AWWA ACE68690

The objective of this paper is toexamine the control of precursors for various emerging N- and C-DBPs and how that compareswith the control of THM precursors.A full-scale survey of 16 U.S. drinking water treatment plants (DWTPs) was conductedin 2006 and 2007 (each plant was sampled once or twice). The focus of this study was onDWTPs that treated wastewater and/or algal impacted water, which are sources ofprecursors for N-DBPs. All of the DWTPs in this study treated surface water. DWTPs sampled used a range of treatment processes (coagulation, lime softening, ultrafiltration,filtration with granular activated carbon [GAC]) and disinfectants (chlorine [Cl₂], chlorinedioxide, chloramines [NH₂Cl], ozone, UV). The sample sites were in various geographicalregions of the U.S.Analytical parameters are detailed in this paper, along with study results. A summary of the study indicated that utilities have installed and modified treatment practices to control the formation ofregulated DBPs (e.g., THMs). In this study, DBPFP tests were conducted on samples fromdifferent points in the surveyed plants. These tests not only showed the removal or destructionof DBP precursors with various unit processes, but the contribution of certain processes toincreasing DBPFP (e.g., use of certain polymers increasing NDMAFP; ozonation increasingTCNMFP). In order to balance the control of regulated DBPs with that of emerging DBPs of health concern,utilities will need to optimize a series of various unit processes to minimize the formation of awide range of DBPs. Includes 20 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

33

File Size:

1 file , 770 KB