Effects of radiation on corn starch sols

The effect of gamma radiation from cobalt-60 on the sedimentation and degradation of corn starch sols in polyethylene bottles was investigated for doses between 103 and 106 rad. The degree of sedimentation was determined by spectrophotometric measurements on the sols before and after irradiation, and the degree of degradation was determined similarly by observations on the starch-iodine complex after the addition of iodine. In contrast to the results obtained by other investigators using synthetic sewage colloids (see Wat. Pollut. Abstr., 1964, 37, Abstr. No. 1801), it was found that at higher radiation doses the degree of sedimentation was decreased, although greater degradation of the starch occurred and this resulted in a reduction in turbidity.