(706c) Optimization of Nano-Composite Membrane Applied in Electrodialysis

Electrodialysis is electro-membrane process to separate ions/electrolytes from their solution. This has been applied since last three decades but due to more popular methods (due to process simplicity) like reverse osmosis or ultra filtration, this has seen lesser attention in development of technology. Recently it has again become popular due to energy crisis and it is thought to be less energy intense than that of the already popular techniques. The process efficiency depends on membrane resistance, concentration of salts, type of ions and voltage applied. The synthesis technique, ion selectivity and cost involved in membrane manufacturing limits its application in commercial in large scale.

Recently a focus is towards minimization of the electrical resistance of the membrane being used in ED apparatus. Few have reported that incorporation of nano particles into the polymer matrix would lead to reduction of resistance and would help water uptake. In this direction, we have tried to find an optimum concentration of meso-porous silica nano particles (as cross linked with PVA and free blended mode) incorporation that may be utilized to obtain maximum ionic flux in separation of NaCl, maximum ionic conductance, and highest transport number. It is needless to mention that mechanical property of membrane was not compromised in this optimization process. Silica particle added physically to the polymer solution did not give desired mechanical stability and ignored for optimization. The cost analysis indicate that cross linked silica while blended with polymer matrix reduces the cost drastically if the quality of water is high value.

Keywords – Optimization, Electrodialysis membrane, silica content, Transport number, Conductivity, Ionic Flux.