A Novel Preparation and Application of Orange Peels Aerogel for Removal of Oil Contaminants in Soils

Existing soil remediation approaches are either lacking in cost effectiveness, environmental impacts or societal acceptance. Environmental remediation techniques are often characterized by considerable time requirements, and may leave residual effects on the natural ecosystems, thereby potentially compromising net environmental benefits. This study investigated the oil adsorption capacity of aerogels produced from waste orange peels. Aerogels are highly porous three-dimensional materials made from organic and inorganic materials, with low density, and high adjustable specific surface area. Orange peels aerogel was produced from waste orange peels using combined methods of physical, chemical, and thermal modification process, and was dried using freeze-drying method. Adsorption and reusability test were conducted after characterization of the aerogel. Surface characterization of the orange peels aerogel indicated it has an ultra-light density of 0.010417g/cm3, high porosity of 99%, and contact angle measurement of 102o. Adsorption experiment was conducted with sandy and clay soils, and the maximum oil adsorption capacities of the orange peels aerogel was 13.55mg/g and 9.60mg/g for sandy and clay soil respectively. High oil adsorption capacity was shown by the produced aerogel and attributed to the ultra-light density of 0.010417g/cm3 and high porosity of 99% of the orange peel aerogel. In conclusion, the higher oil adsorption capacity of orange peels aerogel in sandy soil than clay soil indicated that soil texture and aerogel properties influenced the oil remediation capacity of orange peel aerogels. The reusability test in three adsorption trials indicated that orange peels aerogel is a sustainable material for the remediation of oil-contaminated soil.