Evaluating the productivity and bioremediation potential of two tropical marine algae in petroleum hydrocarbon polluted tropical marine water

Abstract

Bioremediation using tropical marine algae provides cost effective and eco-friendly alternative mean of removing toxic and harmful substances from the environment. Bioremediation is an important tool in sustainable environmental management and protection. This study examined the productivity and bioremediation potential of Nannochloropsis oculata and Porphyridium cruentum in Water Soluble Fraction (WSF) of petroleum fuels by investigating the growth of Nannochloropsis oculata and Porphyridium cruentum at 0%, 10% 20% 30% 40% 50% 75% 100% of WSF of kerosene, diesel, and gasoline. Growth was monitored optically every two days for fourteen days using 721 Visible Spectrophotometer. Productivity was measured using prescribed procedure. Bioremediation potential of test algae were examined using standard method for the GC analysis of diesel range organics in 100% WSFs. The minimum growth for both species was recorded at 100% in all the fuels. The maximum growth of Porphyridium cruentum was obtained at 10% in all fuels, while the maximum growth of Nannochloropsis oculata was obtained at 30% in both kerosene and gasoline and at 50% in diesel. Whereas Porphyridium cruentum was greatly inhibited by all fuels, Nannochloropsis oculata was stimulated at lower concentration of the fuels. Nannochloropsis oculata proved more efficient for bioremediation of the petroleum fuels with 84.58%, 65.51% and 70.77% removal efficiency for kerosene, diesel and gasoline respectively, while Porphyridium cruentum was 58.94%, 46.64% and 56.67% respectively. Nannochloropsis oculata is a very strong and reliable candidate for bioremediation of petroleum hydrocarbons and should be subjected to further examination for sustainable and eco-friendly remediation of petroleum pollution.

NOVELTY STATEMENT

In this study, bioremediation of 100% Water Soluble Fraction (very high concentration) of the three most commonly used petroleum fuels (gasoline, diesel, kerosene) were examined. The bioremediation potential of the test algae were examined simultaneously in three petroleum fuels to enhance comparative assessment and to reduce the effect of environmental changes. This study identifies specific tropical marine alga that has high biomass productivity and bioremediation efficiency in tropical marine or coastal waters polluted with very high concentration of WSF of petroleum hydrocarbons. The result of this study is recommended for adoption by the bioremediation industries for the removal of high concentration of WSF of petroleum hydrocarbons in tropical marine waters and industrial waste waters. It may also be subjected to further examination.

Keywords:

• Algae
• bioremediation
• eco-friendly
• hydrocarbon
• marine environment
• pollution

Acknowledgments

We appreciate Dr. (Mrs.) J. E. Ukpebor and all staff of Chemistry Department, University of Benin technical staff who assisted in the analysis of hydrocarbons. We appreciate Dr. Jeffrey Uyi Ogbebor for his moral assistance. We acknowledge and appreciate every staff of Limnology and Algology Laboratory, Department of Plant Biology and Biotechnology, University of Benin, Nigeria where this research was carried out.

Authors’ contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Raymond Sunday EZENWEANI. The study was supervised by Medina Omo Kadiri. The first draft of the manuscript was written by Raymond Sunday EZENWEANI and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

The datasets generated during and/or analyzed during the current study are not publicly available but are available from the corresponding author on reasonable request.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.