Continuous Multistage Electrochemical Precipitation Reactor for Water Softening

Electrochemical precipitation is an attractive method in recirculated cooling water treatment. However, the currently available single electrochemical precipitation reactors are usually poor in softening performance. In this paper, we presented a multistage electrochemical precipitation reactor with eight series-wound cells for water softening. Hydraulic characterization showed that the new reactor proposed had less back mixing, short circuit, and dead zone. Softening investigation further demonstrated that the new reactor had better performance. The precipitation rate, energy consumption, and current efficiency were 71.1 g/h/m2, 3.17 kWh/kg CaCO3, and 37.6%, respectively. It was also found that the multistage reactor could run steadily, with almost no deterioration in softening efficiency detected after long-term operation.