ABSTRACT
The application of ozone is not exclusive to the treatment of drinking water. Ozone also has numerous applications for the treatment of wastewater. Here, chlorine is mainly used for disinfection purposes, leading to many problems in the aquatic environment where treated wastewater is released.17 Thus, organochlorine compounds generated from wastewater chlorination can harm aquatic organisms in receiving waters. The U.S. Environmental Protection Agency (EPA) has established a limit of less than 11 0g/L for total residual chlorine in fresh water,18 which is usually surpassed when chlorinated wastewater is discharged.19 Thus, wastewater treatment plant operators must often balance two contradictory aspects: the use of chlorine for wastewater disinfection and the preservation of aquatic life. Thus, alternative oxidant-disinfectant agents are needed for wastewater treatment. As shown in Chapter 6, ozone has been used in the treatment of a variety of wastewater. It should be highlighted, however, that ozone, like other oxidants, also produces byproducts such as bromate (in water containing bromide), which can be harmful.20 The EPA promulgated the Stage 1 Disinfectants/Disinfection By-Products (D/DBP) Rule to regulate the MCL of bromate (10 0g/L), chlorite (1 mg/L), THMs (80 0g/L), and haloacetic acids (10 0g/L).21 This rule took effect on January 1, 2002 but the EPA
22 So, when using DBPs as much as possible.
