CAREER: Innovative Soil Remediation Methodologies - CAREER Development

Northeastern University, Boston MA

Investigators

Abstract

This action is taken within the NSF Faculty Early Career Development (CAREER) Program NSF 00-89, to support a research/education career plan in geoenvironmental engineering, with emphasis on innovative soil remediation. The research component investigates the use of electroosmosis for transport of oxygen (produced by electrolysis) into fine-grained soils in order to stimulate in situ bioremediation of trapped organic contaminants. The educational component integrates the technical tasks of the project into the broader aspects of teaching in geoenvironmental engineering so as to reach students at different levels. Oxygen delivery is generally the limiting factor for in situ bioremediation due to low soil permeabilities and preferential flow paths. The use of electric currents is being investigated to overcome oxygen injection problems. Application of a direct current (dc) results in controlled oxygen production by water electrolysis at the anode. Electroosmotic flow then delivers oxygenated water into contaminated silt and clay layers to stimulate bioremediation of trapped organic contaminants. This process is complex and involves as-yet-undetermined hydrogeological, electrochemical and biogeochemical interactions, such as microbial behavior under electric fields. The research focuses on (a) rates of oxygen production and transport in fine-grained soils by dc electric fields, (b) impact of electric fields on microbial growth and transport in porous media, (c) stimulating in situ degradation of organic contaminants in fine-grained soils by electrochemical production/transport of oxygen, and (d) enhancing degradation in heterogeneous soils. The goal of the education component is to incorporate the findings of this project in a new undergraduate geoenvironmental engineering course being developed by the Principal Investigator. Undergraduate students will participate in the research through the Northeastern University Cooperative (Co-op) education program. The PI will also reach out to high school students by developing an educational CD-ROM that will (a) demonstrate the link between the basic sciences and engineering applications (geotechnical and environmental engineering in particular) and (b) attempt to promote civil and environmental engineering as exciting fields of study and practice. The PI will also partner with CONNECTIONS, a NSF funded project that is designed to help women transition into careers in science, engineering, and math (SEM). The PI will provide opportunities for high school girls, girl scouts and undergraduate women, sponsored by CONNECTIONS, to learn about geotechnical and environmental engineering, evaluate the educational CD-ROM, and participate in the research and educational tasks of this project. Graduate students will participate in the research and gain an excellent experience in cutting-edge, practice-oriented geoenvironmental research. A final goal is to further the PI's development as an educator by adopting innovative teaching and assessment techniques. A WEB site will be developed and continuously updated to present the research and educational components of this project.