452 HAZARDOUS WASTE MANAGEMENT
vapor extraction (SVE) and thermal desorption. It is impor-
tant to note that there are many derivative technologies that
will now stand a greater chance of receiving government and
industry support as a result.
Remediation technologies that are derived from soil
vapor extraction include dual phase extraction and sparing.
The two phases are typically a) removal of free product or
contaminated groundwater and b) vapor. The in-situ addition
of certain compounds by sparging into the soil and ground-
water has made bioremediation attractive. The addition of
the additional components to an earlier technology that was
moderately successful has made the modified treatment train
much more effective. The new treatment train is therefore
more approvable.
On a financial level, methods have been developed for
the evaluation of large projects to provide a greater degree
of financial assurance. The concept of the “unknown” cost
of remediation due to the inability of scientists to accurately
see and measure subsurface contamination is diminishing.
Probabilistic cost analyses are frequently completed on
assignments so that final remediation costs can be predicted
within a much narrower range.
Management practices have changed dramatically over
the past 20 years at most industries. They have been driven
by the improvements in technologies, as well as the laws and
regulations. The real estate boom of the 1980s also impacted
operating practices, as many properties were bought and sold
during this time. The desire of buyers to be assured that they
were purchasing “clean” properties, as well as some state
environmental property transfer requirements, was the gen-
esis of facility environmental audits as we now know them.
For purposes of discussion, hazardous wastes fall primar-
ily into two categories, organic and inorganic. Some manage-
ment technologies will apply to both, but in general organic
material can be destroyed to relatively innocuous end prod-
ucts while inorganic material can only be immobilized. The
key technologies for hazardous waste management include:- Pollution Prevention
- Recycling and Reuse
- Waste Minimization
- Chemical Treatment and Detoxification
- Destruction
- Stabilization
- Land disposal
Of these, land disposal is the least attractive alternative from
the standpoint of long-term liability exposure and environ-
mental impact.Waste Concentration—A Key Where a waste must be ulti-
mately disposed of, concentration or volume reduction is
beneficial. The simplest approach to this is to separate wastes
at the source; that is, at the place of origin. This will increase
handling costs and effort, but will more than pay dividends in
minimizing analytical and disposal costs. First, it will mean
that analysis must be done less frequently. Second, waste can
be disposed of at the lowest degree of care consistent with themost hazardous contaminant, thus minimizing the volume of
waste that must get a greater degree of care because of slight
cross-contamination by a more toxic material. This is true
whether the material is in the liquid or solid state.
Another method of reducing volume is concentration.
For liquids, this generally means distillation or evapora-
tion. Evaporation to date has been acceptable, however, with
increased emphasis on the presence of volatile hazardous
materials in the atmosphere, evaporation ponds, will, in all
probability, no longer meet the necessary standards for waste
control and management. In addition, ponds must be per-
mitted under RCRA, which imposes additional financial and
operating requirements on the waste concentrator. Double
and triple effect evaporators and distillation units will be
acceptable but are very energy-expensive. Innovative tech-
niques will be required because of the high energy of the
traditional liquid separation systems.
Where a material is dissolved in water or an organic sol-
vent, precipitation may be advisable. The solid can then be
separated out from the majority of the liquid by filtration
or other liquid/solid separation technology. Typical of this
would be the precipitation of lead by the use of a sulfide salt,
resulting in lead sulfide which has extremely low solubility.
The solid may be suitable for reclamation at present or be
stored in a secure landfill in a “non- or less-hazardous form”
for eventual reuse.Pollution Prevention The passage of Pollution Prevention
Laws has driven many industries toward better utilization of
their resources. Many companies now actively participate
in the preparation and update of a pollution prevention pro-
gram, designed to guide personnel toward goals established
to improve waste generation and disposal practices.
Traditional environmental quality and pollution control
programs typically focus on an end-of-pipe approach. The
pollution prevention plan approach typically begins earlier
in the “equation” by reviewing an operation and making
modifications that will positively impact a facility. Some
examples include reducing harmful chemical purchases,
increasing operation efficiencies, and ultimately generating
a smaller quantity of waste.
The pollution plan approach will include involvement
by a wider range of facility personnel than the traditional
environmental management approach. Purchasing, account-
ing, production and engineering all participate. Proponents
suggest that a program is easy to implement, although corpo-
rate personnel involved in the effort know that it is an effort
which requires broad-based management support, is time
consuming, and not necessarily inexpensive to implement.
The benefits are potentially significant, as reduced emissions
make it easier to comply with discharge standards, and will
reduce long-term liabilities.Recycling and Reuse In many cases, in addition to eco-
nomically attractive alternatives, a very attractive alternative
will be recycling or reuse of hazardous wastes. The eco-
nomic realities of the regulations, where disposal of a barrel
of waste can demand a 5–$10 per gallon, and up to $1,200 perC008_001_r03.indd 452C008_001_r03.indd 452 11/18/2005 10:28:44 AM11/18/2005 10:28:44 AM