Removal of Crystal Violet and Acid Red 1 Dyes from Wastewater by Mechanically Activated Talc

Afifi, Sofia Mohamed; Farhat, Mohsen; Abdel-Khalek, M A; El-Dars, Farida

doi:10.21608/ijmti.2023.244260.1097

Removal of Crystal Violet and Acid Red 1 Dyes from Wastewater by Mechanically Activated Talc

Document Type : Original Article

Authors

¹ Applied chemistry, Science, Helwan, Cairo, Egypt

² CMRDI

³ Prof. and Head of Mineral Beneficiation Dept, CMRDI

⁴ Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Helwan, Cairo, 11795, Egypt

10.21608/ijmti.2023.244260.1097

Abstract

Raw talc (RT) and mechanically activated talc (MAT) were prepared and used as adsorbents in the removal of Crystal Violet (CV) and Acid Red 1 (AR1) from aqueous solutions. The effect of pH, dye concentration, conditioning time, and temperature on the removal efficiency of acid and basic dyes by RT and MAT samples was investigated. The results showed that the maximum adsorption capacities for CV and AR1 by MAT were 160 mg/g and 130 mg/g, respectively, which is 2-3 times that of RT. The experimental data indicated that the adsorption of both dyes by RT followed the Temkin isotherm, while MAT followed the Freundlich isotherm. The data also suggested that the adsorption behavior of CV and AR1 on MAT and RT followed a pseudo-second-order process, with intra-particle diffusion being the rate-limiting step for the adsorption kinetics of AR1 dye onto RT. The increase in the adsorption performance of MAT was attributed to the high pore volume and the presence of multi-charged sites caused by the rupture of chemical bonds through intensive material grinding. The change in the physical properties of (RT) and (MAT) were also investigated using XRD analysis, FTIR, zeta potential, particle size, and Brunauer–Emmet–Teller (BET) analysis. The results have shown that the energy released during the intensive grinding caused significant crystal dislocation in raw talc, along with a noticeable shift in its isoelectric point (IEP), an increase in surface area, and a decrease in pore size. These findings support the experimental results.

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