Photochemistry of nitrite and nitrate in aqueous solution: a review

It has long been known that the photolysis of nitrite and nitrate solutions results in the formation of (OH)-O-. radicals. The mechanism of NO3- photolysis has been the subject of considerable controversy in the literature, however. This review summarizes the experimental work on NO2- and NO3- photolysis in the context of recent advances in the understanding of the chemistry of the peroxynitrite anion (ONOO-) in biological experiments. ONOO- has been found to play a far more significant role in the overall reaction mechanism of NO3- photolysis than had previously been suspected. Research on NO2- and NO3- photolysis, as a pathway to the destruction of organic contaminants in natural waters, is summarized. The possible impact of NO2- and NO3- on Advanced Oxidation Technologies (AOTs), in which (OH)-O-. radicals are used to initiate the destruction of hazardous organic pollutants in drinking water and industrial waste streams, is explored. (C) 1999 Elsevier Science S.A. All rights reserved.