Nanotechnological utilization of cellulose is gaining interest in sustainable development in different fields of applications. In this work, cellulose nanofibers (CNFs) based aerogel was prepared from major agriculture waste residue (i.e. wheat straw) available in the Indian subcontinent. CNFs were modified by polymethylsilsesquioxane, sepiolite and Trichloro(1H,1H,2H,2H-perfluorooctyl) silane to mitigate required thermal conductivity, flame resistivity and hydrophobicity. Synthesized aerogel demonstrated superhydrophobicity (contact angle-154°), incredibly low density (~8kg/m3) and high porosity (~99.76%). Specific surface area and pore diameter were evaluated ~86.62m2g-1 and 12-65 nm respectively. Thermal conductivity at room temperature to high temperature (up to 200°C) of aerogels was determined by the transient plane source method. Super-hydrophobic modifications have been in the same pristine aerogel by simple esterification reaction with stearic acid chloride. The contact angle has been shown almost 160 degrees. The prepared aerogels were found to be very efficient in separating a series of oil/water mixtures and various organic solvents with excellent selectivity and recyclability. The absorption capacity of the aerogels was at least 35 times higher than their dry weight. Field Emission Scanning Electron Microscopy analysis (FESEM) and X-ray microtomography illustrated three dimensional homogeneous, monolithic, and porous aerogel.