When oil is dispersed in the form of droplets in water in the presence of a suitable surfactant, oil-in-water (O/W) emulsions are formed. They have unique chemical properties covering a wide range of applications from environmental technologies to foodstuffs. In this book, authors discuss the preparation of O/W emulsions and their implications in environmental and food problems, covering hot topics including the composition and spill behaviour of diluted bitumens, the use of O/W emulsions as platforms for the synthesis of waterborne particles, new methods to separate oil from water in oily wastewater, emerging technologies for the preparation of O/W emulsions, control of the oxidative status of lipids in oil by employing antioxidants to minimize lipid oxidation, parameters affecting O/W microbial stability and environmental issues and evaluation of interfacial barriers created by emulsifiers.