Removal of nitrate-nitrogen from aqueous medium by adsorbents derived from pomegranate rind

摘要

Thermally treated carbons derived from pomegranate rind were investigated to find the suitability of its application for the removal of nitrate in aqueous solution through adsorption process. Two types of activation namely thermal at 200, 300, and 400 ℃ and boiling treatment (boiling at 150 ℃) were used for the production of the adsorbents. A control (untreated pomegranate rind (UPR)) was used to compare the adsorption capacity of the adsorbents produced from these processes. The results indicated that the thermally treated carbon derived at the temperature of 400 ℃ showed maximum adsorption capacity in the aqueous solution of nitrate. Batch adsorption studies showed an equilibrium time of 6h for the thermally treated carbon derived at 400 ℃. It was observed that the adsorption capacity was higher at lower pH (2-3) and higher value of initial concentration of nitrate (200mg/L). The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of nitrate adsorption onto adsorbents were also studied to evaluate the adsorption rate.