TOXICITY, TRANSPORT & BIOREMEDIATION AT SUPERFUND SITES

本项目的重点是（1）开发评估风险的方法 （2）从危险废物处置场，以评估可行性 利用原生土壤微生物或细菌来降低这些风险 具有特定的生物降解特性。 我们的假设是一个垃圾场 是一个动态的系统，带来不断变化的风险。 这些不断变化的风险， 位于现场附近的生物体是有毒物质运动的函数， 现场内外的化学品，化学和微生物催化 废物的转化和毒物的相互作用， 暴露于多种化学物质。 了解正在发生的变化 在这个系统内，可能会导致补救策略的设计， 最危险的材料在一个特定的网站。 选择用于研究的化学品是氯代烃和有毒物质 金属. 大量使用氯化烃作为 在其有毒之前几十年的溶剂（例如，致癌性 成立了。 他们经常被不当处置，而且，作为一个 因此，它们是最广泛和潜在危险的 环境污染物。 因为氯化碳氢化合物由 碳、氢和氯，可以设想可以 完全矿化为二氧化碳水和氯离子 金属代表了一个非常不同的环境问题。 虽然 金属的化学和物理形态是受操纵的，金属 无法被摧毁 它们的毒性更难评估，因为 金属从生物体中缓慢排出， 组织. 因此，金属代表了一种截然不同的 风险评估和补救工作都面临挑战。

The focus of this project is (1) to develop methods to evaluate the risks from a hazardous waste disposal site and (2) to assess the feasibility of mitigating those risks using either native soil microorganisms or bacteria with specific biodegradative traits. Our hypothesis is that a waste site is a dynamic system which presents evolving risks. These changing risks to organisms located near the site are a function of the movement of toxic chemicals within and off the site, chemical and microbiologically catalyzed transformation of waste materials, and toxicant interactions based on exposures to multiple chemicals. Understanding the changes occurring within this system may lead to the design of remediation strategies for the most hazardous materials at a particular site. The chemicals chosen for study are the chlorinated hydrocarbons and toxic metals. A number of chlorinated hydrocarbons were heavily employed as solvents for decades before their toxic (e.g., carcinogenic) properties were established. They were frequently disposed of improperly, and, as a consequence, they are among the most widespread and potentially dangerous environmental contaminants. Because chlorinated hydrocarbons consist of carbon, hydrogen, and chlorine, techniques can be envisioned which can completely mineralize them to carbon dioxide, water, and chloride ion. Metals represent a much different environmental problem. Although the chemical and physical form of the metal is subject to manipulation, metals cannot be destroyed. Their toxicity is more difficult to evaluate because slow elimination from organisms permits metals to accumulate in living tissue. Consequently, metals represent a vastly different kind of challenge to both risk assessment and remediation efforts.