State-of-the-art predictive modeling of heavy metal ions removal from the water environment using nanotubes

In this research, molecular dynamics (MD) simulation is used to investigate the efficiency of carbon nanotubes (CNT) and boron nitride nanotubes (BNNT) in removing lead ions from contaminated waters. Then the effect of functionalizing nanotubes with -COO- and COOH- functional groups and the nanotubes' absorption performance of two different concentrations of lead ions are studied. To better evaluate adsorption process, the set of descriptors, such as interaction energies, radial distribution function, etc., are calculated. The MD results show that the absorption performance is significantly improved by modifying the surface of CNT and BNNT with functional groups. In addition, the adsorption capacity increases in higher concentrations of Pb ions at BNNTCOO- and CNTCOOH systems. The interaction energy of BNNTCOO- with a concentration of 50 lead ions is - 2879.28 kJ/mol, which is about 106 kJ/mol more negative than BNNTCOO- at a concentration of 20 lead ions. Also, it is observed that the functionalization of both nanotubes with -COO- increases their absorption capacity. The obtained results from this study provide significant information about the mechanisms of lead adsorption on the surface of nanotubes.