Enhancement of crude oil polluted soil by applying single and combined cow-dung and hydrogen peroxide as remediating agents

Abstract

The study aimed at enhancing the remediationof crude oil polluted soil of the Niger Delta using cow dung and hydrogen peroxide in either single or combined forms. 5 kg of soil each was polluted with 200 ml of crude oil representing 4% w/v. Five  amendment treatments labelledA- E were done in order of A (polluted soil + 1.2 kg cow dung), B (polluted soil + 1000 ml Hydrogen peroxide), C (polluted soil + 0.6 kg cow dung +500 ml hydrogen peroxide), D (polluted soil without amendment) and E (unpolluted soil without amendment).pH, conductivity, organic carbon, organic matter, phosphate, nitrate, total hydrocarbon content, potassium and microbial population were analyzed before and after remediation. The results showed that addition of cowdung and H2O2 enhanced remediation of the polluted soilespecially in treatment A and C with significant increase (p=0.05) in soil conductivity, pH and nutrients when compared to the un-amended soil. Reduction in the total hydrocarbon content (THC) was in the order of A (79.48%)>C (77.95%) >B (75.75%)  >D(46%)with significant increase in hydrocarbon degrading microbes in the amended soil.The amendments have the capacities to enhance remediation of crude oil polluted soil.Also, the combined treatments did not have any advantage over the single treatment options as the use of cowdung single treatment perform best in terms of its remediation potential. Therefore, nutrient enhancement should be  considered a critical factor in the remediation of crude oil polluted soil.

Keywords: remediation, physiochemical, parameters, soil, crude oil.