First row transition metals are heavy metals that are very abundant in their compound form and widely applied in industrial fields because of their unique physical and chemical properties. These industrial activities often produce waste that still contains toxic transition metal. To overcome that problems, the transition metal must be separated by an effective and efficient method, that is the emulsion liquid membrane (ELM) because simultaneous separation process. ELM is a separation method that involves three phases. The determinant of the success of the ELM process is the stability of the emulsion which depends on the concentration and type of the surfactant used. Types of surfactants that can be used in the first row transition metal separation using the ELM method are non-ionic surfactants such as Span 80, a mixture of Span 80-Tween 80 and Polyamine ECA 4360J. Therefore, this review article aims to determine the effect of concentrations and type of that surfactants on emulsion stability and extraction efficiency in the separation of first row transition metals using the ELM method.Keywords: First row transition metals, emulsion liquid membrane, surfactant

Rare earth metals (REM) are scarce elements and are only found in the form of complex compounds of phosphate and carbonate. REM consists of 17 elements classified into light REM, medium REM, and heavy REM. This article is focused on lightweight REM, which is widely applied in various industrial fields. Many REM applications are increasing the demand for high-purity and bulk REMs. However, REM has almost the same physical and chemical properties, making it difficult to separate. Therefore, the separation of REM is interesting to study with various methods, one of which is Emulsion Liquid Membrane (ELM). ELM is developing a solvent extraction method involving three phases: the external phase, the internal phase, and the membrane phase. The key to the success of ELM lies in the stability of the emulsion, which is very dependent on the type and concentration of surfactants, so in the ELM process, it is necessary to choose the right concentration and type of surfactant. Therefore, this article was made to know the effect of surfactants such as span-80, span-85, and T154 in separating light REM using the ELM method.