Evaluation of Ph Behaviour and Adsorption Performance of Coconut Husk Adsorbent in Industrial Wastewater Treatment

Industrial wastewater containing heavy metals poses significant environmental challenges due to its impact on water quality parameters, particularly pH and contaminant concentration. The presence of copper ions can increase the acidity of wastewater, affecting both treatment efficiency and environmental safety. Therefore, there is a need for sustainable and cost-effective treatment methods that not only remove contaminants but also stabilize pH levels. This study aims to evaluate the pH behaviour and adsorption performance of a coconut husk adsorbent in industrial wastewater treatment. The adsorbent was prepared from coconut husk through washing, chemical activation using sodium hydroxide (NaOH), and low-temperature carbonization. Synthetic wastewater was formulated using kaolin and different concentrations of copper. Batch adsorption experiments were conducted to assess changes in pH and absorbance before and after treatment. The results showed that the initial pH decreased with increasing copper concentration, with values of 4.85, 4.66, and 4.01 recorded for Sample 1, Sample 2, and Sample 3, respectively. After treatment, the pH increased to 5.12, 4.99, and 4.60, indicating improved pH stabilization. In terms of adsorption performance, absorbance values decreased from 2.137 to 1.956 and from 2.494 to 2.357 for Sample 2 and Sample 3, respectively, demonstrating effective contaminant removal. However, a slight increase in absorbance from 1.292 to 1.404 was observed for Sample 1, suggesting reduced adsorption efficiency at lower contaminant concentration. In conclusion, the coconut husk adsorbent demonstrated promising potential as a low-cost and sustainable material for industrial wastewater treatment. Its ability to improve both pH stability and adsorption performance highlights its applicability as an alternative to conventional adsorbents, particularly under moderate to higher contaminant loading conditions.

Adsorption; Chemical Activation; Coconut Husk; Wastewater

1. Adeleke, A. E., Onifade, A. P., Sangoremi, A. A., Anifowose, A. J., Isola, O. E., & Olawoye, B. M. (2023). Adsorption of Pb2+, Co2+, and Cd2+ from Aqueous Solution Using Nitric Acid Modified Kola Nut Husk Adsorbent. Journal of Applied Sciences and Environmental Management, 27(5), 919–925. https://doi.org/10.4314/jasem.v27i5.5 [Google Scholar] [Crossref]

2. Ayoub, A., & Vishakha, V. (2026). Removal of Heavy Metals from Wastewater using Sustainable Low Cost Absorbents. International Journal For Multidisciplinary Research, 8(1). https://doi.org/10.36948/ijfmr.2026.v08i01.66695 [Google Scholar] [Crossref]

3. de Araújo, A. P. F., do Nascimento, M. A., Sales Bezerra, J. C., Santos Oliveira, M. dos, Silva do Lago, T. G., & Silva Marques, A. da. (2024). Green coconut shell as energy biomass: a bibliometric and systematic analysis of scientific literature. International Journal of Hydrology, 8(3), 106–114. https://doi.org/10.15406/ijh.2024.08.00381 [Google Scholar] [Crossref]

4. Himu, H. A., Dip, T. M., Emu, A. S., Ahmed, A. T. M. F., & Syduzzaman, Md. (2024). Plant Biomass for Water Purification Applications. In Plant Biomass Derived Materials (pp. 465–515). Wiley. https://doi.org/10.1002/9783527839032.ch18 [Google Scholar] [Crossref]

5. Hu, Q., & Hao, L. (2025). Adsorption Technologies in Wastewater Treatment Processes. Water, 17(15), 2335. https://doi.org/10.3390/w17152335 [Google Scholar] [Crossref]

6. Hussain, A., Madan, S., & Madan, R. (2021). Removal of Heavy Metals from Wastewater by Adsorption. In Heavy Metals - Their Environmental Impacts and Mitigation. IntechOpen. https://doi.org/10.5772/intechopen.95841 [Google Scholar] [Crossref]

7. Jock, A. A., Ibrahim, M., Nuhu, S. K., & Anietie, A. J. (2022). Preparation Of Activated Carbon Adsorbent From Coconut Husk For The Adsorption Of Lead (Ii) Ions From Aqueous Solution. Nigerian Journal of Tropical Engineering, 16(1). https://doi.org/10.59081/njte.16.1.001 [Google Scholar] [Crossref]

8. Lemessa, F., Simane, B., Seyoum, A., & Gebresenbet, G. (2023). Assessment of the Impact of Industrial Wastewater on the Water Quality of Rivers around the Bole Lemi Industrial Park (BLIP), Ethiopia. Sustainability, 15(5), 4290. https://doi.org/10.3390/su15054290 [Google Scholar] [Crossref]

9. Molchanova, O., Novikova, L., Tomina, E., & Meshcheryakova, A. (2025). Effect Of Solution Ph And Mass Of The Sorbent On Sorption And Degree Of Purification Of Water From Copper Ions By Magnesium And Zinc Ferrites. Materials of the International Scientific Conference of Scientists and Students «Energy-Saving And Environmentally Friendly Technologies In The Forestry Industry», 133–138. https://doi.org/10.58168/E-SEFTFI2024_133-138 [Google Scholar] [Crossref]

10. Nath, A. (2026). Low-Cost Agricultural Waste-Derived Adsorbents for Dye Removal from Wastewater: Source, Mechanism and Sustainability Perspectives: A Critical Review. Asian Journal of Chemical Sciences, 16(1), 64–77. https://doi.org/10.9734/ajocs/2026/v16i1421 [Google Scholar] [Crossref]

11. Oyedeji, O. A., & Osinfade, G. B. (2010). Removal of copper (II), iron (III) and lead (II) ions from Mono-component Simulated Waste Effluent by Adsorption on Coconut Husk. African Journal of Environmental Science and Technology, 4(6), 382–387. https://doi.org/10.5897/AJEST09.224 [Google Scholar] [Crossref]

12. Pandey, S., Shukla, R. K., & Srivastava, A. (2023). Treating Wastewater Through Adsorption Process By Using Agricultural Waste: A Review. Plant Archives, 23(2). https://doi.org/10.51470/PLANTARCHIVES.2023.v23.no2.078 [Google Scholar] [Crossref]

13. Rangamani, T. P., M. Srinivasulu, Lakshmi, L. B., & T. Srinivas. (2025). Reusable Coconut Waste Derived Adsorbent For Effective Elimination Of As (Iii) And Cr (Vi) From Aqueous Solutions. Rasayan Journal of Chemistry, 18(03), 1736–1743. https://doi.org/10.31788/RJC.2025.1839337 [Google Scholar] [Crossref]

14. Shrestha, R., Ban, S., Devkota, S., Sharma, S., Joshi, R., Tiwari, A. P., Kim, H. Y., & Joshi, M. K. (2021). Technological trends in heavy metals removal from industrial wastewater: A review. Journal of Environmental Chemical Engineering, 9(4), 105688. https://doi.org/10.1016/j.jece.2021.105688 [Google Scholar] [Crossref]

15. Shukor, H., Yaser, A. Z., Shoparwe, N. F., Mohd Zaini Makhtar, M., & Mokhtar, N. (2022). Biosorption Study of Methylene Blue (MB) and Brilliant Red Remazol (BRR) by Coconut Dregs. International Journal of Chemical Engineering, 2022(1). https://doi.org/10.1155/2022/8153617 [Google Scholar] [Crossref]

16. Sonkar, G. (2023). Metal‐Organic Framework Adsorbents for Indutrial Heavy‐Metal Wastewater Treatment. In Metal Organic Frameworks for Wastewater Contaminant Removal (pp. 337–354). Wiley. https://doi.org/10.1002/9783527841523.ch15 [Google Scholar] [Crossref]

17. Реимбаев, Е. Қ., Қанатбек, Ұ. Ғ., Куртебаева, А. А., Орынбаев, С. А., Helder, T. G., & Қалмаханова, М. С. (2025). Application Of Natural Clay And Bio-Based Activated Carbon For The Adsorptive Removal Of Paracetamol From Wastewater. Mechanics and Technologies, (3), 128–137. https://doi.org/10.55956/NGYZ3478 [Google Scholar] [Crossref]

• Performance Analysis of Silicon PV Array Using Infrared Thermography and Detecting Temperature Non-Uniformities
• Dynamic Capabilities and Digital Transformation Performance: The Role of Organizational Agility in the Public Sector
• Comparative Effectiveness of Neural Mobilization Versus Positional Release Technique in Cervical Radiculopathy – An Experimental Study
• Soil Moisture Mapping of Solano Nueva Vizcaya: A Comparison and Review
• Silent Assistance for Emergencies (SAFE): A Mobile-Based Emergency Reporting Application for the Deaf and Mute Community