Degradation of bis-p-nitrophenyl phosphate using zero-valent iron nanoparticles

5th Nanosafe International Conference on Health and Safety issues related to nanomaterials for a socially responsible approach

物理学;医药卫生;材料科学

Valle-Orta, Maiby^1 ; Diaz, David^2 ; Dubé, Inti Zumeta^2 ; Quinonez, José Luis Ortiz^2 ; Guerrero, Rubén Saldivar^1

Centro de Investigación en Quimica Aplicada, Blvd. Enrique Reyna Hermosillo No. 140, Saltillo Coahuila

C.P. 25294, Mexico^1

Universidad Nacional Autónoma de México, Facultad de Quimica, Ciudad Universitaria, Ciudad de México, Coyoacán

C.P.04510, Mexico^2

关键词: Bis-p-nitrophenyl phosphates;    Degradation mechanism;    Degradation process;    Hydrolysis process;    Inorganic nanoparticle;    Nitrophenyl phosphates;    Organophosphorous compounds;    Zero-valent iron nanoparticles;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/838/1/012034/pdf
DOI  :  10.1088/1742-6596/838/1/012034

来源: IOP

【 摘 要 】

Phosphate esters are employed in some agrochemical formulations and have long life time in the Environment. They are neurotoxic to mammals and it is very difficult to hydrolyze them. It is easy to find papers in the literature dealing with transition metal complexes used in the hydrolysis processes of organophosphorous compounds. However, there are few reports related with degradation of phosphate esters with inorganic nanoparticles. In this work bis-4-nitrophenyl phosphate (BNPP) was used as an agrochemical agent model. The BNPP interaction with zero-valent iron nanoparticles (ZVI NPs), in aqueous media, was searched. The concentration of BNPP was 1000 times higher than the ZVI NPs concentration. The average size of the used iron nanoparticles was 10.2 ± 3.2 nm. The BNPP degradation process was monitored by means of UV-visible method. Initially, the BNPP hydrolysis happens through the P-O bonds breaking-off under the action of the ZVI NPs. Subsequently, the nitro groups were reduced to amine groups. The overall process takes place in 10 minutes. The reaction products were identified employing standard substances in adequate concentrations. The iron by-products were isolated and characterized by X-RD. These iron derivatives were identified as magnetite (Fe3O4) and/or maghemite (γ-Fe2O3) and lepidocrocite (γ-FeOOH). A suggested BNPP degradation mechanism will be discussed.