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Application of Coconut Shell Activated Carbon for the Adsorption of Toxic Heavy Metals from Wastewater

Authors

  • Felicia Omolara Afolabi Email ORCID Institute of Systems Science, Durban University of Technology, Durban 4001, South Africa
  • Paul Musonge ORCID Institute of Systems Science, Durban University of Technology, Durban 4001, South Africa; Faculty of Engineering, Mangosuthu University of Technology, Durban 4031, South Africa
  • Oludolapo Akanni Olanrewaju ORCID Institute of Systems Science, Durban University of Technology, Durban 4001, South Africa

DOI:

https://doi.org/10.30564/re.v8i5.116997

Received:6 May 2026 |Revised:21 July 2026 |Accepted:27 July 2026 |Published Online:26 October 2026

Abstract

Copper and lead are poisonous, non-biodegradable heavy metals that persist in the environment and can cause severe health challenges in the human body. This study investigates the effectiveness of coconut shell activated carbon (CSAC) as an adsorbent for the removal of copper and lead ions from wastewater in a batch mode. The effects of varying operating parameters in the adsorption process namely, initial concentration (10–200 mg/L), pH (2–12), adsorbent dosage (1–5 g) and particle size (75–300 µm) using the central composite design (CCD). The adsorbent was characterised prior to and after adsorption to determine the functional groups, morphological structure and the elemental composition with the aid of Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analytical instruments respectively. The analysis of variance (ANOVA) indicated a strong coefficient of determination (R2) for Cu2+ and Pb2+, measuring 0.9761 and 0.9689, respectively. Adsorption of Pb2+ showed higher capacity and stronger affinity than Cu2⁺. Isotherm studies showed that the Langmuir, Temkin, and Dubinin–Radushkevich (D–R) models provided a strong fit for Pb2+ but were significantly less suitable for describing the Cu2+ adsorption data. while kinetics followed pseudo-second order, confirming chemisorption. This research aids in the application of commercial activated carbon derived from coconut shell for treating water contaminated with copper and lead metal ions.

Keywords:

Activated Carbon, Response Surface Methodology, Coconut Shell, Copper, Lead, Wastewater

References

[1] Bayuo, J., Rwiza, M., Mtei, K., 2022. A comprehensive review on the decontamination of lead(II) from water and wastewater by low-cost biosorbents. RSC Advances. 12(18), 11233–11254. DOI: https://doi.org/10.1039/d2ra00796g

[2] Chakraborty, R., Asthana, A., Singh, A.K., et al., 2022. Adsorption of heavy metal ions by various low-cost adsorbents: A review. International Journal of Environmental Analytical Chemistry. 102(2), 342–379. DOI: https://doi.org/10.1080/03067319.2020.1722811

[3] Olawale, S.H., Alahmad, W., Darwish, I.A., et al., 2025. Synthesis of biochar/MoS₂ composite modified with poly(acrylic acid) (BC/MoS₂/PAA) for the removal of Cd(II) and Pb(II) from wastewater. RSC Advances. 15(37), 30123–30134. DOI: https://doi.org/10.1039/d5ra03405a

[4] Kuczajowska-Zadrożna, M., Filipkowska, U., Jóźwiak, T., 2020. Adsorption of Cu(II) and Cd(II) from aqueous solutions by chitosan immobilized in alginate beads. Journal of Environmental Chemical Engineering. 8(4), 103878. DOI: https://doi.org/10.1016/j.jece.2020.103878

[5] Wang, T., Zheng, J., Liu, H., et al., 2021. Adsorption characteristics and mechanisms of Pb2⁺ and Cd2⁺ by a new agricultural waste–Caragana korshinskii biomass derived biochar. Environmental Science and Pollution Research. 28(11), 13800–13818. DOI: https://doi.org/10.1007/s11356-020-11571-9

[6] Abbas, M.N., Ali, S.T., Abass, R.S., 2020. Rice husks as a biosorbent agent for Pb2⁺ ions from contaminated aqueous solutions: A review. Biochemical and Cellular Archives. 20(1), 1813–1820. Available from: https://www.connectjournals.com/file_full_text/3142501H_1813-1820.pdf

[7] Alsulaili, A., Elsayed, K., Refaie, A., 2024. Utilization of agriculture waste materials as sustainable adsorbents for heavy metal removal: A comprehensive review. Journal of Engineering Research. 12(4), 691–703. DOI: https://doi.org/10.1016/j.jer.2023.09.018

[8] Ali Redha, A., 2020. Removal of heavy metals from aqueous media by biosorption. Arab Journal of Basic and Applied Sciences. 27(1), 183–193. DOI: https://doi.org/10.1080/25765299.2020.1756177

[9] Rashid, R., Shafiq, I., Akhter, P., et al., 2021. A state-of-the-art review on wastewater treatment techniques: The effectiveness of adsorption method. Environmental Science and Pollution Research. 28(8), 9050–9066. DOI: https://doi.org/10.1007/s11356-021-12395-x

[10] Singh, S., Kumar, V., Datta, S., et al., 2020. Current advancement and future prospect of biosorbents for bioremediation. Science of the Total Environment. 709, 135895. DOI: https://doi.org/10.1016/j.scitotenv.2019.135895

[11] De Gisi, S., Lofrano, G., Grassi, M., et al., 2016. Characteristics and adsorption capacities of low-cost sorbents for wastewater treatment: A review. Sustainable Materials and Technologies. 9, 10–40. DOI: https://doi.org/10.1016/j.susmat.2016.06.002

[12] Packialakshmi, S., Anuradha, B., Nagamani, K., et al., 2023. Treatment of industrial wastewater using coconut shell based activated carbon. Materials Today: Proceedings. 81, 1167–1171. DOI: https://doi.org/10.1016/j.matpr.2021.04.548

[13] Kuok, K.K., Chiu, P.C., Rahman, M.R., et al., 2024. Sustainable bamboo and coconut shell activated carbon for purifying river water on Borneo Island. Waste Management Bulletin. 2(1), 39–48. DOI: https://doi.org/10.1016/j.wmb.2023.12.008

[14] Ahmed, A., Vora, T., Padmapriya, G., et al., 2025. Valorization of coconut husk into biochar for lead (Pb2⁺) adsorption. Green Processing and Synthesis. 14(1), 20240230. DOI: https://doi.org/10.1515/gps-2024-0230

[15] Huno, S.K.M., Das, J., van Hullebusch, E.D., et al., 2023. Nitrate removal from groundwater using chemically modified coconut husk based granular activated carbon: Characterization of the adsorbent, kinetics and mechanism. Systems Microbiology and Biomanufacturing. 3(2), 370–383. DOI: https://doi.org/10.1007/s43393-022-00108-5

[16] Aboli, E., Jafari, D., Esmaeili, H., 2020. Heavy metal ions (lead, cobalt, and nickel) biosorption from aqueous solution onto activated carbon prepared from Citrus limetta leaves. Carbon Letters. 30(6), 683–698. DOI: https://doi.org/10.1007/s42823-020-00141-1

[17] Alkherraz, A.M., Ali, A.K., El-Dali, A., et al., 2019. Biosorption study of Zn(II), Cu(II), Pb(II) and Cd(II) ions by palm leaves activated carbon. To Chemistry Journal. 4, 8–17. Available from: https://www.purkh.com/articles/biosorption-study-of-znii-cuii-pbii-and-cdii-ions-by-palm-leaves-activated-carbon.pdf

[18] Owamah, H.I., 2014. Biosorptive removal of Pb(II) and Cu(II) from wastewater using activated carbon from cassava peels. Journal of Material Cycles and Waste Management. 16(2), 347–358. DOI: https://doi.org/10.1007/s10163-013-0192-z

[19] Wiśniewska, M., Marciniak, M., Gęca, M., et al., 2022. Activated biocarbons obtained from plant biomass as adsorbents of heavy metal ions. Materials. 15(17), 5856. DOI: https://doi.org/10.3390/ma15175856

[20] Afolabi, F.O., Musonge, P., Bakare, B.F., 2021. Bio-sorption of a bi-solute system of copper and lead ions onto banana peels: Characterization and optimization. Journal of Environmental Health Science and Engineering. 19(1), 613–624. DOI: https://doi.org/10.1007/s40201-021-00632-x

[21] Pap, S., Bezanovic, V., Radonic, J., et al., 2018. Synthesis of highly-efficient functionalized biochars from fruit industry waste biomass for the removal of chromium and lead. Journal of Molecular Liquids. 268, 315–325. DOI: https://doi.org/10.1016/j.molliq.2018.07.072

[22] Asim, N., Amin, M.H., Samsudin, N.A., et al., 2020. Development of effective and sustainable adsorbent biomaterial from an agricultural waste material: Cu(II) removal. Materials Chemistry and Physics. 249, 123128. DOI: https://doi.org/10.1016/j.matchemphys.2020.123128

[23] Babapoor, A., Rafiei, O., Mousavi, Y., et al., 2022. Comparison and optimization of operational parameters in removal of heavy metal ions from aqueous solutions by low-cost adsorbents. International Journal of Chemical Engineering. 2022, 3282448. DOI: https://doi.org/10.1155/2022/3282448

[24] Pang, X., Jiang, H., Yang, J., et al., 2025. Insight into the adsorption behavior of Cd(II) and Pb(II) from mud by HCl-modified coconut shell biochar: Experimental and DFT studies. Chemistry. 7(6), 202. DOI: https://doi.org/10.3390/chemistry7060202

[25] Cachola Maldito Lowden, V.M., Alexandre-Franco, M.F., Garrido-Zoido, J.M., et al., 2026. Coconut shell-derived activated carbons: Preparation, physicochemical properties, and dye removal from water. Molecules. 31(2), 263. DOI: https://doi.org/10.3390/molecules31020263

[26] Sukmono, Y., Kristanti, R.A., Foo, B.V., et al., 2024. Adsorption of Fe and Pb from aqueous solution using coconut shell activated carbon. Biointerface Research in Applied Chemistry. 14(2), 30. DOI: https://doi.org/10.33263/BRIAC142.030

[27] Tolkou, A.K., Trikalioti, S., Makrogianni, O., et al., 2023. Magnesium modified activated carbons derived from coconut shells for the removal of fluoride from water. Sustainable Chemistry and Pharmacy. 31, 100898. DOI: https://doi.org/10.1016/j.scp.2022.100898

[28] Yusop, M.F.M., Mohd Johan Jaya, E., Mohd Din, A.T., et al., 2022. Single-stage optimized microwave-induced activated carbon from coconut shell for cadmium adsorption. Chemical Engineering & Technology. 45(11), 1943–1951. DOI: https://doi.org/10.1002/ceat.202200051

[29] Irshad, S., Xie, Z., Qing, M., et al., 2024. Application of coconut shell activated carbon filter in vertical subsurface flow constructed wetland for enhanced multi-metal bioremediation and antioxidant response of Salvinia cucullate. Environmental Pollution. 346, 123597. DOI: https://doi.org/10.1016/j.envpol.2024.123597

[30] Ruszczyk, L.C., Tochetto, G., Dervanoski, A., et al., 2024. Kinetic modeling and optimization of triclosan adsorption onto coconut shell activated carbon. Journal of Hazardous Materials Letters. 5, 100131. DOI: https://doi.org/10.1016/j.hazl.2024.100131

[31] Aziz, M.A., Chowdhury, I.R., Mazumder, M.A.J., et al., 2019. Highly porous carboxylated activated carbon from jute stick for removal of Pb2⁺ from aqueous solution. Environmental Science and Pollution Research. 26(22), 22656–22669. DOI: https://doi.org/10.1007/s11356-019-05556-6

[32] Mandal, S., Calderon, J., Marpu, S.B., et al., 2021. Mesoporous activated carbon as a green adsorbent for the removal of heavy metals and Congo red: Characterization, adsorption kinetics, and isotherm studies. Journal of Contaminant Hydrology. 243, 103869. DOI: https://doi.org/10.1016/j.jconhyd.2021.103869

[33] Ahmad, A., Rafatullah, M., Sulaiman, O., et al., 2009. Removal of Cu(II) and Pb(II) ions from aqueous solutions by adsorption on sawdust of Meranti wood. Desalination. 247(1–3), 636–646. DOI: https://doi.org/10.1016/j.desal.2009.01.007

[34] Zhang, Z., Wang, T., Zhang, H., et al., 2021. Adsorption of Pb(II) and Cd(II) by magnetic activated carbon and its mechanism. Science of the Total Environment. 757, 143910. DOI: https://doi.org/10.1016/j.scitotenv.2020.143910

[35] Deng, Z., Sun, S., Li, H., et al., 2021. Modification of coconut shell-based activated carbon and purification of wastewater. Advanced Composites and Hybrid Materials. 4(1), 65–73. DOI: https://doi.org/10.1007/s42114-021-00205-4

[36] Ighalo, J.O., Omoarukhe, F.O., Ojukwu, V.E., et al., 2022. Cost of adsorbent preparation and usage in wastewater treatment: A review. Cleaner Chemical Engineering. 3, 100042. DOI: https://doi.org/10.1016/j.clce.2022.100042

[37] Isaac, R., Siddiqui, S., Aldosari, O.F., et al., 2023. Magnetic biochar derived from Juglans regia for the adsorption of Cu2⁺ and Ni2⁺: Characterization, modelling, optimization, and cost analysis. Journal of Saudi Chemical Society. 27(6), 101749. DOI: https://doi.org/10.1016/j.jscs.2023.101749

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