کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
628268 1455486 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Retention modelling of the bivalent cations in crossflow nanofiltration investigation in the porous models
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Retention modelling of the bivalent cations in crossflow nanofiltration investigation in the porous models
چکیده انگلیسی

Our work concerns the feasibility of certain models based on approach of a capillary type, and applied before in ultrafiltration process, for the prediction of the divalent salts retention by a nanofiltration membrane. The model solutions that we chose are those of cadmium and copper salts – whose cations constitute toxic elements introduced into the environment by the effluents coming from industries like those of surface treatment – calcium salt solutions, used within the framework of the nanofiltration softening of the aqueous solutions. The study of the bibliography on the salts retention through a membrane enabled us to formulate some observations: The flow of solvent depends on the membrane permeability; the aqueous solution flow depends on the solvent nature and membrane structure. On this basis, we also could highlight the existence of two mechanisms observed during the filtration of salts: the first, of type solubilization diffusion with the Donnan effect which does not take account of the membrane porosity; the second, electrokinetic who takes account of the membrane porosity. The mathematical models chosen, which seem quite suitable and which derive from this second type of mechanism are: TREMBLAY model; VERNIORY model; NAKAO model. The application of these mathematical models (for the study of the retention evolution of bivalent salts according to volumic flow) requires the development of a data-processing program which finally led to software simulation. We confronted this modeling with experimental results allowing to estimate the principal parameters of transport: the optimal pore radius, reflection coefficient σ and membrane permeability for solute PS. Apparently, the comparison carried out between the experimental results and numerically results obtained (VERNIORY model in particular) gave a good correspondence for a pore radius close to that evaluated by porosimetry method [1]. Moreover, this confrontation authorized us to underline the essential role of certain parameters influencing the retention such as: pH, transmembrane pressure, temperature, concentration of solution treatment and components nature in the solution.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Desalination - Volume 204, Issues 1–3, 5 February 2007, Pages 359-367