This study evaluated the effect of chemical oxidation on the bioremediation of polycyclic aromatic hydrocarbons (PAHs) contaminated sediments. Sediments were treated in sequential steps: biotreatment, chemical oxidation, and biotreatment. The first biotreatment step was initiated via addition of nutrients, microbial seeds, co-metabolites, and/or Tween 80 (surfactant). The chemical oxidation step was conducted using Fenton?s Reagent, ozonation, and peroxone (combination of ozone and hydrogen peroxide). The objective was to enhance the PAHs bioavailability via oxidation of natural organic matter and transformation of Heavy PAHs into more biodegradable compounds. Biotreatment was reestablished as a final polishing step to further degrade remaining PAHs and more biodegradable oxidation by-products. The proposed mechanism was proven successful for the less contaminated sediment (Scioto River) and not the highly contaminated and chemically more complex sediment (Lake Superior). Given this mechanism only worked for the Scioto River sediment, further research is required to determine the mechanisms limiting treatment.