Use of Brazilian Kaolin as a Potential Low-cost Adsorbent for the Removal of Malachite Green from Colored Effluents

Abstract

This study investigated the potential of Brazilian kaolin as a low-cost adsorbent for the removal of Malachite Green (MG) from colored effluents. The morphology, chemical structure and surface properties of the adsorbent were investigated by characterization techniques such as X-ray diffraction, N2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, X-ray fluorescence spectrometry, scanning electron microscopy, thermogravimetric analysis and particle size distribution. A possible technological application of raw kaolin is the MG removal from aqueous media, which was investigated using batch adsorption experiments. The adsorption kinetics was studied using the pseudo-first order, pseudo-second order and Elovich models. The adsorption isotherms were studied using the Langmuir, Freundlich and Sips models. The Elovich model was the more adequate to represent the adsorption kinetic, while the equilibrium was well represented by the Langmuir model. The maximum adsorption capacity, at pH of 6.3 and temperature of 25ºC, was 128 mg g -1 , and this satisfactory result may be associated with some adsorbent properties. Therefore, the results revealed that raw kaolin can be utilized as a promising low-cost adsorbent to remove MG from colored effluents.

Synthesis and characterization of Ethiopian kaolin for the removal of basic yellow (BY 28) dye from aqueous solution as a potential adsorbent

“…Kaolin clay is a promising adsorbent and attracts attention due to the alternative low-cost, eco-friendly, and highly abundant. Specifically, kaolin from different country has been investigated to remove different dyes form aqueous solution like malachite green [9], basic red 46 and direct blue 85 [10], methyl orange [11], violet 5Rand acid blue 25 [12], methylene blue, crystal violet and congo red [13], methylene blue [14,15], methyl violet 10B [16], basic yellow 28 dye [17], brilliant green and crystal violet [18], reactive red 120 [19]. The other important thing is that natural adsorbents, such zeolite, and clay-based (bentonite, kaolin, and montmorillonite) adsorbents, in addition to good rheological and adsorptive properties, are cost-effective, eco-friendly, widely used owing to their simplicity, and good efficiency and their simple regeneration techniques [20].…”

Synthesis of silver nanoparticle from Vigna unguiculata stem as adsorbent for malachite green in a batch system

“…Most of the dyes discharged from industries are synthetic, containing complex aromatic rings of large molecular size which makes them stable against photo-bleaching, resistant to biologically degradation and aerobic digestion [2].…”

“…Whilst numerous technologies including membrane filtration, reverse osmosis, and electrochemical methods have been applied worldwide to remove dyes from water, the development of an economic, effective and rapid water treatment at a large scale remains a challenging issue. Adsorption technology is considered to be the most auspicious and robust method to purify aqueous solutions at low cost and with high-efficiency [1,2]. This technique has been found to be beneficial above other techniques in terms of initial cost, ease of implementation, insensitivity to toxic substances, simplicity of design and capability to remove dyes at low concentrations as opposed to other techniques where purification becomes less effective at very low contaminant concentration.…”

“…Once saturated, pollutants can no longer be removed from a solution. Clay based adsorbents [2], sawdust [3], nanoparticles, and other low cost adsorbents have been employed to remove MG from water. Nanoparticle adsorption however is an emerging technique in the area of removal of dyes.…”

Obtaining of Fe3O4@C Core-Shell Nanoparticles as an Adsorbent of Tetracycline in Aqueous Solutions

“…Among the methods of removal of tetracycline, the adsorption is a process fast, economical and low energy cost process, and does not form secondary compounds [18][19][20][21] . Adsorption is widely applied in environmental treatment applications around the world.…”