Microbiological Evaluation of Various Oilfield Wastewaters from Oben Land Rig Location in Edo State, Nigeria

Abstract

Oilfield wastewater contains poisonous and dangerous compounds that harm microorganisms and the quality of the water. According to estimates, Nigerian oil industry operations generate significant amounts of wastewater that are improperly treated before being released into the environment. For a period of two months, biweekly analyses of the microbiological effects of various oilfield wastes on the microbial population and variety of aquatic environments were conducted. Water samples collected 10 cm from pit 1, pit 2, pit 3, camp pit 1, and camp pit 2 were analyzed for total heterotrophic bacterial count, hydrocarbon utilizing bacterial count, total fungal count, and hydrocarbon utilizing fungal count, and for microflora using standard microbiological methods. Total heterotrophic bacteria (THB) counts ranged from 4.0×104 Log10cfu/ml to 4.4×104 Log10cfu/ml, total fungal (TF) count ranged from 2.0×104 Log10cfu/ml to 2.2×104 Log10cfu/ml. The total hydrocarbon utilizing bacterial (THUB) count ranged from 3.0 ×104 Log10cfu/ml to 3.1 ×104 Log10cfu/ml, while the total hydrocarbon utilizing fungal (THUF) count ranged from 1.0×104 Log10cfu/ml to 1.1×104 Log10cfu/ml. Statistical analysis showed that there was no significant difference in the THB between the pits and the sampling stations. The types of bacteria isolated in the study included Kurthia spp, Bacillus spp, Pediococcus spp, Enterococcus spp, Aeromonas spp, Micrococcus spp, Pseudomonas spp, Escherichia coli, Alcaligenes spp and Lactobacillus spp. The fungi isolated included Aspergillus fumigatus, Penicillium brevicompactum, Rhizopus oryzae and Fusarium spp. The study's bacterial and fungal counts showed how oilfield effluent affected aquatic microorganisms. According to the significant frequency of hydrocarbon-using bacteria, the water under investigation contained active native hydrocarbon utilizers that might be used in the bioremediation process.