膜法提溴过程的研究与对比

Bromine extraction processes with membrane

利用疏水性聚偏氟乙烯(PVDF)中空纤维膜及组件,对膜吸收法浓海水提溴过程进行了研究。首先考察了膜丝寿命,结果表明,浓海水浸泡123天后,膜的孔径和强度未变,透水压力未降低。将该膜应用于浓海水提溴过程,并比较了直接接触式膜吸收法(DCMA)、减压膜吸收法(VMA)和鼓气膜吸收法(ABMA)的提溴效果。实验结果表明,ABMA中溴脱出速率最快,且设备简单;DCMA操作方便,易于控制;VMA中溴的脱出最慢。因此,探讨了ABMA浓海水提溴系统中鼓气强度、吸收液浓度、吸收液温度、吸收液高度和吸收液附加鼓气等因素对工艺的影响。

Bromine extraction with membrane absorption from concentrated seawater was studied with hydrophobic PVDF hollow fiber membrane and its assemblies. The membrane working life was firstly investigated, the membrane strength and water penetration pressure remained unchange after being immersed in brine with bromine for 123 days. Extraction efficiencies via three absorption approaches were compared, including direct contact membrane absorption （DCMA）, vacuum membrane absorption （VMA） and air-blowing absorption （ABMA）. ABMA gave faster bromine removal rate with a simple device, DCMA provided a convenient operation with easy control, and VMA exhibited a lowest bromine removal rate. Therefore, further research was focused on the ABMA approach in optimizing the process factors, such as air-blowing intensity, absorbent concentration, temperature and height as well as additional air-blowing intensity.