Numerical modeling of wastewater treatment using HOLLOW fiber membrane contactors based on the stiff spring method

Abstract

In this study the efficiency of a porous HOLLOW fiber membrane module (PHFMM) was studied using a simple and generic method. Stiff spring method (SSM) was applied in order to solve two-dimensional transient model equations of transport of diluted species through an extractive HOLLOW fiber membrane contactor (HFMC). The influence of equilibrium partition coefficient on membrane efficiency and exit concentration has also been investigated. The predictions made by the present model matched the experimental data obtained for Cu2+removal in a kerosene solution of di 2-Ethylhexyl phosphoric acid (D2EHPA) from wastewater. The results of the model showed that the predictions are in good agreement with the experimental data obtained for different values of species concentration. Furthermore, it was demonstrated that the membrane efficiency and exit concentration could not be predicted well for many ranges of equilibrium partition coefficients by applying non-stiff method. The efficiency of membrane which predicted 56%, can be calculated by non-stiff method only if the partition coefficient considered 800 or more. In contrast, the membrane efficiency was completely fixed and in quite good agreement with the experimental data over a wide range of equilibrium partition coefficients from very low values of 0.02 to a very high values of more than 800 upon application of stiff spring-based method. Similarly, the exit concentration of Cu2+ predicted very well to about 0.4 mol/m3 when the inlet concentration was 1 mol/m3 for a very wide range of partition coefficient by stiff-spring method. However, the outlet concentration of Cu2+ could not be predicted well by non-stiff method unless the partition coefficient supposed to be more than 800. Ultimately, simulation results verify that the stiff spring method is more reliable and accurate in comparison with non-stiff spring method.