Removal of Acid Green 25 from Aqueous Solution by Adsorption

The adsorptive removal of Acid Green 25 by Ananas Comosus (L) Activated carbon was investigated in this study. The effects of initial dye concentration, contact time, pH and temperature were studied for the adsorption of Acid Green 25 in batch mode. At 100 mg/L of initial dye concentration the adsorbent removes 182.6 mg/g of dye from solution; it further increases on increasing the temperature. The calculated values of Delta G degrees indicate that the adsorption process is spontaneous, negative Delta H degrees indicate that the adsorption process is exothermic and the positive value of Delta S degrees indicates the increase in randomness. The rate of dye adsorption follows pseudo second order model with an r(2) value of 0.999. Standard adsorption isotherms were used to fit the experimental equilibrium data. The Langmuir, Freundlich, and Tempkin models are appropriate to explain the adsorption phenomenon with good fit.