Separation of nitrate ion from water using silicon carbide nanotubes as a membrane: Insights from molecular dynamics simulation

• Published in: Computational materials science Vol. 119; pp. 74 - 81
• Main Authors: Khataee, Alireza, Azamat, Jafar, Bayat, Golchehreh
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2016
• Subjects: Chairs; Computer simulation; Membranes; Molecular dynamics; Nanostructure membrane; Nanotubes; Nitrate ion; Nitrates; RDF; Separation; Silicon carbide; Silicon carbide nanotube; Nanostructure membrane; Silicon carbide nanotube; Nitrate ion; RDF
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2016.03.046

A snapshot of the simulated system with size of 34×39×80Å3 containing silicon carbide nanotubes, silicon nitride membrane, nitrate sodium and ions and water molecules. (Sodium: green, nitrogen: blue, yellow: silicon, cyan: carbon, oxygen: red and hydrogen: white). Nitrate and sodium ions are displayed with van der Waals modes. [Display omitted] •Removal of nitrate using SiC nanotubes by MD simulation.•Calculation of the RDFs between ions and water.•Study of structure of water molecules in the simulation system. Molecular dynamics (MD) simulations were performed to investigate the separation of nitrate ion as contaminant from aqueous solution by means of armchair silicon carbide (SiC) nanotubes. The (7,7) and (8,8) SiC nanotubes embedded in a silicon nitride (SiN) membrane as a membrane immersed in an aqueous solution of NaNO3. An external electric field was applied to the system along the z axis of the simulation cell. In order to investigate these systems, we calculated the ion current, the radial distribution function of water-nanotube and ion-water, the retention time of ions, water density, the hydrogen bond of water, and the autocorrelation function of the hydrogen bond. The results showed that the considered armchair SiC nanotubes can be used for separating nitrate ion from water. The results revealed that nitrate ions were separated successfully using the (8,8) SiC nanotube, though these ions did not pass through the (7,7) SiC nanotube.