Batch adsorption experimentsSorbent

Batch adsorption experiments
Sorbent was transferred into bottles containing 50 mL of
phenol solution to give a final sorbent concentration of
4 mg/mL. The phenol concentrations were in the range of
10–100 ppm. Distilled water was used in preparing the solutions. A temperature-controlled shaker (Kottermann, Germany) was used to agitate the mixture at the desired temperature. Experiments were carried out at 20 7C, unless otherwise stated. Samples from the solutions were taken at predetermined time intervals, for the purpose of studying the kinetics of the sorption process. Otherwise, the mixture was allowed to attain equilibrium and then the bottles were removed from the shaker for analysis. The sorbent was separated from the samples by centrifu- gation (300 g, for 10 min) and the supernatant was then analyzed for residual concentration of phenol. The method of Gales and Booth (1976), which is based on spectophotometric analysis of the developed color resulting from the reaction of phenol with 4-aminoanti- pyrine, was followed.