PhreeqcUsers Discussion Forum

Conceptual Models => Example Input Solutions => Topic started by: Tom on March 12, 2014, 10:01:10 AM

Title: Seawater compositions
Post by: Tom on March 12, 2014, 10:01:10 AM
Examples of seawater compositions:

Please contribute those that you have found/used and any associated information (location, determination methods, date of determination and full reference(s) if possible).

#Seawater (Nordstrom et al., 1979), as described in the PHREEQC questions thread. Answers by D. Parkhurst.

units ppm
pH 8.22
pe 8.451
density 1.023
temp 25.0
redox O(0)/O(-2)
Ca 412.3
Mg 1291.8
Na 10768.0
K 399.1
Si 4.28
Cl 19353.0
Alkalinity 141.682 as HCO3
S(6) 2712.0
O(0) 1.0 O2(g) -0.7


#Full reference:

#Nordstrom, D.K., Plummer, L.N., Wigley, T.M.L., Wolery, T.J., Ball, J.W., Jenne, E.A., Bassett, R.L., Crerar, D.A., Florence, T.M., Fritz, B., Hoffman, M., Holdren Jr., G.R., Lafon, G.M., Mattigod, S.V., McDuff, R.E., Morel, F., Reddy, M.M., Sposito, G., and Thrailkill, J. (1979). A comparison of computerized chemical models for equilibrium calculations in aqueous systems. In: Jenne, E.A. (Ed.). Chemical Modeling in Aqueous Systems. American Chemical Society Symposium Series, vol. 93. American Chemical Society, Washington, D. C., pp. 857892.


#Seawater (Mediterranean Sea) (Pulat et al., 2014)

SOLUTION 2 #pH not provided
units ppm
Ca 486.6
Mg 1481.4
Na 12301.5
K 487.7
Cl 23852.0
Br 70.3
S(6) 3115.2
Sr 15.5


#Full reference:

#Pulat, H.F., Yukselen-Aksoy, Y., and Egeli, I. (2014). The effect of soil mineralogy and pore fluid chemistry on the suction and swelling behavior of soils. Bulletin of Engineering Geology and the Environment. 73, 37-42.


#Seawater major ions (Pilson, 1998 for salinity, S of 35.000 %)

SOLUTION 3 #pH not provided
units ppm
Ca 411.9
Mg 1284
Na 10781
K 399
Cl 19353
Br 67.3
S(6) 2712
Sr 7.94
F 1.3
Alkalinity 126 as HCO3
B 25.7


#Full reference:

#Pilson, M.E.Q. (1998). An Introduction to the Chemistry of the Sea. Prentice Hall Publ. Co. 431 pp.

Title: Re: Seawater compositions
Post by: rfembilejr on December 21, 2016, 05:32:11 AM
Hi Tom,

I am currently working with artificial seawater for my simulations, what database do you recommend to use?
I have heard Pitzer or SIT may suit the high ionic strength but for some  of the minerals I wanted to use, they are not in these databases. I figure I can just add them in the database.

Any thought?

Thanks in advance.

Title: Re: Seawater compositions
Post by: dlparkhurst on December 21, 2016, 03:05:09 PM
Depends on which minerals you need to use. The main problem with the Pitzer database is that it does not contain aluminum, so no aluminosilicate minerals can be added (silica is present minimally), and it does not contain redox couples, so no redox reactions. It may be possible to find other databases or data that would remove these limitations.

If you can use pitzer.dat, it is probably more reliable. You can always run with both Pitzer and ion association to get a feel for the differences.