Application of biosurfactants in the removal of oil from emulsion

Abstract Biological surface-active compounds (biosurfactants) are commonly used in many industries (cosmetics, food, agriculture, oil, petrochemicals, etc.). The ability of biosurfactants to reduce the interfacial tensions between two liquid phases is a crucial property that makes them useful in separating oil from water or water from oil. Biosurfactants help to separate the two phases by changing the interfacial forces between oil and water molecules. Biosurfactants are biomolecules generated by microorganisms. They are nontoxic or less toxic than chemical surfactants. They are typically classified based on their chemical compound and microbial origin. There are several recognized biosurfactants in the literature that may be used for this function, including sophorolipids, glycolipid, trehalolipids, rhamnolipids, lipopeptides and lipoproteins, surfactin, lichenysin, and polymeric biosurfactants. This chapter aims to review different types of biosurfactants, their properties, their synthesis methods from different microorganisms (e.g., bacteria and fungi), and their role in demulsification process of water from oil. Eventually, the impact of various parameters on the biodemulsification process was reviewed, which include type of microorganisms, temperature, pH, the water content in the emulsion, and gravity effect.