Chitin was used to prepare an alternative, eco-friendly and low-cost adsorbent by a simple pyrolysis process. The adsorbent, named chitin derived biochar, was characterized and applied to treat colored effluents containing methyl violet dye (MV). Pyrolysis using N-2 flow rate of 0.25 L min(-1), heating rate of 10 degrees C min(-1) until 800 degrees C was suitable to prepare a chitin derived biochar with good characteristics. Chitin derived biochar presented surface area of 275.0 m(2) g(-1). The MV adsorption on the chitin derived biochar was favored in alkaline conditions and ambient temperature. The adsorption process presented fast kinetics and, the maximum adsorption capacity was higher than 1000 mg g(-1). Chitin derived biochar can be used for 7 consecutive adsorption/desorption cycles maintaining the same adsorption capacity. Also, the material was suitable to treat colored effluents, reaching color removal percentage of 95%. In brief, it was demonstrated that chitin derived biochar is a low-cost and efficient material to treat colored effluents. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.