Abstract
The solution-diffusion model was used to predict the behaviour of four nanofiltration membranes, two were made of polyamide (NF-99 and NF-97) and the other two were made of polypiperazineamide (DL and DK), when used for the removal of atrazine from aqueous solutions. The mass transfer model applied is very simple and its linearization facilitates rapid calculation of the relevant parameters. The two main parameters, permeate concentration and volumetric permeate flux, are obtained from three different coefficients: water permeability, A w, solute permeability, B s, and osmotic pressure coefficients, Ψ. Good agreement between the experimental and the predicted atrazine concentrations was obtained for the NF-99, DL and DK membranes when the concentration was low. However, only the NF-99 membrane provided accurate values for the two main parameters in the whole range of concentrations studied, which suggests that the solution-diffusion model can only be applied to this membrane.
Acknowledgements
This work is a result of the 08683/PI/08 research project, financed by the Generation of Scientific Knowledge of Excellence Programme of the Foundation Séneca, Agency of Science and Technology of the Region of Murcia (Spain), in the II PCTRM 2007–2011. During this research, M. Gómez and D.S. Barbosa were beneficiaries of Juan de la Cierva and FPI scholarships from MICINN and M.D. Murcia was the beneficiary of Saavedra–Fajardo scholarship from Foundation Séneca.