Organic fouling behavior of commercially available anion-exchange membranes (AEMs), AMX and ASM was examined by measuring the voltage drop between probe electrodes in an electrodialysis (ED) system consisting of AEM and NaCl solutions containing sodium dodecylbenzene-sulfonate (DBS) as an organic foulant. The slope of the time-voltage curves through AEMs increases with increasing DBS concentration. The slope of the two AEMs increases with increasing current density. ASM has a higher anti-organic fouling property than AMX at high DBS concentrations and/or high current densities because of its high water content.
New technology to perform cooling crystallization accompanying a supply of minute bubbles was developed. Minute nitrogen (N2) bubbles are supplied continually into a saturated sodium chloride (NaCl) solution, and the supplying effect of minute N2 bubbles on cooling crystallization phenomena of NaCl was investigated. minute N2 bubbles were generated using self-supporting bubble generator. When the saturated NaCl solution was cooled down at a constant cooling rate, the induction period of NaCl crystallization was reduced owing to the supply of minute N2 bubbles compared with non-supplying crystallization. Furthermore, a cohesion restraint of NaCl fine particles was observed owing to the presence of minute N2 bubbles.