Adsorptive studies of hazardous dye Tropaeoline 000 from an aqueous phase on to coconut-husk

This contribution presents result pertaining to the adsorptive removal of water-soluble hazardous dye Tropaeoline 000, on to a low cost adsorbent-coconut-husk and its efficiency in the dye colour sorption was compared with activated carbon (AC). The results obtained from the batch experiments revealed the ability of the coconut-husk to remove the Tropaeoline 000 dye. The adsorption of dye was carried out at different pH, temperatures, amount of adsorbent, contact time, concentration of adsorbate (initial dye concentration) and particle size. The adsorption studies revealed that the ongoing adsorption validates both Langmuir and Freundlich adsorption isotherm at temperatures 30, 40 and 50 degrees C. The adsorption isotherm data was also employed to calculate thermodynamic parameters like DeltaG degrees , DeltaH degrees and DeltaS degrees . The negative values of DeltaG degrees indicate that the dye adsorption process is a spontaneous in nature. The positive value of DeltaH degrees shows the endothermic nature of AC/coconut-husk system whereas negative value of DeltaH degrees indicates that the exothermic nature of AC/coconut-husk. The adsorption was found to undergo via a pseudo-second order adsorption kinetics and the results revealed that coconut-husk, an agricultural waste, proved to be an excellent low cost adsorbent.