Ammoniacal bromamines: A review of their influence on bromate formation during ozonation

Ammonia can inhibit the formation of bromate in ozonated drinking water by reacting with free bromine (HOBr/OBr-), an intermediate in bromate formatio n, to form bromamines. Bromamines do not participate in bromate formation, however, they will decay due to autonomous decomposition and through reacti on with ozone and hydroxyl radicals. The reaction with ozone controls the o verall decay rate. This reaction also results in a net loss of ammonia from the system, leading to the possibility that all ammonia may be oxidized be fore the ozone residual in the water is eliminated, allowing bromate format ion to resume. This paper presents a review of our understanding of bromami ne chemistry and identifies areas that are not adequately understood, which may prevent an accurate estimation of ammonias impact on bromate formation . (C) 2001 Elsevier Science Ltd. All rights reserved.