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Solid-to-water phase ratio

Note that for the total (dissolved and particulate) concentration, Ct, the abrupt change of the solid-to-water-phase ratio, rsw (Eq. 9-15), at the sediment surface acts like a phase change. The numerical example given in Table 19.1 demonstrates that the transition from the open water column of a lake or the ocean to the sediments involves an increase of rsw by 5 to 6 orders of magnitude. Typically, in the open water, rs p is of order 10 3 kg m-3 while in the sediment column lies between 102 and 103 kg nr3. Thus, at equilibrium the total (dissolved and sorbed) concentration per unit bulk volume on either side of the interface for compounds with small to moderate solid-water distribution ratios (Ki <10 m3kg ) is approximatively given by (see Box 19.1, Eq. 4) ... [Pg.851]

Concentration of suspended solids (solid-to-water phase ratio, rsw) surface water deep water... [Pg.1052]

Figure 23.2 Removal of suspended particles (described by the solid-to-water phase ratio rsw) with uniform sinking velocity vs. (a) No mixing constant particle flux Fs = rsw vs until upper horizon reaches the bottom after time t = h /vs (b) homogeneously mixed system exponential decrease of rsw (c) change of mean particle flux across level z0 for the case of heterogeneous distribution of particles and a spatially variable vertical velocity component. Figure 23.2 Removal of suspended particles (described by the solid-to-water phase ratio rsw) with uniform sinking velocity vs. (a) No mixing constant particle flux Fs = rsw vs until upper horizon reaches the bottom after time t = h /vs (b) homogeneously mixed system exponential decrease of rsw (c) change of mean particle flux across level z0 for the case of heterogeneous distribution of particles and a spatially variable vertical velocity component.
The corresponding balance equation for the concentration of suspended solids in the SMWL (expressed as solid-to-water phase ratio, rs ,x) is ... [Pg.1087]

Porous media have much larger solid-to-solution phase ratios (rsw) than surface waters (lakes and rivers). Therefore, even the transport of a chemical with moderate to small solid-water distribution ratios (/Q may be influenced by sorption processes. The basic mathematical tools which are needed to quantify the effect of sorption on transport are described in Section 18.4 and summarized in Box 18.5. [Pg.1170]

Measurements of dissolved sorbing phase (e.g., weight of dissolved solids, turbidity, and DOC) demonstrate the increased loading of nonsettling microparticles or macromolecules in the supernatants of batch equilibrium experiments as the solids-to-water ratio increases. It is clear that nonsettling microparticles or macromolecules vary regularly with suspended solid concentration. [Pg.127]

Henry s Law constant (i.e., H, see Sect. 2.1.3) expresses the equilibrium relationship between solution concentration of a PCB isomer and air concentration. This H constant is a major factor used in estimating the loss of PCBs from solid and water phases. Several workers measured H constants for various PCB isomers [411,412]. Burkhard et al. [52] estimated H by calculating the ratio of the vapor pressure of the pure compound to its aqueous solubility (Eq. 13, Sect. 2.1.3). Henry s Law constant is temperature dependent and must be corrected for environmental conditions. The data and estimates presented in Table 7 are for 25 °C. Nicholson et al. [413] outlined procedures for adjusting the constants for temperature effects. [Pg.283]

Finally, noting that we refer to the quotient, A/S/Vw, as the solid-water phase ratio, rsw (e.g., kg-L ) in the environmental compartment of interest, we may describe the fraction of chemical in solution as a function of Kid and this ratio ... [Pg.286]

The fraction of the total volume, Ftot, that is not occupied by solids, the porosity, 0, is often used instead of rsw to characterize the solid-water phase ratio in some environmental systems like sediment beds or aquifers. In the absence of any gas phase, 0 is related to parameters discussed above by ... [Pg.287]

Let us formulate the dynamic mass balance equation of the chemical in the SMSL. Fig.23.5 summarizes all processes. At this point we have to select the variable which shall characterize the SMSL. (Remember for the open water box we have chosen the total concentration Ctop.) Due to the large solid-to-water ratio of sediments rss, chemicals with moderate to large distribution coefficients (Kd > 0.1 m3kg ) are predominantly sorbed to the solid phase. Therefore, C offers itself as the natural choice for the second state variable. [Pg.1075]

Optionally, the solids phase from the first alkali extraction may be extracted a second time, with 1 5 solids-to-water ratio at pH 9, and re-centrifuged, with the resulting fractions combined with those from the initial centrifugation. Although the process is not yet sufficiently efficient to become the main commercial means for extracting soybean oil, the resulting SPCs and SPIs are extremely stable to oxidation and have properties that may be functionally useful in selected applications. UP and RO membrane techniques were also tried with AEP. Additional information on AEP is provided in the Chapter Oil Recovery from Soybeans. [Pg.705]

A substance released to the environment can volatilize from water to air, or sublime from solid to vapor phase. It can also be washed out of the air with rainfall that deposits the substance on land or in surface water. Scientists characterize the tendency of a chemical substance to partition between air and water by its vapor pressure and solubility in water, or, in dilute solutions at equilibrium, by the Henry s law coefficient (which can be measured or calculated from the ratio of the vapor pressure to solubility at a specified temperature). The Henry s law coefficient is sometimes referred to as an air-water partition coefficient. [Pg.7]

Liquids and Solids Content. Oil, water, and solids volume percent is determined by retort analysis as in a water-base mud. More time is required to get a complete distillation of an oil mud than of a water mud. Then the corrected water phase volume, the volume percent of low gravity solids, and the oil-water ratio can be calculated the chart in Figure 4-108 can be used for the calculations [24]. [Pg.658]

As shown in Fig. 3, CHEMGL considers 10 major well-mixed compartments air boundary layer, free troposphere, stratosphere, surface water, surface soil, vadose soil, sediment, ground water zone, plant foliage and plant route. In each compartment, several phases are included, for example, air, water and solids (organic matter, mineral matter). A volume fraction is used to express the ratio of the phase volume to the bulk compartment volume. Furthermore, each compartment is assumed to be a completely mixed box, which means all environmental properties and the chemical concentrations are uniform in a compartment. In addition, the environmental properties are assumed to not change with time. Other assumptions made in the model include continuous emissions to the compartments, equilibrium between different phases within each compartment and first-order irreversible loss rate within each compartment [38]. [Pg.55]

To assess the extent to which a compound is associated with solid phases in a given system at equilibrium (see below), we need to know the ratio of the compound s total equilibrium concentrations in the solids and in the aqueous solution. We denote this solid-water distribution coefficient as Kid (e.g., in L kg 1 solid) ... [Pg.282]

Typically, reactants and products are represented by their atomic or molecular formulas, but molecular structures or simple names may be used instead. Phases are also often shown (s) for solid, ( ) for liquid, and (g) for gas. Compounds dissolved in water are designated (aq) for aqueous. Lastly, numbers are placed in front of the reactants or products to show the ratio in which they either combine or form. These numbers are called coefficients, and they represent numbers of individual atoms and molecules. For instance, to represent the chemical reaction in which coal (solid carbon) burns in the presence of oxygen to form gaseous carbon dioxide, we write the chemical equation... [Pg.292]


See other pages where Solid-to-water phase ratio is mentioned: [Pg.852]    [Pg.876]    [Pg.882]    [Pg.1056]    [Pg.1074]    [Pg.1086]    [Pg.852]    [Pg.876]    [Pg.882]    [Pg.1056]    [Pg.1074]    [Pg.1086]    [Pg.1060]    [Pg.193]    [Pg.226]    [Pg.2]    [Pg.290]    [Pg.156]    [Pg.467]    [Pg.189]    [Pg.203]    [Pg.219]    [Pg.145]    [Pg.361]    [Pg.394]    [Pg.169]    [Pg.22]    [Pg.259]    [Pg.85]    [Pg.595]    [Pg.223]    [Pg.149]    [Pg.90]    [Pg.270]    [Pg.364]    [Pg.46]    [Pg.358]    [Pg.1430]    [Pg.111]    [Pg.113]   


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