Influence of Preozonation on the Formation of Chlorination Disinfection By-products - A Case Study: The Uzquiza Reservoir Water

The influence of preozonation on the formation of chlorination disinfection by-products (DBPs) is studied for three different types of water: a natural water from the Uzquiza Reservoir (Burgos, Spain), synthetics waters prepared using natural fulvic and humic acids extracted from the Uzquiza Reservoir and a synthetic water prepared using a commercially supplied humic acid. The main factors intervening in this process have been reviewed: the delay time between ozonation and chlorination, the ozone reaction pathway, the type of NOM, the applied ozone dose and the presence of bromide ion. Preozonation decreases trihalomethane formation potential (THMFP) for both humic and fulvic acids, being this effect more significant for the humic acids. The molecular pathway of ozone seems to be more selective than the radical pathway for THMFP removal from humic acids. Ion bromide content of the raw water greatly influences the effect of preozonation on THMFP. The influence of preozonation on the formation of some minority DBPs has been studied too.