DATABASE C:\Program Files (x86)\USGS\Phreeqc Interactive 3.1.4-8929\database\phreeqc.dat SOLUTION_MASTER_SPECIES; Urea Urea 0 1 1 # 1 g urea = 1 "mol" SOLUTION_SPECIES; Urea = Urea; log_k 0 SOLUTION 1 units mol/kgw temp 25.000000 pH 9.91 charge # comp 5 pe 4.0 O2(g) -0.68 # comp 6 Urea 40 KINETICS 1 Urea_degradation -formula Urea 1 -m0 0 -parms 4.3e-9 8.7e-3 #-steps 17.28e6 in 20 -steps 10000 day in 10 RATES Urea_degradation -start 1 v_max = parm(1); 2 k_m = parm(2) 10 S = tot("Urea") 20 if S < 1e-9 then goto 50 30 rate = - v_max * S /(k_m + S) 40 moles = rate * time 50 save moles -end PRINT -reset true -selected_output true #ende SELECTED_OUTPUT -file phout_sel.dat -high_precision -reset false #ende USER_PUNCH 20 PUNCH TOT("Urea") 30 PUNCH -LA("H+"), -LA("e-") 60 PUNCH KIN("Urea_degradation") #ende END