High effective adsorption/removal of illegal food dyes from contaminated aqueous solution by Zr-MOFs (UiO-67)

• Published in: Food chemistry Vol. 254; pp. 241 - 248
• Main Authors: Yang, Qingfeng, Wang, Yue, Wang, Jing, Liu, Fangbing, Hu, Na, Pei, Hanna, Yang, Weixia, Li, Zhonghong, Suo, Yourui, Wang, Jianlong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.07.2018
• Subjects: Adsorption; Aqueous drinks; Congo Red - chemistry; Congo Red - isolation & purification; Food Coloring Agents - chemistry; Food Coloring Agents - isolation & purification; Food Contamination; High-adsorption capacity; Illegal food dyes; Kinetics; Metal organic framework; Metal-Organic Frameworks - chemistry; Photoelectron Spectroscopy; Recycle; Rosaniline Dyes - chemistry; Rosaniline Dyes - isolation & purification; Solutions; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Water - chemistry; X-Ray Diffraction; Zirconium - chemistry; Metal organic framework; High-adsorption capacity; Aqueous drinks; Illegal food dyes; Recycle
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2018.02.011

•UiO-67 has been applied in adsorption and removal of illegal food dyes for the first time.•The adsorption capacity of CR and MG on UiO-67 is higher than that of the most reported adsorbents.•The Zr-based UiO-67 also exhibits high adsorption capacity for CR in the practical application. UiO-67, a bifunctional adsorbent, was successfully applied to remove illegal food dyes (Congo red and Malachite green) from aqueous solution. The relevant adsorption conditions were optimized: pH 6, 120 min for contact time, and 10.0 mg L−1 adsorbent dose for Congo red. Adsorption behavior of UiO-67 exhibits a better fitting to pseudo-second-order kinetic model and Langmuir model. Moreover, the maximum adsorption capacities of Congo red (1236.9 mg g−1) and Malachite green (357.3 mg g−1) are higher than that of the most reported adsorbents. Thermodynamic analysis reveals that adsorption processes are spontaneous and endothermic in nature. Powder X-ray diffraction patterns, Fourier-transform infrared spectra and the X-ray photoelectron spectroscopy analysis indicates Zr-OH groups have positive influence on binding of target molecules. What's more, UiO-67 could be reused without significant loss of its capacity after seven cycles. These results prefigure the promising potentials of UiO-67 in food safety risk management.