The reliability of innovative membrane contactors technology (i.e. Gas/Liquid Membrane Contactors, Membrane Distillation/Crystallization) is today increasing for seawater desalination processes, where traditional pressure-driven membrane separation units are routinely operated. Furthermore, conventional membrane operations can be integrated with membrane contactors in order to promote possible improvements in process efficiency, operational stability, environmental impact, water quality and cost. Seawater is the most abundant aqueous solution on the earth: the amount of dissolved salts covers about 3% of its composition, and six elements (Na, Mg, Ca, K, Cl, S) account for more than 90% of ionic species. Recent investigations on Membrane Distillation-Crystallization have shown the possibility to achieve significant overall water recovery factors, to limit the brine disposal problem, and to recover valuable salts (i.e. calcium sulphate, sodium chloride, magnesium sulphate) by combining this technology with conventional RO trains. In this work, the kinetics of CaSO4 ⋅ 2H2O, NaCl and MgSO4 ⋅7H2O crystallization is experimentally investigated in order to improve the design of the membrane-based crystallization unit.

시차주사 열분석기를 이용하여 poly(ethylene oxide)(PEO)/poty(styrene-co-acrylic acid) (SAA) blonds에 대한 등온 결정화 속도를 blend의 조성, 사용한 SAA의 공중합조성 및 결정화 온도에 따라 조사하였다. 실험결과는 Avrami 방정식을 이용하여 분석하였다. Avrami지수는 결정화 온도에 관계없이 거의 모든 blend 시료에서 2의 값을 나타내었다. 결정화 속도는 blend시료의 SAA 함량 및 사용한 SAA 공중합체의 아크릴산함량이 증가함에 따라 급격히 느려졌다.