Application of Brazilian-pine fruit coat as a biosorbent to removal of Cr(VI) from aqueous solution—Kinetics and equilibrium study

In the present study we reported the feasibility of the Brazilian-pine fruit coat, named piñon wastes (PW; Araucaria angustifolia) as biosorbent to remove Cr(VI) from aqueous solutions.The PW biosorbent was characterized by N2 adsorption–desorption isotherms, FTIR spectroscopy, scanning electron microscopy, elemental analysis, mineral composition determination, and functional groups detection.The ability of PW to adsorb Cr(VI) was investigated by using batch adsorption procedure. The effects such as pH, contact time and biosorbent dosages on the adsorption capacity were studied. The adsorption kinetics followed the Elovich chemisorption kinetic model, obtaining the following the initial adsorption rate, 284.9, 396.9 and 461.5 mg g−1 h−1 using a 500.0, 700.0 and 1000.0 mg L−1 initial concentration of Cr(VI), respectively. The maximum adsorption capacity of PW was 240.0 mg g−1 for Cr(VI), using Sips isotherm model. This high adsorption capacity of PW places this biosorbent as one of the best adsorbents for removal of Cr(VI) from aqueous effluents.