Sustainable bioelectrochemical systems for bioenergy generation via waste treatment from petroleum industries

Petroleum industries are large water consumers and generate a lot of wastewater at various stages of industrial operations. Wastewater from the petroleum industries contain recalcitrant pollutants such as hydrocarbons that are present in high concentrations, dissolved solids and sulfur compounds that can pose potential environmental threat. Bioelectrochemical systems (BESs) are known to be sustainable processes to treat the various kinds of wastewaters such as petroleum wastewater, while simultaneously generating the bioelectricity and value-added chemicals. This review focuses on various applications of BESs such as microbial fuel cells (MFC), microbial electrolysis cells (MEC), and microbial desalination cells (MDC) using diverse types of wastewaters (petroleum sludge, produced water, formation water, and petroleum refinery wastewater) from the petroleum industries. Overall, a hybrid type BES with hydrocarbon wastewater achieved a 98% of columbic efficiency, 96.5% of chemical oxygen demand (COD), 99% of phenanthrene, 94% of pyrene and 80% of TDS removal which are superior to single and dual chamber BES performances. The review also compares the existing biological processes with BESs in terms of the treatment of hydrocarbons and process sustainability. Treatment efficiency of petroleum wastes via the BES can be further improved by integrating the biological and electrochemical processes to develop a sustainable approach to bio-refinery route.