v/EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-82-011 Oct. 1982
Project Summary
Emerging Technologies for the
Control of Hazardous Wastes
Barbara H. Edwards, John N. Paullin, and Kathleen Coghlan-Jordan
:. Environmental Protection Agency
'; C:c--;;.-. DC, .rijorn Street
'cago, iinnois 60604.
.-.;>
Investigations were conducted of
new and emerging technologies for
the disposal of hazardous wastes.
These methods involve new techno-
logies or a recent variation on an
established one. In addition, a survey
was made of potential users of haz-
ardous waste information. The need
for a data base for emerging hazardous
waste technologies and/or a news-
letter was evaluated. Information on
the emerging technologies was ac-
quired by computerized search, library
searching, and personal contacts. The
emerging technologies discussed
include molten salt combustion,
f luidized bed incineration, high energy
electron treatment of trace organic
compounds in aqueous solution, the
catalyzed wet oxidation of toxic
chemicals, dehalogenation of com-
pounds by treatment with ultraviolet
(UV) light and hydrogen, UV/ chlo-
rinolysis of organics in aqueous
solution, the catalytic hydrogenation-
dechlorination of polychlorinated bi-
phenyls (PCBs), and ultraviolet/ozone
destruction. Theory, specific wastes
treated, and economics are discussed.
The major technologies investigated
in detail were molten salt combustion,
fluidized bed incineration, and ultra-
violet/ozone destruction.
Among the wastes treated by emerg-
ing technologies are PCBs, various
Dioxins, pesticides and herbicides,
chemical warfare agents, explosives
and propellents, nitrobenzene, and
hydrazine plus its derivatives.
This document encompasses a
target audience ranging from laymen
to natural scientists. The information
presented here was derived solely for
application to hazardous wastes.
Readers requiring more specific in-
formation about theory and the eco-
nomics of start-up plus operating and
maintenance costs for technologies
that may by applied to a specific haz-
ardous waste not discussed in this re-
port are referred to the literature cited
in this report and to documents about
state-of-the-art situations for a parti-
cular technology.
This Project Summary was devel-
oped by EPA's Industrial Environ-
mental Research Laboratory. Cincin-
nati, OH. to announce key findings of
the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
The material for the identification and
evaluation of these technologies has
been gathered through an intensive
literature survey conducted over the
course of a year. Although extensive
use has been made of manual and
computerized data bases, it was also
necessary to monitor the recent liter-
ature and forthcoming conferences and
symposia abstracts access material not
yet in the literature. Personal commun-
ications were alsp used in the survey.
Major hazardous waste generators in
the United States were surveyed for
their hazardous waste information
needs. Fifty-three of the 72 companies
surveyed were identified by a Waste
Disposal Site Survey Report from the
House of Representatives Committee
on Interstate and Foreign Commerce
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(Subcommittee on Oversight and In-
vestigations) as the largest domestic
generators of hazardous waste.
Conclusions
Molten salt combustion
Molten salt technology has existed
for many years, but it has not been used
for the disposal of hazardous wastes
until recently In the process, hazardous
material is combusted at temperatures
below its normal ignition point, either
beneath or on the surface of a pool of
molten salt Individual alkali carbonate
salts such as sodium carbonate, or
mixtures of these salts, are usually used
as the melt, but other salts can be
employed based on the characteristics
of the waste. Containers for the molten
salts are made of ceramics, alumina,
stainless steel, or iron. Ideally, during
the molten salt process, organic sub-
stances are totally oxidized to carbon
dioxide and water. Generally, the salt
bath is stable, nonvolatile, nontoxic, and
may be recycled for further use until the
bath is no longer viable. The technology
has progressed from bench-scale through
the pilot plant stage to the construction
of a demonstration-sized coal gasifi-
cation unit. Portable units mounted on
trucks have been tested.
Some of the advantagesof molten salt
combustion are as follows:
Combustion is nearly complete.
Non-polluting off-gases are gen-
erally emitted.
* Operating temperatures are lower
than in normal incineration;
thus, they are fuel efficient.
The system is amenable to recy-
cling generated heat.
A wide variety of wastes can be
combusted.
Bulky wastes can be combusted
after recycling.
Many wastes can be combusted
in compliance with EPA regula-
tions.
Some of the problems of mol-
ten salt combustion are as follows:
Particulate emissions from some
wastes are high.
The technology is not readily
adaptable to aqueous wastes.
Eventually waste salt and ash
must be disposed of or the fluidity
of the melt will be destroyed.
A hazardous waste with greater
than 20% ash cannot be com-
busted.
Detailed economic information
for a demonstration-sized system
is not currently available for
many wastes (1980).
2
Fluid/zed bed incineration
Fluidized bed systems have had many
industrial uses since the technology
was proposed by C.E. Robinson about a
century ago, yet fluidized bed inciner-
ation of hazardous wastes is a relatively
new technique. A hot fluidized bed is
ideal for combustion. Air passage
through the bed produces strong
agitation of the bed particles, which
promotes rapid and relatively uniform
mixing of carbonaceous materials The
bed mass is large in relation to the
injected waste, and bed temperatures,
which usually range from 750°-1000°C,
are usually uniform Bed materials have
included sand, sand mixtures, dolomite,
and alumina.
Some advantages of fluidized bed
incineration are as follows:
The combustor design is simple
and does not require moving
parts after the initial feeding of
fuel and waste.
Fluidized bed incineration has a
high combustion efficiency.
Designs are more compact due to
high volumetric rates.
Comparatively low gas temper-
atures and excess air require-
ments minimize the formation of
nitric oxide.
In some cases, the bed itself
neutralizes some of the hazardous
products of combustion.
A vertical induced draft inciner-
ator was converted into a fluidized
bed.
The bed mass provides a large
surface area for reaction.
Temperatures throughout the
bed are relatively uniform
Fluidized beds are able to process
aqueous waste slurries
If the waste contains sufficient
calorific value, the use of auxiliary
fuel is unnecessary; moreover,
the excess heat'may be recycled
in some cases.
The bed can function as a heat
sink; start-up after weekends
may require little or no pre-heat
time.
Disadvantages of fluidized bed com-
bustion are as follows:
Bed diameters and height are
limited by design technology.
Ash removal presents a potential
problem.
Systems requiring low tempera-
tures may have carbon build-up
in the bed due to increased
residence time.
Certain organic wastes w
cause the bed to agglomerate.
Paniculate emissions can be
major problem.
UV/ozone destruction
Ozone treatment is an estabhshe
technology for the treatment of som
hazardous wastes; the combination c
UV light and ozonation recently ha
been found to be a more effectiv
process for destroying hazardous wast
than the use of ozonation alone. Th
addition of UV light to the ozonatio
process has greatly expanded th
number of compounds that can b
destroyed. PCBs are among the halo
genated compounds destroyed Com
pounds with shielded multi-bondei
carbon atoms, sulfur compounds, ani
phosphorous compounds are les
susceptible to UV/ozonation. Dioxms
nitrobenzene, and hydrazines hav<
been destroyed by UV/ozonation
Some advantages of UV/ozonatior
are as follows:
Aqueous or gaseous waste
streams can be treated.
Capitol and operating costs are
not excessive.
Chemical carcinogens and mut
agens can be treated.
The system is readily adaptable
to on-site treatment of the haz-
ardous waste.
It can be used as a final treatment
to supplement partial treatment
systems.
It can be used as a preliminary
treatment for certain hazardous
wastes.
It can be used to meet effluent
discharge standards.
Modern systems are usually
automated, thereby reducing
labor requirements.
Some disadvantages of UV/ozonation
are as follows:
Ozone is a non-selective oxidant;
therefore, the waste stream
should contain primarily the
waste of interest.
UV/ozone systems are generally
restricted to 1 % or lower levels of
hazardous compounds. Frequent-
ly, hazardous substances are
treated at ppm levels
Ozone decreases rapidly with
increasing temperature; therefore
excess heat must be rapidly
removed.
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Results of hazardous waste
information survey.
Fifty-three major hazardous waste
generators were surveyed for their
hazardous waste information needs.
Major information needs are
new technologies for hazardous
waste disposal,
state-of-the-art methods for
hazardous waste disposal,
best technologies available for
destruction of specific wastes
plus costs,
updated federal and state regu-
lations for waste generation,
transportation, storage, and de-
struction of landfills,
techniques to identify mixed
waste streams,
toxicity data on specific hazardous
wastes,
location of approved hazardous
waste disposal sites and tech-
nology available at the site;
identity of hauling contractors,
waste exchange and recycling
information.
Recommendations
The emerging technologies evaluated
in this study can be considered as
alternatives to landfill disposal of
hazardous waste. It is presumed that
the emerging technologies will destroy
the waste or at least attenuate it to
acceptable levels. The advantages and
disadvantages of each emerging tech-
nology presented must be carefully
considered when selecting the technol-
ogy most suitable for the control of
specific hazardous wastes is selected.
The information needs for major
hazardous waste generators could best
be met by the use of a hazardous waste
data base supplemented by newsletters
and telephone "hotlines "
Hazardous wastes destroyed
by emerging technologies
A. Molten salt combustion:
Miscellaneous
PCB's
Chloroform
Perchloroethylene distillation bottoms
Trichloroethane
Tributyl Phosphate
Nitroethane
Monoethanolamine
Diphenylamine HCI
Rubber tire buffings
Para-Arsanilic Acid
Contaminated ion exchange resins
(Dowex and Powdex)
High-Sulfur Waste Refinery Sludge
Acrylics Residue
Tannery wastes
Aluminum Chlorohydrate
Pesticides and herbicides
Chlordane
Weed B Gone
DDT powder
Malathion
Sevm
DDT powder with Malathion
2, 4-D Herbicide-Tar Mixed waste
Real and simulated pesticide
containers
plastic, rubber, and a blend of these
Feasible pesticides and nitrite
herbicides
Pesticides Nitrile Herbicides
trifluralin
2, 4, 5-T dichlorobinil
MCPA
dieldrin
heptachlor
aldrin
toluidme
B. Fluidized bed incineration:
Miscellaneous
HCI spent pickling liquor
Organotin in spent steel slag blasting
abrasive
Organic dye slurries
red dye slurry (1 -methylaminoan-
thraquinone and starch gum)
yellow dye slurry (dibenzpyrene-
quinone and benzanthrone)
Chlorinated hydrocarbons
PVC waste from a chemical plant
PVC mixed with coal
PVC insulation over copper wire
Chlorinated hydrocarbon waste with
90% chlorine
Munitions (slurry)
TNT
RDX(cyclotrimethylenetrinitramme)
Composition B
C. UV/ozonation technology:
Miscellaneous
PCB's
TCDD (2, 3, 7, 8-tetrachlorodi-
benzo-p-dioxin)
OCDD (octachlorodibenzo-p-dioxin)
Chlorodioxins (other dioxins are
feasible)
Hydrazine
Monomethyl hydrazine
Dimethyl hydrazine (asymmetrical)
Copper process waste stream
Nitrobenzene
Barbara H. Edwards, John N. Paullin, and Kathleen Coghlan-Jordan are with
Ebon Research Systems, Washington, DC 20011
T. L. Baugh is the EPA Project Officer (see below).
The complete report, entitled "Emerging Technologies for the Control of
Hazardous Wastes," (Order No. PB 82-236 993; Cost: $15.00, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
ĞU.8.GOVERNMENTHtlNTWa OFFICE: 1M2-559-017/0839
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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
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