Brine system reports

In the brine system, iodide is mixed with raw salt. It precipitates in membranes in the electrolysis process causing the loss of current efficiency in the membrane. Synergy effects in combination with other impurities have been reported [7, 8]. 

Vapor and brine from the Brandon vent of the East Pacific Rise have identical Fe isotope compositions, implying that phase separation does not produce an isotopic fractionation (Beard et al. 2003a). The role that sulfide precipitation plays in controlling the Fe isotope composition of the fluid remains unknown. The precision of the two sulfide analyses reported by Sharma et al. (2001) was not sufficient to resolve if sulfide precipitation would produce Fe isotope fractionation in the vent fluid. In a detailed study of sulfldes from the Lucky Strike hydrothermal field from the mid Atlantic Ridge, however, Rouxel et al. (2004) found that sulfldes span a range in 5 Fe values from -2.0 to +0.2%o, and that pyrite/marcasite has lower 5 Fe values ( l%o) as compared to chalcopyrite. The variations in mineralogy and isotope composition are inferred to represent open-system equilibrium fractionation of Fe whereby... 

A direct organocatalytic Michael reaction of ketones or aldehydes with /3-nitrostyrene has been reported in brine solution, using a bifunctional catalyst system proline-derived diamine (70) and TFA.203 In some cases the conversion, yield, de, and ee all exceeded 95%. Results in water were poor, mainly due to polymerization, which is catalysed by amines. It is proposed that sodium cations stabilize the anionic intermediate formed from (70) and /3-nitrostyrene, thus minimizing polymer formation. While organic co-solvent is not required, an organic-rich phase is proposed to concentrate the Michael reactants and catalysts, thus accelerating the reaction. 

Kaler et al. [50] reported on the viscosity changes in association with a percolative phenomenon for systems containing the commercial surfactant TRS 10-80, octane, tertiary amyl alcohol, and various brines. Their viscosity results were interpreted as evidence for a smooth transition from an oil-continuous to a bicontinuous one in which both oil and water span the sample. A second transition was observed and was attributed to a transition from a bicontinuous to a water-continuous system. 

Rabagliati et al. (14) studied the polymerization of styrene in a three phase system containing an anionic-nonionic surfactant mixture and brine. Both AIBN and potassium persulfate initiators were used. The system was reported to be microemulsion continuous and even multicontinuous. (14). No autoacceleration was observed and the authors concluded that the polymerization exhibits an inverse dependence of the degree of polymerization on initiator concentration, similar to bulk solution polymerization. 

Another type of interfacial instability occurred in both systems whenever liquid crystal penetrated the brine to contact the brine-microemulsion interface. At high magnification (40x), rapid convection of liquid crystal particles to the interface was observed at volcano-like instabilities (Figure 11). Reported earlier for the same systems (4), this type of instability forms convection currents in the surrounding brine phase. After times ranging from a few seconds to a few hours, the instabilities choke-off." The mechanism by which this small-scale convection is initiated, maintained, and terminated is as yet unknown. 

These simulations can be easily extended to systems containing solutes, namely simple salts. However, most of the reported simulation studies concerned only the behavior of the solute at the stable ice/water interface.Only recently results of successful simulations of the brine rejection process involving a moving ice/solution boundary have been reported. 

Researchers have used physical models of porous media to study flow problems for many years. For example, the Hele-Shaw cell appeared in the late 1800s (Sahimi, 1993). The first reported use of such models for two-phase systems is attributed to Chatenever and Calhoun (1952), who used Lucite and glass bead packs to view immiscible displacement of brine and crude oil (Buckley, 1991). Subsequently, etched and photo-etched glass were used to construct physical models. The use of molded resins for model construction was introduced in the 1970s (Buck-ley, 1991). 

Pressure effects on surfactant systems containing conventional liquid alkanes have not often been studied because of the very low compressibility of liquids. Conflicting results have been reported [38-40]. It is likely that the changes in cohesive energy density (solubility parameter) of the phases over the pressure ranges used were too low to produce definitive trends in phase behavior. The solubility parameter of compressed liquid propane, however, is moderately adjustable with pressure, and therefore a propane-brine-AOT system could be expected to show pressure-driven phase transitions [20,22,41]. 

As just stated, the L3 phase resembles structurally a bicontinuous microemulsion, which makes it interesting to compare their rheological properties. Viscosity measurements on an L3 phase [in the system cetylpyridinium chloride-hexanol-brine (0.2 M NaCl)] showed Newtonian flow behavior for the range of shear rates of 0.1-100 s" [113]. The viscosity of this highly interconnected, spongelike system is always very low and close to the solvent viscosity, even for a volume fraction of 0.2 it is less than 10 mPa s. (Similar viscosity values have been observed in the L3 phase of the system tetradecyldimethylamine oxide-hexanol-water [114].) It increases linearly with the volume fraction of the amphiphilic material, where it is interesting to note that extrapolation to zero concentration does not yield the solvent viscosity but a value about three times as high. A similar value for the extrapolated viscosity was also reported more recently for another L3 phase (in the system SDS pentanol-dodecane-water [115]), and it seems that this enhanced viscosity is a universal property connected to the structure of the L3 phase. 

The main primary sources of solid-liquid solubility data, i.e. those which report experimental measurements together with the full literature source references, are those of Stephen and Stephen (1963), Seidell (1958) and the continuing multivolume lUPAC Solubility Data Series (1980-91) which by the end of 1991 had reached its 48th volume. The series covers gas-liquid, liquid-liquid and solid liquid equilibria, but up to the present time fewer than one quarter of the published volumes are devoted to solid-liquid systems. In all these publications, ternary as well as binary data are reported and solvents other than water are considered. Blasdale (1927) and Teeple (1929) give extensive data on equilibria in aqueous salt solutions relevant to natural brines and natural salt deposits, ranging from binary to quinary complex systems. The compilation by Wisniak and Herskowitz (1984) is an excellent literature source reference, but no actual data are recorded. 

The large deviation in the exponent for the viscosity from the prediction of the living polymer model has also been reported for other systems [2, 3]. For example, Khatory et al. have performed rheological measurements on cetypyridinium chlorate micelles in NaClOs brine [31]. The obtained exponents are 2 and 1 for 0.1 M and 1M NaClOs, respectively. Hoffmann has measured the viscosity on tetrade-cyldimethylaminoxide (C14DMAO)/ decanol/water system for different ratios of CuDMAOidecanol [2, 3]. He has shown that the exponent decreases from about 5.4 to 1.3 as the ratio of decanol increases from 0 to C14DMAO decanol = 5 1. 

Reuse of existing facilities requires removal of contained mercury but not dismantling and detoxification of the debris. Demercurization of brine treatment systems, for example, is straightforward and sometimes quite easy to apply. TTiis is particularly so when the brine recycle system has been operated with a low level of dissolved chlorine to prevent mercury precipitation. Lott [19] reports that such a system was drained, washed with dilute acid to remove deposits and then with dilute hypochlorite solution to solubilize mercury, and finally flushed with hot water. The residual mercury concentration was well within the specification for the new membrane cells. 

---