Cold-induced (>0 oC) Salt-Free Aqueous Two-Phase System (ATPS): For Heavy Metal Ions Removal

Abstract

Abstract An aqueous two-phase system (ATPS) induced by low temperature has been achieved and is capable to the application of heavy metal ions removal. Such system consists the water solution of acetonitrile and triethanolamine (H2O + MeCN + TEOA) that are low-cost materials, which suggested its compatibility for biological issues and satisfactory to large scare industrial applications. The critical temperature has been determined upon the variation of composition proportion. It should be note here that this ATPS could be formed above 0 oC, which is higher than that reported in previous works on MeCN-H2O systems (-16 oC). It proved that the introduction of TEOA can greatly elevated the critical temperature for phase separation. Moreover, such ATPS has been certified restorative when it presented at 7.3 oC, and the process is proved reversible. Interestingly, such ATPS can easily obtain via vacuum process attributed to temperature descend. In this study, the estimation on the removal efficiency of various heavy metal ions has been conducted, which proves them are the excellent candidates addressing the environmental issues.