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31.
建立了超声辅助离子液体液-液微萃取(USA-IL-DLLME)结合液相色谱-串联质谱测定水中六溴环十二烷3种异构体(α-HBCD、β-HBCD、γ-HBCD)的分析方法。实验中分别考察了离子液体萃取剂的种类及体积、超声时间、样品p H及盐浓度等因素的影响。在最佳条件下,HBCDs 3种异构体在0.5~100μg/L质量浓度条件下有较好的线性关系,相关系数大于0.998,最低检出限分别为156.4、84.6、85.5 ng/L,测定下限分别为0.626、0.339、0.342μg/L。相对标准偏差(n=5)为5.3%~9.7%。采用该方法对实际环境水样进行了检测与加标回收实验,在1、20μg/L 2个添加水平下,加标回收率为71%~102%。方法具有简单快速、有机溶剂用量少、绿色环保的特点。  相似文献   
32.
利用西安市环境监测站超级站2013年9月1日—2015年5月31日黑碳气溶胶(BC)的监测数据,研究空气中BC浓度特征及其与气象因素和常规污染物相关性。结果表明:BC小时平均浓度均值在春季、夏季和冬季的变化趋势呈"W"型,秋季呈"V"型,且冬季的第一个最低值和峰值比春季和夏季的分别延迟1 h和2~3 h,且20:00~次日6:00秋季BC小时平均浓度均值高于当年冬季。BC浓度在秋季和冬季较高,夏季较低。冬季BC/PM_(2.5)基本最低,秋季BC/PM_(2.5)相对最高。BC日平均浓度与气温、降水和风速的日平均值为极负显著相关,且风速小于1.0 m/s时,其与风速呈最显著的负相关。除O_3外,BC日平均浓度与其他常规空气污染物浓度呈显著相关,表明其同源性很强,且受机动车尾气排放的影响更大。  相似文献   
33.
Hainan, the largest tropical island in China, belongs to the Indo-Burma biodiversity hotspot and harbors large areas of tropical forests, particularly in the uplands. The Changhua watershed is the cradle of Hainan's main river and a center of endemism for plants and birds. The watershed contains great habitat diversity and is an important conservation area. We analyzed the impact of rubber and pulp plantations on the distribution and area of tropical forest in the watershed, using remote sensing analysis of Landsat images from 1988, 1995 and 2005. From 1988 to 1995, natural forest increased in area (979-1040?sq?km) but decreased rapidly (763?sq?km) over the next decade. Rubber plantations increased steadily through the study period while pulp plantations appeared after 1995 but occupied 152?sq?km by 2005. Rubber and pulp plantations displace different types of natural forest and do not replace one another. Because pulp is not as profitable as rubber and existing pulp processing capacity greatly exceeds local supply, considerable pressure exists on remaining upland forests. We recommend for future management that these plantation forests be reclassified as 'industrial', making a clear policy distinction between natural and industrial forestry. Additionally, the local government should work to enforce existing laws preventing forest conversion on marginal and protected areas.  相似文献   
34.
Along with the progressive acceleration of urbanization, the need to identify potentially troublesome “Not In My Back Yard” (NIMBY) facilities in the city is inevitable. To resolve NIMBY conflict, it is important to know people’s NIMBY risk acceptability for these facilities. A questionnaire survey was used among Chinese and Japanese college students to identify NIMBY risk acceptability. LISREL was used to construct a structural equation model to analyze the difference in NIMBY risk acceptability between the Chinese and Japanese college students. Factors that may affect NIMBY risk acceptability were analyzed: “perceiving utility,” “perceiving risk,” “trust in government,” “reasonable compensation,” and “procedural justice.” The findings show that Japanese students’ concerns were greater than Chinese students’ concerns. Perceiving utility and perceiving risk were the most important factors that affect people’s NIMBY risk acceptability, followed by procedural justice, trust in government, and reasonable compensation. There is a difference between the different cultural backgrounds in confronting the risk: Chinese students focus more on the reputation and value of real estate, while Japanese students pay more attention to environmental pollution and damage to health. Furthermore, cultural influences play a role in students’ risk perception. To improve the risk acceptability for NIMBY facilities and provide a basis for resolving NIMBY conflicts, it is necessary to ensure the benefits of the NIMBY facility while reducing environmental pollution. The findings of this study may be of interest for policy makers and practitioners to devise future NIMBY strategies.  相似文献   
35.
Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0–20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20–40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40–60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P?I geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.  相似文献   
36.
翟由涛  刘莉 《环境科技》2003,16(4):37-38
对燃煤电厂的环评工作中,项目选址、总平面布置、污染防治与清洁生产:冷却塔噪声等一些值得注意的问题进行了探讨,并提出了一些初步意见。  相似文献   
37.
Adsorption and degradation of levonorgestrel (LNG) by two hydrophytes, Cyperus alternfolius (CA) and Eichhornia crassipes (EC), were investigated under light-shielding conditions in the water column. Variations of LNG concentrations in water, plant root epidermis, root, stem and leaf of the plants were analyzed. The results indicated that the removal efficiency of LNG by hydrophytes over the period of 50 days was significantly greater than the blank control (p 〈 0.05), with the removal rates of 79.80%± 3.10% and 78.86% ± 2.55% for CA and EC, respectively. Compared with bio-adsorption, bio-conversion of LNG was found to be the dominant elimination pathway, evidenced by relatively high conversion rates (77.31% ±2.68% for CA and 77.82% ± 2.95% for EC), while the adsorption rates were lower (1.77% ± 0.90% for CA and 1.05% ± 0.40% for EC). The bio-adsorption and conversion of LNG showed no significant differences between the two hydrophytes. Additionally, the mineralization on root epidermis played an important role in the reduction of LNG in water.  相似文献   
38.
This paper employs a review of the technical literature to estimate the potential decrease in greenhouse gas (GHG) emissions that could be achieved by increasing the application of gas engines in China in three sectors: urban public transport vehicle; shipping; and thermal power plants. China’s gas engine development strategies and three types of gas resource are discussed in the study, which indicates that gas engines could decrease GHG emissions by 520 megatonnes (Mt) of carbon dioxide equivalent (CO2e) by 2020. This would account for 9.7 % of the government’s target for decreasing GHG emissions and is dominated by methane recovery from the use of coal mine gas (CMG) and landfill gas (LFG) for power generation. In the public urban transport vehicle and shipping sectors the low price of natural gas and the increasing demand for the control of harmful emissions could spur the rapid uptake of gas engine vehicles. However, the development of CMG- and LFG-fuelled power plants has been limited by the unwillingness of local enterprises to invest in high-performance gas engine generators and the associated infrastructure. Therefore, further compulsory policies that promote CMG use and LFG recovery should be implemented. Moreover, strict regulations on limiting methane leakage during the production and distribution of gas fuels are urgently needed in China to prevent leakage causing GHG emissions and largely negating the climate benefits of fuel substitution. Strategies for increasing the application of gas engines, promoting gas resources and recovering methane in China are instrumental in global GHG mitigation strategies.  相似文献   
39.
40.
为提升环保工作效果,促进环保工作高效、有序开展,指出了环境监测在环保工作中的重要作用:进一步明确环保工作方向,为环保工作开展提供科学数据支持,提高环境质量评价的准确性.分析了环境监测在水污染防治、大气污染防治、土壤污染防治中的具体实践,提出提高环境监测质量的措施:及时解决环境监测中发现的问题,强化对环境监测数据的分析和...  相似文献   
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