as3_cl2.msx

[TITLE]
AsIII-Chlorine reaction kinetic model

[OPTIONS]
RATE_UNITS  MIN
AREA_UNITS  FT2
RATE_UNITS  DAY
SOLVER      ROS2
COUPLING    FULL
TIMESTEP    300
RTOL        1.E-3
ATOL        1.E-3

[SPECIES]
; Type   Name      Units   RTol   ATol
BULK    CL2       MG      1.E-3  1.E-3
BULK    AsIII     MG      1.E-3  1.E-3

[COEFFICIENTS]
CONSTANT KB         6.94444E-4  ;1/24/60=Free chlorine bulk decay rate == 1/day
CONSTANT K2         69.4        ;100000/24/60= Arsenite oxidation velocity;
CONSTANT MWChlorine 70.9        ;mg/mmol free chlorine as Cl2
CONSTANT MWAsIII    74.92       ;mg/mmol arsenite as As
PARAMETER   Kw                                1.000000e+00

[TERMS]
Kf     1.5826e-4 * RE^0.88 / D

[PIPE]
RATE CL2 -KB*CL2 - K2*CL2*AsIII/MWAsIII - (4/D)*Kw*Kf/(Kw+Kf)*CL2
RATE AsIII    -K2*CL2*AsIII/MWChlorine