Nitrate removal performance of 3D printing of porous Fe-based metallic glasses with triply periodic minimal surface structures

The excessive discharge of nitrate-laden wastewater may cause severe environmental and human health risks. Traditional chemical reduction methods often employ powdered materials, which tend to agglomerate during the reaction process, impeding the complete removal of nitrate ions. Herein, we propose to use selective laser melting 3D printing technology to create porous Fe-based metallic glasses (MGs) with triply periodic minimal surface (TPMS) structure. Firstly, the 3D printing parameters are optimized. Our findings then indicate that the porous MGs effectively avoid powders agglomeration, meanwhile they can achieve 100 % nitrate removal within 25 min due to the multiple active sites including micropores and surface residual stress gaps. In terms of reusability, the efficiency of MGs powders gradually declines below 80 % after 5 cycles, while the porous MGs maintains high removal efficiency after multiple cycles in the absence of powders agglomeration. This study offers a promising approach to powders agglomeration in the nitrate wastewater remediation process.