A study was conducted to enhance the performance of an advanced oxidat
ion process in treating chlorinated ethenes in groundwater at IBM's gr
oundwater treatment system at its Essex Junction, Vermont facility. A
model describing the reaction kinetics and mass transfer of a co-curre
nt ozone injection process is presented. This model, in conjunction wi
th experiments, demonstrates that the treatment performance of the ozo
ne treatment process at a given ozone/air concentration and ozone mass
flowrate cannot be improved by varying process operating parameters s
uch as number of ozone injectors utilized use of a static mixer, or va
riation of groundwater flowrate through each injector This is because
dissolved ozone reaches equilibrium with the injected ozone/air mixtur
e within two seconds of initial contact. Also, the Venturi-type ozone
injection system presently in use destroys nearly half of the injected
ozone. Injection of hydrogen peroxide in conjunction with ozone incre
ases the overall tetrachloroethylene (PCE) treatment efficiency by a f
actor of four (in comparison to ozone alone) at a H2O2/O-3 mass ratio
of between 1 and 2. Treatment of trichloroethylene (TCE) is enhanced b
y a factor of two. This enhancement of the oxidative treatment process
results in a reduction in solvent mass load to a granular activated c
arbon (GAC) adsorption system located downstream thus potentially redu
cing the usage GAC and regeneration of spent GAG. However, residual hy
drogen peroxide and/or hydroxyl free radicals from the oxidation proce
ss effluent may interact adversely with certain grades of GAC; the cau
ses of this interaction and methods to attenuate it (i.e., the use of
more resistant graces of GAC) are discussed. Overall O-3/H2O2/GAC syst
em operating costs can potentially be reduced significantly (up to $20
K annually). An economic analysis and system operation/cost optimizati
on study are presented.