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911.
Xiaojing SHEN Junying SUN Xiaoye ZHANG Yangmei ZHANG Lu ZHANG Ruxia FAN 《Frontiers of Environmental Science & Engineering》2016,10(5):5
New particle formation (NPF) event at multi rural sites in China Identifying the characteristics of NPF event Comparing NPF event between clean and polluted conditions Quantifying contribution to the cloud condensation nuclei Implication of climate and air quality Long-term continuous measurements of particle number size distributions with mobility diameter sizes ranging from 3 to 800 nm were performed to study new particle formation (NPF) events at Shangdianzi (SDZ), Mt. Tai (TS), and Lin’an (LAN) stations representing the background atmospheric conditions in the North China Plain (NCP), Central East China (CEC), and Yangtze River Delta (YRD) regions, respectively. The mean formation rate of 3-nm particles was 6.3, 3.7, and 5.8 cm−3·s−1, and the mean particle growth rate was 3.6, 6.0, and 6.2 nm·h−1 at SDZ, TS, and LAN, respectively. The NPF event characteristics at the three sites indicate that there may be a stronger source of low volatile vapors and higher condensational sink of pre-existing particles in the YRD region. The formation rate of NPF events at these sites, as well as the condensation sink, is approximately 10 times higher than some results reported at rural/urban sites in western countries. However, the growth rates appear to be 1–2 times higher. Approximately 12%–17% of all NPF events with nucleated particles grow to a climate-relevant size (>50 nm). These kinds of NPF events were normally observed with higher growth rate than the other NPF cases. Generally, the cloud condensation nuclei (CCN) number concentration can be enhanced by approximately a factor of 2–6 on these event days. The mean value of the enhancement factor is lowest at LAN (2–3) and highest at SDZ (~4). NPF events have also been found to have greater impact on CCN production in China at the regional scale than in the other background sites worldwide. 相似文献
912.
913.
Tilman Floehr Hongxia Xiao Björn Scholz-Starke Lingling Wu Junli Hou Daqiang Yin Xiaowei Zhang Rong Ji Xingzhong Yuan Richard Ottermanns Martina Roß-Nickoll Andreas Schäffer Henner Hollert 《Environmental science and pollution research international》2013,20(10):6934-6971
The Yangtze River has been a source of life and prosperity for the Chinese people for centuries and is a habitat for a remarkable variety of aquatic species. But the river suffers from huge amounts of urban sewage, agricultural effluents, and industrial wastewater as well as ship navigation wastes along its course. With respect to the vast amounts of water and sediments discharged by the Yangtze River, it is reasonable to ask whether the pollution problem may be solved by simple dilution. This article reviews the past two decades of published research on organic pollutants in the Yangtze River and several adjacent water bodies connected to the main stream, according to a holistic approach. Organic pollutant levels and potential effects of water and sediments on wildlife and humans, measured in vitro, in vivo, and in situ, were critically reviewed. The contamination with organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans, polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), and others, of water and sediment along the river was described. Especially Wuhan section and the Yangtze Estuary exhibited stronger pollution than other sections. Bioassays, displaying predominantly the endpoints mutagenicity and endocrine disruption, applied at sediments, drinking water, and surface water indicated a potential health risk in several areas. Aquatic organisms exhibited detectable concentrations of toxic compounds like PCBs, OCPs, PBDEs, and PFCs. Genotoxic effects could also be assessed in situ in fish. To summarize, it can be stated that dilution reduces the ecotoxicological risk in the Yangtze River, but does not eliminate it. Keeping in mind an approximately 14 times greater water discharge compared to the major European river Rhine, the absolute pollution mass transfer of the Yangtze River is of severe concern for the environmental quality of its estuary and the East China Sea. Based on the review, further research needs have been identified. 相似文献
914.
915.
用核子微探针进行单个大气颗粒物的分析 总被引:7,自引:1,他引:7
本文对单个大气颗粒物进行了分析研究,用核子微探针对首钢地区单个大气颗粒物进行了扫描分析,用三维等高线法给出了各种元素在一群单个大气颗粒物中的二维分布。从一群单个大气颗粒物中各元素的二维分布可对首钢地区大气污染的特征及来源进行分析研究。 相似文献
916.
珠三角城市群典型城市土壤邻苯二甲酸酯污染特征 总被引:20,自引:1,他引:20
选择了经济相对发达的珠江三角洲城市群中的典型中小城市的菜园和果园表层土壤(0~20 cm)进行调查取样,采用气相色谱法,对土壤样品中的16种邻苯二甲酸酯(PAEs)进行了测定,分析了其分布特征,并初步探讨了本区域的PAEs的污染控制问题.结果表明:在珠三角城市中,东莞土壤的PAEs含量最高,各地土壤中的PAEs均值高低顺序依次为东莞>深圳(珠海)>中山(惠州);菜园土壤中的平均PAEs含量比果园高37%左右;从珠三角城市菜地和果园的平均PAEs分布来看,东莞和深圳的菜地PAEs明显高于果园;珠海、中山和惠州菜地的平均PAEs与果园基本持平.16种PAEs类化合物在珠江三角洲不同城市的分布的差异非常大,不同城市所受到的主要PAEs化合物污染的种类不同;与美国土壤PAEs控制标准相比,珠三角城市果园和菜地土壤的PAEs主要为DEP和DnBP超标,这两类PAEs化合物应该成为重点的污染控制对象. 相似文献
917.
沉积物中多环芳烃和有机氯农药定量分析的质量保证和质量控制 总被引:118,自引:8,他引:118
以美国EPA为方法为基础,进行了沉积物中多环芳烃和有机氯农药分析的质量保证和质量控制实验,采用回收率指示物控制回收率,用内标法定量。结果表明多环芳烃的指示物回收率为50.67-97.33%,目标化合物的回收率为58.67-96.33%,方法检测限为3.30-9.26μg.kg^-1。 相似文献
918.
919.
Yuqing Xu Zedong Lu Wenjun Sun Xiaohui Zhang 《Frontiers of Environmental Science & Engineering》2021,15(6):131
920.
Occurrence of PAHs, PCBs and organochlorine pesticides in the Tonghui River of Beijing, China 总被引:48,自引:0,他引:48
Tonghui River, a typical river in Beijing, People's Republic of China, was studied for its water and sediment quality, by determining the levels of 16 polycyclic aromatic hydrocarbons (PAHs), 12 polychlorinated biphenyls (PCBs) and 18 organochlorine pesticides in water and sediment samples. Total PAHs, PCBs and organochlorine pesticides concentrations in water varied from 192.5 to 2651 ng/l, 31.58-344.9 ng/l and 134.9-3788 ng/l, respectively. The total PAHs, PCBs and organochlorine pesticides concentrations in surficial sediments were 127-928 ng/g, 0.78-8.47 ng/g and 1.79-13.98 ng/g dry weight, respectively. The results showed that the concentration of these selected organic pollutants in sediment was higher than those in surface water. It may be due to the fact that organic hydrophobic pollutants tend to stay in the sediments. The PAHs were dominated by 2-, 3-ring components in water samples and by 3- and 4-ring compounds in sediment. For organochlorines, alpha-HCH, delta-HCH, Heptachlor, Endosulfan II, DDT are the major organochlorine pesticides in water while Heptachlor, Dieldrin and DDE composed of 95% of total organochlorine pesticides in sediment. For HCHs (HCHs=alpha-HCH+beta-HCH+gamma-HCH+delta-HCH), the predominance of alpha-HCH of total HCHs were clearly observed in water and sediment. PCB18, PCB31 and PCB52 were predominant in water, on average these compounds collectively accounted for 67% of total PCBs. But in sediment, the predominant compounds were PCB28, PCB31 and PCB153, which accounted for 71% of total PCBs in sediment. The levels of micro pollutants in our study areas were compared with other studies. 相似文献