Comparative Performance of Granulated Carbon and Commercial Resin as Adsorbents for the Extraction of Phytohormones from Coconut Water in Batch Adsorption Experiments

The study evaluated coconut-shell derived granulated carbon as a cost-effective, sustainable alternative to commercial synthetic resin for extracting phytohormones from waste coconut water via batch adsorption experiments. The adsorption performances were compared in terms of the following parameters: isotherm type, adsorption capacity, effective loading, equilibration time, separation factor, and extracted phytohormones. Although commercial resin provides higher adsorption capacity of 61.8 mL/g (versus 14.6 mL waste coconut water/g adsorbent) and desirably lower effective loading of 20 g/L (versus 200 g adsorbent/L waste coconut water), granulated carbon offers faster equilibration time of 1 h (versus 3 h) and more favorable separation factor of 0.008 (versus 0.040) at a lower adsorbent cost of PHP 7/L (versus PHP 300/L waste coconut water). Both adsorbents follow Freundlich isotherm of reversible, physical adsorption, for which all obtained extracts contain gibberellic acid 3, indole-3-acetic acid, with kinetin as the most dominant phytohormone. Despite its lesser capacity, granulated carbon could potentially deliver lower processing costs for phytohormone extraction from waste coconut water especially if considering an upscale production.