Disinfection By-Products (DBP) Precursor Monitoring
Chlorine has long been used as a primary disinfection method for many water and wastewater treatment applications. However, there is growing concern about the harmful DBP’s produced by the use of chlorine.
DBP’s, such as triahalomethanes (THMs), can occur when the natural organic matter (NOM) that is present in the water is combined with chlorine. More specifically, the portion of NOM in the water that is aromatic is the most reactive with chlorine and therefore possesses the most potential for DBP formation. The following provides an illustration of this reaction.
The aromaticity of the organic content in the water is best determined by the UV254 water quality parameter, as sited by the U.S. EPA – Stage 2 Disinfectants & Disinfection Byproducts Rule Operational Evaluation Guidance Manual “...UV254, which is generally linked to the aromatic and unsaturated components of NOM, is considered a good predictor of the tendency of a source water to form TTHM & HAA5.”
Therefore, monitoring the aromaticity of the dissolved organics in a water supply by use of Real Tech’s Real UV254 series of continuous monitors and portable meters can serve as invaluable tools for indicating the potential formation of DBP’s.