Newport River

Tester, P.A., Geesey, M.E., Guo, C., Paerl, H.W., and Millie, D.F. (1995) Evaluating phytoplankton dynamics in the Newport River estuary (North Carolina, USA.) by HPLC-derived pigment profiles. Mar. Ecol. Prog. Ser. 124, 237-245. 

Titrations were performed on untreated, filtered, and UV-treated filtered river water samples at in situ and adjusted pH values. The effect of pH on copper speciation was investigated by titration of filtered Newport River water at pH 7.0 and filtered Newport and Neuse waters at pH 8.0. Newport River water was adjusted to pH 7.0 by decreasing the partial pressure of CO2 from the initial ambient value of about 10 times the atmospheric level. To adjust the pH to 8.0, sodium bicarbonate was added to bring the river water samples to a concentration of 0.5 mM with subsequent adjustment of Pc02 Titrations were also conducted at pH 7,0 in model solutions consisting of 0.01 KNO3 and 0.1 mM NaHC03 with and without the addition of 0.75 histidine to test electrode behavior in solutions of known chemistry. 

Non-ideal behavior of the cupric ion electrode occurs at pECujot] > 7 in the titrations of both filtered and unfiltered Newport River water at pH 5.95 and filtered water at pH 7.0 and 8.0. At low total copper concentrations, measured pCu values approach a constant value independent of the total copper in solution. Similar behavior was observed for filtered Neuse River water at pH 8.0, but not at pH 6.78. 

As indicated by titration data (Figures 6 and 7), binding of copper in both Neuse and Newport River water decreases with increasing total copper in a manner consistant with a stepwise titration of a number of different ligands and/or binding sites. Binding of copper increases with increasing pH consistant with reactions with protonated weak acids. 

M. Data at the highest concentrations of total copper in Newport River water at pH 7.0 and pH 8.0 were also excluded because pCu values approach those predicted for the formation of solid copper hydroxide, i.e., pCu 6.7 at pH 8.0 and 4.7 at pH 7.0. 

Thus, the general picture that emerges is that the binding characteristics of the organic matter in the Newport River water is similar to that in the Neuse with the major difference being the quantity of binding sites present as indicated by the difference in the quantity of dissolved organic carbon. 

It is likely that most if not all of the observed binding of copper to organic matter results from complexation to fulvic or humic acids. Newport River water has a pronounced yellowish-brown color and shows continuously increasing light absorption with decreasing wave length (13) consistent with the presence of... 

Figure 9. Relationship between the log of the conditional stability constant and the log of the binding site concentration per gram dissolved organic carbon for individual binding sites. Newport River pH 8.00 ( ) Neuse River pH 8.00 (O) Newport River pH 7.00 (%) Neuse River pH 6.78 (A) Newport River pH 5.95 (A) water fio).

Figure 10. Chemical speciation model for dissolved copper in the Newport River at 25°C as a function of total copper concentration, (a) In situ pH 5.95, [Aik] = 0.05mM and I = 0.0005M (b) pH 7.00, [Aik] = 0.05mU and I = 0.005M and (c) pH 8.00, [Aik] = 0.55mM and I =...

Table 5-2 presents plutonium levels detected in several surface waters and groundwaters. The Pacific Ocean was sampled for plutonium and Northern Pacific concentrations were, on the average, greater than those detected in the Southern Pacific for both plutonium-239, -240 and plutonium-238 (Miyake and Sugimura 1976). The plutonium content of the particulate matter in three South Carolina estuarine systems was investigated by Hayes et al. (1976). The Neuse and Newport River estuaries received plutonium only through atmospheric fallout the Savannah River estuary received effluent from the Savannah River Plant. Concentrations detected in the three estuaries are comparable. 

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