PAH-contaminated water containing benzo (a) pyrene (Bap) was treated by oxidative catalytic decomposition using a heterogeneous fibrous (polyacrylontrile-PAN) catalyst in a modified Fenton reaction. This attempted to ameliorate the challenges of conventional homogeneous catalytic method using Fenton reagent in soil and groundwater treatment which is limited by natural processes such as pH buffering, iron precipitation, and the need for recovery of iron in the homogeneous catalyst to comply with environmental regulations. For this purpose several bench scale tests were performed, with hydrogen peroxide and modified PAN catalyst. Optimum reaction conditions were investigated by varying H2O2 concentrations, heterogeneous PAN catalyst, contaminant concentration, and pH. BaP concentration was determined using HPLC. The Fenton-like oxidation was efficient at pH 4-5, neutral, and even above neutral, with degradation efficiencies of 84–100%. With the optimization of the working scale for the catalysis, the optimum condition for the degradation of 0.1 mg/L of BaP in water matrices (50 mg/L H2O2, 2g PAN catalyst, pH 4.5, at normal room temperature) could completely break down BaP in 45 minutes. There was no significant difference in activity of the catalyst after using to fresh feed for seven cycles reflecting the stability and reusability of the PAN catalyst, an indication of its potential use in continuous processes. The overall result indicate that oxidative catalytic decomposition using a heterogeneous fibrous (polyacrylontrile-PAN mesh) catalyst would have a promising application to site remediation.