Affiliation:
1. Environment and Water Directorate, Ministry of Science and Technology, Baghdad, Iraq
2. Department of Chemistry, College of Science for Women, University of Baghdad, Iraq
Abstract
Green synthesis of bimetallic nanoparticles of Fe/Ni (G-Fe/Ni-NPs) and zeolite-5A supported (G-Z-Fe/Ni-NPs) as heterogeneous Fenton-like oxidation for the decolourisation of reactive red 120-dye (RR120) from the aqueous medium using green tea extract as a reducing agent. Zeolite-5A from local kaolin is prepared and characterised using the hydrothermal method and is used as a supporting material for Fe/Ni-NPs. (SEM), (EDX), (AFM), (XRD), (FT-IR), (BET). Its zeta potential were used to characterise G-Fe/Ni-NPs and G-Z-Fe/Ni-NPs. The decolourisation efficiency (Ed) of the RR120-dye using a heterogeneous Fenton-like for G-Fe/Ni-NPs and G-Z-Fe/Ni-NPs is 99.8% and 99.9%, respectively, under the optimum conditions: [H2O2] = 20 and 1 mmol/L, respectively, by G-Fe/Ni-NPs, NPs dosage = 0.1 g/L, [RR120-dye] = 25 mg/L and pH = 3. The results show that the reactivity of Fe/Ni-NPs was improved when zeolite-5A was used as support, showing fast removal. Three kinetic models (first-order, second-order, and Behnajady–Modirshahla–Ghanbary, BMG) were evaluated. The first-order, (econd-order and BMG models were found to be the best models representing the experimental kinetic data of RR120-dye in the state of G-Fe/Ni-NPs and G-Z-Fe/Ni-NPs, respectively. The study of the thermodynamic parameters (ΔG°, ΔH°, and ΔS°) for the removal of RR120-dye at 30°C, 40°C and 50°C indicates an appropriate, spontaneous, and endothermic reaction. The Ed using Fenton-like and adsorption processes are compared.
Subject
Pollution,Water Science and Technology