Malays. J. Anal. Sci. Volume 29 Number 6 (2025): 1767

Research Article

Synthesis and characterization of silver-loaded activated carbon for microfiber removal from laundry wastewater

Dahalan Sukor¹, Iwani W. Rushdi¹, Nur Sakinah Roslan⁴, Maisarah Jaafar¹, Noorlin Mohamad¹, Yusof Shuaib Ibrahim^1,2, Wan Mohd Afiq Wan Mohd Khalik¹, Sabiqah Tuan Anuar¹, Sofiah Hamzah³, Asmadi Ali@Mahmud³, Nor Salmi Abdullah⁴, Nasehir Khan E.M Yahya⁴, Ahmad Fuad Shahruddin⁵ and Alyza A. Azmi^1,3*

¹Microplastic Research Interest Group (MRIG), Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

²Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

³Environmental Sustainable Materials Research Interest Group, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

⁴Water Quality Laboratory, National Water Research Institute of Malaysia (NAHRIM), Lot 5377, Jalan Putra Permai, Rizab Melayu Sungai Kuyoh, 43300, Seri Kembangan, Selangor, Malaysia.

⁵Raf Technologies Sdn Bhd, 17, Jalan Meranti Jaya 8, Taman Perindustrian Meranti Jaya, 47120 Puchong, Selangor, Malaysia.

^*Corresponding author: alyza.azzura@umt.edu.my

Received: 11 August 2025; Revised: 10 November 2025; Accepted: 10 December 2025; Published: 28 December 2025

Abstract

The discharge of microfibers (MFs) from domestic laundry effluents contributes significantly to microplastic pollution. In this paper, silver nanoparticle-loaded activated carbon (AC-Ag) was synthesized from rice husk through thermal–chemical activation followed by silver deposition. Material characterization using XRD, FTIR, XPS, SEM, and BET confirmed the formation of an amorphous carbon matrix with embedded face-centered cubic silver nanoparticles and a hierarchical porous structure favourable for MF capture. AC-Ag achieved 94-99% removal efficiency, surpassing bare rice husk activated carbon (~72-77%). MF removal was optimized using Response Surface Methodology (RSM) with a Box-Behnken Design (BBD) considering flow rate, MF loading, and AC-Ag bed height. Across 17 runs, AC-Ag achieved optimum MFs removal of 97.33% at 25.0 ml/min flow rate, 50 MFs, and 0.2 cm AC-Ag bed height. The quadratic model showed excellent predictive accuracy (R² = 0.9865, p < 0.0001), identifying adsorbent bed height as the dominant factor. Enhanced performance was attributed to increased residence time and multilevel pore trapping facilitated by the silver-modified porous carbon. These findings demonstrate that AC-Ag derived from agricultural waste are an effective and sustainable material for mitigating MF pollution in domestic wastewater.

Keywords: microplastic, nanoparticle, activated carbon, adsorbent, response surface methodology

References

1. Salahuddin, M., and Lee, Y.-A. (2022). Are laundry balls a sustainable washing option for consumers? Investigating the effect of laundry balls on microfiber pollution through the lens of cradle-to-cradle design model. Sustainability, 14(21), 14314.

2. Athey, S. N., and Erdle, L. M. (2022). Are we underestimating anthropogenic microfiber pollution? A critical review of occurrence, methods, and reporting. Environmental Toxicology and Chemistry, 41(4), 822–837.

3. Buss, N., Sander, B., and Hua, J. (2022). Effects of polyester microplastic fiber contamination on amphibian–trematode interactions. Environmental Toxicology and Chemistry, 41(4), 869–879.

4. Gavigan, J., Kefela, T., Macadam-Somer, I., Suh, S., and Geyer, R. (2020). Synthetic microfiber emissions to land rival those to waterbodies and are growing. PLOS ONE, 15(9), e0237839.

5. Cui, J., Yang, Y., Hu, Y., and Li, F. (2015). Rice husk-based porous carbon loaded with silver nanoparticles by a simple and cost-effective approach and their antibacterial activity. Journal of Colloid and Interface Science, 455, 117–124.

6. Devi, T. B., Mohanta, D., and Ahmaruzzaman, M. (2019). Biomass-derived activated carbon loaded silver nanoparticles: An effective nanocomposite for enhanced solar photocatalysis and antimicrobial activities. Journal of Industrial and Engineering Chemistry, 76, 160–172.

7. Gonçalves, S. P. C., Strauss, M., Delite, F. S., Clemente, Z., Castro, V. L., and Martinez, D. S. T. (2016). Activated carbon from pyrolysed sugarcane bagasse: Silver nanoparticle modification and ecotoxicity assessment. Science of the Total Environment, 565, 833–840.

8. Dawelbeit, A., and Yu, M. (2021). Tentative confinement of ionic liquids in nylon 6 fibers: A bridge between structural developments and high-performance properties. ACS Omega, 6(5), 3535–3547.

9. Rao, P. N., Sabavath, G., and Paul, S. (2021). Impact of MTA blend percentage in melt spinning process and polyester properties. SN Applied Sciences, 3(2), 184.

10. Gies, E. A., LeNoble, J. L., Noël, M., Etemadifar, A., Bishay, F., Hall, E. R., and Ross, P. S. (2018). Retention of microplastics in a major secondary wastewater treatment plant in Vancouver, Canada. Marine Pollution Bulletin, 133, 553–561.

11. Mintenig, S. M., Int-Veen, I., Löder, M. G. J., Primpke, S., and Gerdts, G. (2017). Identification of microplastic in effluents of wastewater treatment plants using focal plane array-based micro-Fourier-transform infrared imaging. Water Research, 108, 365–372.

12. Novotná, J., Tunák, M., Militký, J., Křemenáková, D., Wiener, J., Nováková, J., and Ševců, A. (2025). Release of microplastic fibers from polyester knit fleece during abrasion, washing, and drying. ACS Omega, 10(14), 14241–14249.

13. Periyasamy, A. P., and Tehrani-Bagha, A. (2022). A review on microplastic emission from textile materials and its reduction techniques. Polymer Degradation and Stability, 199, 109901.

14. Militký, J., Novotná, J., Wiener, J., Křemenáková, D., and Venkataraman, M. (2024). Microplastics and fibrous fragments generated during the production and maintenance of textiles. Fibers, 12(7), 51.

15. Yuliusman, Sipangkar, S. P., Fatkhurrahman, M., Farouq, F. A., and Putri, S. A. (2020). Utilization of coconut husk waste in the preparation of activated carbon by using chemical activators of KOH and NaOH. AIP Conference Proceedings, 2255(1), 060026.

16. Yuliusman, Farouq, F. A., Sipangkar, S. P., Fatkhurrahman, M., and Putri, S. A. (2020). Preparation and characterization of activated carbon from corn stalks by chemical activation with KOH and NaOH. AIP Conference Proceedings, 2255(1), 060006.

17. Ramasundaram, S., Manikandan, V., Vijayalakshmi, P., Devanesan, S., Salah, M. B., Babu, A. R., Priyadharsan, A., Oh, T. H., and Ragupathy, S. (2023). Synthesis and investigation on synergetic effect of activated carbon loaded silver nanoparticles with enhanced photocatalytic and antibacterial activities. Environmental Research, 233, 116431.

18. Katta, V., Dubey, R., and Joshi, G. (2023). Experimental investigation of activated carbon nanoflakes produced by thermal and chemical activation processes. Fullerenes, Nanotubes and Carbon Nanostructures, 31(1), 10–17.

19. Soffian, M., Abdul Halim, F., Aziz, F., Rahman, A., Mohamed Amin, M., and Awang Chee, D. (2022). Carbon-based material derived from biomass waste for wastewater treatment. Environmental Advances, 9, 100259.

20. Meng, Y. (2015). A sustainable approach to fabricating Ag nanoparticles/PVA hybrid nanofiber and its catalytic activity. Nanomaterials, 5, 1124–1135.

21. Farooqi, M. A., Bae, S., Kim, S., Kausar, F., Farooqi, H. M. U., Hyun, C. G., and Kang, C. U. (2024). Eco-friendly synthesis of bioactive silver nanoparticles from black roasted gram (Cicer arietinum) for biomedical applications. Scientific Reports, 14(1), 22922.

22. Dao, M. U., Hoang, H. Y., Tran, A. K., and Cong, H. H. (2021). Assessment and treatment of floodwater in the Vietnamese Mekong Delta using a simple filter system based on silver nanoparticles coated onto activated carbon derived from rice husk. RSC Advances, 11(63), 39838–39847.

23. Zhao, Y., You, J., Wang, L., Bao, W., and Yao, R. (2021). Recent advances in Ni₃S₂-based electrocatalysts for oxygen evolution reaction. International Journal of Hydrogen Energy, 46(79), 39146–39182.

24. Sarkar, S., and Basak, D. (2013). One-step nano-engineering of dispersed Ag–ZnO nanoparticles hybrid in reduced graphene oxide matrix and its superior photocatalytic property. CrystEngComm, 15(37), 7606–7614.

25. Doğan, M., Sabaz, P., Biçil, Z., Kızılduman, B. K., and Turhan, Y. (2020). Activated carbon synthesis from tangerine peel and its use in hydrogen storage. Journal of the Energy Institute, 93(6), 2176–2185.

26. Chen, C., Qu, B., Wang, W., Ji, G., and Li, A. (2021). Rice husk and rice straw torrefaction: Properties and pyrolysis kinetics of raw and torrefied biomass. Environmental Technology and Innovation, 24, 101872.

27. Rahmat, A., Nissa, R., Nuraini, L., Nurtanto, M., and Ramadhani, W. (2023). Analysis of rice husk biochar characteristics under different pyrolysis temperature. IOP Conference Series: Earth and Environmental Science.

28. Faisal, H. A., Mohammed, A. K., Sbani, N. H. A., and Isaha, W. N. R. W. (2025). Comparative study of activated carbon and silver nanoparticle-loaded activated carbon derived from tea waste for removal of tetracycline from aqueous solution. Tikrit Journal of Engineering Sciences, 32(2), 1–17.

29. Wazir, A. H., Wazir, I. U., and Wazir, A. M. (2024). Preparation and characterization of rice husk-based physical activated carbon. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 46(1), 4875–4885.

30. Serafin, J., and Dziejarski, B. (2024). Activated carbons—Preparation, characterization and their application in CO₂ capture: A review. Environmental Science and Pollution Research, 31(28), 40008–40062.

31. Pérez-Mayoral, E., Matos, I., Bernardo, M., and Fonseca, I. M. (2019). New and advanced porous carbon materials in fine chemical synthesis: Emerging precursors of porous carbons. Catalysts, 9(2), 133.

32. Li, P., Liu, J., and Zhang, H. (2022). Insights into the interaction of microplastic with silver nanoparticles in natural surface water. Science of the Total Environment, 805, 150315.

33. Wang, Z., Sedighi, M., and Lea-Langton, A. (2020). Filtration of microplastic spheres by biochar: Removal efficiency and immobilisation mechanisms. Water Research, 184, 116165.

34. Jaber, L., Backer, S. N., Laoui, T., Abumadi, F., Koujan, M. M. S., Khalil, K. A., Shanableh, A., and Atieh, M. A. (2024). Recent trends in surface impregnation techniques on activated carbon for efficient pollutant removal from wastewater. Desalination and Water Treatment, 100562.

35. Tavakoli, H., Hashemi, S., Amirkhani, R., and Gholampour, M. (2023). Silver nanoparticles loaded on silica nanoparticles and activated carbon prepared for use in portable water treatment. Journal of Synthetic Chemistry, 1(3), 137–147.

36. Acarer, S. (2023). A review of microplastic removal from water and wastewater by membrane technologies. Water Science and Technology, 88(1), 199–219.

37. Uogintė, I., Pleskytė, S., Pauraitė, J., and Lujanienė, G. (2022). Seasonal variation and complex analysis of microplastic distribution in different WWTP treatment stages in Lithuania. Environmental Monitoring and Assessment, 194(11), 829.

38. Rushdi, I. W., Hardian, R., Rusidi, R. S., Khairul, W. M., Hamzah, S., Khalik, W. M. A. W. M., Abdullah, N. S., Yahaya, N. K. E., Szekely, G., and Azmi, A. A. (2025). Microplastic and organic pollutant removal using imine-functionalized mesoporous magnetic silica nanoparticles enhanced by machine learning. Chemical Engineering Journal, 510, 161595.

39. Arenas, L. R., Gentile, S. R., Zimmermann, S., and Stoll, S. (2021). Nanoplastics adsorption and removal efficiency by granular activated carbon used in drinking water treatment process. Science of the Total Environment, 791, 148175.

40. Metcalf and Eddy, Abu-Orf, M., Bowden, G., Burton, F. L., Pfrang, W., Stensel, H. D., Tchobanoglous, G., Tsuchihashi, R., and AECOM. (2014). Wastewater engineering: Treatment and resource recovery. McGraw-Hill Education.

41. Subair, A., Krishnamoorthy Lakshmi, P., Chellappan, S., and Chinghakham, C. (2024). Removal of polystyrene microplastics using biochar-based continuous flow fixed-bed column. Environmental Science and Pollution Research, 31(9), 13753–13765.