摘要
正渗透技术以其低能耗高效率等特点在分离领域有广泛的应用前景,而驱动液的缓慢发展限制了该技术的进一步应用.传统的无机盐驱动溶质如NaCl等在正渗透过程中会产生严重的浓差极化现象和驱动溶质流失,导致驱动效率下降和溶质损失.针对上述问题现以氯化钠为参考,考察了乙二胺及乙二胺四乙酸有机盐作为正渗透驱动溶质对水通量和盐损失的影响.以商业HTI正渗透膜为评价介质,驱动溶质为0.5mol/L时,EDTA盐,EDA和NaCl盐的水通量分别为14.5、12.8、12.5L/(m2·h),它们对应的特性溶质逆向扩散值(JS/JW)分别为0.3、1.1、1.0g/L.结果表明EDTA盐作为正渗透驱动溶质时可提高正渗透过程的水通量并可显著的降低驱动溶质流失,说明该类物质有作为正渗透驱动溶质的发展前景.
Forward osmosis uses the osmotic pressure difference across a semipermeable membrane as the driving force for the concentration and desalination of the feed solution.Although the development of FO processes has attracted a lot of attention by virtue of its energy-efficiency and high water recovery rate,the FO flux is far below the theoretical prediction because of the internal concentration polarization and high salt leakage in the FO process.In this report,ethylenediamine （EDA） and ethylenediaminotetraacetate （EDTA）,are used as organic draw solutes for forward osmosis and compared with NaCl.The osmotic pressure,FO flux with different membrane orientations,and reverse solute flux were measured using commercial HTI membranes.It was found that in the AL-DS mode,at a draw solution concentration of 0.5 mol/L,the FO water fluxes were 14.5,12.8,and 12.5 L/（m2 · h）,and the specific reverse solute flow rates （Js/Jw） were 0.3,1.1,1.0 g/L for EDTA,EDA,and NaCl,respectively.The reasons behind the very low reverse solute flow of EDTA were analyzed and ascribed to its larger hydration diameter and possible negative net charge.These results showed that such organic species are promising draw solutes for forward osmosis.
出处
《膜科学与技术》
CAS
CSCD
北大核心
2013年第6期87-91,共5页
Membrane Science and Technology
基金
国家重大基础研究“973”项目(2012CB623402
2012CB720903)
国家自然科学基金资助项目(21176119)
