Seawater artificial

MicrobiologicaHy influenced corrosion, which results from the interaction of microorganisms and a metal, is receiving increased emphasis (1,3,9). The action of microorganisms is at least one of the reasons why natural seawater is more corrosive than either artificial seawater or sodium chloride solutions. Microorganisms attach to the surfaces of metals and can, for example, act as diffusion barriers produce metaboHtes that enhance or initiate... 

Fig. 5-7 Effect of potential on the composition of the blister liquid, shot-peened pipe with 300 to 500 jim EP-tar, artificial seawater, 1300 days at 25°C.

Quality control tests are intended to detect produced materials which deviate from manufacturing specifications, and thus may result in questionable performance. The materials are usually subjected to spectrographic analysis which is the primary quality control check. The exposure tests are necessarily of short duration (hours or days), in which the test conditions attempt to reflect the environment of operation, for example using artificial seawater for a marine application. Since a property that is reproducible and indicative of a consistent quality anode is all that is required, there is no attempt to mirror, except in the crudest fashion, current density profiles. 

Djogic R, Branica M (1991) Dissolved uranyl complexed species in artificial seawater. Marine Chem 36 121-135... 

Harada H (2001) Isolation of hydrogen from water and/or artificial seawater by sonophoto-catalysis using alternating irradiation method. Int J Hydrogen Energy 26(4) 303-307... 

Working solutions (1 litre) which were 10 7 mol/1 in one of the elements to be studied were prepared by appropriate addition of the radioactive stock solutions to pH-adjusted artificial seawater. After the pH had been checked, 100 ml portions were transferred to the bottles to be tested. The filled bottles were shaken continuously and gently in an upright position, at room temperature and in the dark. At certain time intervals, ranging from 1 min to 28 d, 0.1 ml aliquots were taken. These aliquots were counted in a 3 x 3 in Nal (TI) well-type scintillation detector, coupled to a single-channel analyser with a window setting corresponding to the rays to be measured. 

Table 1.9 shows the percentage loss as a function of time for silver, cadmium, and zinc from artificial seawater stored in polyethylene, borosilicate glass, PTFE at various pH and R values. 

Table 1.9. Sorption behaviour as percentage of silver, cadmium and zinc in artificial seawater [54]... 

The amount of phthalate bound to the glass test tubes appears to be a function of the aqueous solubility of the phthalate. The solubilities of the phthalates have been reported to be 3.2 mg dibutyl phthalate and 1.2 mg bis (2-ethylhexyl) phthalate per litre of artificial seawater [70]. Table 1.10 shows that the more soluble dibutyl phthalate is absorbed far less than bis (2-ethylhexyl) phthalate. 

The accuracy of the method was tested experimentally by running duplicate titrations on distilled water, artificial seawater with and without sulfate, and artificial Dead Sea waters. For each run, alkalinity was calculated by two methods ... 

Stein et al. [673] have described a simplified, sensitive, and rapid method for determining low concentrations of cadmium, lead, and chromium in estuarine waters. To minimise matrix interferences, nitric acid and ammonium nitrate are added for cadmium and lead only nitric acid is added for chromium. Then 10,20, or 50 pi of the sample or standard (the amount depending on the sensitivity required) is injected into a heated graphite atomiser, and specific atomic absorbance is measured. Analyte concentrations are calculated from calibration curves for standard solutions in demineralised water for chromium, or an artificial seawater medium for lead and cadmium. 

Hiraide et al. [737] developed a multielement preconcentration technique for chromium (III), manganese (II), cobalt, nickel, copper (II), cadmium, and lead in artificial seawater using coprecipitation and flotation with indium hydroxide followed by ICP-AES. The metals are simultaneously coprecipitated with indium hydroxide adjusted to pH 9.5, with sodium hydroxide, ethano-lic solutions of sodium oleate and dodecyl sulfate added, and then floated to... 

The results show that good recoveries were obtained from artificial seawaters, even at the 0—05 xg/l level, but for natural seawater samples the recoveries were lower (74-85%). This effect could be attributed to organic sample components that eluted from the column together with dimethyl arsinate. 

H. Harada (2001)Isolation of hydrogen from water and for artificial seawater by sono-photocatalysis using alternating irradiation method Int J. Hydrogen Energy, 26 3003-2007... 

The use of synthetic media is preferable to natural filtered and/or sterilised media, as trace substances are expensive to remove from natural waters. In addition to this, the reproducibility of assays is improved if synthetic media are used. Different artificial seawater compositions have been used in toxicity testing. From the media investigated by our group, (see Table 7.1.2) the ASTM substitute ocean water [66] gave the best results for growing microalgae. 

The equilibrium pH in the multistate equilibrium as a function of the solid/water ratio (Cole and Pytkowicz, in preparation) for artificial seawaters with modified (Mg +). The last two columns for calcite refer to... 

Unless otherwise noted, all repotted solubilities were determined using distilled water. For some compotmds, solubilities were determined using groundwater, natural seawater or artificial seawater. 

Photolytic. Fukuda et al. (1988) studied the photodegradation of acenaphthene and alkylated naphthalenes in distilled water and artificial seawater using a high-pressure mercury lamp. Based upon a rate constant of 0.23/h, the photolytic half-life of acenaphthene in water is 3 h. Behymer and Hites (1985) determined the effect of different substrates on the rate of photooxidation of acenaphthene using a rotary photoreactor equipped with a 450-W medium pressure mercury lamp (X = 300-410 nm). The photolytic half-lives of acenaphthene absorbed onto silica gel, alumina, and fly ash were 2.0, 2.2, and 44 h, respectively. The estimated photooxidation half-life of acenaphthene in the atmosphere via OH radicals is 0.879 to 8.79 h (Atkinson, 1987). 

At 20 °C 180, 118, 107, and 126 nmol/L in doubly distilled water. Pacific seawater, artificial seawater and 35% NaCl, respectively (modified shake flask method-fluorometry, Hashimoto et al., 1984)... 

Fukuda et al. (1988) studied the photodegradation of anthracene and other polycyclic aromatic hydrocarbons in distilled water and artificial seawater using a high-pressure mercury lamp. Based upon an experimentally rate constant of 0.660/h, the photolytic half-life of anthracene in water is 1 h. 

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