Total organic carbon distribution

Resin evaluation of both new and used resins (titration of total binding sites, total protein capacity, flow vs. pressure, particle size distribution, total organic carbon removed by cleaning procedures, and microbial and endotoxin analysis)... 

Chemical analysis of water samples collected from monitoring wells and adjacent ditches was performed for BTEX, total organic carbon (TOC), chromium, and lead. Results of analysis presented a complicated chemical distribution in a dynamic... 

What we always try to avoid is chemical treatment of water. In fact, we use chlorination only as a safety measure to have some hygienic control in the distribution system. Yet, when the organic content of the water is even as low as possible, preferably 1 mg of total organic carbon per liter (not more), and you use chlorination, you increase the mutagenicity. That is well-known. 

Each port was located in an area of turbulence with the sampling tube directed into the flow so that small and large oil drops entered with equal facility. A Coulter Counter Model T -X 11 was used to measure the oil-drop size distributions. A Beckman Model 915A Total Organic Carbon Analyzer was used to measure oil concentration. 

A number of indexes based on the distribution of organic C in humic and nonhumic fractions are used for the evaluation of the humification level in organic amendments and amended soils (Senesi, 1989). Among others these include the degree of humification (DH), which is calculated as DH% = 100 x (HAC + FAC)/ TEC the humification rate (HR), which is calculated as HR% = 100 x (HAC + FAC)/ TOC and the humification index (HI), which is calculated as HI = NHC/ (HAC + FAC) (Sequi et al., 1986 Ciavatta et al., 1988). TOC represents the total organic carbon in the sample TEC represents the total extractable C by an alkaline solution (NaOH and/or Na4P207) HAC and FAC represent the C content in HA and FA fractions, respectively and NHC represents the nonhumified C content calculated by difference, that is, NHC = TEC - (HAC + FAC). 

One approach to help overcome this disparity between spot and passive sampling data is to use additional water quality data. If average values of DOC, suspended particulate matter, and total organic carbon content are known, it may be possible to estimate the total concentration using empirical relationships that describe the distribution of a chemical between the different phases that may be present in an environmental water sample.121 There is, however, uncertainty associated with this approach, as a number of assumptions are made in the calculations and a better understanding of the partitioning behavior of priority pollutants between the different phases is needed. 

Solid phase chemical analyses included determination of total organic C content, and the distribution of S between iron monosulfides (acid-volatile sulfur or AVS) and pyrite (the difference between total reducible sulfur and AVS). Total organic carbon was measured coulometrically following combustion at 1050°C (7). Acid-volatile sulfur and total reducible sulfur analyses followed the procedure of Canfield et al. (8). A microbiological assay of the abundance of sulfate reducing bacteria was performed according to (9). 

At the catalytic reactor exit gas and liquid samples are taken every 10 minutes and analyzed by chromatography and by Total Organic Carbon (T.O.C) determination techniques. These measurements allow to know the variation of the product distribution along the time-on-stream of the catalyst. 

Correspondence between the vertical distribution of total organic carbon (TOC) at station 3C (approximately 6-8 km downcurrent from the outfall system) and the mass emissions of suspended solids from the outfall system during the period 1946-1981 is illustrated in Fig. 6. Following World War 11 and up until 1971, the monotonic increase in emissions of suspended solids from the LACSD paralleled the population trend in Los Angeles. Thereafter, solids emissions declined in response to improved source control and advances in waste treatment (Stull et al, 1996). The vertical concentration profile of TOC in the 3C (1981) core records the historical trend in effluent solids emissions and indicates that, for this period, the outfalls dominated sedimentation of organic carbon on the shelf. The dechne in emissions of suspended solids from the outfalls after 1971 became a matter of concern because of the potential for remobilization of heavily contaminated sediments that had been laid down in earlier years. 

Fig. 2. Distribution of (a) total organic carbon (TOC, %), (b) total sulfur (TS, %), (c) total iron (Fct, %) and (d) acid-extractable iron (Foa, %) in surficial sediments. Isobaths and submarine canyons are also...

Several researchers have found that if the distribution coefficient is normalized relative to the aquifer matrix total organic carbon content, much of the variation in observed Kj values between different soils is eliminated. Distribution coefficients normalized to total organic carbon content are expressed as Kqc- Tbe following equation gives the expression relating to K , ... 

The equilibrium between water and sediments can be described by the equation C = Kf.Cy where Cj = concentration of PCBs in sediments, CjY = concentration of PCBs in water and fCp = equilibrium constant that reflects the character of sediments. To calculate the Kf value, tabulated values of Kqq (soil adsorption coefficient) can be used and Kf values calculated using the equation Kf =Kfy,.TOC (total organic carbon). For a description of the behaviour (or distribution) of individual PCB congeners between water and sediments a linear relationship between K( and tabulated Kq values can be used logfr = 0.85 log Q y -F 0.13. The relationship is valid within the range of values of log Kq = 4.S-7.7. 

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