AEPA
United States
Environmental Protection
Agency
EPA/540/F-92/004
February 1992
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Emerging Technology Bulletin
Laser Induced Photochemical Oxidative Destruction
Energy and Environmental Engineering, Incorporated
Technology Description: The process developed by Energy
and Environmental Engineering, Incorporated, is designed to
photochemically oxidize organic compounds in wastewater by
applying ultraviolet radiation using an Excimer laser. The photo-
chemical reactor can destroy low to moderate concentrations of
organics in water. The energy is sufficient to fragment the bonds
of organic compounds, and the radiation is not absorbed to any
significant extent by the water molecules in the solution. The
process is envisioned as a final treatment step to reduce organic
contamination in ground water and industrial wastewaters to
acceptable limits.
The overall reaction chemistry uses hydrogen peroxide as the
oxidant in the reaction:
CaHbX + (2a+0.5 (b-1))H2O2"»-» aCO2 + (2a+(b-1 ))H2O + HX
where C HbX is a halogenated toxic component in the aqueous
phase, the reaction products are carbon dioxide, water, and the
corresponding halogen acid, HX.
The existing process equipment has a capacity of 1 GPM when
treating a solution containing 32 ppm of total organic carbon. It
consists of a photochemical reactor, where oxidation is initiated,
and an effluent storage tank to contain reaction products (Figure
The skid-mounted system can be used in the field and stationed
at a site. The exact makeup of the process will depend on the
chemical composition of the groundwater or wastewater being
treated.
Typically, contaminated groundwater is pumped from a feed well
through a filter unit to remove suspended particles. The filtrate is
then fed to the photochemical reactor and irradiated. The chemi-
cal oxidant (H2O2) is introduced to the solution to provide hydroxyl
radicals required! for oxidation.
The roactor effluent is directed to a vented storage tank, where
the CO2 oxidation product is vented. An appropriate base (such
Waste
Water
Q
FC
Metering Pump
Initiation
Photochemical
Reactor
Vent
Decontaminated
Effluent
Effluent
Storage Tank
& Propagation
Reactor
Figure 1. Process Flow Scheme,
Printed on Recycled Paper
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as CaCO,) may be added to the storage tank to neutralize any
hatogenafed acids formed when treating fluids contaminated with
halogenated hydrocarbons.
The reaction kinetics depend on:
a) toxicant concentration
b) peroxide concentration
c) irradiation dose
d) irradiation frequency
Waste Applicability: This technology can be applied to
groundwater and industrial wastewater containing organics.
T©St Results: Table 1 presents typical reaction times for given
levels of destruction for several toxicants of concern.
7aWe "t . Destftsstlen of Toxic Organics by Laser-Induced Photochemical
Oxidation
Reaction Time (hr) Destruction Achieved
Benzene
B@ftZidin8
Ghhfobmzena
Chfofophenol
Dieftlofoethene
Phmoi
96
268
114
72
624
72
0.91
0.88
0.98
0.99
0.88
0.99
Destruction Achieved,,,,-^,
.,„
Where
C^ * » Contaminant Concentration in to reactor, with irradiation
C^" = Contaminant Concentration out of reactor, with irradiation
Cfe «• Contaminant Concentration in to reactor, no irradiation
O = Contaminant Concentration out of reactor, no irradiation
Table 2 lists the compounds that can be treated successfully by
Laser-Induced Photochemical Oxidative Destruction.
Table 2. Compounds Treated with UV/Oxidation
Ethers
BTEX
Phenol
TCE
PCE
DCE
Polynitrophenols
Ketones
Vinyl Chloride
Pesticides
Citric Acid
TCA
DCA
Ma a,
Cresols
PCBs
PCP
TNT
Aromatic Amines
Complexed Cyanides
PolynuclearAromatics
Dioxins
Hydrazine
RDX
1,4 Dioxane
EDTA
Hydrazine
The process is now entering the initial phases of commercializa-
tion, with the company offering to conduct treatability studies for
prospective clients. Preliminary cost evaluation shows that the
process is very competitive compared to other UV oxidation
processes and carbon adsorption.
For Further Information:
EPA Project Manager:
Ronald F. Lewis
U.S. EPA Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7856 (FTS: 684-7856)
Technology Developer Contact:
James H. Porter
President
Energy and Environmental Engineering, Inc.
East Cambridge, MA 02141
617-666-5500
United States
Environmental Protection
Agency
Center for Environmental
Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/540/F-92/004
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