For the first time, successful fabrication of the cotton aerogels and cotton-cellulose aerogels is achieved using recycled fibers from environmental waste for oil absorption. The pure cotton and cotton-cellulose aerogels are obtained using a cost-effective mixing-blending method with polyamide-epichlorohydrin as strengthening additives. The obtained aerogels are silanized using methyltrimethoxysilane via a facile chemical vapor deposition to endow aerogels with hydrophobic surface. Effects of fiber concentrations and cotton-to-cellulose mass ratio on oil absorption performance in various solvents are also investigated. The cotton aerogel with an initial concentration of 0.25wt% presents the highest oil absorption capacity over 100gg−1. Besides, the cotton/cellulose aerogels also demonstrate good absorption capacity in different pollutant organics. The absorption kinetics of the aerogels with different cotton concentrations are also investigated using pseudo first-order model. Both equilibrium absorption and absorption kinetics demonstrate cotton/cellulose aerogels as promising materials for oil absorption and environmental pollution treatment. Graphic abstract Display omitted •Cotton aerogel with absorption capacity over 100gg−1 was prepared through simple solution routine.•Silanized cotton and cotton/cellulose aerogel present good hydrophobicity.•Cotton/cellulose aerogels show remarkable absorption capacity in various contaminates.•Cellulose helps to improve absorption reversibility for the composite aerogels.