Abstract
Dyes exposure in aquatic environment creates risks to human health and biota due to their intrinsic toxic mutagenic and carcinogenic characteristics. In this work, a metal-organic frameworks materials, zeolitic imidazolate framework-8 (ZIF-8), was synthesized through hydrothermal reaction for the adsorptive removal of harmful Congo red (CR) from aqueous solution. Results showed that the maximum adsorption capacity of CR onto ZIF-8 was ultrahigh as 1250 mg g−1. Adsorption behaviors can be successfully fitted by the pseudo-second order kinetic model and the Langmuir isotherm equation. Solution conditions (pH condition and the co-exist anions) may influent the adsorption behaviors. The adsorption performance at various temperatures indicated the process was a spontaneous and endothermic adsorption reaction. The enhanced adsorption capacity was determined due to large surface area of ZIF-8 and the strong interactions between surface groups of ZIF-8 and CR molecules including the electrostatic interaction between external active sites Zn−OH on ZIF-8 -and −SO3 or –N=N– sites in CR molecule, and the π–π interaction.
Highlights
Nowadays, dyes and pigments are widely used in chemical industries, which may enter ecosystems during dyes production and subsequent application processes.[1]
Results showed that the maximum adsorption capacity of Congo red (CR) onto zeolitic imidazolate framework-8 (ZIF-8) was ultrahigh as 1250 mg g−1
In all previous studied techniques, adsorption is regarded as a competitive one due to its simplicity, low cost and effectiveness and until now, various adsorbent materials have been examined for CR removal, including activated carbon, clay materials, modified biosorbents and synthetic materials.[8,9,10,11,12]
Summary
Dyes and pigments are widely used in chemical industries, which may enter ecosystems (e.g. aquatic, soils) during dyes production and subsequent application processes.[1]. Due to its high chemical stability and low biodegradability, conventional biological process was found to be ineffective to decolorize and degrade CR wastewater treatment. Some physical-chemical techniques have been investigated for CR removal from aquatic systems, for example, sonophotocatalytisis, photolysis, coagulation/ flocculation and adsorption.[4,5,6,7] In all previous studied techniques, adsorption is regarded as a competitive one due to its simplicity, low cost and effectiveness and until now, various adsorbent materials have been examined for CR removal, including activated carbon, clay materials, modified biosorbents and synthetic materials.[8,9,10,11,12]
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.
