Identification and Correlation of Disinfection By-Product Precursors in a Biofilm Matrix

摘要

Disinfection by-product (DBP) formation in drinking water systems is a persistent issue forwater utilities. Although DBP formation is complex due to the multitude of chemical andbiological interactions that occur, unremoved natural organic matter (NOM) entering the waterdistribution system is generally regarded as the primary precursor for DBP formation. Inaddition, NOM also provides nutrient material that supports microbial growth. Resulting biofilmand its extracellular polymeric substances (EPS) provides a dynamic repository for organicmatter accumulation as well as being a DBP precursor itself. The relative contribution to DBPformation as a result of the reaction between these precursors and disinfectant is still not verywell understood. To help elucidate this interaction, heterotrophic plate counting coupled withDBP formation potential tests and parallel factor analysis (PARAFAC) of fluorescent dissolvedorganic carbon were performed. Obtained results suggest accumulation of organic matter inbiofilm matrix contributes significantly towards DBP formation depending on the pipe material.Corrosion of iron pipes provides not only more opportunity for growth of biofilm, but increasedadsorption sites for humic substances, both of which lead to increased DBP formation.