The LIPOD process oxidizes low levels of toxic organic chemicals in aqueous solutions. The toxic organic compounds include unsaturated and chlorinated organic compounds. These compounds rank high on the EPA’s list of priority pollutants. Because of low concentrations (parts per billion) removal of these compounds from wastewater can be difficult.

The oxidation process uses a UV laser to excite organic compounds in the presence of an oxidant to initiate a chain oxidation reaction. The UV source is an excimer laser, which excites gas to produce a high-intensity coherent energy source. The oxidant is hydrogen peroxide, which mixes with water. The laser’s energy initiates hydrogen peroxide oxidation of the organic compounds. Hydroxyl radicals, which are powerful oxidants, are produced when the laser impacts the hydrogen peroxide.

Sufficient oxygen or hydroxyl radicals are formed to completely oxidize the organic compounds to carbon dioxide, water, and inorganic ions. The narrow band UV radiation is preferentially absorbed by the organic molecules and hydrogen peroxide. Little radiation is absorbed by the surrounding water molecules. The process requires no ozone use. The wastewater needs to be exposed to the UV light for a short time (less than 50 seconds) to initiate the oxidative chain reaction. Only a portion of the contaminated water is exposed to the UV radiation source in the presence of hydrogen peroxide. The exposed water can be mixed with unexposed water to cause a chain oxidation reaction. These chain reactions can last 40 to 62 hours. In the LIPOD process, the feed stream containing the toxic organic compounds and hydrogen peroxide flows countercurrent to the laser beam in a photochemical reactor where the compounds are irradiated. When oxidizing halogenated solutions, the reaction byproducts are carbon dioxide, water, and the halide ion.

The compliance benefits listed here are only meant to be used as a general guideline and are not meant to be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g. the amount of workload involved.

Consult your local Industrial Health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing any of these technologies.

• The LIPOD is effective in destroying benzene, chlorobenzene, chlorophenol, dichloroethene, benzidine, and phenol. Destruction percentages of the test compounds measure using LIPOD ranged from 89% to greater than 99%. Destruction of other contaminants can be achieved by varying the electromatic.
• The destruction of the chemicals occurs during the initiation phase of the reaction when reactants are exposed to the light source, and continues as the reaction proceeds in the absence of light. Limited destruction is also achieved during the photochemical initiation phase for all compounds irradiated. Increased destruction can occur during this phase only when a greater irradiation dose is applied. After several days, changes in the percent destruction is dependent on the concentrations of toxic organic compounds and hydrogen peroxide, and the irradiation dose applied during the initiation phase.

Based on a 50 mg/L initial toxic concentration, the cost to operate the LIPOD range from $0.01/L to $0.02/L ($0.03/gal. to $0.07/gal.). The cost reflects the complete conversion of toxic organic compounds to carbon dioxide and water.