Formation of brominated products in irradiated titanium dioxide suspensions containing bromide and dissolved organic carbon

We report the irradiation of TiO(2) suspensions containing Br(-) and dissolved organic carbon (DOC). In the absence of DOC, we found no evidence for the formation of BrO(3)(-) upon irradiation of 1gL(-1) P25 suspensions with UV light for initial Br(-) concentrations up to 10mgL(-1). In the presence of DOC (Lake Hohloh, Germany and salicylic acid), we found no evidence for the formation of either BrO(3)(-) or trihalomethanes (THMs). However, small amounts of adsorbable organic halogen (AOX) were formed at high bromide concentrations (3mgL(-1)). When irradiating P25 suspensions containing bromide and 2,4-dihydroxybenzoic acid (DHBA, high bromoform formation potential), we observed the formation of significant amounts of bromoform (up to 10microgL(-1)). Bromoform appeared only after the DHBA had been degraded.