Vermiremediation of crude oil contaminated soil using eudrillus euginae and lumbricus terrestris

Abstract

The negative and cost implications of remediation of petroleum contaminated sites using physical and chemical techniques have necessitated the use of biological techniques like vermiremediation. In this study the individual and synergistic abilities of two earthworms – Eudrillus euginae and Lumbricus terrestris to clean up crude oil contaminated soil were evaluated. It involved experimentally contaminating the soils with various quantities of crude oil. The total petroleum hydrocarbon (TPH), pH and nutrient contents of the soils were determined immediately after contamination and after thirty days of earthworm activities. Data obtained were statistically analysed using graphpad prisms 6.0 and SPSS 20.0 softwares. Activities of E. euginae led to 88.50% TPH loss, L. terrestris led to 76.42% loss while combined activities of the two earthworms led to 73.06% loss of TPH from the soil contaminated with 3ml crude oil after 30days. In soil without any earthworm but contaminated with same amount of crude oil there was only 21.19% loss of TPH for same period of time. Similar trends were observed in soils contaminated with 1ml and 2ml of crude oil for same period of study. The pH, sulphate, phosphate, nitrate and organic matter contents of the contaminated soils were reduced after 30 days and the reduction was more in soils with the earthworms than in the soils without the earthworms. The findings of this study show that the E. euginae and L. terrestris can help in the remediation crude oil contamination soil and that they are more effective individually than in a combined form. Also E. euginae had more impact on the contaminated soil than L. terrestris.