Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

Sagarika Mohanty,Suparna Mukherji,Jublee Jasmine

doi:10.1155/2013/328608

Sagarika Mohanty, Suparna Mukherji + Show 1 more

Open Access

https://doi.org/10.1155/2013/328608

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Abstract

Surfactant enhanced bioremediation (SEB) of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL) pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs). Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review.

Highlights

Widespread use of petroleum hydrocarbons, generation of petroleum wastes in large quantities, and their recalcitrance lead to the accumulation of these pollutants [1, 2]
Based on the above observations reported in the literature, it is evident that surfactant-enhanced degradation of oil is a complex process
The success/failure of Surfactant Enhanced Bioremediation” (SEB) depends on numerous factors including the choice of surfactant and its dose to be applied at the contaminated site, the hydrocarbon degrading microorganisms present in the environment and their response to oil/hydrocarbons, the interaction of the hydrocarbon degraders with the surfactants, and surfactant biodegradability and toxicity considerations

Summary

Introduction

Widespread use of petroleum hydrocarbons, generation of petroleum wastes in large quantities, and their recalcitrance lead to the accumulation of these pollutants [1, 2]. The recalcitrance of petroleum hydrocarbons is primarily due to the inaccessibility of these compounds to most microorganisms In such a scenario, surfactants may be added to alter the properties of solution interfaces, thereby enabling the access of hydrocarbons to the microorganisms [5,6,7]. Facilitated transport refers to all other types of processes which favor mass transfer of hydrocarbons either by the interaction of oil with a single surfactant monomer or surfactant aggregates or by the interaction of surfactants with sorbed oil. All these mechanisms are very closely linked, and, at times, it is very difficult to distinguish between them. The primary focus is on the application of chemical surfactants for SEB

Microbial Degradation of Petroleum Hydrocarbons

Surfactant Aided Biodegradation of Petroleum Hydrocarbons

Surfactant Selection

C H3 C

Consequences of SEB

Conclusions