THE USE OF OZONE AND ASSOCIATED OXIDATION PROCESSES IN DRINKING-WATERTREATMENT

This paper summarizes the main applications of ozonation and associate d oxidation processes in the treatment of natural waters (surface and ground waters) for drinking water production. In fact, oxidants may be added at several points throughout the treatment: pre-oxidation, inte rmediate oxidation or final disinfection. So, the numerous effects of chemical oxidation are discussed along the water treatment: removal of inorganic species, aid to the coagulation-floculation process, degrad ation of organic matter and disinfection. Of prime importance in potab le water production is the removal of organic matter (natural humic su bstances, as well as micropollutants, especially pesticides) to avoid degradation of the distributed water (mainly bad odors and tastes; for mation of disinfection by-products such as trihalomethanes; microbial regrowth in the distribution system). Consequently, this point has bee n particularly detailed in this paper. As a matter of fact, complete m ineralization hardly occurs during the process; as a consequence, furt her treatment (i.e. sand or granular activated carbon filtration! is r equired to improve the distributed water quality, and to meet the drin king water regulations. (C) 1998 Elsevier Science Ltd. All rights rese rved.