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Metal concentration calculation

The total releases to air from the facility must be entered m Part III, Section 5 of Form R in pounds per year. The stack test results provide the concentration of metallic lead in each exhaust stream in grains per cubic toot and the exhaust rate in cubic feet per minute. Using the appropriate conversion factors, knowing the scrubber efficiency (from the manufacturer s data), and assuming yourfacility operates 24 hours per day, 300 days per year, you can calculate the total lead releases from the stack test data. Because point (stack) releases of lead are 2,400 pounds per year,-which is greater than the 999 pounds per year ranges in column A. 1, you must enter the actual calculated amount in column A.2 of Section 5.2. [Pg.83]

With the aid of a table of solubility products of metallic sulphides, we can calculate whether certain sulphides will precipitate under any given conditions of acidity and also the concentration of the metallic ions remaining in solution. Precipitation of a metallic sulphide MS will occur when [M2 + ] x [S2 ] exceeds the solubility product, and the concentration of metallic ions remaining in the solution may be calculated from the equation ... [Pg.434]

To summarize, an evaluation of the oxidation state of metals in an environment is central to determining their probable fate and biological significance. Redox reactions can lead to orders of magnitude changes in the concentration of metals in various phases, and hence in their mode and rate of transport. While equilibrium calculations are a valuable tool for understanding the direction in which changes are likely to occur, field measurements of the concentrations... [Pg.383]

Distribution coefficients based on adsorption equilibria are independent of the total concentrations of metal ions and suspended solids, as long as the metal concentrations are small compared with the concentration of surface groups. Examples of the Kd obtained from calculations for model surfaces are presented in Fig. 11.1. A strong pH dependence of these Kd values is observed. The pH range of natural lake and river waters (7 - 8.5) is in a favorable range for the adsorption of metal ions on hydrous oxides. [Pg.371]

Figure 5.8 (Bunzl et al., 1976) shows the initial rates of sorption and desorption during the first 10 s of exchange and corresponding half times for Pb2+, Cu2+, Cd2+, Zn2+, and Ca2+ by H-saturated peat using the same concentrations of metal and H30+ added for the experiments shown in Fig. 5.7. The absolute initial rates of sorption decreased in the order Pb > Cu > Cd > Zn > Ca, which is the order observed for the calculated distribution coefficients. This indicates that the higher the selectivity of peat for a given metal ion, the faster the initial rate of sorption. The relative rates of sorption, as shown by half-times (Fig. 5.8), shows that Ca2+ was sorbed the fastest, followed by Zn2+ > Cd2+ > Pb2+ > Cu2+. Thus, even though the absolute rate of Ca2+ adsorption by peat was low, the relative rate was comparatively high, since the total amount of Ca2+ adsorbed was small. The relative rates of desorption, as illustrated by the half-times, show longer times for Pb2+, Cu2+, and Ca2+ but shorter ones for Cd2+ and Zn2+. Figure 5.8 (Bunzl et al., 1976) shows the initial rates of sorption and desorption during the first 10 s of exchange and corresponding half times for Pb2+, Cu2+, Cd2+, Zn2+, and Ca2+ by H-saturated peat using the same concentrations of metal and H30+ added for the experiments shown in Fig. 5.7. The absolute initial rates of sorption decreased in the order Pb > Cu > Cd > Zn > Ca, which is the order observed for the calculated distribution coefficients. This indicates that the higher the selectivity of peat for a given metal ion, the faster the initial rate of sorption. The relative rates of sorption, as shown by half-times (Fig. 5.8), shows that Ca2+ was sorbed the fastest, followed by Zn2+ > Cd2+ > Pb2+ > Cu2+. Thus, even though the absolute rate of Ca2+ adsorption by peat was low, the relative rate was comparatively high, since the total amount of Ca2+ adsorbed was small. The relative rates of desorption, as illustrated by the half-times, show longer times for Pb2+, Cu2+, and Ca2+ but shorter ones for Cd2+ and Zn2+.
Fig. 4. The concentration dependence of various electronic properties of metal-ammonia solutions, (a) The ratio of electrical conductivity to the concentration of metal-equivalent conductance, as a function of metal concentration (240 K). [Data from Kraus (111).] (b) The molar spin (O) and static ( ) susceptibilities of sodium-ammonia solutions at 240 K. Data of Hutchison and Pastor (spin, Ref. 98) and Huster (static, Ref. 97), as given in Cohen and Thompson (37). The spin susceptibility is calculated at 240 K for an assembly of noninteracting electrons, including degeneracy when required (37). Fig. 4. The concentration dependence of various electronic properties of metal-ammonia solutions, (a) The ratio of electrical conductivity to the concentration of metal-equivalent conductance, as a function of metal concentration (240 K). [Data from Kraus (111).] (b) The molar spin (O) and static ( ) susceptibilities of sodium-ammonia solutions at 240 K. Data of Hutchison and Pastor (spin, Ref. 98) and Huster (static, Ref. 97), as given in Cohen and Thompson (37). The spin susceptibility is calculated at 240 K for an assembly of noninteracting electrons, including degeneracy when required (37).
Metal concentrations and metal activities in the pore water are dependent upon both the metal concentration in the solid phase and the composition of both the solid and the liquid phase. In matrix extrapolation, and with emphasis on the pore water exposure route, it is therefore of great practical importance to have a quantitative understanding of the distribution of heavy metals over the solid phase and the pore water. A relatively simple approach for calculating the distribution of heavy metals in soils is the equilibrium-partitioning (EP) concept (Shea 1988 van der Kooij et al. 1991). The EP concept assumes that chemical concentrations among environmental compartments are at equilibrium and that the partitioning of metals among environmental compartments can be predicted based on partition coefficients. The partition coefficient, Kp, used to calculate the distribution of heavy metals over solid phase and pore water is defined as... [Pg.41]

The next metal to be screened was Cd, and Table V presents the results. From these data an additional very significant observation related to the concentration level can be made. Calculation of the probability of significance by using the concentration calculated from the first and second calibration curves produced a standard error of 0.57 and 0.60 ug/ml respectively, and showed the... [Pg.274]

A crucial difference between the total and added risk is in treatment of the eco-toxicity data. The added risk methodology requires the production of a PNECadd, which is calculated by subtracting the background concentration of metal in the control from the effect/no-effect concentration from that test. These data are then used for the derivation of the PNECadd. The ambient background concentration at the site is then added to the PNECadd to produce the standards to which the measured concentration is then compared. [Pg.78]

Fig. 15.5. Calculated metal sorption curves for Pb, Cu and Cd onto the bacterium Bacillus subtilis, shown as a function of pH versus the concentration of sorbed metal. Curves are calculated based on experimental metal sorption data of Fein et al. (1997), and were computed using the geochemical speciation programme JCHESS. The solution depicted contains 1 g 1 bacteria dry wt (155 m g surface area, 8.0 Cm electrical double layer capacitance), 1 mM dissolved CaC03 and 1 iM dissolved lead, copper and cadmium. Adsorption was calculated using a CCM treatment. Fig. 15.5. Calculated metal sorption curves for Pb, Cu and Cd onto the bacterium Bacillus subtilis, shown as a function of pH versus the concentration of sorbed metal. Curves are calculated based on experimental metal sorption data of Fein et al. (1997), and were computed using the geochemical speciation programme JCHESS. The solution depicted contains 1 g 1 bacteria dry wt (155 m g surface area, 8.0 Cm electrical double layer capacitance), 1 mM dissolved CaC03 and 1 iM dissolved lead, copper and cadmium. Adsorption was calculated using a CCM treatment.
Because the mixed potential involves many unknown variables, it is difficult to calculate the concentration of metal ions in the slurry directly from a measurement of the mixed potential. However, relative changes in ion concentration may be inferred from changes in the mixed potential. When the Cu ion concentration increases, the reversible potential increases, shifting the entire Cu/Cu oxidation curve in the noble direction. As a result, the equilibrium with the reduction reaction shifts in the noble direction (higher potential). Thus, an increase in potential is indicative of an... [Pg.97]

As the free metal has no CD absorbance, and there is a measurable change in absorbance with increasing concentration of metal complex formed, we may utilise the Beer-Lambert law to calculate the concentration of the species present from the measured change in absorbance and thus calculate these constants. It was felt that iterative calculations as carried out by Freeman et al were not necessary due to the vast difference between the values of and... [Pg.148]

In analogy to a pH titration curve, pM (— log [M]) may be plotted against the fraction titrated. Under the usual titration conditions, in which the concentration of metal ions is small compared with the concentrations of the buffer and the auxiliary complexing agents, the fractions ay and are essentially constant during the titration. The titration curve then can be calculated directly from the conditional formation constant since it also remains constant. [Pg.197]

Figure 23-11 shows plots of several theoretical curves (see also reference 40) of percentage extraction against pH calculated from (23-38) for V g = V. The curves become steeper with increasing values of n, the charge of the metal ion, and the value of pH for a given system depends on the stability constant of the chelate and the concentration of excess reagent rather than on the concentration of metal ion... [Pg.445]


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