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621.
有机污染土壤通风去污技术优化设计 总被引:5,自引:0,他引:5
有机污染土壤通风去污技术(SVE)是一种经济,安全的场内治理技术,SVE优化设计包括建立污染土壤通风去污模型和抽排去污流场模型,并以此为基础算工程费用,用一虚拟工况对提出的模型及计算公式进行了验证。 相似文献
622.
初步研制的汞蒸汽被动式检气管是建立在气体分子扩散和化学吸收原理基础上的,新制备的碘化亚铜沉淀和乙醇、甘油、硝酸混合、研碎,伴入经活化的层析硅胶,填充到检气管中,当汞蒸气进入管内时,发生显色反应,检气管显色长度的平方与汞蒸汽浓度及采样时间的乘积成线性关系,检测下限为0.001ug/mL(1h)。该法集采样与分析于一体,结构简单,不需动力,便于携带,操作方便,实验室模拟运用,其灵敏度和标准偏差令人满意。 相似文献
623.
分析比较了相关分析法、多元线性回归法与逐步回归法在环境影响因子辨识中的功能异同点。以甘肃省白银市为例 ,用 3种统计学方法对城郊土壤 -作物系统重金属污染影响因子进行判别 ,提出了研究区土壤污染修复方案选择指标的建议 相似文献
624.
Brack W Klamer HJ López de Alda M Barceló D 《Environmental science and pollution research international》2007,14(1):30-38
Background, Aim and Scope
Extensive monitoring programs on chemical contamination are run in many European river basins. With respect to the implementation
of the European Union (EU) Water Framework Directive (WFD), these programs are increasingly accompanied by monitoring the
ecological status of the river basins. Assuming an impact of chemical contamination on the ecological status, the assignment
of effects in aquatic ecosystems to those stressors that cause the effects is a prerequisite for taking political or technical
measures to achieve the goals of the WFD. Thus, one focus of present European research is on toxicant identification in European
river basins in order to allow for a reduction of toxic pressure on aquatic ecosystems according to the WFD.
Main Features:
An overview is presented on studies that were performed to link chemical pollution in European river basins to measurable
ecotoxic effects. This includes correlation-based approaches as well as investigations that apply effect-directed analysis
(EDA) integrating toxicity testing, fractionation and non-target chemical analysis. Effect-based key toxicants that were identified
in European surface waters are compiled and compared to EU priority pollutants. Further needs for research are identified.
Results:
Studies on the identification of effect-based key toxicants focused on mutagenicity, aryl hydrocarbon receptor-mediated effects,
endocrine disruption, green algae, and invertebrates. The identified pollutants include priority pollutants and other well-known
environmental pollutants such as polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins, furans, and biphenyls,
nonylphenol, some pesticides and tributyltin, but also other compounds that were neither considered as environmental pollutants
before nor regulated such as substituted phenols, natural or synthetic estrogens and androgens, dinaphthofurans, 2-(2-naphthalenyl)benzothiophene,
and N-phenyl-2-naphthylamine.
Discussion:
Individual studies at specific sites in a European river basin demonstrated the power of combined biological and chemical
analytical approaches and, particularly, of effect-directed analysis. However, the available information on effect-based key
toxicants is very limited with respect to the entirety of rivers possibly at risk due to chemical contamination and with respect
to toxicological endpoints considered at a specific site. A relatively broad basis of information exists only for estrogenicity
and aryl hydrocarbon, receptor-mediated effects.
Conclusions:
The development of tools and strategies for an identification of key toxicants on a broader scale are a challenging task for
the next years. Since investigations dealing with toxicant identification are too labor and cost-intensive for monitoring
purposes, they have to be focused on the key sites in a river basin. These should include hot spots of contamination, particularly
if there is evidence that they might pose a risk for downstream areas, but may also involve accumulation zones in the lower
reach of a river in order to get an integrated picture on the contamination of the basin.
Perspectives:
While EDA is almost exclusively based on measurable effects in in vitro and in vivo biotests to date, an increasing focus
in the future should be on the integration of EDA into Ecological Risk Assessment and on the development of tools to confirm
EDA-determined key toxicants as stressors in populations, communities and ecosystems. Considering these requirements and applied
in a focused way, toxicant identification may significantly help to implement the Water Framework Directive by providing evidence
on the main stressors and possible mitigation measures in order to improve the ecological status of a river ecosystem. 相似文献
625.
Huang DJ Zhang YM Song G Long J Liu JH Ji WH 《Environmental monitoring and assessment》2007,128(1-3):483-488
The Yellow River, the second largest river in China, is the most important resource of water supply in North China. In the
last 40 years, even in the upper Yellow River, with the development of industry and agriculture, more and more contaminants
have been discharged into this river and greatly polluted the water. Although a routine chemical component analysis has been
performed, little is known about the real toxic effects of the polluted water on organisms at environmental level. To explore
whether the pollutants induced oxidative stress and damage to aquatic organisms, malondialdehyde (MDA) level and activities
of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in hepatopancreas,
kidney and intestine of the field-collected carp Cyprinus carpio from a mixed polluted (Lanzhou Region, LZR) and a relatively unpolluted (Liujiaxia Region, LJXR) sites of the upper Yellow
River were measured. The results showed that when the values of LZR compared with those of LJXR, SOD and GST activities increased
and GPx activity decreased significantly in all the three organs (P < 0.05–0.01); CAT activity decreased but MDA level increased significantly (P < 0.05–0.01) only in kidney and intestine. In conclusion, the results of this study suggest that the pollutants can induce
obvious oxidative damage in the carp, and the SOD, GST and GPx might be better indicators for the oxidative damage in aquatic
organisms. 相似文献
626.
Mercury concentrations are usually significant in historic Hg mining districts all over the world, so the atmospheric environment is potentially affected. In Asturias, northern Spain, past mining operations have left a legacy of ruins and Hg-rich wastes, soils and sediments in abandoned sites. Total Hg concentrations in the ambient air of these abandoned mine sites have been investigated to evaluate the impact of the Hg emissions. This paper presents the synthesis of current knowledge about atmospheric Hg contents in the area of the abandoned Hg mining and smelting works at ‘La Peña–El Terronal’ and La Soterraña, located in Mieres and Pola de Lena districts, respectively, both within the Caudal River basin. It was found that average atmospheric Hg concentrations are higher than the background level in the area (0.1 μg Nm?3), reaching up to 203.7 μg Nm?3 at 0.2 m above the ground level, close to the old smelting chimney at El Terronal mine site. Data suggest that past Hg mining activities have big influences on the increased Hg concentrations around abandoned sites and that atmospheric transfer is a major pathway for Hg cycling in these environments. 相似文献
627.
Panichayapichet P Nitisoravut S Simachaya W 《Environmental monitoring and assessment》2007,135(1-3):181-193
The aim of this study was to investigate the spatial distribution of heavy metal in soil and evaluate the dissolution of metal
from soil to ponded-surface water, leaching through soil profiles and metal uptake in grass as related to different land-use
practices. The data provided a scientific basis for best-management practices for land use in Khli Ti watershed. The watershed
has a Pb-contamination problem from the previous operation of a Pb-ore concentrator and abandoned Zn–Pb mine. Sampling sites
were selected from a land-use map, with land-use types falling into the following four categories: forest, agricultural land,
residential area and road. Soil, ponded-surface water, grass samples and soil profiles were collected. The study related soil
characteristics from different land-use practices and locations with observed metal concentrations in ponded-surface water
and soil. High enrichment factors of Pb and As in soil were found. Partitioning coefficient, Kd values were in the order: Cr > Pb > Ni > Cu > Cd > Zn. Soil disturbance from land-use activities including tillage and traffic
increased leaching of trace metal from soils. Pb in soil was significantly taken up by grass even though the Transfer Factor,
TF values were rather low. Agricultural activities in the watershed must be limited. Moreover, land encroachments in the upper
and middle part of the watershed which have high potential of Pb must be strictly controlled in order to reduce the Pb contamination
from non-point sources. 相似文献
628.
Trace metals assessment in water, sediment, mussel and seagrass species--validation of the use of Posidonia oceanica as a metal biomonitor 总被引:1,自引:0,他引:1
The accumulation of trace metals (Cd, Co, Cr, Hg, Ni and Pb) was measured in water, sediment, the mussel Mytilus galloprovincialis and the seagrass Posidonia oceanica. Samples were collected in three locations of the north-western Mediterranean (Canari, Livorno and Porto-Torres) which present different levels and sources of human impact. Analyses in the different compartments (water, sediment, M. galloprovincialis and P. oceanica) have allowed to identify Canari as the most Cd, Co, Cr and Ni contaminated site; Livorno as the most Hg contaminated and Porto-Torres as the most Pb contaminated. Furthermore, for the first time, metal concentrations found in P. oceanica have been compared with those found in the water column, in the sediment and in the recognized metal bio-indicator species M. galloprovincialis and the results obtained have led to the same conclusions. Thus, this study allows to validate the use of P. oceanica as metal biomonitor of coastal waters. 相似文献
629.
文章利用模拟实验开展了平原地区缓流河道中的水质变化对河道水流速度与来水水质的响应规律研究。结果显示,当流速<0.5m/h时,河道中的各种污染物主要以沉积过程为主。当流速在0.5~1.5m/h时,水体最易受外界有机物输入的影响,容易引起局部水质的恶化。当流速>1.5m/h时,水动力条件有利于河道中的有机物的降解,但促进了底泥磷的释放,并会导致下游河道营养盐的升高。所以在河道改造、城市生态河网建设与管理中,应从区域河网整体着手,也应注意缓流河道中来水水质的管理。 相似文献
630.
Melissa L. Street John C. K. Barber Tracy A. Boyle Katrina H. Ellis Hilary Bullman Tessa Homfray 《黑龙江环境通报》2007,27(9):858-860
We report a case of maternal mosaic trisomy 21 ascertained at prenatal diagnosis as a result of maternal cell contamination of an amniotic fluid sample. A 34 year old female was referred for karyotyping because of a previous trisomy 21 pregnancy. Chromosome analysis of primary in situ cultures showed a karyotype of 47,XX, + 21[6]/46,XY[32]/46,XX[2]. Molecular testing demonstrated maternal cell contamination of the amniotic fluid sample and G-banded karyotyping of maternal blood showed that 3/200 cells had trisomy 21, consistent with the mother being a Down syndrome mosaic. A normal male baby with a 46,XY chromosome complement was delivered at 30 weeks. This case emphasises the need for close collaboration between cytogenetic and molecular genetics laboratories in resolving unusual cases of mosaicism. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献