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901.
冻土区固体废弃物的处理对未来的寒区经济发展、保护冻土及寒区生态环境意义重大。笔者总结近年来我国冻土区所进行的一系列工程和资源开采活动,表明冻土区固体废弃物处理的研究是必要而迫切的。通过介绍国内外近几十年来对冻土区固体废弃物处理的研究方法、思路和技术,并分析其成果与不足;使人们更好地了解和利用冻土区寒冷的气候条件、冻土的冻融循环、回冻等特性及永久冻土层的隔绝作用来处理冻土区的废弃物;同时给出了冻土区废弃物处理的研究成果及对策,还对未来研发的前景展望。 相似文献
902.
Michael N. Coster Robin K. S. Hankin 《Journal of Loss Prevention in the Process Industries》2003,16(6):545-550
This paper considers the risk to major hazard plant from terrorists deliberately causing catastrophic industrial accidents. The United States of America Department of Justice [Assessment of the increased risk of terrorist or other criminal activity associated with posting off-site consequence analysis information on the internet, 2000] reports that “breaching a containment vessel of an industrial facility with an explosive or otherwise causing a chemical release may appear relatively simple to…a terrorist”. They concluded that the risk of such action is “real and credible”.
Analysis of terrorism is often hampered by its being described as ‘irrational’; one corollary would be that it is unpredictable. However, terrorism may usefully be treated as a rational behaviour and in doing so it becomes possible to assess the risks it causes.
We analyse the vulnerability of major hazard plant to terrorist attack and identify nine factors (access, security, visibility, opacity, secondary hazard, robustness, law enforcement response, victim profile, and political value) that might be used as a starting point for more formal risk assessment and management. 相似文献
903.
淮南矿区不同塌陷年龄积水区环境效应分析 总被引:2,自引:0,他引:2
采煤塌陷水域是淮南矿区一种特殊的地表水体。文章选择矿区不同塌陷年龄的塌陷水域,监测分析其水质理化指标和重金属元素。结果表明:塌陷水域环境状况因塌陷年龄和周边环境差异而不同,具有季节性变化。水域受到了不同程度的污染,部分理化指标随时间增长有累计效应。与国家地表水质量标准比较,水域重金属元素除了Hg严重超标外,其它As、Se、Cd、Cr、Cu、Pb、Zn等均不超标,未对塌陷水域构成重金属污染。通过对不同塌陷水域环境效应进行分析与评价,可为其综合利用提供一定的理论依据。 相似文献
904.
西安大气环境要素变化特征分析 总被引:1,自引:0,他引:1
利用1951年至2007年西安气象观测资料及2002年至2007年环境监测资料,对西安市大气环境要素进行分析。结果表明,(1)随着西安城市化进程的加快,和NOx年平均浓度变化具有明显增加的趋势。(2)从1951到2007,西安市气温增长了约2℃,仅21世纪以来,就增长了近1℃。热夜天数自上世纪90年代中期以来明显上升。2008年7月上旬西安市区与周边郊区地表温度温差约为8—10℃。(3)年平均风速,极大风速明显减小。分析认为,随着西安城市规模的扩大、人口的增加,高楼林立,城市下垫面发生巨大变化,使城市热容量增加,耗能增大,有效蒸发减少,增温明显,从而导致城市风速减小、大气污染物浓度增加、温度升高、热岛效应越来越显著。提出建立人工环境与自然环境协调一致的城市规划环境气候图,有效缓解因城市化进程引起的城市大气环境问题。 相似文献
905.
Distribution of Cu,Zn,Pb,Cr,Ni,Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determined.Nineteen sampling sites were distributed around the industrial zone on a surface area of about 100,000 m2.Atomic absorption spectroscopy and Alpha spectroscopy were used to quantify the heavy elements and polonium-210,respectively.Investigation on a particle scale was conducted by TEM and SEM coupled to EDX and X-ray cartography to determine the nature of heavy elements carders and their distribution.Heavy elements were mainly concentrated inside the particle size fraction < 50μm.Their levels decreased with distance increasing from the industry.According to the reference soil,enrichment factors were about 10,15,32 and 100 times for Zn,Pb,Cu,and Cr,respectively inside the particle size fraction < 50 μm on the closest sites to the industry.The main contaminant sources were transport and storage of row materials and the free release of phosphogypsum waste.Heavy elements were entrapped inside agglomerates of sulfates,phosphates and iron oxihydroxides in a diffused shape.Polonium-210 with an enrichment factor of about 56,showed the same behavior of the spatial distribution of the trace elements. 相似文献
906.
907.
TIAN Dalun ZHU Fan YAN Wende Fang Xi XIANG Wenhu DENG Xiangwen WANG Guangjun PENG Changhui 《环境科学学报(英文版)》2009,21(3):340-345
Phytoremediation can be used as a sustainable technology for mine spoil remediation to remove heavy metals. This study investigated
the concentration of 7 heavy metal contamination in soil and plant samples at an abandoned mine site. We found that, after vegetation
remediation at the abandoned mine site, the reduction rates for 7 heavy metals were in the range of 4.2%–86%, where reduction rates
over 50% were achieved for four heavy metals (Zn, Mn, Cd, Ni). Transfer coe cients of the panicled goldenrain tree (Koelreuteria
paniculata Laxm) and the common elaeocarpus (Elaeocarpus decipens) for Zn, Mn, Ni, and Co were more than 1. Enrichment
coe cients of both trees for Mn were higher than 1. Our results suggest that the panicled goldenrain tree and the common elaeocarpus
tree may act as accumulators in remediation. Moreover, the woody vegetation remediation in abandoned mining areas play an important
role in improving scenery besides removing heavy metal from contaminated soil. 相似文献
908.
西江上游河水悬浮物中稀土元素的地球化学特征 总被引:1,自引:0,他引:1
采用改进的BCR逐级提取法和ICP-MS测试技术,对西江上游河流悬浮物中稀土元素进行了研究。结果表明:河流悬浮物稀土元素总量的含量变化范围在188~402mg/kg之间,并主要来源于流域内岩石的风化,反映了源区的物质特征。西江上游河水悬浮物中三种非稳定态(即酸可提取态、铁锰氧化物结合态和有机物硫化物结合态)稀土元素页岩(PAAS)标准化配分模式均显示出中稀土富集的特征。这种配分模式可能是由于流域内广布的海相沉积岩中磷酸盐矿物的风化所造成的。稳定态(即残渣态)的配分曲线较为平直,没有体现出明显的稀土分异。悬浮态稀土各赋存形态含量的顺序为:残渣态有机物硫化物结合态、铁锰氧化物结合态酸可提取态。中稀土元素Sm、Eu、Gd相对于轻、重稀土元素的稳定态所占比例偏低,而相对于三种非稳定态所占比例偏高,反映了其潜在的地球化学活性。 相似文献
909.
910.
Plant uptake factor (PUF), single-variable regression of natural log-transformed concentrations in rice grain/vegetables versus natural
log-transformed concentrations in soil and multiple-variable regression with soil concentrations and pH, was derived, validated and
compared based on the paired crop and soil data collected from studies regarding As, Cd and Pb contaminated croplands in China.
Results showed that the median value of PUF did not present deterministic prediction. But after natural logarithm transformation, the
PUF followed Gaussian distribution which could be useful in risk assessment. The single-variable regression models were significant
for As, Cd and Pb uptake both by rice and vegetables; however, the standard errors of all the regressions were comparatively large.
Soil pH as a variable was generally significant but it only contributed positively to model fit for Cd uptake. After model comparison
and selection, the upper 95% prediction limits of the multiple regression model for Cd uptake by rice was recommended to calculate
screening value of Cd for paddy soil based on the limit for Cd concentration in rice grain. 相似文献