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861.
苏南地区香樟树皮中有机氯农药(OCPs)的污染水平及来源解析 总被引:2,自引:1,他引:1
利用树皮作为被动采样介质,2012年8月于苏南地区采集了33个香樟树皮进行有机氯农药(OCPs)的分析.结果表明,苏南地区香樟树皮中六氯苯(HCB)、滴滴涕(DDTs)和氯丹(Chlordanes)的含量范围(以干重计)分别为0.31~1.81、0.40~17.3和n.d.~1.03 ng·g-1.由于六氯苯挥发性较强,其含量的空间差异性不明显.同其它研究结果相比,苏南地区树皮中六氯苯含量相对较低.苏南地区DDT主要来源于工业DDT的历史残留和三氯杀螨醇的使用.根据反式氯丹(TC)/顺式氯丹(CC)的比值判定,苏南地区城区中氯丹可能来源于近期的直接使用,而乡村地区则来源于历史残留. 相似文献
862.
863.
Shilei Long Jianrong Zeng Yan Li Liangman Bao Lingling Cao Ke Liu Liang Xu Jun Lin Wei Liu Guanghua Wang Jian Yao Chenyan M Yidong Zhao 《环境科学学报(英文版)》2014,26(5):1040-1051
Sulfate, nitrate and ammonium(SNA) are the dominant species in secondary inorganic aerosol, and are considered an important factor in regional haze formation. Size-fractionated aerosol particles for a whole year were collected to study the size distribution of SNA as well as their chemical species in Shanghai. SNA mainly accumulated in fine particles and the highest average ratio of SNA to particulate matter(PM) was observed to be 47% in the fine size fraction(0.49–0.95 μm). Higher sulfur oxidation ratio and nitrogen oxidation ratio values were observed in PM of fine size less than 0.95 μm. Ion balance calculations indicated that more secondary sulfate and nitrate would be generated in PM of fine size(0.49–0.95 μm). Sulfur K-edge X-ray absorption near-edge structure(XANES) spectra of typical samples were analyzed. Results revealed that sulfur mainly existed as sulfate with a proportion(atomic basis) more than 73% in all size of PM and even higher at 90% in fine particles. Sulfate mainly existed as(NH4)2SO4 and gypsum in PM of Shanghai. Compared to non-haze days, a dramatic increase of(NH4)2SO4 content was found in fine particles on haze days only, which suggested the promoting impact of(NH4)2SO4 on haze formation. According to the result of air mass backward trajectory analysis, more(NH4)2SO4 would be generated during the periods of air mass stagnation. Based on XANES, analysis of sulfate species in size-fractionated aerosol particles can be an effective way to evaluate the impact of sulfate aerosols on regional haze formation. 相似文献
864.
Long-term changes of fish biotic integrity in the Sanmenxia Wetland,North China,since the 1950 s were assessed using the fish index of biological integrity(FIBI). The water and sediment quality was evaluated by the water quality index(WQI) and sediment pollution index(SPI). The results showed that FIBI continuously decreased from 46 to 20 during the past 5 decades,which indicated that the fish community state shifted from fair to very poor conditions,and damming by itself did not affect the fish biotic integrity. At the same time,WQI fell from 83 to 44.1,and SPI increased from 0.99 to 2.14 since the 1960 s,resulting from fast regional socio-economic development and insufficient wastewater treatment. Correlation analysis suggested that water quality significantly affected biotic integrity(r = 0.867,p 〈 0.05) through direct effects on the fish community. As a representative example of many wetlands in North China,our study clearly demonstrated that the biological integrity was degraded,induced both by water quality deterioration and sediment pollution,further driven by the contradiction between rapid development of regional economy and lagging development of sewage treatment facilities,which were thought to be the main factor responsible for the degradation of biological integrity. 相似文献
865.
Medilanski E Chuan L Mosler HJ Schertenleib R Larsen TA 《Environmental management》2007,39(5):648-662
We conducted a study of the institutional barriers to introducing urine source separation in the urban area of Kunming, China.
On the basis of a stakeholder analysis, we constructed stakeholder diagrams showing the relative importance of decision-making
power and (positive) interest in the topic. A hypothetical decision-making process for the urban case was derived based on
a successful pilot project in a periurban area. All our results were evaluated by the stakeholders. We concluded that although
a number of primary stakeholders have a large interest in testing urine source separation also in an urban context, most of
the key stakeholders would be reluctant to this idea. However, the success in the periurban area showed that even a single,
well-received pilot project can trigger the process of broad dissemination of new technologies. Whereas the institutional
setting for such a pilot project is favorable in Kunming, a major challenge will be to adapt the technology to the demands
of an urban population. Methodologically, we developed an approach to corroborate a stakeholder analysis with the perception
of the stakeholders themselves. This is important not only in order to validate the analysis but also to bridge the theoretical
gap between stakeholder analysis and stakeholder involvement. We also show that in disagreement with the assumption of most
policy theories, local stakeholders consider informal decision pathways to be of great importance in actual policy-making. 相似文献
866.
我国北方秋冬季节的空气重污染过程已经成为影响人们生活的重大环境事件,不仅受到公众和科研工作者的广泛关注,也已成为各地各部门政策制订者最为重视的关键问题之一.针对众说纷纭的空气重污染过程的形成机理、治理方案、控制对策等,利用2013-2016年秋季(9-11月)中国环境监测总站公布的逐时空气质量监测数据,重点对北京奥体中心站的空气重污染过程的演变进行了分析.结合中国气象局发布的天气形势分析图,系统地分析了我国4 a来秋冬季节出现大范围空气重污染过程的气候背景.结果表明:秋季我国东北和华北地区出现持续时间长、影响范围广的空气重污染过程,除了排放源的影响之外,天气形势同样起着重要作用. 2013-2016年秋季北京奥体中心的PM2.5污染状况仍以优良天气为主,其间中度及以上污染的持续时间虽然不长,但其影响[高ρ(PM2.5)]也不容忽视.秋季北京奥体中心ρ(PM2.5)日均值超标(二级)日数占25.8%,其中2014年最为严重,超标日数达44 d,占37.4%.通过对空气重污染过程与我国传统节气的对比分析发现,入秋后我国北方首次出现持续48 h以上的空气重污染过程分别是在秋分和寒露两个节气,而最严重的空气重污染过程则出现在寒露和霜降两个节气.从时间序列来看,4 a来北京奥体中心ρ(PM2.5)没有特别显著的改善,优良时数占60%左右,而中度以上的污染时数则维持在25%左右,但严重污染事件[ρ(PM2.5)≥ 250 μg/m3]的有效时数则有明显的变化.此外,白天污染物的浓度明显低于夜晚.研究还发现,西伯利亚高压指数的异常偏低往往会导致持续时间长、影响范围广和污染强度强的重度污染事件. 相似文献
867.
868.
Yi H. Liu Jian Chen Yi R. Guo Chun M. Wang Xiao Liang Guo N. Zhu 《Journal of environmental science and health. Part. B》2013,48(4):313-320
A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC50 and IC10 of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos. 相似文献
869.
运用Agilent(安捷伦)1200系列高效液相色谱和多环芳烃专用柱ZORBAX Eclipse PAH(4.6×250mm、5μm,P.N.959990-918,S.N.USPAB01066),对16种多环芳烃化合物混合溶液进行分析,根据具体实验条件优化EPA8310中色谱分离条件并得到了更节省时间、分离效率更好的流动相梯度变化程序。 相似文献
870.
为研究城市空间结构对汽车尾气扩散规律,根据高分辨率遥感影像建立了某城市核心区域几何模型。以当地常年气象风向作为重要的边界条件之一,应用CFD多相流技术,模拟了十字交叉口车辆队列怠速等候35,45,55 s时的尾气扩散过程,并对45 s时4个监测点的体积分数进行了实测,最后,通过建筑高度优化,降低了该区域的尾气含量。以上研究结果表明:在空间狭小区域,近地空间CO体积分数达1.0×10-7,与研究域平均体积分数相差100倍以上,说明城市空间结构对尾气扩散影响较大,仿真所揭示的规律与实测吻合。建筑设计时应结合当地气象风向和风速,应设计一定的建筑高度梯度,可以促使污浊气体迅速扩散至远地空间。 相似文献