Adsorption of Rhodamine 6G and humic acids on composite bentonite\u2013alginate in single and binary systems

Fatima Gomri,Thierry Zimny,Mokhtar Boutahala,Antonio Gil,Sophia A Korili,Gisèle Finqueneisel

doi:10.1007/s13201-018-0823-6

Abstract

In this work, the preparation, characterization, and sorption of rhodamine 6G and humic acids on a composite sodium alginate–bentonite were investigated. Their structure and morphology were analyzed by several techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, and N2 adsorption at − 196 °C. A synergetic sorption mechanism was observed in binary systems; humic acids adsorption was enhanced by the presence of Rh6G in the mixture. The kinetic studies revealed that the sorption follows a pseudo-first-order kinetic model and the sorption capacities of Rh6G increased with the pH value. The Langmuir isothermal model well described the adsorption isotherm data, showing a maximum adsorption capacity for Rh6G up to 429.5 mg/g at 20 °C. On the basis of the data of the present investigation, it is possible to conclude that the composite exhibited excellent affinity for the dye and humic acids, and it can be applied to treat wastewater containing dye and natural organic matter.

Highlights

Dyes have been the subject of much interest in recent years (Abou Taleb et al 2012)
According to the IUPAC classification, the N2 adsorption of composite and bentonite is of type II with H 3 hysteresis, typical of mesoporous solids with slit-shaped pores
It can be observed that bentonite shows some characteristic peaks at 2θ = 6.33° (d001 = 13.95 Å), 19.63° (d003 = 4.51 Å), 34.87° (d006 = 2.57 Å), 62.11° (d060 = 1.63 Å), respectively (Yadav and Rhee 2012)

Summary

Introduction

Dyes have been the subject of much interest in recent years (Abou Taleb et al 2012). Discharging dyes produced during various industrial activities can be harmful to aquatic life and human beings. Keywords Adsorption · Alginate · Bentonite · Composite · Humic acids · Rhodamine 6G Equilibrium adsorption isotherms from single solutions (Rh6G) were obtained by 0.02 g of the composite with 200 cm3 of Rh6G aqueous solutions of various initial concentrations (20–800 mg/dm3) until equilibrium was attained.

Results

Conclusion