A pilot plant for freeze wastewater treatment producing an annular ice layer in a square pillar shape was constructed. Experiments were carried out to examine ice productivity and the effect of operating conditions such as ice seeding, solution concentration and flow rate on ice crystallization using glucose solution as a substitute for the actual wastewater. The productivity of ice per unit floor area of the ice maker was 578.6 kg/m(2) h in one batch operation of 70 min. A 1.4 fold concentrated solution was obtained after this freeze wastewater treatment. Ice seeding was important for removal of solute during ice crystal growth. Although inclusion of solute in the ice occurred at high concentrations of solution, the effect was reduced with increasing flow rate.