An Experimental Study on Freezing Behavior of NaCl and Heavy Metal Aqueous Solution Using Freeze Concentration Method

Kim, Jung-Sik; Lim, Seung-Taek; Oh, Cheol

Journal of Navigation and Port Research 2013;37(2):129-135.
Published online April 30, 2013.

동결농축법을 이용한 염수 및 중금속 수용액의 동결거동에 관한 실험 연구

김정식, 임승택, 오철

An Experimental Study on Freezing Behavior of NaCl and Heavy Metal Aqueous Solution Using Freeze Concentration Method

Jung-Sik Kim, Seung-Taek Lim, Cheol Oh

Abstract

Recently, waste water treatment system is developed in small and middle size to get more economic advantage . Freeze concentration system has high thermodynamic efficiency and low energy consumption, can re-use purified water and cold energy obtained from ice. This study was experimentally performed to investigate pollution containment in frozen layer by cooling wall temperature, air-bubble flow methods, initial ice-lining thickness of frozen layer in NaCl aqueous solution and the representative heavy metals, Pb and Cr aqueous solution. As the result, a decrease in the cooling wall temperature bring a higher growth rate of ice front and the more solute was involved in frozen layer. The method to inject directly air-bubble into ice-liquid interface through ring shape nozzle gave high purity of ice compared to indirect method. Ice lining in 5㎜ thickness resulted in frozen layer with higher purity than 1㎜ thickness.

Key Words: 초기동결층 freeze concentration;freezing behavior;freezing velocity;air-bubble flow method;initial ice-lining