smile_chem_eq.hpp

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/*
 * smile_chem_util.hpp
 *
 * Header for the functions implementing the main chemical relations for the equilibrium.
 *
 */
#include <algorithm>
#include <cmath>
 
#ifndef _SMILE_CHEM_UTIL_HPP_
#define _SMILE_CHEM_UTIL_HPP_
 
//TODO: Note that exp10 is a GNU extension. It does not work even under macOS with clang.
//#ifdef UG_WIN32
#define exp10(x) exp(2.30258509299404568402*(x))
//#endif
 
/* Throughout in this file: Units of the concentrations in the arguments are [mol/l], not [mol/m^3]! */
 
namespace ug {
namespace smile { 
 
/* Thermodynamic constants for calcite */
const double logKspCc = - 8.481;
const double logKspgG  =  10.35;
 
// Thermodynamic complex formation constants for aqueous species
const double logKHCO3 =  16.6808;
const double logKCO3  =  10.3289;
const double logKAlOH = -4.9573;
const double logKAlOH2  = -10.5943;
const double logKAlOH3  = -16.4328;
const double logKAlOH4  = -22.8797;
const double KHCO3    = exp10(logKHCO3);
const double KCO3   = exp10(logKCO3);
const double KAlOH    = exp10(logKAlOH);
const double KAlOH2   = exp10(logKAlOH2);
const double KAlOH3   = exp10(logKAlOH3);
const double KAlOH4   = exp10(logKAlOH4);
 
const double logIW_0  = -13.9995; // Ion activity product of water at infinite dilution
 
// Ion-Ion interaction parameters (SIT)
const double epsHCl   =  0.12;
const double epsOHNa  =  0.04;
const double epsAlCl  =  0.33;
const double epsAlOHCl  =  0.09;
const double epsAlOH2Cl = -0.27;
const double epsAlOH4Na = -0.07;
const double epsHCO3Na  =  0.0;
const double epsCO3Na = -0.08;
const double epsCaCl  =  0.14;
 
const double ADH    = 0.5114;   // Debye-Hueckel coefficient A at 25 degC
const double NaCl_sat = 5428.78;  // Concentration of saturated NaCl in mol/m^3 at 25 degC
 
// Computes the chemical equilibrium
int SmartEquilibrate
(
  // The following values are assumed to be in mol/l (scale by 1e-3 to convert from mol/m^3),
  // in particular s which should be the concentration (to get from the mass fraction, scale additionally by 5428.78)
  double &H_T, double &OH_T, double &s, double &Ca_T, double &DIC_T, double &SO4_T, double &Al_T, double &Cc_T
);
 
// Activity coefficients
struct t_gamma
{
  double H;
  double OH;
    double Al3;
    double AlOH;
    double AlOH2;
    double AlOH4; 
  double CO3;
  double HCO3;
  double Ca;
};
 
number pH_of_sHD (number s, number H, number D);
 
void Compute_I_D
(
  double s, double Ca, double Al, double DIC, double SO4, // [i]
  double *I, double *D, t_gamma *gamma // [o]
);
 
void Compute_I_pH
(
  number s, number H, number Ca, number Al, number DIC, number SO4, // [i]
  number& I, number& pH // [o]
);
 
} // end namespace smile
} // end namespace ug
 
#endif // _SMILE_CHEM_UTIL_HPP_
 
/* End of File */