acidication

Acidification, also referred to as acidication in some contexts, is the process of increasing the acidity of a substance or environment, typically evidenced by a decrease in pH and an increase in hydrogen ion (H+) concentration. It is the opposite of alkalinization and can occur in liquids, soils, and biological compartments.

Acidification can result from direct addition of acids (strong or weak), removal of basic components, or from chemical reactions that generate hydrogen ions. In aqueous systems, dissolution of carbon dioxide from the atmosphere forms carbonic acid, lowering pH. Biological and industrial processes also produce organic or inorganic acids, such as lactic, acetic, sulfuric, or nitric acid, contributing to overall acidity.

Common contexts include chemistry laboratories, where pH control is essential; environmental science, where acid rain or carbon dioxide uptake alters ecosystems; food science, where acidification is used to adjust flavor, texture, and preservation; and medicine, where intracellular acidification of organelles regulates enzyme activity and trafficking.

Ocean acidification is a prominent environmental example: CO2 dissolves in seawater to form carbonic acid, decreasing pH and reducing carbonate ion availability. This shift lowers the saturation state of calcium carbonate, affecting calcifying organisms such as corals, mollusks, and some plankton, and can cascade through marine ecosystems. Acidified soils can also experience nutrient leaching and altered microbial activity, impacting plant growth and soil health.

Mitigation and management strategies include reducing emissions of CO2 and acid-forming pollutants, buffering affected systems through chemical amendments, and monitoring pH and related chemical parameters to guide interventions.