Use of activated Chromolaena odorata biomass for the removal of crystal violet from aqueous solution: kinetic, equilibrium, and thermodynamic study

Environ Sci Pollut Res Int. 2023 Feb;30(6):14265-14283. doi: 10.1007/s11356-022-22822-2. Epub 2022 Sep 23.

Abstract

In the present study, biomass from the Chromolaena odorata plant's stem was activated using sulfuric acid to adsorb crystal violet (CV) dye. The adsorption operation of CV dye was studied considering the effect of variables like pH, initial dye concentration, time, adsorbent dosage, and temperature. The pseudo-second-order equation best fitted the kinetic study. The thermodynamic parameters such as activation energy (9.56 kJ/mol), change in Gibbs energy (81.43 to 96.7 kJ/mol), enthalpy change (6.89 kJ/mol), and entropy change (-254.4 J/mol K) were calculated. Response surface methodology estimated that at pH (4.902), adsorbent dosage (8.33 g/L), dye concentration (82.30 ppm), and temperature (300.13 K) dye removal of 97.53% is possible. FTIR, SEM, XRD, BJH, and BET confirmed adsorption operation. The adsorbent can be reused for 3 cycles effectively. Langmuir isotherm which best fitted the adsorption operation was used for designing a theoretical single-stage batch adsorber for large-scale operation.

Keywords: Adsorption; Chromolaena odorata biomass; Crystal violet dye; Kinetic model; Singles-stage batch adsorber design.

MeSH terms

  • Adsorption
  • Biomass
  • Chromolaena*
  • Gentian Violet / chemistry
  • Hydrogen-Ion Concentration
  • Kinetics
  • Temperature
  • Thermodynamics
  • Water
  • Water Pollutants, Chemical*

Substances

  • Gentian Violet
  • Water
  • Water Pollutants, Chemical