Hemodialysis generates a considerable volume of spent dialysate containing various uremic toxins, particularly water-soluble compounds such as creatinine. Dialysate regeneration and reuse require efficient and selective adsorbents to remove these toxins. ZSM-5 zeolite is a promising material because of its porous structure, modifiable physicochemical properties, and potential to be developed as a molecular recognition material. However, improving the selectivity of ZSM-5 toward creatinine remains a challenge. Therefore, this study aimed to develop creatinine-imprinted ZSM-5 zeolite (IZ) to enhance the selective removal of creatinine from dialysate and evaluate its application in a cellulose acetate-based mixed-matrix membrane.
METHODS
ZSM-5 zeolite was synthesized using a hydrothermal method and then modified through a molecular imprinting approach, with creatinine serving as the template molecule. The synthesized ZSM-5, non-imprinted zeolite (NIZ), and imprinted zeolite (IZ) were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), surface area analysis (BET), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). Adsorption performance was evaluated by optimizing contact time, adsorbent mass, and initial creatinine concentration. Adsorption isotherm, kinetic, and selectivity analyses were also conducted. Subsequently, IZ was incorporated into a cellulose acetate-based mixed-matrix membrane and tested for creatinine removal under flow conditions.
RESULTS
The results confirmed the successful synthesis and creatinine-specific imprinting of ZSM-5. IZ exhibited a crystallinity of 79%, compared with 57% for the synthesized ZSM-5. The pore diameter increased from 3.22 nm in ZSM-5 to 5.42 nm in IZ, indicating the formation of specific creatinine recognition sites. IZ demonstrated better adsorption performance, with an optimum adsorption capacity of 55 mg g⁻¹ within 15 minutes, compared with 36 mg g⁻¹ for ZSM-5 at a contact time of 30 minutes. Creatinine removal efficiency reached 84% for IZ, while ZSM-5 achieved 42%. Selectivity analysis showed an improved ability to recognize creatinine, with a selectivity coefficient 4.074 times higher than that of ZSM-5. The MMM/IZ membrane exhibited an adsorption capacity of 18.7 mg g⁻¹ and a removal efficiency of 28.8%. Overall, molecular imprinting successfully enhanced the selectivity, adsorption capacity, and adsorption rate of ZSM-5, indicating its potential for further development as a selective adsorbent for dialysate regeneration and uremic toxin removal.
Author: Yanuardi Raharjo, Ph.D.
Detailed information about this research can be found in our article at:
http://pubs.rsc.org/ra/article/16/38/42241/1281158
Yanuardi Raharjo, Maipha Deapati Arief, Novia Amalia Sholeha, Triyanda Gunawan, Dayang Norfizan Awang Chee, Aemi Syazwani Abdul Keyon, Hartati, Aida Rifdatul Aisy, Muhammad Nidzhom Zainol Abidin and Nur Fariha Mahmuda
ZSM-5 Zeolite with Molecular Imprinting for the Selective Removal of Creatinine from Dialysate: Toward Enhanced Uremic Toxin Clearance, RSC Advances, 2026, 16, 42241
https:// DOI: 10.1039/d6ra05654g
This article is a repost from the Popular Scientific Articles page of Universitas Airlangga (UNAIR) and has been adapted for publication on the UNAIR Chemistry website.
Original source: “ZSM-5 Zeolite with Molecular Imprinting for the Selective Removal of Creatinine from Dialysate: Toward Enhanced Uremic Toxin Clearance”
