Trihalomethane Reduction (THMs)
How Ozone Technology Reduces Disinfection ByproductsRecently, much attention has been focused on disinfection byproducts, particularly disinfection with chlorine. A recent survey in Texas for public drinking water plants serving populations below 10,000 people found alarming levels of trihalomethanes (THM). For the record, a total of 400 municipalities were served notice of violation by the Texas Commission on Environmental Quality. Another byproduct of chlorine oxidation is known to be haloacetic acids (HHA5). PTHM and HHA5 are known to be carcinogens and long-term exposure may cause liver, kidney, and rectal cancer; also birth defects and nervous-system problems.
BiOzone's water treatment process trains are not designed to remove trihalomethanes from the drinking water because trihalomethanes are inert to ozone oxidation, and only ozonation with catalysts or a photolyst could achieve a breakdown using reaction times in excess of 60 minutes.
Ozone is most effective, however, by either eliminating or significantly reducing precursors in the raw water responsible for THM formation. The ozonation process train applied to oxidize and render these precursors harmless is described on the home page. Oxidation and subsequent carbon filtration will significantly reduce the total organic carbon content or chemical oxygen demand of the raw water. Experience has told us that with the proper ozone dosage, ozone concentration, reaction times, and proper selection of the activated carbon, significant reductions of organic loading of up to 95 percent can be achieved. Not only have we reduced the precursors; we have also generated organic chemicals, with ozone oxidation, which show a much higher degree of resistance to chlorination.