Common treatment technologies for halogenated SVOCs in soil,
sediment, and sludge include biodegradation, dehalogenation,
incineration, and excavation with off-site disposal.
All types of biodegradation, in situ and ex situ, can be
considered to remediate soils: in situ bioremediation,
bioventing, composting, controlled solid phase, or landfarming.
Slurry phase biological treatment is also applicable but is less
widely used. Treatability studies should be conducted to evaluate
design parameters, such as degradation rates, supplemental
organism addition, cleanup levels achievable, degradation
intermediates, and nutrient/oxygen addition.
a process in which indigenous or inoculated microorganisms (e.g.,
fungi, bacteria, and other microbes) degrade (i.e., metabolize)
organic contaminants found in soil and/or . In the presence of
sufficient oxygen (aerobic conditions), microorganisms will
ultimately convert many organic contaminants to carbon dioxide,
water, and microbial cell mass. In the absence of oxygen
(anaerobic conditions), the contaminants will be ultimately
metabolized to methane and carbon dioxide. Sometimes contaminants
may not be completely degraded, but only transformed to
intermediate products that may be less, equally, or more
hazardous than the original contaminant.
The in situ bioremediation of soil typically involves the
percolation or injection of ground water or uncontaminated water
mixed with nutrients. Ex situ bioremediation typically uses
tilling or continuously mixed slurries to apply oxygen and
nutrients, and is performed in a prepared bed (liners and
aeration) or reactor.
adds reagents to soils contaminated with
halogenated SVOCs. The dehalogenation process is achieved by
either the replacement of the halogen molecules or the
decomposition and partial volatilization of the contaminants.
high temperatures, 870o to 1,200o C (1,400o
to 2,200o F), to volatilize and
combust (in the presence of oxygen) organic constituents in
hazardous wastes. The destruction and removal efficiency (DRE)
for properly operated incinerators exceeds the 99.99% requirement
for hazardous waste.
Distinct incinerator designs available for solids are rotary
kiln, fluidized bed, and infrared units. All three types have
been used successfully at full scale.
For incineration of halogenated SVOCs, off-gas treatment is
needed to neutralize the acidic gas as the products of oxidation.
Excavation, retrieval, and
off-site disposal of contaminated soil (with or
without stabilization) to a landfill have been performed
extensively at many sites. Landfilling of hazardous materials,
especially hazardous wastes, is becoming increasingly difficult
and expensive as a result of growing regulatory control, and may
be cost-prohibitive for sites with large volumes, greater depths,
or complex hydrogeologic environments. Determining the
feasibility of off-site disposal requires knowledge of land
disposal restrictions and other regulations developed by state