Bimetallic nZVI-induced chemical denitrification modelling using the shrinking core model

In this work the shrinking core model was used for the mathematical modelling of Cu(II)/Fe(0)-induced chemical denitrification in aqueous system. The nano-zero valent iron particles have already been demonstrated their efficiency in the nitrate removal process, and various authors have investigated the influence of several parameters, such as pH and Fe(0)/NO3-molar ratio, on the process. In particular, the addition of a second metal, such as Cu, has proved to improve the kinetic of the overall process, allowing to reduce also the nano-particle surface passivation. The present study reports the classical formulation of the shrinking-core model, applying it to the Fe(0)-Cu(II)/NO3-aqueous system. The static-film simplified hypothesis was assumed and the electrolyte transport equations for dilute system were considered to take into account in the model the influence of other ion species in solution. The model was then employed to fit the experimental data reported in a previous work, in order to estimate the diffusional and kinetic parameter of the process.