Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

• Published in: Applied water science Vol. 7; no. 4; pp. 2063 - 2074
• Main Authors: Albroomi, H. I., Elsayed, M. A., Baraka, A., Abdelmaged, M. A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2017; Springer Nature B.V
• Subjects: Activated carbon; Activation; Adsorbents; Adsorption; Aquatic Pollution; Azo dyes; Capacity; Carbon; Coefficients; Color removal; Columns (process); Comparative Law; Dye concentrations; Dyes; Earth and Environmental Science; Earth Sciences; Efficiency; Enthalpy; Entropy; Exhaustion; Flow rates; Flow velocity; Free energy; Hydrogeology; Industrial and Production Engineering; International & Foreign Law; Mathematical models; Nanotechnology; Original Article; Parameters; Private International Law; Removal; Surface area; Surface chemistry; Tartrazine; Temperature; Temperature effects; Waste Water Technology; Water Industry/Water Technologies; Water Management; Water Pollution Control; Fixed-bed column; Adsorption of tartrazine azo-dye; Apricot stones; Breakthrough curve
• ISSN: 2190-5487; 2190-5495
• DOI: 10.1007/s13201-016-0387-2

This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m 2 /g) and pore volume (1.26 cm 3 /g) can be manufactured from apricot stones by H 3 PO 4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium ( q e ) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (Δ G 0 ), enthalpy (Δ H 0 ) and entropy (Δ S 0 ) were determined and the positive value of (Δ H ) 78.1 (K J mol −1 ) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2  ≥ 94.