Bioremediation of Oil and Natural Gas Industry Waste Using Methanogens: Current Status and Future Perspective to Biohythane Production

The oil and gas industry produces significant amounts of waste including petroleum wastewater, waste drilling fluid, and oil sludge. Bioremediation uses microorganisms and plants to degrade toxic substances. This offers a cost-effective and less labor-intensive solution for managing waste and recovering contaminated areas. Methanogens play a key role in the production of biohythane, a high-value fuel composed of biomethane and biohydrogen. In cooperation with hydrocarbon degraders and fermentative bacteria, they can make the biomethanation processes thermodynamically favorable under anaerobic conditions. This study reviews the use of H2-dependent methylotrophic methanogens for bioremediation in the oil and gas industry, highlighting their effectiveness in hydrocarbon methanogenesis in various environments. We have also addressed the importance of methanogens in shale reservoirs, oil-produced water, petroleum refinery oil sludge, and coal-bed methane reservoirs. This review provides a comprehensive analysis of methanogenic bioremediation and its effectiveness at mitigating environmental pollution. It discusses the challenges faced in practical implementation, such as ensuring methanogen survival and activity under harsh conditions. The factors influencing hydrocarbon methanogenesis and microbial community structure are not fully understood, making it challenging to ensure the survival and activity of methanogens under harsh conditions. Future research directions and technological advancements are required for practical implementation of consolidated methanogenic bioprocessing of petroleum refinery oil sludge for biohythane production. Thus, this review explored the potential of methanogens as a sustainable waste management resource in the oil and natural gas industries.