Adsorption of anionic dyes monoazo and diazo using organo-bentonites

Abstract

Adsorption of orange and yellow dyes, containing mono-and di-azoic groups, respectively, were studied by the use of a natural and organo-bentonites, which were obtained by treatment with hexadecyl-trimethyl-ammonium bromide (Br-HDTMA). Two different bentonites from Argentina were used. X-ray diffraction, UV-visible spectrometry, infrared spectrometry and thermal analysis were used for the characterizations. The results were interpreted by using isotherms that fit properly to the mathematical model of Langmuir. The structural and physicochemical properties of the clay, and the arrangement of hexadecyl-trimethyl-ammonium cation (HDTMA +) into the interlayer of the smectites, the main clay mineral composition of the bentonites, were responsible for the retention of dyes. The retention of the azo dyes not only increased with the HDTMA + modification of the bentonites but also depended on the clay mineral (smectite types) composition of the pristine bentonite.

Green Synthesis of ZnO Coated Porous Activated Carbon Prepared from Pontederia crassipe Leaves for the Adsorptive Removal of Toxic Organic Dyes

“…Adsorption can be considered as an effective wastewater treatment process due to its low cost, ease of operation and high efficiency. Materials that can be used as dye absorbents include activated carbon, zeolite, clay, agricultural solid waste, chitosan, metal oxides, polymers, carbon nanotubes, and graphene (Sheeja et al 2021;Hammood et al 2021;Martinez et al 2019;El-Bery et al2022;Ibrahim et al 2020;Elfeky et al 2020;Mok et al 2020;Kar et al 2020;Poton et al 2022). Activated carbon is one of the most efficient and low cost materials to remove colored materials from polluted water, perhaps due to the high surface area associated with its porous structure (Kheddo et al 2020).…”

Emerging Contaminants Removal from Wastewater Using Organo-Modified Bentonite Clay

“…Conversely, because adsorption requires a strong separation between the adsorbent and the pollutant, it has drawbacks such as low selectivity and harmful waste products. A variety of materials, such as metal oxides, polymers, carbon nanotubes, activated carbon, zeolite, clay, agricultural solid waste, and graphene, can be utilized as dye absorbents [23][24][25][26][27][28][29][30][31].…”