预分散溶剂萃取平衡与传质特性

预分散溶剂萃取(predispersed solvent extraction,简称PDSE）是一种新型的液-液萃取方法.该过程首先将溶剂制成胶质液体泡沫(colloidal liquid aphron ,简称CLA)，同时借助胶质气体泡沫(colloidal gas aphron,简称CGA)实现溶质的分离.本文以磷酸三丁酯（TBP）-煤油为溶剂，以十二烷基苯磺酸钠（SDBS）为水相表面活性剂，以TWEEN 80为油相表面活性剂制备了胶质液体泡沫（CLA）. 用十六烷基三甲基溴化胺（HTAB）为水相表面活性剂制备了胶质气体泡沫（CGA）. 利用半间歇式PDSE过程萃取苯酚溶液.研究了pH值、表面活性剂浓度、相比等对萃取率和平衡分配系数的影响.实验发现，PDSE过程更适用于小相比（油相∶水相为1∶1000或更小）和极稀溶液的萃取.实验还发现, PDSE过程的萃取率随着CLA中TBP浓度的增加而增加, 随相比的增加而提高.利用刚性球模型计算了CLA的传质系数，并与传统的液滴进行了比较.在相同的粒径下，CLA比传统的液滴具有更高的分散相总传质系数；与传统萃取塔中存在的液滴相比，CLA也具有一定的优势.此外，对于两者K_da的比较，更体现了CLA的优越性.

MASS TRANSFER CHARACTERISTICS OF PREDISPERSED SOLVENT EXTRACTION PROCESS

Predispersed solvent extraction( PDSE ) is a new method for separating solutes from aqueous solution by solvent extraction showing promise for efficient and quick extraction from extremely dilute solution.The use of colloidal liquid aphrons in predispersed solvent extraction may ameliorate the problems such as emulsion formation,reduction of interfacial mass transfer and low interfacial mass transfer areas in solvent extraction process.In the present work,colloidal liquid aphrons were successfully generated by using kerosene as a solvent,tributyl phosphate(TBP) as an extractant,sodium dodecyl benzene sulphate(SDBS) as a surfactant in aqueous phase and Tween-80 in oil phase. Colloidal gas aphrons were generated by using hexadecyltrimethyl ammonium bromide(HTAB). Extraction of phenol from dilute solution was studied by using colloidal liquid aphrons and colloidal gas aphrons in a semi-batch extraction column.The effect of pH,surfactant concentration,phase volume ratio on the extraction efficiency of PDSE process was studied.Calculations of mass transfer coefficients of both CLA and conventional liquid droplets revealed that CLA has much higher mass transfer coefficient of the dispersed phase.The PDSE process has a great advantage over traditional single-stage extraction process in K _d a .