Biodegradation of Anionic Surfactants from Oilfield Detergents in Aquatic Systems

Abstract

The biodegradability of anionic surfactants in oilfield detergents was investigated using water samples from the New Calabar River and Tap water. The detergents analyzed were D.D-Y, D.G-X, SUR-500, SW-1000 and Bio-Boost. The anionic surfactant, Sodium dodecyl sulphate (SDS) was employed as a reference. The total heterotrophic counts in the water samples were determined using the spread plate technique while the detergent-utilizers were investigated using Mineral salt agar. Biodegradation was evaluated by monitoring Methylene Blue Active Substance (MBAS) using the "River die-away" method. The percentage MBAS remaining, after the 28 day study period, in increasing order was SDS < SUR-500 < SW-1000 < Bio-boost < D.D-Y < D.G-X; SDS was the most biodegraded. SUR-500, SW-1000 and Bio-boost supported the highest growth of utilizers. The detergent-utilizing bacteria isolated belonged to the genera Proteus, Acinetobacter, Enterobacter, Staphylococcus, Bacillus, Pseudomonas, Arthrobacter, Corynebacterium and Micrococcus. A steady increase in total viable count, pH and optical density was observed during biodegradation. The detergents tested could be considered biodegradable as they had an average of 91%-97% primary biodegradation at the end of the 28 day test period which is within the biodegradability standards set by the Soap and Detergent Association (SDA) and the Organisation for Economic Cooperation and Development (OECD).

Effect of Feedstock Type on Biostimulation Efficiency and Microbial Community Structure during Biochar-Facilitated Remediation of Petroleum Contaminated Soil

“…The post-acclimatisation period is, therefore, characterised by increased numbers of bacteria with the genetic disposition to degrade petroleum hydrocarbons as observed in the current study. This rapid proliferation also corroborates several related studies [29][30][31]. The period of acclimatisation has been linked to the biodegradation efficiency of the microorganisms and the microbial growth cycle is deemed to be indicative of the biodegradation rate [32,33].…”

“…The emergence of Bacillus species as the most abundant genus may be attributed to its spore-forming character which allows it to survive the presence of environmental stressors. Moreover, as in the present study, Pseudomonas has been frequently highlighted for its role in hydrocarbon degradation [29,40,46]. Solomon [47], likewise, highlighted the dominant role of Pseudomonas spp.…”