Chemical oxidations by hydrogen peroxide and/or persulfate represent promising pretreatment step foregoing bioremediation for removal of hydrophobic contaminants. The feasibility of hydrogen peroxide based and sodium persulfate-based oxidation treatments on the real contaminated soil collected from petroleum lagoon deposit were evaluated. The results showed poor insignificant degradation of pollutants (expressed as C-10-C-40 concentration) in hydrogen peroxide variants (avg. of 9% +/- 30% decrease) in comparison to persulfate treatment variants (avg. of 55% +/- 13% decrease). In accordance, microbial community activity indicators showed substantial inhibition of viability only by persulfate, base and Fe3+ activated variants. The highest contaminant removal efficiency was achieved by Fe3+ activated persulfate system (78% +/- 3%). Persulfate was thus demonstrated as a promising chemical oxidant for degradation of petroleum contaminants, however activation mechanism and initial dosage of the oxidant should by chosen carefully in respect to the soil microorganisms. (C) 2016 Elsevier B.V. All rights reserved.