摘要
采用聚偏氟乙烯固体微孔膜,与溶解在煤油中的三烷基氧磷组成支撑液膜(SLM),分离稀水溶液中的乳酸。考察了pH值、料液浓度、载体浓度、温度、料液及解析液流量对传质速率的影响。同时进行了膜稳定性的定性研究。发现乳酸以分子形式通过SLM;载体浓度为40%时传质速率最大;SLM对乳酸的通量与稀水溶液中乳酸浓度成正比。料液和解析液预先用有机相饱和时,膜的稳定性可大大改善。
Experimental studies were carried out on extraction of lactic acid from a aqueous solution using a PVDF Supported Liquid Membrane (SLM) containing 40% (v/v) trialkyl phosphine oxide(TRPO) in kerosene as a carrier. The effects of pH, lactic acid concentration, carrier concentration, flow rates of the feed and strip solutions and temperature on the flux of lactic acid across SLM were investigated. The qualitative discussion on the membrane stability was also made. It was observed that only undissociated molecules of lactic acid can penetrate through the SLM, and that the membrane soaked with 40% TROP-60% kerosene possesses a maximum transfer rate of lactic acid. The transfer rate of lactic acid is proportional to the concentration of lactic acid in the feed solution. The membrane stability can be greatly improved by presaturating the feed and strip solutions with the carrier solvent.
关键词
聚偏氟乙烯
分离
萃取
乳酸
polyvinylidene fluoride
separation
extraction
lactic acid
supported liquid membrane