Enhanced oil recovery (EOR) processes are technologies used in the oil and gas industry to maximize the extraction of residual oil from reservoirs after primary and secondary recovery methods have been carried out. The injection into the reservoir of surface-active substances capable of reducing the surface tension between oil and the rock surface should favor its extraction with significant economic repercussions. However, the most commonly used surfactants in EOR are derived from petroleum, and their use can have negative environmental impacts, such as toxicity and persistence in the environment. Biosurfactants on the other hand, are derived from renewable resources and are biodegradable, making them potentially more sustainable and environmentally friendly. The present review intends to offer an updated overview of the most significant results available in scientific literature on the potential application of biosurfactants in the context of EOR processes. Aspects such as production strategies, techniques for characterizing the mechanisms of action and the pros and cons of the application of biosurfactants as a principal method for EOR will be illustrated and discussed in detail. Optimized concepts such as the HLD in biosurfactant choice and design for EOR are also discussed. The scientific findings that are illustrated and reviewed in this paper show why general emphasis needs to be placed on the development and adoption of biosurfactants in EOR as a substantial contribution to a more sustainable and environmentally friendly oil and gas industry.

This research used an aqueous leaf extract of Allium Caliphalum Wendelbow as an eco-friendly stabilizing and capping agent for the production of ZnO NPs. Different characterization techniques, including SEM, UV-Vis spectroscopy, FTIR, XRD, and EDX, were employed to analyze the morphology, structural, optical, and chemical properties of the ZnO nanoparticles. The SEM analysis revealed that the average particle sizes ranged between 30 and 72 nm depending on pH, but the crystallite sizes obtained from XRD ranged from 15 to 24 nm. UV-Vis spectroscopy indicated a bandgap energy range of 3.14 to 3.25 eV, dependent on the pH of the reaction mixture. The FTIR spectra confirmed the existence of functional groups from the plant extract that facilitate the reduction and stabilization process. The photocatalytic efficacy of ZnO NPs was assessed by decomposing methyl orange dye under ultraviolet irradiation. The nanoparticles produced at an ideal pH of 8 demonstrated the greatest degrading efficiency of 74% in 140 min, owing to their reduced size, enhanced crystallinity, and advantageous bandgap energy (~ 3.25 eV). The findings underscore the substantial impact of pH on the physicochemical and photocatalytic characteristics of biosynthesized ZnO NPs, providing a sustainable method for wastewater treatment applications.