Insights into rhamnolipid-assisted bioelectrochemical system for remediating soil pollution: A promising green approach towards the sustainable environment

Abstract

Several physical and chemical methods have been developed for the remediation of a variety of toxic pollutants from soil. These methods may not be feasible and environmentally safe because of their high operational costs, energy requirements, and cause of secondary pollution. Bioremediation is a promising approach, but it is also a time-consuming process. Alternatively, the Bioelectrochemical system (BES) is an innovative technology for remediating diverse types of recalcitrant pollutants. However, there still exist some bottlenecks to BES for field-scale applications i.e., low mass transfer, poor electrical activity of anodes as electron acceptors, low bioavailability of organic matter, and limited beneficial bacterial activity. To overcome these challenges, various types of synthetic and natural surfactants have been investigated, though only biological surfactants like rhamnolipids were considered as possible interventions in terms of environmental safety. Therefore, this review of literature provides a brief overview of challenges associated with polluted soil remediation and describes currently available technologies including physico-chemical, biological and other available options. Subsequently, the advances of BES and their application for various types of pollutants remediation including petroleum hydrocarbons (PHs), polycyclic aromatic hydrocarbons (PAHs), azo dyes, pesticides, and polychlorinated biphenyls (PCBs) were comprehensively discussed. Further, the potential of rhamnolipid-assisted BES, its challenges and prospects to enhance bioremediation of soil pollutants were addressed.