DATABASE phreeqc.dat # contains the PWP calcite rate RATES Calcit2 # simplified rate... -start 10 rate = 10^-6.91 - 10^-1.52 * (tot("Ca"))^2 # mmol/cm2/s 20 save 1 * rate * time # integrate in moles/L -end SOLUTION 1 temp 10; pH 6 charge; C 1 CO2(g) -1.5 EQUILIBRIUM_PHASES 1 CO2(g) -1.5 KINETICS 1 Calcit2; formula CaCO3; -m0 1; -step 30000 in 20 INCREMENTAL_REACTIONS USER_GRAPH -head time Ca pH; -axis_titles "Time / 1000s" "Ca / mM" "pH" -start 10 graph_x total_time/1e3; 20 graph_y tot("Ca")*1e3; 30 graph_sy -la("H+") -end END # Simulation 2, using the parent PWP rate... USE solution 1; USE equilibrium_phases 1 KINETICS 1 Calcite; -m0 1; -parms 10 0.67; -step 30000 in 20 END