Dependence of biopolymer activity on pH and their influence on soil moisture behavior

The study presents the treatment of soil with chitosan and xanthan gum, examines the influence of the pH of base solutions on the solubility and activity of these biopolymers, and investigates the changes in soil properties resulting from their application. The first stage of the study is devoted to the peculiarities of preparing soil reinforcement with biopolymers and their mixing process. The obtained samples were analyzed for their texture, which allowed identifying the optimal conditions for maximum solubility. The second stage of the study is devoted to evaluating the modified soil's behavior under wetting conditions. The moisture level of the soil directly affects its physical and mechanical properties. Understanding these changes makes it possible to predict the behavior of the soil under different service conditions. The study considered 10 soil samples prepared with base solutions of different acidity (pH 4, pH 7, pH 9), among which one sample serves as a control sample without modification with biopolymers. This makes it possible to evaluate the effect of modification on soil properties and to identify optimal conditions for its use. The analysis showed that the solutions' moisture level and acidity significantly affect the samples' structural characteristics. At the same time modified soils show improved performance compared to the control sample, the sample reinforced with chitosan increased density by 16 %. These data are important for the development of effective solutions in geotechnical and construction engineering.