Abstract

Variation in the Carbon (C), Phosphorus (P) and Nitrogen (N) Utilization during the Biodegradation of Crude Oil in Soil

Oje Obinna A, Ubani Chibuike S and Onwurah INE

This study was aimed at determining the effect of varying concentration of crude oil pollution on the macronutrients in the soil. Various macro-nutrients (such as soil ammonium concentration, soil nitrate concentration, and available phosphorus), oxidizable organic carbon, and total petroleum hydrocarbon were determined. The result revealed that as the time increases, the oxidizable carbon, which is also a function of the organic matter decreases, which is as a result of the conversion of carbon to carbon (IV) oxide during cellular metabolism. This decrease showed that there was an increase in the activity of that leads to the breakdown of the carbon components in the soil. The soil phosphate concentration determination did not show any pattern in their increase or decrease, which shows that increase in crude oil concentration, did not significantly affect the phosphate concentration in the soil. The soil ammonium concentration increased from 24th hour to 168th hour but decreased before the end of the experiment. This increase could be attributed to ability of the Azotobacter vinelandii to fixed nitrogen as an innate responsibility, while Pseudomonas sp. which is known to contain nitrogen fixing genes. The result also showed that there is a constant increase in soil nitrate concentration which is affected as the concentration of the pollutant (crude oil) increases. This study has shown that the consortium of these organisms can be used as a bio-fertilizer as well as in bioremediation.