How calcium hydroxide can help restore the chemical balance of the oceans
Ocean acidification is a phenomenon that scientists have been observing for years.
Climate change and rising CO₂ levels in the atmosphere are causing the pH value of the oceans to fall.
First of all, it must be taken into account that the oceans and seas play an essential role in carbon absorption: they naturally absorb around 25% of the CO₂ emitted into the atmosphere. When carbon dioxide reacts with water molecules, carbonic acid is formed, which in turn dissociates, releasing hydrogen ions. The hydrogen ions lower the pH of the water, so that as CO₂ absorption increases, the acidity of the water also increases.
This reduces the amount of available carbonate ions, which are essential for many marine organisms such as corals and molluscs to form their calcium carbonate structures. Ocean acidification therefore weakens these organisms, which can have an impact on the entire marine food chain. This is a fact that worries scientists, as the weakening of marine ecosystems could also have consequences for humans, whether due to the nutritional composition of seafood or the spread of pollutants in the marine environment.
Scientists have been searching for solutions to this acidification for several years, and it appears that calcium hydroxide or slaked lime could play a very important role in this. Scientists at the University of Notre Dame (USA) conducted an experiment in the Apalachicola estuary (Florida) with very positive results. They injected 2,000 litres of lime-enriched seawater and found that some of the acid in the water was neutralised and that CO₂ could also be removed. Thanks to this experiment, it has been proven that “ocean liming” would be possible in a natural ecosystem, which would mitigate the effects of human activities on our planet.
Source: https://www.science.org/content/article/ocean-geoengineering-scheme-aces-its-first-field-test
