Re: input file PHREEQC

["David L Parkhurst" <dlpark@xxxxxxxx>]

The default conversion from mass to mol for Si uses the gram formula wt for
SiO2. If your data are reported as ppm of Si, then you need to have the
following in the SOLUTION data block:

Si 5.25 as Si

or

Si 5.25 gfw 28.08

(default is equivalent to Si 5.25 as SiO2).

David


David Parkhurst (dlpark@xxxxxxxx)
U.S. Geological Survey
Box 25046, MS 413
Denver Federal Center
Denver, CO 80225


                                                                                                                                    
                      "Teresa Melo"                                                                                                 
                      <tmelo@xxxxxxxxx         To:      <dlpark@xxxxxxxx>                                                           
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In-Reply-To: <000901c0d593$4af43100$f15588c1@xxxxxxxxxxxxxxxxxxx>
                                               Subject: input file PHREEQC                                                          
                      05/05/01 11:43                                                                                                
                      AM                                                                                                            
                                                                                                                                    
                                                                                                                                    



Dear Dr Parkhurst,

Just a quick question to check if I can use Si data instead of SiO2 (in
ppm) in the PHREEQC input file.
The following Solution 1 has 5.25 mgL-1 of Si. Is the input file correct or
do I need to convert the Si to SiO2?

 SOLUTION 1
 temp                20.8
 pH                  7.65
 units ppm
 Na              128.0000
 K                10.4000
 Ca               13.0000
 Mg                6.4400
 Si                5.2500
 Cl              132.0000
 Alkalinity      136.0000 as HCO3
 S(6)               68.6000 as SO4
 N(5)                0.0000 as NO3
 N(+3)              0.0000 as NO2
 Amm               0.0000 as NH4
 Al                0.0053
 B                 0.2200
 Ba                0.0650
 Br                0.3210
 F                 0.5200
 Fe                0.3220
 Li                0.0182
 Mn                0.0242
 Sr                0.1150

Thanks a lot for your kind help.

Regards, Teresa