Effects of Waste Engine Oil on the Microflora and Physico-chemical Quality of Soils from two West African Countries

Abstract

A study of the bioremediation of diverse levels of simulated contamination of waste engine oil (WEO) in soil using natural attenuation, bioaugmentation, mycoremediation and phytoremediation was carried out. This required a preliminary study of the microbiological and physico-chemical quality of waste engine oil contaminated soils from as it were, a “naturally” contaminated site, as a check that the characteristics of the “natural” and simulated samples match. Thus, WEO contaminated soil samples were randomly collected with controls and pooled together respectively from Owerri, Imo State, in the Eastern part of Nigeria and Kumasi in the Ashanti region of Ghana. The most occurring microorganism isolated from all the samples is Bacillus sp. The mean logarithm (mlog) of the total heterotrophic bacterial counts (THBC), total heterotrophic fungal counts (THFC), hydrocarbon utilizing bacterial count (HUBC) and hydrocarbon utilizing fungal counts (HUFC) for the WEO contaminated samples from Kumasi and Owerri were 3.85±0.01 and 3.89±0.01; 3.79±0.07 and 3.98±0.01; 4.37±0.01 and 4.35±0.01 and 4.12±0.02 and 4.22±0.01 respectively. Some Physico-chemical parameters such as pH, total hydrocarbon, total organic carbon, phosphate, nitrate and sulphate content; Polycyclic aromatic hydrocarbon (PAH) and heavy metals content of the respective samples were analyzed.