Tertiary or pretreatment of organic effluents by advanced oxidation processes (Aop)[1-5] catalyzed by a source of sun light  and a powerful oxidant is a promising  alternative for the effective removal of color and refractory organics  form the effluent. Accrual feature in disguising such systems is the optimization of operating condition (such as UV- and oxidant dosages), which yield maximum removal at acceptable costs. The present study describes modeling approach to keep the oxidant dosage at the most effective level to sustain maximum rate of organic degradation.