NDMA adsorption and degradation by a new-type of Ag-MONT material carrying nanoscale zero-valent iron

Nitrosamines, which are emerging nitrogenous disinfection by-products, have raised great concern owing to their carcinogenicity and genotoxicity. Thus, exploring efficient materials to remove nitrosamines from the environment is of vital importance. In this work, NaBH4 was taken as a reducing agent and Ag-based metal organic nanotubes (Ag-MONTs) were impregnated in FeSO4 center dot 7H(2)O to prepare nanoscale zero-valent iron (nZVI) supported on the nanotubes (nZVI@Ag-MONTs). The new material was then characterized and applied to N-dimethylnitrosamine (NDMA) adsorption and degradation in water. The material had excellent ability to adsorb and degrade NDMA, and the total concentrations of iron and silver remaining in water did not exceed standard limits after 120 min of adsorption. Coexisting substances, such as NO3-, Cl-, CO32- humic acid, trichloromethane, and trichloronitromethane, did not affect the NDMA removal efficiency of the adsorbent. The NDMA removal efficiency of the new material exceeded 88% even in the presence of SO42- and PO43-. The NDMA degradation mechanism of nZVI@Ag-MONTs included a catalytic hydrogenation reaction and resulted in dimethylamine as the final degradation product. The nZVI@Ag-MONTs showed favorable stability and reusability. Taking the results together, the nZVI@Ag-MONTs proposed in this work are applicable to NDMA adsorption and degradation in water. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Nitrosamines are a type of emerging nitrogenous disinfection by-products that have raised concerns due to their carcinogenic and genotoxic properties. This study introduced a new material, nZVI@Ag-MONTs, which showed excellent ability to adsorb and degrade N-dimethylnitrosamine (NDMA) in water. The material remained stable and reusable, making it a promising option for NDMA removal in water.