Adding value to natural clays as low-cost adsorbents of methylene blue in polluted water through honeycomb monoliths manufacture

M Ahrouch,H Vidal,K Draoui,J M Gatica

doi:10.1007/s42452-019-1636-4

M Ahrouch, H Vidal + Show 2 more

Open Access

https://doi.org/10.1007/s42452-019-1636-4

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Abstract

A natural Moroccan illite–smectite was used as an adsorbent for the removal of methylene blue (MB) from aqueous solutions. The clay was characterized by FTIR spectroscopy, TGA, SEM–EDS, X-ray fluorescence, XRD and N2 physisorption. The influence of pH, temperature and time on the MB adsorption by the clay was investigated. The maximum equilibrium adsorption capacity was 100 mg g−1 at 45 °C. The kinetic behavior and the isotherms better-fitted with the pseudo-second-order and Langmuir models, respectively. Clay honeycomb monoliths (50 cells cm−2) were obtained by means of extrusion from the starting material without any additive except water. The structured filters exhibited better performance under dynamic conditions than the powdered clay, adding value to the application of this low-cost adsorbent.

Highlights

The releases of textile industry are in general loaded with organic micropollutants, in particular different detergents and dyes
The most intense bands are perfectly understandable in terms of clay lattice vibrations, some of which are of the same nature as those of quartz (Si–O–Si or O–Si–O vibrations) [44], except the small peak at 1384 cm−1 which might correspond to some carbonates [45]
The adsorption isotherms of methylene blue (MB) dye could be satisfactorily described by the equations of Langmuir model

Summary

Introduction

The releases of textile industry are in general loaded with organic micropollutants, in particular different detergents and dyes. Anionic dyes carry a net negative charge due to the presence of sulfonate (SO3−) groups [3, 4], while cationic dyes carry a net positive charge due to the presence of protonated amine or sulfurcontaining groups [5] Due to their strong interaction with many surfaces of synthetic and natural fabrics [6], a broad variety of physicochemical and biological techniques has been developed and tested in the treatment of effluents loaded with these contaminants [7, 8]. These processes include precipitation, ionic exchange, filtration on membrane and irradiation. The use of other adsorbent materials such as clays or natural zeolites is of great interest [17, 18]

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