Application of date stone activated carbon for the removal of caffeine molecules from water

Date stone activated carbon was prepared by impregnating the grounded date stone in 40% phosphoric acid solution. The obtained date stone activated carbon (DSAC) was applied against the caffeine mixed water to scavenge the caffeine molecules from the water. The independent variables such as activated carbon dosage (0.5-10 g/L), contact time (1-80 min), initial concentration of the caffeine (12-260 ppm), and temperature (25-50 degrees C) were varied and observed its effect on the adsorption efficiency of the DSAC. The recovery of the adsorbed caffeine molecules from the surface of DSAC was also studied with NaOH (0.1 N) solution and hot water. The 8 g/L activated carbon dosage was set for recovery after allowing them to adsorb in 100 +/- 3 ppm caffeine solution. The desorption efficiency of date stone activated carbon was observed around 27.90 +/- 1.08% for hot water and 28.84 +/- 0.64% for NaOH (0.1 N) solution. The date stone activated carbon are an efficient adsorbent, which was applied successfully in scavenging and recovery caffeine from the aqueous solutions. (c) 2019 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 4th International Conference on Green Chemical Engineering and Technology: Materials Science.