Adsorptive Removal of Phenol by Activated Palash Leaves

1 Adsorptive Removal of Phenol by Activated Palash Leaves 

Some of the advantages of using low-cost adsorbents include simple technique requiring little processing, good adsorption capacity, low cost, free availability and easy regeneration. Thus, in the present study, palash leaves have been used as adsorbent as they are 

All the reagents were analytical reagent (AR) grade. Phenol was purchased from Ranbaxy Fine Chemicals, New Delhi, India. The initial pH was adjusted with 0.1 N NaOH or 0.1 N HCl solutions. A stock solution of 1000 mg/L was prepared by dissolving accurately weighed amounts of phenol in double distilled water (DWW). The desirable experimental concentration of solutions was prepared by diluting the stock solution with distilled water when and if necessary. 

Palash leaves collected from a MANIT Campus, Bhopal, India were first washed with DWW and then dried. The dried adsorbent was crushed in a laboratory mill and sieved to obtain particles ranging from 1 to 2 mm. The mass was then placed in a furnace and heated slowly to reach the desired temperature of 600°C. It was left for 1 h and then cooled to ambient temperature. The material was activated by treating with phosphoric acid in a heating plate with constant for 3 days. The activated adsorbent was washed repeatedly with DWW until neutral pH was obtained and dried overnight in a vacuum oven at 100°C. The dried sample was sieved to 200 mesh particle size and stored in desiccators. 

The batch experiment was conducted in a 100 mL stopper Erlenmeyer flask which consisted of 20 mL of phenol solution of known concentration, pH and a known amount of the activated palash leaves. This mixture was agitated with a temperature controlled at constant speed of 150 rpm (Metrex Scientific Instruments, New Delhi) maintained at 303 K. Samples were withdrawn at appropriate intervals and were filtered using 0.45 pm filter paper to determine the residual concentrations using UV-visible spectrophotometer. Experiments were carried out at initial pH ranging from 2 to 9, which was adjusted by the addition of dilute 0.1 N HCl or 0.1 N NaOH solutions. 

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