Electrochemical determination of diclofenac sodium using modified carbon paste electrode-based Zn/Fe-PANI and its efficient removal using three different layered double hydroxides

• Published in: International journal of environmental analytical chemistry 2024-12, Vol.104 (20), p.9454-9473
• Main Authors: Ahmed Anwar, Alaa A., Mahmoud, Rehab, El-Fatah, Gehad Abd, Farghali, Ahmed A., Hassouna, Mohamed E. M.
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Aluminum; Cobalt; DCFS; Diclofenac; differential pulse voltammetry (DPV); Electrochemistry; Electrodes; Electron microscopes; Electron microscopy; Exothermic reactions; Field emission; Fourier transforms; Hydroxides; Infrared spectroscopy; Investigations; Iron; Isotherms; kinetic; LDHs; Nickel; Nonsteroidal anti-inflammatory drugs; Parameter modification; Parameters; Polyanilines; Pore size; Pore size distribution; Potassium; Potassium ferricyanide; Regression analysis; Regression coefficients; Residues; Scanning electron microscopy; Size distribution; Sodium; Voltammetry; X-ray diffraction; Zeta potential; Zinc; Zn/Fe-PANI/CPE
• ISSN: 0306-7319; 1029-0397
• DOI: 10.1080/03067319.2023.2233913

Zn/Fe LDH-PANI was prepared and characterized by Fourier transform infrared (FTIR), X ray diffraction (XRD), and scanning electron microscopy (SEM). Cyclic voltammetry (CV) was utilized for the electrochemical investigation of unmodified and modified electrodes with Zn/Fe-polyaniline using potassium ferricyanide as a redox probe. Differential pulse voltammetry (DPV) has been used for investigating the oxidative behavior of diclofenac sodium (DCFS) using Zn/Fe-PANI as sensing material. Two types of DPV parameters, including both deposition potential and time, were optimized and discussed. Using DPV, Zn/Fe-PANI/CPE showed a linear range of 1-30 µM with a limit of detection (LOD) of 0.235 µM and a limit of quantification (LOQ) of 0.784µM for DCFS. Antibiotic residues show huge danger to aquatic and ecological areas in recent years. Development of low-cost, high-efficiency adsorbents is critical. Three new adsorbents, viz., ternary, quaternary, and quinary layered double hydroxides (Fe-Co-Ni, Al-Fe-Co-Ni, and Zr-Al-Fe-Co-Ni) were prepared as efficient adsorbents for DCFS residues. Full characterization of them was carried out using XRD, FTIR), Zeta potential, particle size, field emission scanning electron microscope (FESEM), EDX, and BET analysis for specific surface area, pore size distribution, and specific pore volume. Adsorbent dose, time, pH and temperature were investigated and optimized. Studies were carried out on the adsorption isotherm and the Chai equation. The adsorption process was fitted using nonlinear equilibrium isotherm models, and a significant regression coefficient (R 2 - X 2 ) of 0.99 showed an adsorption capacity of (155.05) mg/g for DCFS using the quaternary Al-Fe-Co-Ni LDH as adsorbent. Kinetic studies were best represented with the pseudo-first, second order, Avrami, and 1, 2 mixed order models. The thermodynamic parameters such as ΔS°, ΔGº, and ΔH° were evaluated, assuring exothermic reactions for the adsorption processes. Also, the recycling of the used adsorbents was investigated and discussed. The mechanism of adsorption was monitored using FTIR study of the prepared LDHs.