Tuning adsorption capacity of metal–organic frameworks with Al3+ for phosphorus removal: Kinetics, isotherm and regeneration

• Published in: Inorganic chemistry communications 2021-10, Vol.132, p.108804, Article 108804
• Main Authors: Yang, Zaifu, Zhu, Tong, Xiong, Meiyu, Sun, Anran, Xu, Yujuan, Wu, Yansheng, Shu, Wenjun, Xu, Zhinan
• Format: Article
• Language: English
• Subjects: Eutrophication; Fe-Al-MOF; Isotherm; Kinetics; Phosphate adsorption; Water treatment
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2021.108804

[Display omitted] •Fe-Al-MOF was successfully synthesized via solvothermal one-step treatment.•The adsorption capacity of metal–organic frameworks for phosphorous removal was tuned by Al3+.•Fast kinetics, high sorption capacity and strong selectivity were demonstrated. The separation and recycling of phosphate from sewage are indispensable to be explored due to eutrophication and phosphorus deficiency. Herein, iron-aluminum metal organic framework (Fe-Al-MOF) was successfully synthesized via solvothermal one-step treatment. The Fe-Al-MOF was measured using scanning electron microscopy (SEM), infrared spectrometry (IR), thermogravimetric analysis (TGA) and X-ray powder diffractometer (XRD). Fe-Al-MOF was selected to explore phosphate adsorption performance and its mechanism. The results showed that Fe-Al-MOF adsorbent demonstrated an excellent phosphate sorption capacity of 38.33 mg P/L, strong interference immunity in the presence of co-existing ions and optimal pH adapted to real wastewater. The experimental data was in accordance with the Langmuir model and the pseudo-second-order model, indicating monolayer adsorption as well as physical and chemical adsorption. More importantly, Fe-Al-MOF could reserve over 80% after four continuous regeneration cycles in comparison with the first adsorption capacity, showing its economics. A series of characterizations declared that chemical adsorption, ligand exchange and electrostatic attraction were main adsorption mechanisms by Fe-Al-MOF. Overall, Fe-Al-MOF has high stability, good reusability and high economy to apply for controlling wastewater and eutrophication.