doi: 10.18178/ijesd.2026.17.5.1608
Valorization of Coconut Husk: FeCl₃-activated Biochar for Efficient Nitrate Removal from Simulated Fertilizer Effluent
Jan Marvin Frias1
,
Alexandra Nicole Lusterio2 ,
Eina Gem Hyacinth Remo2 ,
Lalaine Tumlos2 ,
Tristan Roy Panaligan2,*
- 1Department of Chemical Engineering, National Tsing Hua University, East District, Hsinchu City, Taiwan
- 2Mapúa Institute of Technology at Laguna, Mapúa Malayan Colleges Laguna, Cabuyao City, Laguna, Philippines
- Manuscript receivedOctober 20, 2025
- revisedNovember 24, 2025
- acceptedFebruary 3, 2026
- publishedOctober 21, 2026
Abstract
Nitrate contamination from fertilizer industry effluents poses serious risks to both the environmental and public health. This study investigated the nitrate removal efficiency of coconut husk–derived activated carbon using ferric chloride (FeCl₃) as an activating agent through a batch bioadsorption approach. The effects of adsorbent dosage, contact time, and initial nitrate concentration were evaluated, along with adsorption isotherms and kinetics. Two types of bioadsorbents were tested: Untreated Activated Carbon (UAC) and FeCl₃-treated activated carbon (FeAC), both synthesized from coconut husk. Batch adsorption experiments were conducted using 50 mL of nitrate solution under varying conditions. The average nitrate removal efficiency of FeAC was 86.00%, which was consistently better than UAC. The highest removal of 76.50% was achieved with an optimal dosage of 0.4 g. The maximum removal efficiency for contact time was 92.58% at 120 min, whereas the maximum removal efficiency for initial nitrate concentration was 92.50% at 40 mg/L. Chemisorption was indicated by adsorption kinetics that fit the pseudo-second-order model with R-squared of 0.9926. The Langmuir model, with R-squared of 0.9879, was shown to be the best fit by isotherm analysis, indicating monolayer adsorption behavior.
Keywords
- nitrate removal
- coconut husk biochar
- ferric chloride activation
- adsorption
- wastewater treatment
- sustainable materials
How to Cite
Jan Marvin Frias, Alexandra Nicole Lusterio, Eina Gem Hyacinth Remo, Lalaine Tumlos, and Tristan Roy Panaligan, "Valorization of Coconut Husk: FeCl₃-activated Biochar for Efficient Nitrate Removal from Simulated Fertilizer Effluent," International Journal of Environmental Science and Development, vol. 17, no. 5, pp. 485-492, 2026. https://doi.org/10.18178/ijesd.2026.17.5.1608
Copyright & License
Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).