Abstract

The adsorption of methylene blue (MB) dye onto activated rice bran and CuFe₂O₄/rice bran (CRB) composite was investigated. Activated rice bran was prepared by treating with NaCl. The CuFe₂O₄/rice bran was prepared by chemical co-precipitation method. The adsorbents were characterized by XRD and SEM analyses. The adsorption of MB was strongly dependent on the pH (pH 12). The process was very fast initially and maximum adsorption was attained within 60 min of contact time. The specific surface area (BET method) of rice bran, activated rice bran and CuFe₂O₄/ rice bran were 0.44, 35 and 68 m²g⁻¹, respectively. The adsorption isothermal data could be well interpreted by the Langmuir isotherm model. The adsorption process follows pseudo second-order kinetics and rate constant 0.112 for ARB and 0.17 for CRB (g mg^-1 min^-1). Thermodynamic parameters were evaluated.

Key words: Adsorption, composite, methylene blue, kinetic, rice bran.