Bio-based aerogel absorbents for oil-water separation

Leakage of crude oil during transportation and from different platforms is instigating unadorned pollution to the aqueous environment, which is damaging the aqueous habitation and the inhabitants. It has a high potential to damage the marine food chain and hamper the seafood industry. In addition, it is also causing serious health issues in human beings. Therefore, oil contamination is now the greatest environmental concern, which recently gained huge public awareness. Unfortunately, still there is no viable and applied approach to minimize the harmful effects caused by oil spills in an aqueous environment. Therefore, researchers are striving to develop some economical and ecological adsorbents to clean the oil spillage over water. Recently, it was proved that biocarbon-based aerogels are much effective for oil cleaning and can be a feasible solution. Aerogels can be produced with comparatively low density and high surface area. These are excellent materials of choice for separation application having higher sorption rates and strong buoyant qualities. Considering the current environment-sensitive scenario, modern aerogels are factually produced from various biomaterials, which are typically amphiphilic and require further modifications to become hydrophobic similar to conventional sorbents. Sequentially, biomaterials are dissolved in some suitable solvent thermochemically, dried using a freeze-dryer, and then pyrolyzed without the need for any additional reagents to produce a hydrophobic aerogel sorbent. Although the developed methods are environmentally friendly and sustainable, there are still some challenges to the commercial application of aerogels due to high production costs. The introduction of more realistic preparation techniques might increase the viability of aerogels. Foams stabilized by nanoscale biomaterials can be air-dried, which is an intriguing substitute for freeze drying when producing aerogels, which will surely improves the process economics. However, the remarkable advantage of these aerogels is high recovery and recycling ability. In this chapter, a comprehensive discussion on aerogels preparation and application in oil-water separation is provided. An insight into the future prospects is also provided.