Determination of Total Petroleum Hydrocarbon Composition and Screening for Metallotolerant Bacteria from Polluted Effluent Discharge in Kaduna Metropolis, Nigeria

Abstract

The presence of hydrocarbons in high concentration alongside heavy metals present in contaminated sites poses a health risk to humans, plants and animals. This study was aimed at determining the hydrocarbon composition as well as screening for metallotolerant bacteria from a polluted effluent discharge in Kaduna metropolis, Nigeria.  Physicochemical assessment, determination of total petroleum content, and heavy metal screening of the wastewater samples were conducted through standard protocols. Heavy metallotolerant bacteria were identified and screened using standard methods. It was revealed from the result that, on the total petroleum hydrocarbons (TPHs), eicosane had the highest composition occurrence with percentage quality (99%), while oxasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl (50%) was the lowest.  Total alkalinity and carbon dioxide in the sample were higher as compared to the standard. Lead had the highest concentration 0.95 Mg/L, while zinc had the least value 0.057 Mg/L. The bacterial species identified from the wastewater samples were: Escherichia coli, Staphylococcus aureus, Klebsiella sp, Pseudomonas sp and Bacillus species.  Furthermore,  the tolerance assay results showed that Pseudomonas species and Bacillus species had the maximum tolerance for Cu,  Bacillus species and Pseudomonas species for Pb,  Escherichia coli and Pseudomonas for Zn,  Staphylococcus aureus and Bacillus species for Fe respectively. Based on the maximum tolerance exhibited by these bacterial isolates to heavy metals, this study proved they are good candidates for us in bioremediation and bioaugmentation of heavy metals in the polluted industrial sites.