Activated carbon derived from Dodonaea Viscosa into beads of calcium-alginate for the sorption of methylene blue (MB): Kinetics, equilibrium and thermodynamics

J Environ Manage. 2023 Feb 1:327:116925. doi: 10.1016/j.jenvman.2022.116925. Epub 2022 Dec 6.

Abstract

Dyes are valuable color compounds used in textile industries but at the same time their toxic and carcinogenic properties distract environmental system due to the chemical intricacy and multiplicity smearing them non-biodegradable. Therefore, the aim of present research rests in the use of cost effective, easily available and eco-friendly reformed novel biosorbents of Dodonaea Viscosa (DV). For this purpose AC-alginate beads were synthesized successfully through clogging AC derived from Dodonaea Viscosa (ACAB) into beads of calcium-alginate for removal of methylene blue (MB) from diluted solution. The external morphology (SEM, EDX) and functional groups (FT-IR) supported the favorable conditions for adsorption. The thermal properties have been evaluated using thermo-gravimetric study (TGA). After proper optimization like at pH 8, and biosorbent dose of 250 mg, temperature 350 K and time at 60 min the obtained adsorption capacity for DV leaves was set up to be 239 mg/g and for ACAB was 370 mg/g. By applying different adsorption isotherm models, the Freundlich was found to be best suited with highest R2 = 0.998 for DV and 0.995 for ACAB biosorbents. While the various kinetics models were also verified and data was well matched to Pseudo-second order kinetics model (R2 = 0.99 for DV and 0.99 for ACAB). Thermodynamics parameters enlightened that the adsorption process was endothermic (ΔH = 19,097 for ACAB and 10,899.6 J/mol for DV, ΔS = 89,087 for ACAB and 5.94 (J/mol for DV) and spontaneous in nature. The desorption study was satisfactory up to five number of absorption-desorption cycles for both the adsorbents particularly ACAB reflected an excellent percent removal (>90%). Consequently, the viability of DV can be used as a possible potential precursor for AC preparation besides cost effective adsorbent in the real sample treatment for dye removal.

Keywords: Activated carbon; Biosorption; Cost effective; Dodonaea viscosa; Methylene blue.

MeSH terms

  • Adsorption
  • Alginates* / chemistry
  • Calcium
  • Charcoal / chemistry
  • Coloring Agents / chemistry
  • Hydrogen-Ion Concentration
  • Kinetics
  • Methylene Blue / chemistry
  • Spectroscopy, Fourier Transform Infrared
  • Thermodynamics
  • Water Pollutants, Chemical* / chemistry

Substances

  • Alginates
  • Methylene Blue
  • Charcoal
  • Calcium
  • Water Pollutants, Chemical
  • Coloring Agents