Removal of Neutral Red from aqueous solution by using modified hectorite

The object of this work was to study the modified hectorite as effective adsorbent for Neutral Red (NR) from aqueous solution. The adsorbent capacity of modified hectorite was discussed. The effects of surfactant content, adsorbent content, pH and adsorption temperature on the sorption of NR on modified hectorite were studied. Experimental results showed that the equilibrium adsorption data fitted well with Langmuir isotherm and the adsorption capacity was 393.70 mg/g for the modified cetylpyridinium bromide hectorite (CPB-Hect). Kinetic studies showed that the dynamical data fitted well with the pseudo-second-order kinetic model. For thermodynamic studies, parameters such as the Gibbs free energy (ΔG0), the enthalpy (ΔH0) and the entropy (ΔS0) indicated that the adsorption process was spontaneous and endothermic in nature.

Research Highlights
► The results of these studies clearly indicated that compared with hectorite, the adsorption capacity for CPB-Hect was calculated to be 393.7 mg/g and was greatly improved.
► Effects of various treated conditions, such as adsorbent content and adsorption temperature were investigated.
► The adsorption isotherms, kinetics and thermodynamics for NR from aqueous solution on modified hectorite were studied.