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排序方式: 共有1368条查询结果,搜索用时 31 毫秒
471.
上海市浦东新区作为承接国家自由贸易区的先行试点地区,近年来吸引大批国内外企业入驻,同时经济发展与环境友好型社会矛盾依然突出。本文以2014年-2018年来浦东新区区域噪音与交通噪数据为依据,分析本地区声环境状况,结果表明声环境质量有所下降,一类功能区及交通噪音需进一步加强治理。通过源头屏蔽,大力发展张江、周浦、滴水湖等科技园区建设,阻断企业对居民区的噪声影响等措施,进而提升和改善浦东新区声环境质量状况。 相似文献
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473.
Lin-Chi Wang Wen-Jhy Lee Wei-Shan Lee 《Environmental pollution (Barking, Essex : 1987)》2010,158(10):3108-3115
Here we show that combustion sources, including waste incinerators, metallurgical processes, power-heating systems and so on, are also important emitters of polybrominated diphenyl ethers (PBDEs) to the atmosphere. Geometric mean PBDE concentrations in the stack flue gases of the combustion sources ranged from 8.07 to 469 ng/Nm3. The sinter plants (24.7 mg/h), electric arc furnaces (EAFs) (11.3 mg/h) and power plants (50.8 mg/h) possessed the largest PBDE emission rates, which were several orders higher than those of the other reported sources. The occurrences of the PBDEs in the flue gases of the power plants and vehicles, as well as their PBDE concentrations statistically highly correlated with combustion-originated PCDD/Fs, revealing that PBDEs should be the products of combustion. The ranking of major PBDE emission sources in Taiwanese PBDE inventory for combustion sources was power plants (30.85 kg/year), vehicles (14.9 kg/year) and metallurgical processes (5.88 kg/year). 相似文献
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475.
锦州地区地下水饮用水源污染因素及防治对策研究 总被引:1,自引:0,他引:1
通过对锦州地区地下水饮用水源水质监测数据分析,评价地下水饮用水源水质现状;针对部分水源水质超标现象,分析其成因,并在实地考察的基础上从工矿企业污染源、生活污染源、养殖业污染源、农业污染源和不合理开采等几方面进一步阐述水源地潜在污染因素;在此基础上从预防、治理、生态修复及加强监管等方面提出地下水饮用水源污染防治对策。 相似文献
476.
基于主成分分析法的辽河水体中溶解性金属来源分析 总被引:1,自引:0,他引:1
在测定辽河水体中几种主要的溶解性金属(包括7种重金属)的含量和分析其空间分布特征的基础上,运用主成分分析(PCA)法分析了金属的可能来源。结果表明,辽河水体中溶解性金属的平均浓度为Al>Cu>Zn>Cr>Hg>As>Pb>Cd,与欧美发达国家的主要水体相比,辽河水体的金属污染状况总体较重;辽河水体中溶解性金属的污染来源主要分两类:农业面源和工业废水污染源,工业综合污染源;根据主成分得分系数可知,采样点2(通江口)、3(三合屯)、7(朱尔山)的金属污染主要来源于农业面源和工业废水污染源;采样点6(药王庙)的金属污染主要来源于工业综合污染源;基于PCA法的金属来源分析对辽河流域水体金属污染治理对策的制定有着重要的指导意义。 相似文献
477.
In this study, ambient air samples from different atmospheric environments were examined for both PBDE and PCDD/F characteristics to verify that combustion is a significant PBDE emission source. The mean ± SD atmospheric PBDE concentrations were 165 ± 65.0 pg Nm−3 in the heavy steel complex area and 93.9 ± 24.5 pg Nm−3 in the metals complex areas, 4.7 and 2.7 times higher than that (35.3 ± 15.5 pg Nm−3) in the urban areas, respectively. The statistically high correlation (r = 0.871, p < 0.001) found between the atmospheric PBDE and PCDD/F concentrations reveals that the combustion sources are the most likely PBDE emission sources. Correspondence analysis shows the atmospheric PBDEs of the heavy steel and metals complex areas are associated with BDE-209, -203, -207, -208, indicative of combustion source contributions. Furthermore, the PBDEs in urban ambient air experience the influence of the evaporative releases of the commercial penta- and octa-BDE mixtures, as well as combustion source emissions. By comparing the PBDE homologues of indoor air, urban ambient air, and stack flue gases of combustion sources, we found that the lighter brominated PBDEs in urban ambient air were contributed by the indoor air, while their highly brominated ones were from the combustion sources, such as vehicles. The developed source identification measure can be used to clarify possible PBDE sources not only for Taiwanese atmosphere but also for other environmental media in other countries associated with various emission sources in the future. 相似文献
478.
479.
To evaluate the quantities of 137Cs from past nuclear tests being transported to and deposited in Japan by naturally-occurring phenomena, the authors developed long-range transport models for 137Cs considering Asian dust. The simulation using these models backed the observed recent increase of 137Cs deposition along the coast of the Sea of Japan in early spring. For the sake of public safety, it is vital to ascertain whether an increase of radioactive deposition is caused by natural phenomena or a nuclear accident. The observations in recent years have suggested that dust and soil containing 137Cs is transported from the regions around Inner Mongolia to Japan by the wind. In this paper, using observation data from the early spring of 2002 and 2006, the authors have found good agreement between the simulations and the measurements. The simulations reproduced the entrainment of 137Cs and subsequent transport to Japan caused by strong winds associated with low pressure areas around the Inner Mongolian grasslands. The most likely cause of high-level 137Cs deposition over northern Japan during March 2002 was 137Cs associated with particles transported at low-altitude (1 km) and subjected to precipitation on the 22nd to 24th. 相似文献
480.
不同碳源添加量对垂直流人工湿地污水处理效果的影响 总被引:4,自引:0,他引:4
以垂直流人工湿地小试系统为研究对象,采用碱处理过的千屈菜(Lythrum salicaria)作为反硝化碳源补充材料,探讨了不同碳源添加量对系统COD及氮、磷去除效果的影响。结果表明,一定剂量经过碱处理的千屈菜材料可以为人工湿地系统脱氮提供反硝化所需要的碳源,而且具有缓效持续释放的特点。添加此碳源材料可明显提高系统的脱氮效率,最高可提升30.85%,但随着C/N比的增加,硝态氮去除率逐渐降低,C/N比为3、5、8时分别为91.20%、87.72%和84.19%。添加碳源量达到C/N比为3时系统能够发生最大程度反硝化,此时不仅人工湿地系统脱氮效果得到提高,同时人工湿地除磷能力也有所增强。碱处理过的千屈菜材料在本系统中的最适宜添加量为5 g,即100 g/m2(C/N=3),远低于在进水中为满足反硝化所需调控的C/N比(5~8),可以节约外加碳源成本。 相似文献