Isotherms, thermodynamics and kinetics of rhodamine B dye adsorption on natural diatomite. In this paper, Phu Yen diatomite was used as adsorbent for adsorption rhodamine B (RB) dye in aqueous solution. Analysis methods, including SEM, XRD, FT -IR, and N2 adsorption-desorption isotherms, were used to characterise the adsorbent. | No 6(31) – 2016, Dec. 2016 Scientific Journal Of Thu Dau Mot University ISOTHERMS, THERMODYNAMICS AND KINETICS OF RHODAMINE B DYE ADSORPTION ON NATURAL DIATOMITE Pham Dinh Du Thu Dau Mot University ABSTRACT In this paper, Phu Yen diatomite was used as adsorbent for adsorption rhodamine B (RB) dye in aqueous solution. Analysis methods, including SEM, XRD, FT-IR, and N2 adsorption-desorption isotherms, were used to characterise the adsorbent. The analysis of experimental adsorption data showed that the adsorption followed Langmuir isotherm model and pseudo-second-order kinetic equation. Based on the adsorption constant in the Langmuir isotherm (KL), thermodynamic parameters ( Go, Ho and So) for adsorption of RB onto the diatomite were calculated. The results indicated that the process is spontaneous and endothermic in nature. Keywords: diatomite, rhodamine B, adsorption. 1. INTRODUCTION The removal of coloured and colourless organic pollutants from industrial wastewater is considered an important application of adsorption processes using a suitable. There is growing interest in using low cost, commercial available materials for the adsorption of dyes. Diatomite is a material that can satisfy these conditions. Diatomite is a sedimentary rock primarily composed of the skeletons of microscopic single celled aquatic plants called diatoms. It consists of a wide variety of shapes and characterized by a high porosity up to 80%, low density and high surface area [1]. These properties show that its is a potential adsorbent for pollutants found in industrial wastewater including dyes [1]. The aim of this work is to examine the effectiveness of local diatomaceous earth for the removal of rhodamine B dye from aqueous solution. The morphology, structure and porosity properties of the diatomite were investigated. 2. EXPERIMENTAL . Adsorbent and methods for material analysis Diatomite was obtained from Phu Yen provine, Vietnam. The samples were washed with distilled water to
