The effects of sunflower seed shell modifying process on textile dye adsorption: kinetic, thermodynamic and equilibrium study


Kocadağistan B., Kocadağistan E.

DESALINATION AND WATER TREATMENT, vol.57, no.7, pp.3168-3178, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 7
  • Publication Date: 2016
  • Doi Number: 10.1080/19443994.2014.980329
  • Journal Name: DESALINATION AND WATER TREATMENT
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3168-3178
  • Keywords: Modified adsorbent, Adsorption, Astrazon red, Acid treatment, AQUEOUS-SOLUTIONS, ACTIVATED CARBON, METHYLENE-BLUE, HEAVY-METALS, CHROMIUM VI, REMOVAL, WASTE, SAWDUST
  • Ataturk University Affiliated: Yes

Abstract

This study investigates the effects of natural sunflower seed shells (NSS) modifying process on the adsorption of a basic dye. For this purpose, adsorption studies were carried out with acid (H2SO4) treated shells and results were compared with that of NSS obtained in our previous studies. Common isotherm models were tested to evaluate the adsorption behaviours. It is concluded that Langmuir isotherm model is more suitable for modified NSS (MSS). The constants of this model were obtained as q(max) = 284.45mg/g and b = 0.017 L/mg for MSS at 30 degrees C. The thermodynamic parameters were calculated as H degrees = 76.24kJ/mol, S degrees = 336.21J/mol and maximum G degrees = -25.45kJ/mol. The adsorption process was followed by the pseudo-second-order equation according to the kinetic studies. Optimum pH and adsorbent dosage were calculated as 7.4 and 10g/L, respectively, for adsorption of astrazon red (AR) on MSS in this study. Final dye concentrations in low-cost MSS decreased at least 45% that of NSS. The dye removal efficiencies were about 99% and the best weight per volume ratio (W/V) of MSS was 4.71 g MSS/L. More suitable and improved data were observed almost in all studied parameters with the adsorbent of MSS.