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

Optimization of cetylpyridinium chloride adsorption using Iraqi date palm frond leaf powder via Taguchi experimental design

Watheq Kareem Salih, Sawsan Abd Muslim Mohammed, and Basma Abbas Abdulmajeed

Scientific Research Commission, Baghdad, Iraq

E-mail: w.saleh1007@coeng.uobaghdad.edu.iq

Received: 1 February 2025  Accepted: 12 September 2025

Abstract:

Biomass-derived bioadsorbents represent an advanced and highly promising approach that can be effectively applied in water treatment, particularly for the removal of pharmaceutical waste substances, which pose a significant environmental risk, especially to aquatic ecosystems. In this study, a powdered bioadsorbent derived from Iraqi date palm frond leaves (IDPFL) as was employed to remove cetylpyridinium chloride (CPC) residues from wastewater. Batch adsorption experiments were designed using the Taguchi method. Four parameters were investigated: concentration (50–250 ppm), adsorbent dose (500–2500 mg/L), shaking speed (50–250 rpm), and shaking time (1–5 h), at an average pH of 7. The Taguchi orthogonal array (L25) consisted of four factors at five levels, with a total of 25 experiments conducted. The optimal conditions determined by Taguchi analysis were an adsorbent dose of 500 mg/L, a mixing speed of 200 rpm, a CPC concentration of 200 ppm, and an adsorption duration of 2 h. Under these conditions, the maximum removal percentage achieved was 74.665%. Eight adsorption isotherm models and four kinetic models were evaluated. The results indicated that the Langmuir adsorption isotherm provided the best fit (R² = 0.9347). Additionally, the pseudo-second-order model aligned perfectly with the kinetic results (R² = 1). The adsorption heat energy, calculated using the Dubinin–Radushkevich isotherm model, was found to be 36 kJ/g, indicating that the adsorption process is favorable and follows a chemisorption mechanism. According to the results, the controlling mechanisms of adsorption are electrostatic interaction and ion exchange. The findings demonstrate that date palm frond powder is a suitable bioadsorbent for the removal of CPC from aqueous solutions and can be effectively utilized in pretreatment stages at treatment facilities located near hospitals or clinical establishments.

Keywords: Cetylpyridinium chloride -CPC; Cationic disinfectant; Medical wastewater; Adsorption; Langmuir; Freundlich; Dubinin–Radushkevich

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04385-x

Chemical Papers 80 (1) 215–231 (2026)