Radiolysis of aqueous solutions of nitrilotriacetic acid

The radiolysis of nitrilotriacetic acid (NTA) in neutral or alkaline solution, was studied in the presence and in the absence of dissolved oxygen. The radiolytic yields of decomposition of NTA and formation of iminodiacetic acid (IDA) were determined; G(- NTA) was found to be equal to G(IDA). The formation of hydrogen peroxide and carbonyl compounds was also followed. The radiolysis was found to be initiated by hydrogen abstraction by both H and OH radicals with the formation of a dehydrogenated radical intermediate which ultimately stabilizes to give products. The radiolytic mechanism under different conditions has been discussed. From competition kinetic studies with sodium formate in neutral solution, the rate constant, k(OH + NTA), was found to be 3.0 x 108 dm3 mol-1 s-1. (author)