This study was carried out to determine the feasibility of applying a freeze-concentration technique to purify wastewater polluted
with dye, such as methylene blue (MB) using a stationary wastewater vessel. In this study, we investigated the impact of freezing
temperature, initial MB wastewater concentration and vessel depth upon the removal ratio of MB. Results showed that when the
freezing temperature was decreased (from –5 °C to –15 °C), the freezing rate increased. The freezing rate was not significantly
affected for the different concentrations of the MB solution. The removal ratios of MB at 0-20 mm of ice layer for the concentrations
of MB of 1000 mg/L, 2000 mg/L and 4000 mg/L were 84. 29 %, 82.17 % and 80. 02 % respectively at the freezing temperature of
–5 °C.