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CHEMICAL ANALYSIS OF REVERSE OSMOSIS MEMBRANE AND XAD RESIN ADSORPTION CONCENTRATES OF WATER DISINFECTED BY CHLORINATION OR OZONATION/CHLORINATION PROCESSES
Citation:
Simmons, J E., S D. Richardson, K M. Schenck, T F. Speth, R J. Miltner, AND A. D. Thruston*. CHEMICAL ANALYSIS OF REVERSE OSMOSIS MEMBRANE AND XAD RESIN ADSORPTION CONCENTRATES OF WATER DISINFECTED BY CHLORINATION OR OZONATION/CHLORINATION PROCESSES. Presented at Environmental Mutagen Society, Anchorage, Alaska, April 27-May 2, 2002.
Description:
Chemical Analysis of Reverse Osmosis Membrane and XAD Resin Adsorption Concentrates of Water Disinfected by Chlorination or Ozonation/Chlorination Processes.
J. E. Simmons1, S.D. Richardson2, K.M. Schenck3, T. F. Speth3, R. J. Miltner3 and A. D. Thruston2
1 NHEERL/ORD/U.S. EPA, RTP, NC
2 NERL/ORD/U.S. EPA, Athens, GA
3 NRMRL/ORD/U.S. EPA, Cincinnati, OH
Disinfection by-products (DBPs) are formed by reaction of chemical disinfectants with natural organic matter in source water. As DBPs are typically present at low levels, ug/L or less, in drinking water, they are frequently concentrated by XAD resin adsorption (XAD) for evaluation of mutagenicity. XAD results in an organic matrix (e.g. ethyl acetate) that must be removed and the remaining DBPs re-suspended in a medium suitable for biological assays. Although rarely used for this purpose, an advantage of reverse osmosis membrane (RO) concentration for preparation of water concentrate samples for in vivo and in vitro toxicological evaluation is that it results in a water matrix. As part of a project to evaluate RO preparation of water concentrates, a source water that had been spiked with bromide and iodide was disinfected either by chlorination (post-chlorination, CL) or by ozonation (pre-ozonation/post-chlorination, OZ/CL) processes and concentrated either by RO or XAD. The concentrates were analyzed by advanced GC/MS techniques (high and low resolution electron ionization and chemical ionization mass spectrometry). Many DBPs were identified in the RO samples, including brominated and iodinated compounds, such as bromo- and iodo-trihalomethanes and -acetaldehydes, halonitromethanes, halopropanones, halonitriles, and haloacetamides. Comparing RO to XAD, RO resulted in better recovery of halo-acetaldehydes, halo-propanoes and halo-nitromethanes. Although OZ/Cl did form a number of halogen-containing byproducts, they were fewer in number and lower in concentration than those formed by CL. These same RO and XAD concentrates were evaluated for mutagenicity in the Salmonella assay by Schenk et al. (poster, this meeting). This abstract may not reflect EPA policy.