Kinetics of Adsorption of Reactive Red 120 Using Bentonite Modified by CTAB and Study the Effect of Salts

Abstract

Commercial bentonite was activated by aluminium hydroxide and then modified by cetyl trimethyl ammonium bromide (CTAB). The properties of modified bentonite were diagnosed using FTIR, X-ray diffraction and SEM. The adsorption of Reactive Red 120 (RR120) onto supported bentonite (B.A.CTAB) was investigated. The influence of various experimental parameters, such as temperature, initial concentration of dye, adsorbent dosages, initial pH and inorganic salts on RR120 removal was studied. The results showed that the optimum conditions for dye adsorption on modified bentonite are: temperature = 303k, pH = 3.5, contact time = 10 min, adsorbent dosage = 0.1 g and RR120 concentration 96 mg.L-1, it achieved a removal efficiency of 91%. The pseudo-second-order version yields a higher fit to the experimental facts than the pseudo-first-order model. The consequences revealed that Langmuir version turned into extra appropriate to explain RR120 adsorption than the Freundlich model. Also, the thermodynamic function such as ΔG°, ΔH° and ΔS° was evaluated. The consequences of various inorganic anions (which included Cl–, SO42-, CO32-, and so forth.) on the removal activity of RR 120 adsorption on modified bentonite was examined.

Keywords

• adsorption, decolorization, modified bentonite, reactive red 120