paint, may have contributed DDTs to various environmental compartments. Risk assessment against existing criteria indicated that the levels of DDTs in water and some fish species may pose adverse effects to humans or wildlife, and those in sediment/soil may also cause negative impacts to the eco-environment of the PRD.     

“加压上浮法”应急除藻技术在水源地的应用示范

近年来,太湖蓝藻水华问题日趋严峻,除藻技术是解决该问题最直接而有效的手段,对现有各类除藻技术进行了比较,并以"加压上浮法"应急除藻技术在苏州阳澄湖局部地区的示范工程为例,介绍了该方法的技术原理、技术实现以及在工程应用中的实际意义,为同行在水源地或特殊功能区除藻技术的应用提供参考。     

水质自动监测在苏州市饮用水源地的应用与思考

以苏州市集中式饮用水源地自动监测系统为例,对该水质自动监测系统的特点、主要功能及在环境管理、蓝藻实时监控等方面的应用作了介绍,并就系统验收、运行管理及系统拓展方面提出了一些对策建议。     

海门市长江水厂饮用水源地富营养化调查及污染防治对策研究

采用综合营养状态指数法对2008年至2011年海门市长江水厂饮用水源地水质状况进行评价，结果表明，该水源地已呈现出富营养化的发展趋势。结合饮用水源地现状，必须采取控制外源和内源的排放、恢复生态系统等措施，遏止水体富营养化，确保人民群众的饮用水源安全。     

用Ames试验检测水源水和自来水中的遗传毒性

用微伤寒沙门氏菌／哺乳动物微粒体酶系的Ａｍａｅｓ试验，研究了不同季节物水源水及管网自来水中的遗传毒性，以ＸＡＤ２树脂为吸附剂，以丙酮－甲醇的混合液为洗脱液，浓率水样中的有机物，并对部分阳性水样进行有机成分的定性分析。结果发现：１３个水样中有７个样品在淡需要代谢活化系统Ｓ９的情况下，可诱导鼠伤寒沙门氏菌碱基移码型菌株的回复突变；不同水样在不同季节不同的诱导作用；同时通过ＧＣ／ＭＳ方法分析，发现阳性水     

Compositional Changes of Aromatic Steroid Hydrocarbons in Naturally Weathered Oil Residues in the Egyptian Western Desert

Naturally weathered oil residues from an arid dumpsite in Al-Alamein, Egypt were analyzed for monoaromatic and triaromatic steranes to demonstrate the utility of biomarker compounds in assessing the chemical composition changes during the degradation of the released oil residues in a terrestrial environment. The characterizations of individual aromatic compounds were based on gas chromatography/mass spectrometry (GC/MS) analyses. The results showed that triaromatic sterane distributions were similar in the oil residues of varying weathering degradation extents and correlated with a fresh crude oil sample of the Western Desert-sourced oil. Molecular ratios of triaromatic sterane compounds (ratios of C 28 20R /C 28 20S , C 27 20R /C 28 20R , and C 28 20S /[C 26 20R + C 27 20S ]) were proved to be suitable for source identification. Major changes in chemical compositions during weathering of the oil residues were the depletion of short chain mono- and tri-aromatic steranes in samples that had undergone extensive degradation. The results of triaromatic sterane distribution are in good agreement with weathering classification based on the analyses of saturate and aromatic hydrocarbons and the ratios of n -alkanes, PAHs and saturate biomarker compounds.