Electrobioremediation of oil spills

Abstract

Annually, thousands of oil spills occur across the globe. As a result, petroleum substances and petrochemical compounds are widespread contaminants causing concern due to their toxicity and recalcitrance. Many remediation strategies have been developed using both physicochemical and biological approaches. Biological strategies are most benign, aiming to enhance microbial metabolic activities by supplying limiting inorganic nutrients, electron acceptors or donors, thus stimulating oxidation or reduction of contaminants. A key issue is controlling the supply of electron donors/acceptors. Bioelectrochemical systems (BES) have emerged, in which an electrical current serves as either electron donor or acceptor for oil spill bioremediation. BES are highly controllable and can possibly also serve as biosensors for real time monitoring of the degradation process. Despite being promising, multiple aspects need to be considered to make BES suitable for field applications including system design, electrode materials, operational parameters, mode of action and radius of influence. The microbiological processes, involved in bioelectrochemical contaminant degradation, are currently not fully understood, particularly in relation to electron transfer mechanisms. Especially in sulfate rich environments, the sulfur cycle appears pivotal during hydrocarbon oxidation. This review provides a comprehensive analysis of the research on bioelectrochemical remediation of oil spills and of the key parameters involved in the process.

Bioremediation in Water Environment: Controlled Electro-Stimulation of Organic Matter Self-Purification in Aquatic Environments

“…physical-chemical technologies, and 2) biological technologies or bioremediation, exploiting the self-purification capacity to assimilate organic matter [12] [61]. Current eco-engineering practices attempting to improve bioremediation focus on physical actions through geomorphological modifications as constructed swales or riffles across urban creeks [62] [63] or constructed wetlands [64].…”

“…This study scale is often referred to as a microcosm study and focuses on the electro-biodegradation of contaminants such as pesticides [9] [175], and petroleum spills [12] [158] [172], and are also used to easily study and optimize some operational electrochemical parameters such as polarization curves, coulombic efficiency and activation, ohmic and transport losses.…”

Structure and Functions of Hydrocarbon-Degrading Microbial Communities in Bioelectrochemical Systems

“…The removal of this class of contaminants from the environment is mandatory and can be achieved with physical-chemical or biological strategies [2]. Biological approaches present several advantages in comparison with classic physical-chemical treatments, as they are more cost-effective and allow the complete mineralization of the organic pollutant [2,3]. However, traditional bioremediation is often limited by several factors, such as (i) the need for long-term addition of suitable electron acceptors (oxygen, nitrate, sulfate, or other oxidized compounds); (ii) the consumption of added amendments by competitive biotic and abiotic reactions; and (iii) the accumulation of undesired side-products [4].…”

The bioelectric well: a novel approach for in situ treatment of hydrocarbon‐contaminated groundwater

“…MET are anaerobic systems in which microorganisms catalyse oxidation or reduction reactions using solid‐state electrodes, suitably deployed in the contaminated matrix, as virtually inexhaustible electron acceptors or donors, respectively (Aulenta et al ., 2009; Zhang et al ., 2010, 2013; Lovley et al ., 2011; Rodrigo Quejigo et al ., 2016; Lai et al ., 2017). Laboratory‐scale studies have shown that MET can be employed to stimulate the anaerobic oxidation of a variety of reduced contaminants in soil and groundwater, including lower chlorinated compounds and PHs (Daghio et al ., 2017). In principle, MET have several potential advantages compared with conventional aerobic bioremediation strategies, such as (i) the possibility to promote the complete oxidation of contaminants with no need for adding oxygen or other electron acceptors [e.g.…”

“…nitrate or soluble Fe(III) species]; (ii) the possibility to colocalize the microorganisms and the electron acceptor (i.e. the electrode) as well as (iii) the possibility to drive, control and monitor the biodegradation reaction (in the subsurface) with electrochemical means (Daghio et al ., 2017). Collectively, all these aspects have the potential to dramatically increase the reliability, predictability and in turn applicability of in situ bioremediation systems.…”