Study of acid-base balance in the soil-groundwater system

• Дата: 2026
• Автори: Khakhel, O.A., Romashko, T.P.
• Формат: Стаття
• Мова: Англійська
• Опубліковано: S. Subbotin Institute of Geophysics of the NAS of Ukraine 2026
• Теми: soil pH; groundwater pH; pH-buffers interaction
• Онлайн доступ: https://journals.uran.ua/geofizicheskiy/article/view/354142
• Назва журналу: Geofizicheskiy Zhurnal

The interaction between pH-buffer systems of soil and groundwater may play a role in shaping the hydrogeochemical conditions that affect pH stability in these two environments. Despite extensive studies of soil and groundwater, the related behavior of these systems remains poorly understood, especially under conditions of spatial heterogeneity and anthropogenic influence. This study aims to investigate the interaction between soil pH-buffering mechanisms and groundwater chemistry, focusing on identifying the dominant processes governing pH regulation. We measured pH, total alkalinity, calcium ion concentrations, and components of the carbonate buffer system. Soil and groundwater exhibited an interrelated buffering mechanism. pH stabilization in the studied system was controlled by the combined effect of multiple buffering mechanisms, including mineral equilibria, ion exchange, and solution-phase reactions. These processes operated in a coupled manner and were influenced by hydrodynamic conditions and local environmental factors. A conceptual model of «collective buffering action» is proposed to describe the integrated effect of interacting buffering processes, whereby soils and groundwater function as an integrated acid-base system. The model is intended as a qualitative framework rather than a fully quantitative representation. Three phases of buffer interaction between soil and groundwater were identified, ranging from background equilibrium to developed alkalization or acidification, with opposite or synchronized shifts in the pH of soil and groundwater depending on the phase. This mechanism can give early warnings of acid-base disturbances and has practical implications for hydrological environmental monitoring.