Lattice-trapping synthesis enhances fixation of As(v) in As@zeolite P†

Abstract

Arsenic (As)(V) pollution in natural water poses a global health crisis, yet existing fixation technologies struggle with pH sensitivity and potential reactivation. In this study, an innovative lattice locking synthesis strategy was proposed, which used waste residues to treat As(V)_aq-containing wastewater and at the same time realized lattice locking of As(V)_aq, ensuring high stability immobilization in a wide pH range. Under the standard conditions of the toxicity characteristic leaching procedure (TCLP), the synthesized As@zeolite P showed a fixation efficiency as high as 99.94%. This study combines experimental approaches with Density Functional Theory (DFT) analysis to thoroughly investigate the implantation mechanism of As(V)_aq in As@zeolite P. The stable integration of As(V) within the zeolite lattice was confirmed using HAADF-STEM and XPS techniques. DFT calculations revealed that the implantation process of As(V)_aq in As@zeolite P possesses a low energy barrier and exhibits a non-coplanar structural configuration within the tetrahedral ring pore framework. The characteristic peaks As–O–Al and As–O–Si are in agreement with the infrared spectroscopy data, validating the accuracy of the theoretical model. The findings of this study hold the promise of offering an efficient and stable novel fixative for the treatment of As(V) contamination.