The study involves on producing of activated carbon from wheat straw, uncooked and cooked corn cobs by using chemical activation method with 50 wt% phosphoric acid followed by carbonization in N2 atmosphere at 500°C. The efficiencies of the activated carbons are tested with the removal capacities of organic waste such as oil. Oil spills on water bodies are harmful to the environment and humans. The best oil adsorption capacity was shown by activated carbon prepared from cooked corn cob 5.25 goil/gsorbent. Under certain process conditions, several active carbons with approached BET surface areas have been produced, reached 1343.75 m2/g and pore volumes 0.9106 cm3/g for cooked corn cob carbon. Activated carbons were characterized by using Fourier transform-infrared (FT-IR) spectroscopy and nitrogen adsorption/desorption isotherms.