An Investigation on Zinc Biosorption with Agar Extraction Waste from Gracilaria tenuistipitata

  • Nikko Angelo S. Carisma Chemistry Department, De La Salle University, Taft Avenue, Manila 1004
  • Reniza Yvonne E. Gonzales Chemistry Department, De La Salle University, Taft Avenue, Manila 1004
  • Nancy Lazaro-Llanos Chemistry Department, De La Salle University, Taft Avenue, Manila 1004
Keywords: Gracilaria tenuistipitata, biosorption, zinc, agar extraction, waste

Abstract

This study determined the biosorption capacity of algal waste, obtained through agar extraction from Gracilaria tenuistipitata, a common red seaweed in the Philippines and potential biosorbent, on Zn2+ ions. Agar was extracted from the seaweed and characterized through Fourier-transform infrared spectroscopy (FT-IR). The algal waste was then subjected to a biosorption study involving various Zn2+ standards. Atomic absorption spectroscopy (AAS) and FT-IR were employed to evaluate sorption processes. Biosorption data was analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms which yielded  values of 0.9680, 0.8103, and 0.5254, respectively. The Langmuir ( ), Freundlich ( ), and D-R ( ) constants garnered were 0.0231 L/mg, 0.9829 mg/g, and 2.159  10-6 mol2 J-2 respectively, qualifying the adsorption of Zn2+ ions onto the algal waste as a favorable and physical process. FT-IR spectra analysis suggests that carboxylic acid and amide groups are involved in biosorption, possibly an ion-exchange process taking place for the uptake of Zn2+ ions. It was concluded that G. tenuistipitata waste is a promising biosorbent for Zn2+ ions. Performing the biosorption procedure in triplicates and the inclusion of kinetic studies are recommended to improve and ensure the accuracy in determining biosorption capacity and optimization in future studies.

Published
2020-08-12
How to Cite
Carisma, N. A. S., Gonzales, R. Y. E., & Lazaro-Llanos, N. (2020). An Investigation on Zinc Biosorption with Agar Extraction Waste from Gracilaria tenuistipitata. KIMIKA, 31(2), 11-26. https://doi.org/10.26534/kimika.v31i2.11-26
Section
Research Articles