Özet : The understanding of wave dynamics of interfacial two-layer film flows is important for many technological applications. Here, a theoretical and numerical study is undertaken in order to understand the propagation of interfacial and surface waves in a two-layer flow down a vertical wall. In this work, the mathematical modeling of a two-layer film flow using an approximate longwave model is studied. The governing system is formulated as a dynamical system in order to calculate bifurcating families of steady-traveling nonlinear periodic waves. For different wavy regimes, absorption of a weakly soluble gas by the film is calculated. Systematic computations have demonstrated that the absorption rate strongly depends on a wave regime. This theoretical result can be used to enhance efficiency of real-life technological processes in chemical engineering, mechanical engineering, bioengineering and pharmaceutical industry.