Method for destruction of toxic substances with ultraviolet radiation

DETAILED DESCRIPTION The present invention provides a method for breaking down toxic compounds of the above sort into their final non-toxic end-products through direct ultraviolet irradiation.
The invention achieves this result by applying sufficiently intense UV radiation from the deep region of the UV spectrum in a sufficiently broad band to form an effective continuum and thereby overlap with the absorption curves for essentially any of the toxins of interest and of their toxic byproducts (if any) from such UV photodissociation.
More particularly, it has been found that effective destruction of toxins with concentrations ranging from 200 parts per million (ppm) to 10 parts per billion (ppb) can be achieved by delivering the deep UV radiation to the target medium in pulsed fashion where the root-mean-square (rms) and peak power delivered by the UV source are related to the average power by characteristic ratios, while the average power density is at least a minimum characteristic value.
The precise values of the characteristic ratios and power densities that optimize the destruction of the target toxins depends upon the concentrations and the carrier medium of the toxins.
Nevertheless, it has been found that the surprisingly effective destruction achieved by the invention will generally be attained when the ratio of rms power to average power falls in the characteristic range of 10:1 to 100:1; the ratio of peak power to average power falls in the characteristic range of 1000:1 to 10,000:1; and the UV average power density is maintained at least at a value of about 0.
1 Watt/cm.
sup.
2 within the carrier medium.
The characteristic profile of the UV radiation provided according to the invention is such that it can be achieved within the bounds of a practical instrument.
Other features and advantages of the invention will be described below or will be apparent to those skilled in the, art from the following description and accompanying drawings.