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An ecologically engineered system for remediation of arsenic-contaminated water: Selecting plant species for northwest Ohio.

机译：生态工程修复砷污染水的系统：为俄亥俄州西北部选择植物物种。

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摘要

Arsenic has become a contaminant of significant concern around the world due to its prevalence and toxicity. The industrial and agricultural history of northwest Ohio created a legacy of arsenic contamination in the area, leaving current and future landowners with the task of remediation. Engineered wetlands could be part of an inexpensive and aesthetically-pleasing treatment strategy for removing arsenic from contaminated water because they rely on naturally-occurring physical, chemical, and biological processes. The role that wetland plants can play in arsenic remediation in temperate climates is not well understood. We do know that in order to maximize the removal of arsenic using wetlands, these plant species need to accumulate arsenic, survive prolonged arsenic stress, function during the course of a growing season, and to survive secondary contaminants that co-occur with arsenic.;During the course of this dissertation I hypothesized that native wetland plants could be used for arsenic phytoremediation and that using mixtures of plant species would maximize arsenic removal in the temperate climate of northwest Ohio. To test this hypothesis I performed four laboratory experiments using native plant species that accumulated arsenic in preliminary tests and have different growing seasons. (i) Carex stricta, Pycnanthemum virginianum, and Spartina pectinata tolerated an environmentally relevant concentration (1.5 mg As L-1) and continued removing arsenic when irrigated with arsenic-laden solutions for seven weeks. Their tolerance toward arsenic was evaluated in terms of contaminant uptake, growth, and chlorophyll content. (ii) When exposed to arsenic in conditions representative of spring and summer in northwest Ohio, the warm-season species ( S. pectinata) performed best in summer conditions, while the cool-season species (C. stricta) exhibited consistent uptake in both sets of conditions. A variety of warm- and cool-season species could be used to maximize the period of arsenic uptake during a growing season. (iii) The age of C. stricta and S. pectinata did not effect uptake by roots, but older plants transferred a greater portion of arsenic to leaves and stems than younger plants. Arsenic extraction could be maximized by allowing plants to accumulate arsenic throughout the growing season, and harvesting aboveground portions in the fall. (iv) The effects of arsenic, copper, and silicon varied in terms of uptake and toxicity in Azolla caroliniana and Lemna minor. Again, a mixture of plant species could be used to maximize the removal of each contaminant.;The results of this research indicate that native plants could be used in wetlands engineered for arsenic remediation, and that a community of plants could maximize uptake throughout the growing season. These findings will be used during the construction of microcosm and pilot-scale systems at a local, industrial site.
机译：由于砷的流行和毒性，它已成为世界范围内备受关注的污染物。俄亥俄西北部的工业和农业历史在该地区造成了砷污染的遗留问题，目前和未来的土地所有者都必须承担整治任务。人工湿地可能是一种廉价且美观的处理策略的一部分，该策略用于从受污染的水中去除砷，因为它们依赖自然发生的物理，化学和生物过程。湿地植物在温带气候下的砷修复中所起的作用尚不清楚。我们确实知道，为了最大程度地利用湿地去除砷，这些植物物种需要积累砷，在长期的砷胁迫下生存，在生长期过程中发挥功能，并与砷共存的次生污染物得以生存。在这篇论文的过程中，我假设本地湿地植物可以用于砷的植物修复，并且在俄亥俄州西北部的温带气候下，使用多种植物的混合物可以最大程度地去除砷。为了验证该假设，我使用了在初始测试中积累了砷且生长季节不同的天然植物物种进行了四个实验室实验。 （i）严格的Carex，严格的Pycnanthemum virginianum和Spartina pectinata耐受与环境相关的浓度（1.5 mg As L-1），并在充满砷的溶液灌溉7周后继续去除砷。根据污染物的吸收，生长和叶绿素含量评估了它们对砷的耐受性。 （ii）在俄亥俄州西北部代表春季和夏季的条件下暴露于砷时，暖季物种（S. pectinata）在夏季条件下表现最佳，而冷季物种（C. stricta）在这两种条件下均表现出一致的吸收套条件。可以使用各种暖季和凉季物种来最大化生长季节中砷的吸收时间。 （iii）C.stricta和S.pectinata的年龄不会影响根系吸收，但较年轻的植物，较老的植物将更多的砷转移到叶和茎上。通过使植物在整个生长季节中积累砷，并在秋季收获地上部分，可以最大程度地提取砷。 （iv）砷，铜和硅对小球藻和小球藻的吸收和毒性影响各不相同。同样，可以使用多种植物物种的混合物来最大程度地去除每种污染物。这项研究结果表明，本地植物可以用于为砷修复而设计的湿地中，并且植物群落可以在整个生长过程中最大限度地吸收季节。这些发现将在本地工业站点的缩影和中试规模系统的构建过程中使用。

著录项

  • 作者

    Rofkar, Jordan R.;

  • 作者单位

    The University of Toledo.;

  • 授予单位 The University of Toledo.;
  • 学科 Biology Ecology.;Engineering Environmental.
  • 学位 Ph.D.
  • 年度 2010
  • 页码 107 p.
  • 总页数 107
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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