Solubility seawater

The pigment phase holds potential for manipulation of the paint properties. For example, in antifouling paints, seawater-soluble pigments play an active role in the paint behaviour (see e.g. Kiil et al., 2002 and later sections on mechanisms). Extenders (fillers) are coarse particles (e.g. natural limestone or clay). They are cheap and added for economic reasons, but also provide strength and resistance to the paint. 

The hydrolysis and erosion mechanism is continually repeated until no polymer is left. Seawater-soluble pigment particles, such as CU2O and ZnO, dissolve near the surface of the paint film. As an example, the reactions of CU2O to form CuCU" and CuCf2" are provided ... 

Seawater-soluble pigments and their potential use in antifouling paints... 

Pigment", in the present context, refers to relevant seawater-soluble particulate solids. The reaction that takes place at the dissolving pigment front (see Fig. 24) can be written, in general terms, as... 

The pigment, P(s), can, in principle, be any seawater-soluble particulate solid that is being considered for a potential use in a self-polishing antifouling paint. Salts, sugars, and proteins (enzymes, peptides, or hormones) are obvious examples. It should be noted that the pigment can also represent a seawater-... 

According to Schneider and Allerman (2001), Alcalase is the name of an enzyme that might be used to hydrolyse e.g. barnacle proteins. Less than 5 wt% (solvent-free basis) enzyme is used in an antifouling paint (Schneider and Allerman, 2001) and so a seawater-soluble carrier material should probably be... 

Kiil, S. Dam-Johansen, K., Weinell, C.E., Pedersen, M.S., (2002c) Seawater-soluble pigments and their potential use in self-polishing antifouling paints simulation-based screening tool, Prog. Org. Coat., 45, 423-434. 

Compound Distilled Water solubility (mg/L) Seawater solubility (mg/L) Freshwater CCAS (mg/L) Saline water CCAS (mg/L)... 

Seawater contains dissolved inorganic salts. An aqueous solution of about 35 gL-1 NaCl is often taken as a model solution for seawater. The salt effect on the solubility of nonelectrolyte organic compounds has been investigated systematically by Sechenov [68] and by Long and McDevit [69]. Correlations between pure water solubility, Sw, and the solubility at different salt concentrations are compound dependent. For example, the seawater solubility, 5SW, of PAHs are from 30 to 60% below their freshwater solubilities [1], depending on the particular structure of the PAH. We concentrate our interest on the question if, for certain compound classes, Ssw can be estimated from known Sw without any input of further compound-specific parameters. 

Hashimoto, Y., et al., Prediction of Seawater Solubility of Aromatic Compounds. Chemo-sphere, 1984 13, 881-888. 

Hashimoto, Y., Tokura, K., Kishi, H., Strachan, W.M.J. (1984) Prediction of seawater solubility of aromatic compounds. Chemosphere 13, 881-888. 

The results of sequential leaching experiments and the bioaccumulation studies reveal a selective assimilation of certain chemical forms of some trace metals by molluscs. There seems to be a relationship between seawater-soluble chromium levels and accumulation of the element in the kidneys of exposed bivalves. Particulate forms of chromium, while present in the digestive glands, do not appear to have been assimilated by the organisms, even though much of the total chromium was dissolved by a relatively mild extractant -25% acetic acid. Thus, an estimation of the bioavailability of particulate metals based on their solubility in dilute acetic acid can be erroneously high, at least for herbivorous filter feeders. 

Hiickel theory [or the Giintelberg or Davies equation (Table 3.3)] may be used to convert the solubility equilibrium constant given at infinite dilution or at a specified / to an operational constant, valid for the ionic strength of interest. In seawater solubility equilibrium constants, experimentally determined in seawater, may be used. For example, the CaC03 calcite solubility in seawater of specified salinity may be defined by = [Ca " ] [CO f ], where [Caj ] and [C03f ] are the total concentrations of calcium and carbonate ions, for example,... 

Equilibrium solubilities for quartz in distilled water at 25°C (also obtained by extrapolation from higher temperatures) are in the range 100-200 fiM 14,19, 21, 22) at 5°C by the same process, ca. 80-120 /xM. The seawater solubility value of quartz at a slightly lower temperature (73 5 fiM at 20°C), obtained recently by Mackenzie and Gees (23), suggests that the data of Morey et al (19) are the most reliable. The latter s estimates are used in this paper. 

The carbonates are among the most abundant and important minerals in the earth s crust. When these minerals come into contact with fresh water or seawater, solubility equilibria are established that greatly affect the chemistry of the natural waters. Calcium carbonate (CaCOs), the most important natural carbonate, makes... 

Figure 2.5 The ratio of the solubility of m-nitrophenol in water (5o) and sodium chloride solution (S) as a function of ionic strength. [Reprinted from Chemosphere 13, 881, Y. Hashimoto, K. Tokura, and W. M. J. Strachan, Prediction of seawater solubility of aromatic compounds . Copyright 1984, with permission from Elsevier.]...

Fig. 21-4. Representative synchronous excitation fluorescence spectra of a whole oil (top) and its seawater soluble fraction (bottom) collected near the IXTOCl blow-out in the Gulf of Mexico (From NAS, 1985).

Metastable phases such as amorphous silica (SiOa) and wurtzite (ZnS) are common in mid-oceanic ridge deposits. These phases form fi om highly supersaturated mixed fluid of hydrothermal solution and seawater. Solubility of metastable phases is higher than that of stable phases. Therefore, metastable phases dissolve and stable phases form after the formation of ore deposits. Wurtzite (metastable phase of ZnS) is observed in active chimney, but sphalerite (stable phase of ZnS) is in nmiactive chimney. It is inferred that sphalerite formed by the dissolution of wurtzite. 

Surface seawater is oversaturated with respect to CaCOa (calcite, aragonite) and biogenic CaCOa forms in surface seawater. Solubility of CaCOa increases with increasing pressure (depth). CaCOa dissolves below CCD (carbonate compensation depth). 

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