Dissolved organic carbon concentrations

Hercules Chemical produced an acidic organic waste derived from the manufacture of dimethyl terphthalate, which is used in the production of synthetic liber. The average dissolved organic carbon concentration was about 7100 mg/L and included acetic acid, formic acid, p-toluic acid, formaldehyde, methanol, terphthalic acid, and benzoic acid. The pH ranged from 3.5 to 4.0. The waste also contained traces (less than 0.5 mg/L) of 11 other organic compounds, including dimethyl phthalate, a listed hazardous waste. 

Abernathy and Cumbie 1977). Mercury concentrations greater than 0.5 mg/kg (but less than l.Omg/kg) FW have been reported in trout from several wilderness lakes in northern Maine (Akielaszak and Haines 1981) and from the Adirondacks region of New York (Sloan and Schofield 1983) these values are considerably higher than might be expected for fish inhabiting remote lakes. These elevated concentrations were usually associated with lakes of low pH, low calcium, low dissolved organic carbon concentrations, and low water hardness and alkalinity. 

Table 2 shows the mean values of the main chemical parameters measured between 2000 and 2004. Dependent on the lake and the parameter the sample number varies between 7 and 10 (data not shown). The chemical water composition is typical for carbonate-poor mountain regions low conductivity, alkalinity and pH and small nutrient and DOC (dissolved organic carbon) concentrations. Data of DOC are not shown, they vary between 0.14 and 0.70 mg C Ortho-phosphate is always smaller than the quantification limit of 4.3 P pg and ammonia and nitrite are negligibly small compared to nitrate (data not shown). 

Consider a well-mixed, nonturbid water body with a dissolved organic carbon concentration (DOC) of 4 mg C L-1. The decadic beam attenuation coefficients, a(A), determined for a water sample at five wavelengths are the following (see other examples given in Fig. 15.11) ... 

Lake-Water Samples. Ten lake-water samples were collected from September 1990 to May 1991. The total soluble phosphorus concentration for the concentrated samples ranged from 23.8 to 60.8 mg of P/L, and the soluble reactive phosphorus concentrations ranged from 1.0 to 18.1 mg of P/L (Table I). Dissolved organic carbon concentration values for the concentrated samples ranged from 5000 to 20,000 mg of C/L. The signal-to-noise ratios from 12-14-h runs achieved for the NMR spectra range from 3.0 to 7.0. The pH of the concentrated samples after the addition of FeEDTA fell between the values of 7.00 and 8.00. Addition of the FeEDTA increased the pH by only a few tenths of a pH unit. 

Eckhardt, B., and T. R. Moore. 1990. Controls on dissolved organic carbon concentrations in streams, southern Quebec. Canadian Journal of Fisheries and Aquatic Sciences 47 1537-1544. 

Grieve, I. C. 1991a. A model of dissolved organic carbon concentration in soil and stream waters. Hydrological Processes 5 301-307. 

Willey, J. D., R. J. Kieber, M. S. Eyman, and G. Brooks Avery, Jr. 2000. Rainwater dissolved organic carbon Concentrations and global flux. Global Biogeochemical Cycles 14 139-148. 

Mulholland, P. J., and W. R. Hill. 1997. Seasonal patterns in streamwater nutrient and dissolved organic carbon concentrations Separating catchment flow path and in-stream effects. Water Resources Research 33 1297—1306. 

Large-Scale Patterns in Dissolved Organic Carbon Concentration, Flux, and Sources... 

II. DISSOLVED ORGANIC CARBON CONCENTRATIONS A. Streams and Rivers... 

McDowell, W. H., and T. Wood. 1984. Podzolization Soil processes control dissolved organic carbon concentrations in stream water. Soil Science 137 23—32. 

Oikari, A, and J. Kukkonen. 1990. Bioavailability of benzo(a)pyrene and dehydroabietic acid from a few lake waters containing varying amounts of dissolved organic carbon concentrations to Daphnia magna. Bulletin of Environmental Contamination and Toxicology 45 54. 

Sabater, F., J. L. Meyer, and R. T. Edwards. 1993. Longitudinal patterns of dissolved organic carbon concentration and suspended bacterial density along a blackwater river. Biogeochemistry 21 73-93. 

Goni, M.A., Gardner, R.L. (2003) Seasonal dynamics in dissolved organic carbon concentrations in a coastal water-table aquifer at the forest-marsh interface. Aquat. Geochem. 9, 209-232. 

These OH radicals produce several environmentally important oxidation reactions. They can be scavenged primarily by dissolved organic matter, DOM (in waters with high dissolved organic carbon concentration, DOC), or by carbonate and hydrogen carbonate ions (in waters with high alkalinity). The bromide ion is their key scavenger in seawater. Nitrate photolysis is likely to provide a key pathway for the oxidation of different types of DOM. 

Martin W. R. and McCorkle D. C. (1993) Dissolved organic carbon concentrations in marine pore waters determined by high-temperature oxidation. Limnol. Oceanogr. 38(7), 1464-1479. 

Toth, V.A., 1998, Spatial and temporal variations in the dissolved organic carbon concentrations in the vadose karst waters of Marengo Cave, Indiana, J. Cave Karst Stud. 60 167-171. 

---