Assessment of Metal Contamination in Doñana National Park (Spain) using Crayfish (Procamburus Clarkii)

Water quality assessment in the Aznalcollar area was attempted using multivariate methods based on heavy metal concentrations in red swamp crayfish (Procamburus clarkii). Trace levels of four heavy metals, copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb), were detected in crayfish from eleven different stations. Principal component analysis (PCA) highlighted a gradient of contamination between the sampling stations. Cluster analysis (CA) distinguished three groups of stations. Discriminant analysis also differentiated three groups. The group centroids of the first discriminant function were used to devise an index that varies according to the source of the crayfish. These standardized values are proposed for use as a water quality index. The ability of this index to successfully predict environmental quality was proved with random samples.     

Monochlorobenzene Marine Risk Assessment with Special Reference to the Osparcom Region: North Sea

This risk assessment on monochlorobenzene was carried out for the marine environment, following methodology given in the EU risk assessment Regulation (1488/94) and Guidance Document of the EU New and Existing Substances Regulation (TGD, 1996). Data from analytical monitoring programmes in large rivers and estuaries in the North Sea area were collected and evaluated for effects and environmental concentrations. Risk is indicated by the ratio of predicted environmental concentration (PEC) to predicted no-effect concentration (PNEC) for the marine aquatic environment. In total, 27 data for fish, 24 data for invertebrates and 13 data for algae were evaluated. Acute and chronic toxicity studies were taken into account and appropriate assessment factors used to define a final PNEC value of 32 micro/l. Recent monitoring data indicate that monochlorobenzene levels in surface waters are below determination limits of 0.1, 0.2, 0.5 microg/l used in monitoring programs. Assuming that half of the lowest determination (0.1 microg/l) is typical, a PEC of 0.05 microg/l was derived. A worst case of 0.5 microg/l is assumed. PEC/PNEC ratios give safety factors of 60 to over 500, taking no account of dilution in the sea. Monochlorobenzene is not a 'toxic, persistent and liable to bioaccumulate' substance sensu the Oslo and Paris Conventions for the Prevention of Marine Pollution (OSPAR-DYNAMEC) criteria. Environmental fate and effects data indicate that current use of monochlorobenzene poses no unacceptable risk to the aquatic environment.     

黔中地区二级阶地堆积物边坡稳定性对工程建设的影响

结合在建工程清水河大花水电站实例,本文对黔中地区二级阶地堆积物边坡成因、堆积物物质成份、结构与其物理力学特性作了分析、总结,初步探讨了贵州省二级阶地堆积物边坡稳定性对工程建设的影响,望能给正在进行工程建设的同行以一定的参考,并对工程建设区的二级地堆积物边坡稳定性引起重视。     

宾夕法尼亚泥盆系卡茨基尔组砂岩型铀矿床附近古含水层中的铀异常

<正> 过去研究砂岩型铀矿床时很少考察或研究矿体外围铀异常的范围和性质,然而在寻找附属矿床时,由矿体和异常晕带所组成的一个较大的目标区可能是很有帮助的。另外,航空放射性测量和分散流地球化学异常的范围都取决于矿体内外的铀分布。根据对砂岩型矿床附近沉积物中铀的区域异常研究的部分结果,我们获得了明显的印象:怀俄明卷型铀矿床的铀所通过的古含水层具有明显的铀异常。另外,还获得了背景样品的一大套数据,从而可以了解铀、钍和主要元素之间的关系,这对于研究沉积岩中的铀和识别岩石样品的弱异常具有普遍的实用价值。     

用与电感耦合等离子体-原子发射光谱结合的计算机控制扫描单色仪测定地球化学和环境样品中的50种元素

<正> 在过去的年代里,矿石、矿物、土壤、沉积物、灰份以及玻璃、颜料等制造品中的主量、少量、甚至痕量元素的测定都是用经典重量法、滴定法和分光光度法完成的。近几十年来,经典方法已经大量地被X-射线萤光、原子吸收光谱电弧发射光谱和质子诱发的X-射线分析等多种仪器方法所代替。     

测定溶液或悬浮液中气体吸收或排放速率的一种装置

<正> 为了寻找一种适合于测定水悬浮液中硫化物矿物氧化速率的方法,作者设计了一种装置,这种装置可用来测定溶液或悬浮液吸收或排放气体的速率。原打算利用常规的瓦尔伯格呼吸计,但这种呼吸计原则上是为生化实验设计的。在这些实验中所研究的物质或者是可溶的,或者是象细胞这样的轻物质的悬浮液。此外,这些实验时间较短,往往是几分钟而不是几小时。如果要研究水悬浮液中矿物颗粒(通常是不溶的重矿物)的氧化作用,那么就需要长得多的反应时间。因此,将常规的瓦尔伯格装置用于这些材料时,在技术上存在很多问题。     

大洋盆地火成岩的稀土元素特征

<正> 一、前言 洋中脊位于近深海深度,但是某些块段被抬高形成了广阔的海底高原或者大洋岛。就火山活动各个不同地区和类型而言,岩浆的产物从洋脊活动典型的拉斑玄武岩变化为高度不饱和岩浆和在许多洋岛上发现的它们的分异     

用蔗渣碱法制浆的黑液废料制取木素磺酸盐

蔗渣造纸工业的主要环境问题是如何消除化学制浆和半化学制浆过程中黑液造成的严重污染。在此情况下,用外部处理的传统方法不足以消除污染,必须同时采用黑液回收系统。由于Tomlinson回收蒸煮锅所具有的优点,在大型工厂碱法制浆的黑液回收系统中应用十分普遍。虽然这个系统能大大减轻污染,但它的成本较高,难以在每日产量小于100吨的纸浆厂中应用。因此,其他的碱回     

过去全球变化的海洋记录(IUGS过去全球变化专题讨论会第一工作组的报告)

论述了海洋沉积物岩心记录在过去全球变化中的作用,按大、中、小三个时间尺度考虑了海洋记录,提出了与这三个时间尺度有关的目标,指出了实现这些目标的战略,列出了对今后研究工作的建议。