Sulfate

Sulfates are salts of sulfuric acid and are formed when the hydrogen atom in H₂SO₄ is replaced by a metal or a functional group. Some are soluble in water, such as sodium sulfate, and others, such as calcium sulfate, are insoluble in water.

Sources of sulfate in water

This ion can be added to water from various sources:

– Rain: Rain contains sulfur dioxide, which is produced by volcanic activity and the combustion of fossil fuels. This gas reacts with water in the atmosphere to produce sulfuric acid, which is eventually converted to sulfate ions.

– Dissolution of rocks and soil: Rocks and soil contain mineral sulfates that, when dissolved in water, add (SO₄²⁻) to it.

– Industrial wastewater: Many industries, especially chemical and mining industries, produce wastewater containing large amounts of (SO₄²⁻).

– Agricultural wastewater: The use of fertilizers containing sulfate can also lead to an increase in the concentration of this ion in groundwater and surface water.

– Wastewater treatment plant effluent: In some cases, wastewater from treatment plants also contains this ion.

Adverse effects of high sulfate concentrations in water

– Bitter and salty taste in water: In high concentrations, it gives an unpleasant taste to water.

– Corrosion: Can cause corrosion of metals in plumbing systems.

Duration of sample storage

The maximum time allowed for the sample to be refrigerated until testing is 72 hours, but it is best to perform the test as soon as possible.

How to measure the sample

The measurement is done with a spectrophotometer.