Sodium metabisulfite, with the chemical formula Na2S2O5, is a common reducing agent widely used in the water treatment industry. Due to its high reducibility and ability to effectively remove harmful substances such as organic pollutants and heavy metal ions from water, sodium metabisulfite plays an important role in ensuring the quality of drinking water.
1. Basic properties of sodium metabisulfite
Sodium metabisulfite is a white crystalline solid with strong reducibility. Under acidic conditions, it can quickly release SO2 gas, which makes sodium metabisulfite have strong deodorization and decolorization ability in water treatment. Meanwhile, as it does not contain toxic substances, it will not cause secondary pollution to the environment.
2. The application of sodium metabisulfite in water treatment
1) Drinking water treatment
In drinking water treatment, sodium metabisulfite is mainly used to remove organic pollutants and heavy metal ions from water. By adding sodium metabisulfite to water, the redox potential of the water can be rapidly reduced, resulting in the decomposition of organic pollutants. At the same time, heavy metal ions can react with pyrosulfite ions to form soluble complexes, which are then separated from water.
2) Industrial wastewater treatment
In industrial wastewater treatment, sodium metabisulfite is mainly used to remove heavy metal ions and organic pollutants from wastewater. It can not only react with heavy metal ions to generate stable complexes, but also decompose organic pollutants into low toxicity or even non-toxic substances through reduction reactions. Meanwhile, the generated SO2 gas can also be used in processes such as pulp bleaching.