ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Adsorption equilibrium and modeling of sulfadiazine removal using carbon-based adsorbents derived from expired instant noodle product

Duyen Thi Cam Nguyen and Thuan Van Tran

Center for Hi-Tech Development, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam

E-mail: tranuv@gmail.com

Received: 9 April 2025  Accepted: 14 August 2025

Abstract:

Here, we conducted the synthesis of carbon-based adsorbents derived from an expired instant noodle product for the removal of sulfadiazine. ZnCl₂ was used as an effective activator at different impregnation ratios (1:4, 1:2, 1:1, and 3:2, w/w) to create activated carbons. We found that ZnCl₂ activation brought a porous structure and increased structural defect. Batch adsorption was performed to evaluate the effect of contact time (0–120 min), dosage (0.25–1.0 g/L), pH (3–9), and SDZ concentration (2.5–20 mg/L). Equilibrium sulfadiazine adsorption was mostly achieved at 60 min and pH 7. Chemisorption and monolayer adsorption might play key roles in sulfadiazine adsorption. The adsorbent activated at an impregnation ratio of 1:1 showed a Q_m of 51 mg/g. Thus, this work suggests that the strategy of converting expired food waste into adsorbents can be feasible to alleviate water contamination caused by pharmaceuticals.

Keywords: Food waste; ZnCl2 activation; Antibiotic contamination; Adsorption models

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04329-5

Chemical Papers 79 (12) 8505–8521 (2025)