Enhanced phosphate removal and antibacterial action using hierarchically structured La MOF-20%-C adsorbents and filter membranes

Abstract

To enhance the phosphate removal performance, a porous material (La MOF-20 %-C) was prepared by selectively removing the thermally unstable NH2-BDC ligand from a lanthanum dual organic ligand MOF through pyrolysis. This innovative approach equips La-MOF-20 %-C with dual functionalities: high phosphate adsorption capacity and robust antibacterial effects. The adsorbent showcased a remarkable phosphate adsorption capacity of 97.24 mg P/g and reached equilibrium within 90 min. The material exhibits good anti-interference capability, and the presence of multiple coexisting ions does not affect its adsorption performance. Additionally, it can be used over a wide pH range (3.0–8.0) and has good reusability. Mechanistic studies indicated that electrostatic attraction and ligand exchange were the primary mechanisms for phosphate adsorption. Moreover, La MOF-20 %-C effectively inhibited the metabolic activities of Escherichia coli and Staphylococcus aureus through phosphorus starvation and electrostatic attraction, demonstrating significant antibacterial properties. Importantly, the fabrication of this material into a filter membrane enabled the successful treatment of 16.8 L of actual wastewater, achieving an overall phosphate removal rate of over 85 %, and effectively removing total bacteria. These findings highlight La MOF-20 %-C as a highly promising material with dual functionality for phosphate removal and bacterial inhibition.