The Effect of Sand Grain Size and Salinity on the Adsorption and Viscosity of Platostoma palustre (Blume) A.J. Paton

Abstract

Platostoma palustre (Blume) A.J. Paton, a natural biopolymer, has shown promise for use in enhanced oil recovery due to its thickening properties. However, limited research has examined how environmental factors such as sand grain size and salinity affect its adsorption behavior and resulting in viscosity changes, which are key parameters in crude oil production from reservoirs. This study investigates how different sand grain sizes (0.149 mm and 0.420 mm) and salinity levels (10,000 and 20,000 ppm) influence the adsorption of P. palustre (Blume) A.J.Paton and how this adsorption affects the solution’s viscosity. The biopolymer was tested in batch systems with concentrations ranging from 2,000 to 6,000 ppm. Four adsorption isotherm models: Henry, Langmuir, Freundlich, and Harkins-Jura were used to analyze adsorption behavior. Results showed that adsorption increased with smaller grain sizes and lower salinity, leading to a significant reduction in solution viscosity. Among the models, Harkins-Jura provided the best overall fit, particularly under high salinity and coarse sand conditions. These findings suggest that optimizing both the environmental conditions and polymer concentration is crucial for maximizing the performance of P. palustre (Blume) A.J. Paton in applications such as polymer flooding.