Abstract
Zeolite imidazole framework-8 (ZIF-8) and the iron doped ZIF-8 (Fe-ZIF-8) were synthesized by the hydrothermal process. The obtained materials were characteristic of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), nitrogen adsorption/desorption isotherms, and atomic absorption spectroscopy (AAS). The results showed that the obtained Fe-ZIF-8 possessed the ZIF-8 structure with a large specific area. ZIF-8 and Fe-ZIF-8 were used for the removal of Remazol Deep Black (RDB) RGB dye from aqueous solutions. The various factors affecting adsorption such as pH, initial concentration, contact time, and temperature were investigated. The results showed that the introduction of iron into ZIF-8 provided a much larger adsorption capacity and faster adsorption kinetics than ZIF-8 without iron. The electrostatic interaction andπ-πinteraction between the aromatic rings of the RDB dye and the aromatic imidazolate rings of the adsorbent were responsible for the RDB adsorption. Moreover, the coordination of the nitrogen atoms and oxygen in carboxyl group in RDB molecules with the Fe2+ions in the ZIF-8 framework played a vital role for the effective removal of RDB from aqueous solution.
Highlights
It is well-known that textile industries, pulp mills, and dyestuff manufacturing discharge a considerable amount of colored wastewaters, which has provoked serious environmental concerns all over the world [1]
The results showed that equilibrium adsorption capacity, qeq, of both adsorbents increased with an increase in temperature which indicated that the process was endothermic
Favorable characteristic parameters of RL for Langmuir isotherm and n for Freundlich isotherm were 0 < RL = 0.034 < 1 and 2 < n = 4.43 < 10, which indicated that both isotherms were favorable. These results confirmed that the equilibrium data of Remazol Deep Black (RDB) adsorption onto Fe-Zeolite imidazole framework-8 (ZIF-8) could be well fitted by the two adsorption isotherm models
Summary
It is well-known that textile industries, pulp mills, and dyestuff manufacturing discharge a considerable amount of colored wastewaters, which has provoked serious environmental concerns all over the world [1]. Remazol Deep Black (denoted as RDB) RGB is a common diazo reactive dye in aqueous solutions and widely used in textile industries [2]. It is stable and hardly biologically degradable due to the presence of aromatic rings. Fe3O4@ZIF-8 showed good adsorption properties for methylene blue, with a maximum adsorption capacity of 20.2 mg g−1 According to these studies, ZIF-8 is highly stable in water and exhibits promisingly high adsorption capacities. ZIF-8 is highly stable in water and exhibits promisingly high adsorption capacities Owing to these features, ZIF-8 should be promising and feasible adsorbents to organic pollutants from aqueous solutions. A possible adsorption mechanism was suggested, based on adsorption at various pH values and surface charges on Fe-ZIF-8
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
