Radiation Treatment of an
Industrial Waste
ALAN I. MYTELKA, Environmental Scientist
AeroChem Research Laboratories, Inc.
Princeton, New Jersey
RAYMOND M. MANGANELLI, Professor
Department of Environmental Sciences
Rutgers, The State University
New Brunswick, New Jersey
INTRODUCTION
Current methods of treating aqueous industrial wastes are not sufficiently
adequate to prevent water pollution; therefore, new methods are needed. Among
those being investigated is wet oxidation by means of different energy sources including chemical, thermal-high pressure, electrical, acoustical, and ionizing
radiation. This paper reports a study of ionizing radiation-induced changes in an
azo dyestuff waste and the effect of these changes on subsequent biological oxidation of the waste.
LITERATURE REVIEW
The use of ionizing-radiation in the fields of water and wastewater treatment
has been reported in the literature. Ridenour and Armbruster (1), Lowe, Lacy,
Surkiewicz, and Jaeger (2) and Dunn (3) have described the sterilization effects of
radiation on water and sewage, and Spragg (4), Grune (5), and Bio-Science Laboratories (6) have reported the effects of radiation on the settleability of sewage
and prepared colloidal solutions.
The reduction of detergent-caused foaming via ionizing radiation was also
investigated by Bio-Science Laboratories (6). A 99 per cent reduction of alkyl-
benzenesulfonate resulted when diluted (14 mg/1) solutions absorbed 35, 000 rads
(one rad = 100 ergs/gram) at 10.4 and 22. 6 rads/min. When the dose rate was increased to 796 rads/min, the same total dose reduced the ABS concentration by
only 70 per cent, indicating that the reactions occurring were dose rate dependent
at this higher dose rate.
To understand the effects of ionizing radiation on dilute aqueous industrial
wastes (less than approximately 0.1 moles of solute/liter), a brief review of pertinent aspects of radiation chemistry follows.
Ionizing radiation interacts with water to form excited molecules and to produce ions and electrons.   The reactions are:
H20   — H20* (1)
H20   —   H20+ + e" (2)
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