Viscosities of aqueous solutions of several electrolytes present in sea water

Abstract

Experimental viscosity and density measurements are reported on ternary solutions of several electrolytes present in sea water, and on a synthetic sea water over the range of ionic strength levels from 0.7 to 3.5 and for sea water up to a concentration factor of 3 and the temperature range from 25' to 1 5 O O C . The experimental viscosity data were correlated with a precision of 0.2 to 0.3%, assuming an additivity of the constants of the Othmer rule. literature data were reviewed and compared with the correlation. Recommended sea water viscosity data are given as a function of temperature and concentration. KNOWLEDGE of viscosities of sea water and brackishwater brines, which contain primarily NaC1, KC1, Na2S04, and MgS04, is important in the development and design of economic desalination processes. In a previous paper (7) the viscosities of the binary mixtures were evaluated on the basis of the Othmer rule or relation based on the properties of a reference substance under a similar condition. The reference substance was water and the single similar condition was temperature.This paper presents viscosity measurements on ternary aqueous solutions and on calcium-free synthetic sea waters from 25" to 150" C., covering ionic strength concentration levels from 0.7 to 3.5. The experimental data were correlated with satisfactory precision, assuming an additivity of the constants of the Othmer rule.The experimental apparatus, method, and calculation techniques have been given (6, 7). EVALUATION OF EXPERIMENTAL DATAsalt was expressed by the Othmer rule ( I 1 ) : Ternary Systems. The viscosity of a solution of a single log qa = c, + m, log q . (la) Similarly, the relative viscosity, which has some advantages and is more frequently used, can be given as:where RR' is the relative viscosity of the solution, q s , / q , qsl is the viscosity of the solution, cp. qw is the viscosity of water a t the same temperature, cp.Bo, = m, -1 and Ao, = C, Ao, and Bo, are temperature-independent Othmer constants for compound i for the linear equation. These constants were expressed as functions of ionic strength in molal units in the forms Ao, = A1,I + A2,12 + Am13 (2) Bo, = B1,I + B J 2 + B3,13 (3) T o correlate the measured viscosities of two salts containing the Othmer constants of the mixture, A M and B M were calculated for each solution a t three constant ionic Present address: Research Foundation, Lowell Technological Institute, Lowell, Mass. 01854strength levels over the entire test temperature range. Since the concentration of the solutions under our test conditions increased somewhat a t high temperatures (this was caused by water evaporation into the vapor space of the closed viscometer system), the measured data were adjusted to constant ionic strength by graphical interpolation. Then, an attempt was made to plot the obtained A M and E M constants as a function of the mixture composition a t each constant ionic strength level. The composition of the mixture was expressed as ionic strength fraction with respect to the salt c...

Thermophysical properties of seawater: a review of existing correlations and data

“…and the data given by Fabuss [64], Isdale et al [66] and Millero [69] with an r.m.s. deviation of ±0.6%.…”

“…Available data on seawater viscosity are those by Krummel [62] (for t = 0 -30°C, S = 5 -40 g/kg), Miyake and Koizumi [63] (for t = 0 -30°C, S = 5 -40 g/kg), Fabuss et al [64] (for t = 25 to 150 o C, S up to 110 g/kg and calcium-free synthetic seawater), Stanley and Butten [65] (for t = 0 to 30 °C, p = 0.1 -140 MPa and S = 35 g/kg), and Isdale et al [66] (for t = 20 -180°C, S = 0 -150 g/kg and synthetic seawater). The available correlations that best fit these experimental measurements are given in Table 5.…”

“…Equation ( 16) is given by Fabuss et al [64] and is a fit to the measured data using Othmer's rule (Othmer and Yu [67]). According to this rule, the logarithm of the ratio of the viscosity of an aqueous solution of a given concentration to the viscosity of pure water is a linear function of the logarithm of water viscosity at the same temperature.…”

Properties of Sea Water

“…The density correlations were developed on the basis of measured data by Fabuss et al (1966) (1928). All published density data (Bein et al, 1925;Hampel, 1950;Hara et al, 1931Hara et al, /1932International Critical Tables, 1928;Knudsen, 1901;Tsurikova, 1960) were used in developing the correlation for sea water.…”

Properties of seawater and its concentrates and related solutions at temperatures up to 400 F

“…Measurements of the viscosity of synthetic sea water is contained in work by Fabus et al . (19) and Grunberg (15).…”