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首页> 外文学位 >Statistical analysis of lead, zinc, copper and cadmium concentrations in the sediment of the Jordan River, Utah.
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Statistical analysis of lead, zinc, copper and cadmium concentrations in the sediment of the Jordan River, Utah.

机译：犹他州约旦河沉积物中铅，锌，铜和镉浓度的统计分析。

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摘要

In the winter of 1996 the General Chemistry (Chemistry 121-1) course at the University of Utah included a service-learning project. The students attempted to determine the lead concentration at various sites along the Jordan River. The Jordan River is the major waterway in the Salt Lake Valley, and the investigated locations were selected to represent interesting features of the river.; On a series of field trips during a 2-week period, underwater sediment samples were collected by the students using a simple core sampler provided by the U.S. Geological Survey. In the laboratory, sample solutions were prepared from portions of these sediments taken by “wet grab” followed by acid digestion according to a simplified protocol based on Method 3050B promulgated by the Environmental Protection Agency. The test solutions were analyzed by inductively coupled plasma atomic emission spectroscopy in the Environmental Laboratory of Kennecott Utah Copper Company, providing not only the lead concentrations needed, but zinc, copper and cadmium concentrations as well.; The students' work was successful. In spite of the limitations and the shortcuts taken, the determined average metal concentrations as a set compare very reasonably to previously published results.; However, inspection of the data revealed an unexpectedly large number of large concentration values, outliers. The abundance of the “wild” concentrations necessitated a statistical evaluation of the analytical results.; The examination of the data uncovered that the results of the usual and customary parametric statistical treatments are false. This failure is due to the invalidity of the parametric model applied. To remedy the situation, robust methods were invoked. The performance of the robust estimates also proved to be severely impaired by the extent of deviation from the model implied.; Nonparametric statistics were used to circumvent the lack of an appropriate model. The metal concentrations in the sediment proved to be quite variable along the river and even between samples collected in close proximity of each other.; The data set in this investigation was large enough to draw attention to some interesting characteristics of the sampled system. It was not sufficiently extensive to resolve all the problems encountered.
机译：1996年冬天，犹他大学的通用化学（化学121-1）课程包括一个服务学习项目。学生试图确定约旦河沿岸各个地点的铅含量。约旦河是盐湖谷的主要水道，所选择的调查地点代表了河的有趣特征。在为期2周的一系列实地考察中，学生使用美国地质调查局提供的简单岩心采样器收集了水下沉积物样品。在实验室中，根据美国环境保护署颁布的Method 3050B的简化方案，通过“湿抓”法，然后通过酸消解，从部分沉积物中制备样品溶液。在肯尼科特·犹他州铜业公司环境实验室中，通过电感耦合等离子体原子发射光谱法对测试溶液进行了分析，不仅提供了所需的铅浓度，还提供了锌，铜和镉的浓度。学生的工作很成功。尽管存在限制和捷径，但确定的一组平均金属浓度与先前公布的结果相比却非常合理。然而，对数据的检查显示出意想不到的大量大浓度值，离群值。大量的“野生”浓度需要对分析结果进行统计评估。对数据的检查发现，常规和常规参数统计处理的结果是错误的。失败是由于所应用的参数模型无效。为了纠正这种情况，调用了健壮的方法。鲁棒估计的性能也因与所暗示的模型的偏离程度而严重受损。非参数统计用于避免缺乏适当的模型。沉积物中的金属浓度沿河甚至在彼此接近的样本之间变化很大。该调查中的数据集足够大，足以引起人们对采样系统有趣特征的注意。它还不足以解决所有遇到的问题。

著录项

  • 作者

    Konya, Gabor.;

  • 作者单位

    The University of Utah.;

  • 授予单位 The University of Utah.;
  • 学科 Chemistry Analytical.; Environmental Sciences.; Geochemistry.
  • 学位 Ph.D.
  • 年度 2003
  • 页码 141 p.
  • 总页数 141
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 化学;环境科学基础理论;地质学;
  • 关键词

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