Authors
1 Master's student, Department of Environmental Health Engineering, Student Research Committee, Faculty of Health, Mashhad University of Medical Sciences, Mashhad, Iran
2 Associate Professor of Environmental Health Engineering, Department of Environmental Health Engineering, School of Public Health, Mashhad University of Medical Sciences, Iran
3 Assistant Professor of Environmental Health Engineering, Department of Environmental Health Engineering, School of Public Health, Torbat Heydariyeh University of Medical Sciences, Iran
Abstract
Synthetic dyes, due to their high chemical stability and toxicity, are considered among the most significant pollutants in industrial wastewater, and their removal from aquatic environments is of particular importance. Among them, Malachite Green is a widely used cationic dye in the textile and aquaculture industries, which poses a serious threat to the environment due to its toxic effects and bioaccumulation potential. Therefore, the main objective of this study was to evaluate the performance of metal–organic frameworks (MOFs), particularly ZIF-8, in the removal of Malachite Green from aqueous solutions. In this research, three types of MOFs, including Cu-doped ZIF-8 (Cu-ZIF-8), octahedral ZIF-8 (ZIF-8 Octa), and Leaf-like ZIF-8 (ZIF-8 Leaf), were synthesized, and their efficiencies under identical conditions were determined as 42%, 39%, and 50%, respectively. Further investigations were carried out on the ZIF-8 Leaf adsorbent. The effects of parameters such as pH, temperature, contact time, dye concentration, and adsorbent dosage were examined. The results showed that, under optimal conditions (pH = 6, dye concentration = 15 mg/L, adsorbent dosage = 0.5 g/L, and contact time = 60 min), the removal efficiency exceeded 99%. Kinetic studies revealed a better fit of the experimental data to the pseudo-second-order model, indicating the chemical nature of the adsorption process. Experiments on real wastewater samples demonstrated removal efficiencies ranging from 26% to 55%. In addition, the regeneration ability of the adsorbent was confirmed through two adsorption–desorption cycles, with the second cycle still showing 82% removal efficiency. Overall, the findings indicated that Leaf-like ZIF-8, due to its high adsorption capacity, stability, and reusability, can be considered an effective and sustainable option for the treatment of dye-containing wastewater.
Keywords
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