Adsorption of PFOA and PFOS on Chitosan-Carbon Nanotubes Hydrogel Beads: Parametric Optimization Using RSM

International Journal of Civil Engineering
© 2025 by SSRG - IJCE Journal
Volume 12 Issue 5
Year of Publication : 2025
Authors : Siphesihle Mangena Khumalo, Babatunde Femi Bakare, Sudesh Rathilal
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Siphesihle Mangena Khumalo, Babatunde Femi Bakare, Sudesh Rathilal, "Adsorption of PFOA and PFOS on Chitosan-Carbon Nanotubes Hydrogel Beads: Parametric Optimization Using RSM," SSRG International Journal of Civil Engineering, vol. 12,  no. 5, pp. 99-113, 2025. Crossref, https://doi.org/10.14445/23488352/IJCE-V12I5P109

Abstract:

The environmental occurrence of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), particularly in potable water sources, is evidence that current wastewater treatment facilities are unable to eliminate these newly recognized environmental contaminants entirely. On the other hand, studies on parametric optimization for solid-liquid adsorption of PFOA and PFOS are scanty. As such, the present study focuses on the parametric optimization of PFOA and PFOS on chitosan-carbon nanotube hydrogel beads from aqueous solution using the central composite design in response surface methodology as the first case. The effect of solution pH (4 – 10), contact time (2 – 48 hours), adsorbate initial concentration (5-20 mg/L), and adsorbent load (0.05 – 1.5 g/L) on the uptake of PFOA and PFOS were investigated using batch adsorption studies. The experimental data were analysed using variance alongside quadratic response models, resulting in R2 values higher than 0.97 with 95% confidence. The study gave optimal conditions of pH 4, contact time of 48 hours, adsorbate concentration of 5 mg/L, adsorbent load of 1.5 g/L, and percentage removals of greater than 90% at a standard deviation of ±1% for both PFOA and PFOS. As such, the present study's findings under optimal conditions indicate that proper adjustment of operating parameters is crucial in maximizing the uptake of the model adsorbate.

Keywords:

Perfluorooctanoic acid, Perfluotorooctane sulfonic acid, Chitosan, Carbon nanotube, Response surface methodology.

References:

[1] Shafali Garg et al., “Remediation of Water from Per-/Poly-Fluoroalkyl Substances (PFAS)–Challenges and Perspectives,” Journal of Environmental Chemical Engineering, vol. 9, no. 4, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[2] Siphesihle Mangena Khumalo, Babatunde Femi Bakare, and Sudesh Rathilal, “The Occurrence and Bioremediation of Emerging Polyfluorinated Compounds in Water Bodies: A Mini Review,” Applied Sciences, vol. 12, no. 23, pp. 1-12, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[3] S.SD. Elanchezhiyan et al., “Synthesis of Magnetic Chitosan Biopolymeric Spheres and their Adsorption Performances for PFOA and PFOS from Aqueous Environment,” Carbohydrate Polymers, vol. 267, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[4] Matthias Kotthoff et al., “Perfluoroalkyl and Polyfluoroalkyl Substances in Consumer Products,” Environmental Science and Pollution Research, vol. 22, pp. 14546-14559, 2015.
[CrossRef] [Google Scholar] [Publisher Link]
[5] Lin Cui et al., “Studies on the Toxicological Effects of PFOA and PFOS on Rats Using Histological Observation and Chemical Analysis,” Archives of Environmental Contamination and Toxicology, vol. 56, pp. 338-349, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[6] Pheruza Tarapore, and Bin Ouyang, “Perfluoroalkyl Chemicals and Male Reproductive Health: Do PFOA and PFOS Increase Risk for Male Infertility?,” International Journal of Environmental Research and Public Health, vol. 18, no. 7, pp. 1-20, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[7] Shuyu Liu, Nuoya Yin, and Francesco Faiola, “PFOA and PFOS Disrupt the Generation of Human Pancreatic Progenitor Cells,” Environmental Science & Technology Letters, vol. 5, no. 5, pp. 237-242, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[8] Shuji Tsuda, “Differential Toxicity between Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA),” The Journal of Toxicological Sciences, vol. 41, pp. SP27-SP36, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[9] Kan Li et al., “Molecular Mechanisms of PFOA-Induced Toxicity in Animals and Humans: Implications for Health Risks,” Environment International, vol. 99, pp. 43-54, 2017.
[CrossRef] [Google Scholar] [Publisher Link]
[10] Sze Yee Wee, and Ahmad Zaharin Aris, “Revisiting the “Forever Chemicals”, PFOA and PFOS Exposure in Drinking Water,” NPJ Clean Water, vol. 6, no. 1, pp. 1-16, 2023.
[CrossRef] [Google Scholar] [Publisher Link]
[11] Minkyu Park et al., “Adsorption of Perfluoroalkyl Substances (PFAS) in Groundwater by Granular Activated Carbons: Roles of Hydrophobicity of PFAS and Carbon Characteristics,” Water Research, vol. 170, 2020.
[CrossRef] [Google Scholar] [Publisher Link]
[12] Jun-Meng Jian et al., “Global Distribution of Perfluorochemicals (PFCS) in Potential Human Exposure Source – A Review,” Environment International, vol. 108, pp. 51-62, 2017.
[CrossRef] [Google Scholar] [Publisher Link]
[13] Yijin Yuan et al., “Rapid Photochemical Decomposition of Perfluorooctanoic Acid Mediated by a Comprehensive Effect of Nitrogen Dioxide Radicals and Fe3+/Fe2+ Redox Cycle,” Journal of Hazardous Materials, vol. 388, 2020.
[CrossRef] [Google Scholar] [Publisher Link]
[14] Akshay Chandrashekar Parenky et al., “Decomposition of Carboxylic PFAS by Persulfate Activated by Silver Under Ambient Conditions,” Journal of Environmental Engineering, vol. 146, no. 10, 2020.
[CrossRef] [Google Scholar] [Publisher Link]
[15] Junkui Cui, Panpan Gao, and Yang Deng, “Destruction of Per-and Polyfluoroalkyl Substances (PFAS) with Advanced Reduction Processes (ARPS): A Critical Review,” Environmental Science & Technology, vol. 54, no. 7, pp. 3752-3766, 2020.
[CrossRef] [Google Scholar] [Publisher Link]
[16] Yueh-Feng Li et al., “Cationic Surfactants Influencing the Enhancement of Energy Efficiency for Perfluorooctanoic Acid (PFOA) Removal in the Electrocoagulation-Flotation (ECF) System,” Chemosphere, vol. 318, 2023.
[CrossRef] [Google Scholar] [Publisher Link]
[17] Michel Hubert et al., “Per-and Polyfluoroalkyl Substance (PFAS) Removal from Soil Washing Water by Coagulation and Flocculation,” Water Research, vol. 249, pp. 1-10, 2024.
[CrossRef] [Google Scholar] [Publisher Link]
[18] Jiaqing Xiong et al., “The Rejection of Perfluoroalkyl Substances by Nanofiltration and Reverse Osmosis: Influencing Factors and Combination Processes,” Environmental Science: Water Research & Technology, vol. 7, no. 11, pp. 1928-1943, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[19] Caihong Liu et al., “Evaluating the Efficiency of Nanofiltration and Reverse Osmosis Membrane Processes for the Removal of Per-and Polyfluoroalkyl Substances from Water: A Critical Review,” Separation and Purification Technology, vol. 302, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[20] Vera Franke et al., “Efficient Removal of Per-and Polyfluoroalkyl Substances (PFASS) in Drinking Water Treatment: Nanofiltration Combined with Active Carbon or Anion Exchange,” Environmental Science: Water Research & Technology, vol. 5, no. 11, pp. 1836-1843, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[21] Jianhua Zhang et al., “PFAS Removal from Wastewater by in-Situ Formed Ferric Nanoparticles: Solid Phase Loading and Removal Efficiency,” Journal of Environmental Chemical Engineering, vol. 9, no. 4, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[22] Shan Huang, and Peter R. Jaffé, “Defluorination of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) by Acidimicrobium Sp. Strain A6,” Environmental Science&Technology, vol. 53, no. 19, pp. 11410-11419, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[23] Melany Ruiz-Urigüen et al., “Biodegradation of PFOA in Microbial Electrolysis Cells by Acidimicrobiaceae Sp. Strain A6,” Chemosphere, vol. 292, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[24] L.B. Yi et al., “Isolation, Identification, and Degradation Performance of a PFOA-Degrading Strain,” Genetics and Molecular Research, vol. 15, no. 2, pp. 235-246, 2016.
[Google Scholar]
[25] Li Long et al., “Novel Chitosan–Ethylene Glycol Hydrogel for the Removal of Aqueous Perfluorooctanoic Acid,” Journal of Environmental Sciences, vol. 84, pp. 21-28, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[26] Beatriz Gomez-Ruiz et al., “Photocatalytic Degradation and Mineralization of Perfluorooctanoic Acid (PFOA) Using a Composite TiO2− rGO Catalyst,” Journal of Hazardous Materials, vol. 344, pp. 950-957, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[27] Wedja Timóteo Vieira et al., “Removal of Endocrine Disruptors in Waters by Adsorption, Membrane Filtration and Biodegradation. A Review,” Environmental Chemistry Letters, vol. 18, no. 4, pp. 1113-1143, 2020.
[CrossRef] [Google Scholar] [Publisher Link]
[28] Qiaoying Zhang et al., “Removal of Perfluorooctane Sulfonate from Aqueous Solution by Crosslinked Chitosan Beads: Sorption Kinetics and Uptake Mechanism,” Bioresource Technology, vol. 102, no. 3, pp. 2265-2271, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[29] Yanyan Gong et al., “Removal of Aqueous Perfluorooctanoic Acid (PFOA) Using Starch-Stabilized Magnetite Nanoparticles,” Science of the Total Environment, vol. 562, pp. 191-200, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[30] Aiza Farhani Zakaria et al., “Recent Advances in Applications of Hybrid Natural Polymers as Adsorbent for Perfluorinated Compounds Removal–Review Paper,” Journal of Polymer Research, vol. 29, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[31] Xiaole Zhang et al., “Chitosan-Coated Octadecyl-Functionalized Magnetite Nanoparticles: Preparation and Application in Extraction of Trace Pollutants from Environmental Water Samples,” Analytical Chemistry, vol. 82, no. 6, pp. 2363-2371, 2010.
[CrossRef] [Google Scholar] [Publisher Link]
[32] Siphesihle Mangena Khumalo et al., “Application of Response Surface Methodology on Brewery Wastewater Treatment Using Chitosan as a Coagulant,” Water, vol. 15, no. 6, pp. 1-13, 2023.
[CrossRef] [Google Scholar] [Publisher Link]
[33] Agnieszka Sobczak-Kupiec et al., “Review of the Applications of Biomedical Compositions Containing Hydroxyapatite and Collagen Modified by Bioactive Components,” Materials, vol. 14, no. 9, pp. 1-51, 2021.
[CrossRef] [Google Scholar] [Publisher Link]
[34] Shahab Karimifard, and Mohammad Reza Alavi Moghaddam, “Enhancing the Adsorption Performance of Carbon Nanotubes with a Multistep Functionalization Method: Optimization of Reactive Blue 19 Removal through Response Surface Methodology,” Process Safety and Environmental Protection, vol. 99, pp. 20-29, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[35] Nhlanganiso Ivan Madondo, Sudesh Rathilal, and Babatunde Femi Bakare, “Utilization of Response Surface Methodology in Optimization and Modelling of a Microbial Electrolysis Cell for Wastewater Treatment Using Box–Behnken Design Method,” Catalysts, vol. 12, no. 9, pp. 1-20, 2022.
[CrossRef] [Google Scholar] [Publisher Link]
[36] Marcos Almeida Bezerra et al., “Response Surface Methodology (RSM) as a Tool for Optimization in Analytical Chemistry,” Talanta, vol. 76, no. 5, pp. 965-977, 2008.
[CrossRef] [Google Scholar] [Publisher Link]
[37] S.SD. Elanchezhiyan, and Sankaran Meenakshi, “Encapsulation of Metal Ions Between the Biopolymeric Layer Beads for Tunable Action on Oil Particles Adsorption from Oily Wastewater,” Journal of Molecular Liquids, vol. 255, pp. 429-438, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[38] Yuanhang Zhan, and Jun Zhu, “Response Surface Methodology and Artificial Neural Network-Genetic Algorithm for Modeling and Optimization of Bioenergy Production from Biochar-Improved Anaerobic Digestion,” Applied Energy, vol. 355, 2024. [CrossRef] [Google Scholar] [Publisher Link]
[39] Mahmood Alimohammadi et al., “Adsorptive Removal of Arsenic and Mercury from Aqueous Solutions by Eucalyptus Leaves,” Water, Air, & Soil Pollution, vol. 228, pp. 1-27, 2017.
[CrossRef] [Google Scholar] [Publisher Link]
[40] Douglas C. Montgomery, Design and Analysis of Experiments, John Wiley & Sons, pp. 1-726, 2017.
[Google Scholar] [Publisher Link]
[41] Fei Wang, and Kaimin Shih, “Adsorption of Perfluorooctanesulfonate (PFOS) and Perfluorooctanoate (PFOA) on Alumina: Influence of Solution pH and Cations,” Water Research, vol. 45, no. 9, pp. 2925-2930, 2011.
[CrossRef] [Google Scholar] [Publisher Link]
[42] Luciana Vera Candioti et al., “Experimental Design and Multiple Response Optimization. Using the Desirability Function in Analytical Methods Development,” Talanta, vol. 124, pp. 123-138, 2014.
[CrossRef] [Google Scholar] [Publisher Link]