Removal of Acid Orange 7 from Aqueous Solution by Metal-Organic Frameworks

Sungwon Yoon,Monica So,James Calvo

doi:10.3390/cryst9010017

Abstract

We investigated the removal of a harmful anionic dye, acid orange 7 (AO7), from aqueous solution using metal-organic frameworks (MOFs). We prepared four different MOFs (ZIF-8, ZIF-67, UiO-66, UiO-66-NH2) by solvothermal reactions and then tested their adsorption of AO7. Infrared spectra and adsorption capacity data confirmed the removal of AO7 from aqueous solution. The factors we investigated affecting adsorption capacity include variation of the organic linkers and metal clusters of the MOFs. Our results suggest that the hydrogen bonding, π–π interactions, and zeta potentials facilitate the removal of AO7 from water. Of the four MOFs examined, ZIF-67 exhibited the highest adsorption capacity of AO7 and can be regenerated easily.

Highlights

Wastewater contaminated with dyes from the printing and textile industries threatens our environment and health [1,2,3]
acid orange 7 (AO7), can understand the factors that are important in adsorptive removal of we explore the use of metal-organic frameworks (MOFs) as an alternative technology for the removal of AO7 from
ZIF-8 and ZIF-67 adsorbed the most AO7 based on their isoelectric points at pH below 8

Summary

Introduction

Wastewater contaminated with dyes from the printing and textile industries threatens our environment and health [1,2,3]. Two main approaches are used to remove dyes from contaminated water sources. Chemical treatment processes, such as physical adsorption [4], electro-Fenton [5], and Fenton and Fenton-like reactions [6,7] are used to decompose refractory pollutants and improve biodegradability of dye-contaminated water, but these processes suffer from high equipment and running costs. Developing tunable filtration materials to remove AO7 in contaminated water becomes crucial. Metal-organic frameworks (MOFs) have captured attention as attractive adsorbent materials, due in part to their synthetical and chemical tunability [14,15,16] and water stability [17,18,19,20]

Methods

Findings

Discussion

Conclusion