ABSTRACT
This chapter describes the mechanisms for removal of contaminants from soils by water and analyses water flushing extended to methanol and surfactant flushing. It discusses the physicochemical properties of surfactant solutions important to enhanced in situ soil flushing. Enhanced soil-flushing methods that have been suggested are the use of solvents and the use of ionic and nonionic surfactants. The chapter describes the remediation of multicomponent mixtures of gasoline-range hydrocarbons. An understanding of the significant mechanisms is needed to assess the practicality of soil flushing as a remediation process. The mathematical model also provides a useful framework for comparing the potential of different flushing processes for in situ remediation of soil. For an in situ process, injection equipment will be required as well as facilities for treating the effluent. Poor contact of the flushing solution with the contaminated region is a limitation for all in situ remediation processes.
