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

Abstract

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 (DG 0), enthalpy (DH 0) and entropy (DS 0) were determined and the positive value of (DH) 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 C 94.

Mechanistic understanding of the adsorption and thermodynamic aspects of cationic methylene blue dye onto cellulosic olive stones biomass from wastewater

“…The lowest percentage removal of MB by the green olive stones at 600 ppm was followed by an increase to 39.8% at 800 ppm and another increase to 48.5% at 1000 ppm. These occurrences could be attributed to several factors discussed by Albroomi et al 52 , as follows: (1) at low initial dye concentrations, the availability of vacant pores, and binding sites on green olive stones are high. However, the fractional adsorption and mass transfer of MB becomes low; leading to the lower percentage removals of MB at initial dye concentrations below 400 ppm, (2) as the initial MB concentrations increase from 300 to 400 ppm, the mass transfer force of MB also increases, leading to high adsorption percentage onto the plenty available binding sites of green olive stones, and (3) as the initial MB concentrations further increases above 400 ppm and particularly at 600 ppm, the ratio of the dye molecules to the available binding sites is at levels that do not support mass transfer.…”

Fixed-Bed Column Studies for the Removal of Congo Red Using <i>Simmondsia chinesis</i> (Jojoba) and Coated with Chitosan

“…However, batch adsorption affords fundamental knowledge about the efficiency of the sorbate-sorbate system. Furthermore, the data gained by the batch condition is not suitable for the most treatment systems (such as column studies) in which the contact time is not sufficient to reach equilibrium [14]. Thus, it is needed to find out the practical applicability of the sorbent in the continuous mode.…”

Heavy Metal Removal by Fixed‐Bed Column – A Review

“…Batch mode adsorption studies provide essential operating parameters and provide practical operational information about specific adsorbent . The advantages of fixed‐bed columns over batch studies are that they can be operated in single, series, and in parallel . Column mode studies are based on the parameters like fixed‐bed height, breakthrough curve, and flow rate.…”