AOP/biofilm processes for DOX precursors

Abstract

Ozone–hydrogen peroxide did not enhance performance, but ultraviolet–hydrogen peroxide performed comparably to ozone, and it is a much simpler process.Batch and continuous‐flow, bench‐scale experiments were performed to assess the performance of two advanced oxidation processes in combination with subsequent biodegradation for the removal of total organic carbon (TOC) and disinfection byproduct (DBP) precursors, as characterized by dissolved organic halogen formation potential (DOXFP). Ozone–hydrogen peroxide (O3–H2O2) and ultraviolet–hydrogen peroxide (UV–H2O2) were studied over a range of oxidation conditions for their ability to promote TOC and DOXFP removal in a subsequent biodegradation step. For the two waters studied, from Lake Austin and Lake Houston in Texas, the addition of H2O2 did not enhance performance after biodegradation relative to O3 alone, indicating that O3–H2O2 oxidation is not worthwhile in waters of this type, i.e., those with low specific UV absorbance. UV–H2O2–biodegradation performed comparably to O3–biodegradation, which suggests it is an alternative technology that may be worth considering for DBP precursor removal, especially for utilities that are interested in avoiding the operational complexities of ozonation.