Novel Low-Cost Magnetic Clinoptilolite Powders/Granules for the Removal of Crystal Violet in Single and Binary Systems

Novel magnetic adsorbents of Clinoptilolite/Fe۳O۴ (Clin/Fe۳O۴) nanocomposite powders and Alginate/Clinoptilolite/Fe۳O۴ (Alg/Clin/Fe۳O۴) nanocomposite granules were synthesized to efficient removal of the cationic crystal violet (CV) dye in single and CV/methylene blue (MB) binary systems. The prepared adsorbents were characterized by FT-IR, XRD, SEM, EDX, dot mapping, and BET analysis. Adsorption tests showed that Clin/Fe۳O۴ and Alg/Clin/Fe۳O۴ had high affinity toward CV removal at ۹۴.۳۲% and ۹۲.۳۵%, in the single system and ۸۴.۱۹% and ۸۰.۲۳%, in the binary system, respectively. Based on the findings, pH was the most effective variable in the elimination process and the highest yield was obtained at pH ۸ for both adsorbents. The equilibrium data followed the Langmuir model (R۲ > ۰.۹) based on which the maximum adsorption capacity (qmax) using Clin/Fe۳O۴ and Alg/Clin/Fe۳O۴ was determined as ۴۴.۶۶۲ mg/g and ۱۶.۵۲۸ mg/g, respectively in the single system and it was computed to be ۱۵.۷۹۷ mg/g and ۱۱.۴۷۶ mg/g, respectively in the binary system. The kinetic data fitted well to the pseudo-second-order model in both systems. The adsorption process was exothermic and thermodynamically spontaneous. Moreover, Clin/Fe۳O۴ and Alg/Clin/Fe۳O۴ adsorbents showed ۹۱.۴۳% and ۸۲.۰۱% recyclability over the desorption tests, thus leading to promising and green-based adsorbents for the removal of dyes. The Electrical Conductivity (EC) of MB, CV, and CV/MB solutions and also real wastewater sampled from a dyeing unit were measured before and after treatment and the results showed that the EC of all samples was reduced.

کلیدواژه ها:

Crystal violet ، Clinoptilolite ، Granules ، Binary System ، Electrical conductivity