A comparative study on the adsorption of toxic cationic dyes by Judas tree (Cercis siliquastrum) seeds


IŞIK B. , UĞRAŞKAN V. , ÇAKAR F. , YAZICI Ö.

BIOMASS CONVERSION AND BIOREFINERY, 2022 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1007/s13399-022-02679-8
  • Journal Name: BIOMASS CONVERSION AND BIOREFINERY
  • Journal Indexes: Science Citation Index Expanded, Scopus, Compendex, INSPEC
  • Keywords: Adsorption, Basic blue 9, Basic green 4, Cercis siliquastrum seeds, MALACHITE GREEN, AQUEOUS-SOLUTION, ACTIVATED CARBON, REMOVAL, EQUILIBRIUM, ISOTHERMS, ADSORBENT, POLYDOPAMINE, PERFORMANCE, RED

Abstract

Cercis siliquastrum seeds were used for the adsorption of the basic dyes namely basic blue 9 and basic green 4 from the wastewater. Adsorption experiments were conducted under various conditions including different temperatures (25, 35, and 45 degrees C), pH (2-12), contact time (0-180 min), adsorbent amount (0.2-4.0 g/L), and concentration (10-50 mg/L). The adsorption processes were applied to various isotherms such as Freundlich, Langmuir, Dubinin-Radushkevich, and Harkins-Jura. Furthermore, different adsorption kinetic models including pseudo-first-order, pseudo-second-order, Boyd, and intraparticle diffusion were studied to comprehend the mechanism of the adsorption of the dyes. The results illustrated that the adsorption was best described by the Langmuir (r(2) = 0.9949 for basic blue 9 dye and r(2) = 0.9939 for basic green 4 dye at 25 degrees C). From the Langmuir isotherm, the q(m) value of basic blue 9 was found as 500.0 mg/g whereas those of basic green 4 was found as 243.9 mg/g at 25 degrees C. According to the thermodynamic parameters, it was determined that the adsorption process occurred endothermically and spontaneously for basic blue 9 and basic green 4 dyes. Considering the capacity of adsorption for both dyes, this study suggests that Cercis siliquastrum seeds are low-cost and environmentally friendly materials for the effective adsorption of basic dyes.