Owing to the worldwide emphasis on eutrophicationproblem and the toxic property of ammonia on the aquaticliving, the discharge of ammonia-containing water toaquifers is intensely focused. The ammonia containingwaste produced in industries is usually characterized byhigh concentration and high temperature and is not treatableby biological methods directly. In this study, a processhas been developed to remove ammonia from water bystripping ammonia from the aqueous phase followed by thegas-phase oxidation of ammonia over a Pt/SDB hydrophobiccatalyst. An equation of the form
r = kPNH3mPO2n modeledthe reaction, the reaction order in ammonia was 1.4 and inoxygen was 0.6, and the activation energy was 17400 cal/mol in a gas reaction system, whereas the reactionorder of ammonia in a trickle-bed reactor was 0.8, andthe activation energy was 10131 cal/mol. The difference wasdue to the presence of water in the trickle-bed reactor.Combining the equilibrium reactions of ammonia in water(
KNH4+,
KH2O), the NH
3 equilibrium between the gas andliquid phase (
HNH3), and the reaction kinetics of ammoniaoxidation (
r = kPNH3mPO2n), a model of
M/
F0 = [0.0435 exp(-10131/
RT)]
-1PO2-0.6journals/esthag/34/i22/eqn/es991300ne10001.gif"> H
-0.8[2
KNH4+C02(1 -
x)
2/(
KH2O +
journals/esthag/34/i22/eqn/es991300ne10002.gif">]
-0.8 dx was established todescribe the ammonia removal in the trickle-bed reactor.