The objective of this essay is to conduct a literature review to describe some particularly interesting and important examples of fluid mechanics from an engineering standpoint.Literature review of a selected topic/phenomenon should provide the theoretical background and describe its engineering applications (or potential applications). The proposed topics are listed below: 1- Fluid mechanical aspects of the pollutant transport. 2- Environmental Fluid Mechanics: Applications to Weather Forecast and Climate Change. 3- Fluid mechanics of bubbles and drops. 4- Bacterial Hydrodynamics. 5- Nano-fluids. 6- Fluids through porous media. You are requested to write a two (2) pages essay describing one of the above listed topics. Short introduction of the selected topic, its theoretical background and the potential applications should be particularly highlighted.