Electrodialysis with bipolar membranes (EDBM) has recently gained increasing attention for the production of acids and bases from the corresponding salt solutions. This process can be very energy-efficient and has a multitude of interesting applications. The intention of this paper is to give a brief overview and technical advantages with the practical applications of EDBM in environmental protection including waste recovery and cleaning production.

This paper investigates the effect of polyethylene glycol (PEG) on the water dissociation of bipolar membranes. To do this, bipolar membranes were prepared by immersing anion exchange membranes in different-concentration solutions of different-molecular-weight PEGs and then casting the solutions of sulfonated polyphenylene oxide (SPPO) on the anion exchange membranes. All the bipolar membranes with PEG in the interface are evaluated by current-voltage curves. The experimental results prove that PEG has excellent catalytic function for water dissociation. Furthermore, this function is enhanced by both PEG amount (PEG concentration) and PEG molecular weight in the interface of a bipolar membrane.

Herein, a back-propagation artificial neural network (BP-ANN), a fit and predictive tool and suitable for bridging the inputs and outputs of a non-linear problem, is used to model the adsorption of bovine serum albumin (BSA) on porous polyethylene (PE) membrane. Based on the adsorption data from FTIR-mapping, the parameters of the neural network with a hidden layer are determined by a trial-and-error method. There is a good agreement between the predicted results by BP-ANN and the experimental data, and the interpolative predictions by BP-ANN are more precise than those by convectional diffusion equation. Though BP-ANN cannot provide detail information concerning the mechanism like a conventional diffusion equation (which can permit an evaluation of diffusion coefficient or mass transfer coefficient), it is a powerful predictive tool as well as a useful compensation to conventional diffusion equation when dealing with the problems of which the mechanism is not entirely understood or very complex.

In this paper, both the percolation theory andthe three-phase model (TPM) are employedto study the ionic transport behavior in sulfonated poly(phenylene oxide) (SPPO) series membranes. The conductive fraction was obtained from TPM, which had consideredcontributions of both the functional group andthe neutral electrolytes impregnatedin the polymer gel. The critical thresholdat which the ions can be transportedthrough the membrane or the membrane transit from insulator to a conductor, was calculated by the experimental data of membrane conductivities with di8erent sulfonation degrees. The results showed that the thresholdchangedslightly from 0.14 to 0.19 when the concentration ranges from 0.01 to 0.1. Since the thresholdis mainly determinedby the active group zone andd istribution, so a geometrically average value 0.16 is reasonably assumedhere. This assumption coincides with the TPM which states that inter-gel fraction is not relatedwith external concentration but relatedwith the membrane properties. This experimental threshold is a little greater than the ideal value of 0.15 for a complete random system, suggesting that these ion cluster phases containing functional groups are not randomly dispersed in a practical SPPO membrane. If contribution of inter-gel is not considered, we will get a slightly larger value 0.18 as described in the previous paper. Therefore, a combination of TPM andpercolation theory can bring us more precise information on ionic transport in SPPO matrices.