Quality of rainwater: a geochemical process of water-air-rock-life interaction

This paper discusses the quality of rainwater from a chemical-physical viewpoint, linking the acquisition of solutes to the interaction processes among different geochemical spheres. The role played by dust in the formation of raindrops and their stability is highlighted. Emphasis is also placed on the solubilization mechanisms of gases and solids responsible for the mineralization and acidity of atmospheric precipitation. The quantitative relationship between the pH of rainwater and its chemical composition is defined by the formulation of a geochemical model, which allows the initial pH of rainwater to be identified before that contamination, such as the addition of substances with high buffering capacity, changed their hydrogen ion composition.