ABSTRACT
This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part provides the reader with a detailed background of the fundamentals involved in the bioremediation of contaminated surface soils, subsurface materials, and ground water. It discusses a number of bioremediation technologies along with the biological processes driving those technologies. The part also presents the application and performance of these technologies. The contaminants of major focus are petroleum hydrocarbons and chlorinated solvents. Location of the contamination in the subsurface is critical to the implementation and success of in-situ bioremediation. In the unsaturated zone, contamination may exist in four phases: air phase - vapor in the pore spaces; adsorbed phase - sorbed to subsurface solids; aqueous phase - dissolved in water; and liquid phase - nonaqueous phase liquids. Dense nonaqueous phase liquids contamination in heterogeneous subsurface environments is difficult to both identify and remediate.
