This document discusses reducing chemical oxygen demand (COD) in petrochemical wastewater. The objective is to reduce COD using hydrogen peroxide activated by two reagents: iron-catalyzed H2O2 (Fenton's reagent) and Al2(SO4)3-catalyzed H2O2. The methodology involves treating wastewater samples with different dosages of the reagents and hydrogen peroxide. Results show Fenton's reagent achieved 68-70% COD removal, while Al2(SO4)3 removal was not effective for COD but achieved up to 55% removal of total suspended solids.