Title
Conversion of Kapok (Ceiba pentandra (L.) Gaertn) husks to an efficient adsorbent for Basic Blue 3 removal: batch adsorption and optimization studies
Authors
JIN-YING TONG, SIEW-TENG ONG and SIE-TIONG HA

Received July 24, 2025
Published Volume 59 Issue 9-10 October-December
Keywords Kapok husks, Basic Blue 3, batch study, Plackett Burman design, Response Surface Methodology

Abstract
Transforming wastes into usable materials is one of the routes to support sustainable development goals. In the current work, the feasibility of using Kapok husks as a promising adsorbent for the removal of Basic Blue 3 (BB3) was studied. Contact time, initial BB3 concentration, adsorbent dosage, agitation rate and pH were included in batch adsorption studies to examine their effects on the adsorption process. The equilibrium adsorption data was found to be best fitted to both Langmuir and BET isotherm model with an R2 value of 0.9972 and maximum adsorption capacity of 197.1 mg/g. The adsorption of BB3 by Kapok husks was found to follow the pseudo-second order kinetic model, with R2 close to unity. The functional groups present on Kapok husks were determined using Fourier transform infrared spectroscopy, and the surface morphology and topography were analyzed using scanning electron microscopy and atomic force microscopy, respectively. Plackett Burman design and Response Surface Methodology were used in the experimental design and optimization studies. The optimum conditions for maximum BB3 uptake were obtained as 180 minutes, 50 mg/L BB3 concentration, pH 10 and 0.03 g of Kapok husks. The system was able to achieve up to 98.20% adsorption under the optimum conditions.