Efficient phosphorus removal using the La-based perovskite oxides: Role of B-site metal for modulating the surface electronic structure

Wang, Lingfeng; Li, Haibo; Dong, Hao; Cheng, Yan; He, Wenjie; Xu, Yin

doi:.0..

DOI: https://doi.org/10.4491/eer.2024.377

Efficient phosphorus removal using the La-based perovskite oxides: Role of B-site metal for modulating the surface electronic structure

Lingfeng Wang, Haibo Li, Hao Dong, Yan Cheng, Wenjie He^†, and Yin Xu^†

Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China

Corresponding Author: Wenjie He ,Tel: +86 18071792646 (W.H.), +86 02788661699 (Y.X.) , Fax: +86 02788661699 (W.H.), +86 02788661699 (Y.X.) , Email: d20240016@hubu.edu.cn (W.H.), yxu@hubu.edu.cn (Y.X.)
Yin Xu ,Tel: +86 18071792646 (W.H.), +86 02788661699 (Y.X.) , Fax: +86 02788661699 (W.H.), +86 02788661699 (Y.X.) , Email: d20240016@hubu.edu.cn (W.H.), yxu@hubu.edu.cn (Y.X.)

Received: June 20, 2024; Accepted: September 12, 2024.

ABSTRACT

Highly efficient removal of phosphate from water bodies is of great importance to controlling eutrophication. Herein, the lanthanum-based perovskites (i.e., LaMnO3, LaFeO3) were synthesized and employed for phosphorus adsorption. Adsorption experiments showed that the phosphate removal by LaMnO3 was well fitted with the pseudo second-order kinetic model, with a multi-stage adsorption process. The LaMnO3 exhibited a maximum adsorption capacity of 51.3 mg/g for phosphate calculated using the Langmuir model, which was 2.1 times higher than that of LaFeO3 under neutral conditions. Characterization and DFT calculation results further revealed that the La element on the surface of perovskite was the main adsorption site via inner-sphere complex and/or electrostatic interactions, whereas the B-site metal (i.e. Mn element) could trigger the surface electronic structure modulation such as the reduction of surface bonding barrier, for further improving the phosphate adsorption. Additionally, the LaMnO3 adsorbent exhibited commendable performance in treating natural water with low phosphorus concentration and good regenerative capability. This work provides insight into the development of novel perovskite-type adsorbents for efficiently removing phosphorus in environmental remediation.

Keywords: Adsorption | Perovskites | Phosphate | Removal mechanism | Water treatment