Solidification/stabilization, also referred to as waste
fixation, reduces the mobility of hazardous substances and
contaminants in the environment through both physical and
chemical means . Stabilization generally refers to the process that
reduces the risk posed by a waste by converting the
contaminant into a less soluble, immobile, and less toxic
form. Solidification refers to the process that encapsulates the
waste materials in a monolithic solid of high structural
integrity . In situ stabilization and solidification involves three main
components: (1) a means of mixing the contaminated soil in
place; (2) a reagent storage, preparation, and feed system;
and (3) a means to deliver the reagents to the soil mixing zone
(Nyer, 1996). In situ and ex situ stabilization/solidification is
usually applied to soils contaminated by heavy metals and
other inorganic compounds. However, stabilization of soils
that contain low levels of organic constituents is feasible,
even for volatile organics . Most stabilization/solidification technologies have
limited effectiveness against organics and pesticides, except
for asphalt batching and vitrification which destroys most
organic contaminants .