Optimization of Crude Oil Biodegradation of Fungi Isolated from Refinery Effluent Site using Response Surface Methodology

E.M Shaibu-Modagbe,U.C Odili,H.I Atta,F.B Ibrahim

doi:10.4314/njtd.v17i4.3

Abstract

The activities involved in the production and exploration of crude oil has constantly polluted the environment. This study investigated the ability of an indigenous fungus to utilize petroleum hydrocarbon. Response Surface Methodology was used to optimize the effects of pH, microbial concentration (spores/ml), and contact time (days) on the crude oil removal efficiency in refinery effluent. Monocillium sp. was isolated and used for the treatment of refinery effluent due to its predominance in the contaminated soil. Twenty experimental runs were analyzed to determine the effect of pH, microbial concentration and contact time on the oil removal efficiency. From theexperimental results obtained, a maximum oil removal efficiency of 98.42 % was achieved at a pH of 6.5, contact time of 14 days, and a microbial concentration of 3 spores/ml. The results obtained showed the percentage of crude oil removal in the effluent sample increased with an increase in time. Optimization of the experimental result was achieved at a removal efficiency of 98.59 %, a contact time of 13.96 days, a pH of 6.85, and a microbial concentration of 3.01 spores/ml. The findings of this study revealed that Monocillium sp. is a viable hydrocarbon degrader, and can be used in the bioremediation of petroleum contaminated environments. Keywords: Response surface, optimization, bioremediation, hydrocarbon, removal efficiency, Monocillium sp.

Highlights

Increase in petroleum-related pollution and degradation of the environment over the past few decades have resulted from the continuous use of fossil fuels (McDonald, 2001; Nwachi et al, 2013)
The indigenous fungal isolate used in this study, (Monocillium sp.) was predominant in the soil contaminated with crude oil from a refinery effluent site
This selection was made based on the results obtained from screening during biodegradation studies, the results showed that among all isolates screened, Monocillium sp. had the highest ability to grow on oil agar, the highest weight loss of crude oil and the highest HUF counts

Summary

Introduction

Increase in petroleum-related pollution and degradation of the environment over the past few decades have resulted from the continuous use of fossil fuels (McDonald, 2001; Nwachi et al, 2013). To effectively tackle oil pollution in water in recent times, some technologies such as the use of absorbents (clay and straws), dispersants, the use of booms and skimmers, oil skimming agents, and oil coagulation have been investigated (Wilde, 2017). These physical and chemical treatment processes are expensive, and leave byproducts that are either incinerated or buried leading to air pollution and groundwater pollution as the case may be (AbdelRahman, 2011; Nilanjana and Preethy, 2011).

Methods

Results

Conclusion