Désacidification

Désacidification, or deacidification, is the process of reducing acidity in a substance or system by increasing the pH or decreasing the hydrogen ion concentration. The concept is used across disciplines, including chemistry, agriculture, food and beverage processing, water treatment, and environmental science.

Common approaches vary by context. In chemical and industrial settings, deacidification often involves neutralization with bases such as calcium carbonate, sodium bicarbonate, or potassium hydroxide; dilution with less acidic material; or removal of acids through ion-exchange, filtration, or electrodialysis. In soils, liming with calcium carbonate or dolomitic lime raises pH and lowers soil acidity, improving nutrient availability and microbial activity. In winemaking, deacidification may employ malolactic fermentation to convert malic acid to lactic acid or the use of mineral-based agents to reduce overall acidity, balancing flavor and stability.

In environmental science, désacidification can refer to efforts to raise ocean or freshwater pH to counteract acidification. The primary driver of ocean acidification is rising atmospheric CO2, so deacidification strategies emphasize reducing emissions and, in some proposals, increasing seawater alkalinity through mineral dissolution or other techniques. These approaches are largely experimental and subject to ecological and regulatory considerations.

Potential trade-offs exist with any deacidification treatment. Chemical neutralization can alter mineral balance or sensory properties in foods; liming may affect soil chemistry beyond pH, including metal availability. In aquatic systems, large-scale pH modification can impact organism health and ecosystem dynamics. Overall, désacidification aims to restore or maintain neutral or near-neutral conditions where acidity poses challenges, while balancing practical feasibility and environmental impact.