UV/H(2)O(2) treatment of drinking water increases post-chlorination DBP formation

Water Res. 2010 Jun;44(12):3703-13. doi: 10.1016/j.watres.2010.04.006. Epub 2010 Apr 14.

Abstract

Ultraviolet (UV) irradiation has become popular as a primary disinfectant because it is very effective against Cryptosporidium and does not directly form regulated disinfection by-products. Higher UV doses and UV advanced oxidation (UV/H2O2) processes are under consideration for the treatment of trace organic pollutants (e.g. pharmaceuticals, personal care products). Despite the disinfection effectiveness of UV light, a secondary disinfectant capable of maintaining a distribution system residual is required to meet current U.S. regulation. This study investigated changes in disinfection by-product (DBP) formation attributed to UV or UV/H2O2 followed by application of free chlorine to quench hydrogen peroxide and provide residual disinfectant. At a UV dose of 1000 mJ/cm(2), trihalomethane (THM) yield increased by up to 4 microg/mg-C and 13 microg/mg-C when treated with low and medium pressure UV, respectively. With the addition of hydrogen peroxide, THM yield increased by up to 25 microg/mg-C (5mg-H2O2/L) and 37 microg/mg-C (10 mg-H2O2/L). Although no changes in DBPs are expected during UV disinfection, application of UV advanced oxidation followed by chlorine addition was assessed with regard to impacts on DBP formation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bromine / analysis
  • Chlorine / analysis
  • Disinfection*
  • Halogenation*
  • Hydrogen Peroxide / chemistry*
  • Hydroxyl Radical / chemistry
  • Organic Chemicals / analysis
  • Pressure
  • Solubility
  • Ultraviolet Rays*
  • Water Purification / methods*
  • Water Supply / analysis*

Substances

  • Organic Chemicals
  • Hydroxyl Radical
  • Chlorine
  • Hydrogen Peroxide
  • Bromine