AWWA ACE91033

Biological treatment, such as slow sand filtration, may help some water systems meet the requirements of the Surface Water Treatment Rule without violating the disinfection byproducts rule. The use of oxidants such as ozone or advanced oxidation processes can increase the biodegradability of natural organic matter (NOM). This paper offers a detailed overview of the subject, beginning with background information on the biodegradability of NOM and the use of ozone to enhance NOM biodegradability. The paper examines the effects of preozonation and water column biofilm support structures on slow sand filter performance and the microbiology of drinking water treatment processes receiving preozonation. The author also compares performance and microbiology of enhanced slow sand filters to conventional drinking water treatment processes using ozone.