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1I - Physicochemical properties (MOP/51) The influence of reverse osmosis on the metal-binding characteristics of dissolved natural organic matter. Ryan, Adam 1, Tomasso, Joseph1, Klaine, Stephen1, 1 Clemson University, Pendleton, South Carolina, USA ABSTRACT- Recently, questions have been raised about the copper binding abilities of dissolved natural organic matter (NOM) from different source locations. If NOM, or rather, dissolved organic carbon (DOC) concentration is to be considered as an input parameter for determination of water quality criteria for copper, then spatial differences that may exist in NOM characteristics could be potentially important. Some investigators have used reverse osmosis (RO) concentrated NOM to attempt to answer these questions. The goals of this study were to elucidate whether or not the RO procedure alters the copper binding characteristics of NOM, and to determine if the RO procedure alters the ability of NOM to influence copper bioavailability to larval fathead minnows (Pimephales promelas). Copper binding abilities and copper toxicity were determined for Edisto River and Black River site waters and for water reconstituted with NOM from the same rivers. Various manipulations were made to the site waters and to the reconstituted waters, so that differences between the characteristics of the site water and reconstituted water were minimized. The results of this study indicate that there is little or no change in the copper binding abilities of NOM following the RO procedure. Further, it appears that the RO procedure does not appreciably alter the ability of NOM to influence copper bioavailability. These results also suggest that investigators can conduct valid studies with RO concentrated NOM to answer questions about the possible spatial heterogeneity associated with various characteristics of NOM. Key words: Reverse Osmosis, Dissolved Natural Organic Matter, Copper, Pimephales promelas |
