Remediation of Petroleum Hydrocarbons in a Tropical Sand Tank Model

Abstract

This paper evaluates In-Situ Chemical Oxidation (ISCO) remediation technique for the remediation of hydrocarbon contaminated soil and groundwater in a laboratory three Dimensional (3D) sand tank model. The sand tank model was used to study natural attenuation and chemical oxidation of petroleum hydrocarbon in groundwater within a Tropical aquifer (porous media) material. Detailed geotechnical, hydraulic and geochemical characterization of the chosen laboratory experimental porous media material were performed. 60 ml of unleaded gasoline was introduced as a contaminant of concern into the 3-D sand tank via the injection wells. Thereafter, samples were taken periodically for 24 days for Benzene, Toluene, Ethyl benzene, and Xylene (BTEX) analysis was done for Natural Attenuation case study. Sand replacement was done for case study of Insitu chemical oxidation (ISCO I and ISCO II), the same volume of gasoline was injected as pollutant, Potassium permanganate (KMnO₄) was chosen as oxidizing agent with varied percentages (1.5% and 5%). Samples were taken periodically for 24 days for BTEX test. The results of BTEX for Natural Attenuation (NA), ISCO I and ISCO II, i.e., 15 g/l and 50 g/l of KMnO₄ were analyzed and compared. Modeling simulation carried out on Natural attenuation of the same Contaminant of concern (COC) revealed a clean-up period of about 45 years. The clean-up period for ISCO I will take about 69 months while the clean-up period for ISCO II will take about 35 months.