Overview on natural materials for oil water separation

Nowadays various kinds of industries such as oil and gas industries like petroleum refining, petrochemicals, metallurgical, and food beverage industries produce an enormous amount of oily wastewater effluents. The hazardous behavior of these disposals may have a significant impact on human health, environment, as well as the aquatic ecosystem. Proper removal of oil from water becomes a crucial challenge to every oil field company. It is needed to be demulsified competently before being discharged into the environment. Though there are several conventional methods for oil/water separation like dissolved air floatation, coagulation, biological treatments, membrane separation processes, and various hybrid processes, herein, the current findings in oil/water separation by utilizing natural or nature derived biomass are discussed. These materials are biodegradable and do not create toxic residues, with size varying from micro to nanoscale. Membranes, sponges/aerogel, materials with properties like superwetting, superoleophobicity, etc., have also been discussed. By using the natural materials as the examples, the ability of those innovative materials to separate different oil/water mixtures, the innate properties of the natural materials, various modifications, and their mechanisms have been overviewed. These natural materials are usually cost-effective, ecofriendly, abundant, renewable, and reduce the problem of the creation of secondary waste. This chapter talks about different natural and nature-derived material candidates as promising materials for oil/water separation and aims to make the readers acquainted with the application value, significance, and further prospects of these materials.