Disinfection by-products which consist of trihalomethanes (THMs) and haloacetic acids (HAAs) are formed when chlorine reacts with organic precursors in the raw water. In order to reduce exposure to disinfectants and their by-products, water systems will use permanganate as a recognized alternative oxidant for use at the intake structure or flash mix of the water plant.
The use of permanganate will also provide iron and manganese oxidation, taste and odor control, and cyanotoxin reduction. Permanganate oxidation alone has been shown to reduce byproduct formation by as much as 5-40%. A water plant in California was able to reduce their THMs by over 70% by moving the pre-chlorine from the flash mix to the filter water and adding CAIROX® potassium permanganate to the raw water as a pre-oxidant.
Jar testing can determine the optimum dosage of permanganate needed for your water. Typical permanganate dosages are 0.5 mg/L to 2.0 mg/L.