Abstract

In the present study, Cloisite® 15A nanoclay has been used to remove Reactive Black 5 dye (RB5) from an aqueous solution. Cloisite® 15A was nano-dispersed in double distilled water. The degree of dispersion was determined by two techniques i.e Transmission electron microscopy and X-ray diffraction. Different parameters like adsorbent dose, time, pH, initial dye concentration, and temperature have been studied to identify the efficiency of Cloisite® 15A adsorbent to remove RB5 by batch mode. The removal percentage decreased with an increase in RB5 concentration. The optimum values for RB5 were found as 0.35g of adsorbent dose, pH 5, and 35min of contact time. The isotherm study was conducted by Langmuir, Freundlich, and Tempkin models. The equilibrium data fitted well to Freundlich isotherm model. The kinetic study was done with pseudo-first and second-order models and it was determined that kinetic followed pseudo-second order with the highest correlation coefficients (0.99997 at 30 °C, 0.99997 at 35 °C, and 0.99999 at 40 °C). The adsorption results show that the Cloisite® 15A adsorbent had an overall efficiency of >99% for RB5 removal in less than 35 minutes.

Keywords: Adsorption; Nanoclay; Reactive black 5; Kinetics; Isotherms

Abbreviations: RB5: Reactive Black 5; MtMIO: Montmorillonite Clay Modified with Iron Oxide; TEM: Transmission Electron Microscopy; XRD: X-Ray Diffraction; MPSD: Marquardt’s Percent Standard Deviation