Effects of Oxygen Diffusion on Physicochemical Characteristics of Petroleum Contaminated Sandy Loam Soil

摘要

Soil pollution by petroleum and its products in Niger Delta region of Nigeria are predominant due to oil exploration, exploitation and transportation. The aim of this study was to examine the effects of oxygen diffusion on the physicochemical characteristics of petroleum contaminated sandy loam soils at 100cm depth when there is sufficient availability of indigenous microorganism in the polluted soils. The soil samples were analysis after pollution with Bonny light crude oil. The purpose of the pollution of the soil samples were to simulate conditions of major crude oil spill. Oxygen was diffused through the impacted soils in reactor C. Physicochemical properties of the sandy loam soils considered for analysis were pH, Electrical conductivity, Total organic carbon, Total Nitrogen, Moisture content, Phosphorous and Total petroleum hydrocarbon at two weeks' interval for six weeks using standard methods. The analysis indicated that bioremediation was faster in the soils at the depth of 100cm with oxygen diffusion. The study showed75% reduction in TPH concentration, pH decreased from 6.47to 6.34, Electrical conductivity increased from 92.1 to169.9μs, Moisture content decreased from 13to 8%, Total organic carbon reduced from 2.301 to 1.716%, Total Nitrogen decreased from 0.199 to 0.032% and Phosphorous reduced from 0.08 to 0.003mg/kg at the end of the study. Physicochemical properties of the treated soils showed similar soil characteristics as compared with the initial conditions of the soil before contamination with Bonny light crude oil. Therefore, this confirmed that oxygen diffusion through petroleum contaminated sandy loam soil was an effective method and a good approach for treatment of petroleum contaminated Sandy loam soil at the depth of 100cm and below.