Example 1

[liakos]

Trying to run Example 1 from version 3 documentation with PHREEQC.DAT, as I think it is implied from the document I get:

WARNING: Could not find element in database, N(-3).
 ERROR: Cannot find master species for redox couple, N(-3)/N(5).

Opening database file I see those two lines I named A and B

A:  # N(-3)   NH4+      NH4   14.0067  in SOLUTION_MASTER_SPECIES

and

B: #NO3- + 10 H+ + 8 e- = AmmH+ + 3 H2O
#   -log_k   119.077
#   -delta_h -187.055   kcal
#   -gamma   2.5   0
#   -Vm  4.837  2.345  5.522  -2.88 1.096  3  -1.456  75.0  7.17e-3  1 # ref. 1 in SOLUTION_SPECIES

Turning the first on (i.e. removing #) I get
ERROR: Expected alkalinity for master species, N, in master species input.

QUESTION 1: Why is there no input for alkalinity contribution here and what are the criteria to choose one?

After choosing alkalinity contribution 0 or 1 I get
ERROR: Elements in species have not been tabulated, NH4+.
ERROR: Reaction for species has not been defined, NH4+.
ERROR: Calculations terminating due to input errors.

The same errors arise when I turn both A and B on.

Turning B on I get
ERROR: Equation does not balance for element, Amm: right - left = -1.0000 moles
ERROR: Equation does not balance for element, H: right - left =  3.0000 moles
ERROR: Equation does not balance for element, N: right - left =  1.0000 moles
ERROR: Equation for species AmmH+ does not balance.
ERROR: Calculations terminating due to input errors.

QUESTION 2: What should I edit in order for the example to function properly. In the documentation I don't see anything about Nitrogen species.

P.S.1: I get an ouput with different databases, as LLNL or WATEQ4F.
P.S.2: Trying to be -relatively- self taught can be hard in every step, especially at the first few. I apologize if my questions are too "dummies".

[dlparkhurst]

Tony Appelo has a database called PHREEQC.DAT that removes the N(-3) from the N (nitrogen) system and replaces it with a non-redox element named Amm. If you are using that database, you should use Amm instead of N(-3) in the SOLUTION definition.

Databases distributed with PHREEQC programs from the US Geological Survey website include phreeqc.dat, which has N(-3) coupled with the rest of the nitrogen redox states, and Amm.dat, which is equivalent to Tony's PHREEQC.DAT.

[liakos]

Thank you!