Sulfate as an ingredient in water

Sulfates can generally be viewed as salts of sulfuric acid (H2SO4). In general, they are all soluble in water, although some, for example barium sulfate, strontium sulfate and lead sulfate, are poorly soluble salts. Since these substances also occur in minerals and rocks, they can be washed out by water over time. One of the most important sulfates is calcium sulfate. This has been an important building material for a long time in the form of its dihydrate as gypsum.

Limit values and beneficial effects of sulfates in water

According to the EU Drinking Water Directive, the officially stated limit values for sulfate are 250 mg/l. However, according to the German drinking water regulations they are 240 mg/l.

However, there are medicinal waters that sometimes contain even more sulphate. Drinking these liquids can alleviate and heal health problems or prevent possible health problems. They support digestion and promote the function of the pancreas and gallbladder. Sulfates are also involved in the construction of proteins and cartilage as well as in the strength of skin and hair. That's why sulfates are also found in many mineral waters sold.

Environmental damage caused by sulfates

Sulfates can cause problems if they end up in the groundwater, largely due to human activity. This can happen, on the one hand, through the manure spread by farmers (this is the faeces of farm animals) or through sulfate-containing waste in landfills, where the more soluble sulfates are washed out by the rain. In these cases, the sulfates provided in this way are gratefully absorbed by the receptive organisms in the water. Since these particularly absorbent organisms are mainly algae and simple aquatic plants, too many sulfates lead to an immense proliferation of these algae and simple plants.

Digested sludge as a negative consequence of sulfate

If these algae and plants then die, their decomposition consumes oxygen. However, if there was a strong increase beforehand, the demand is so high that all oxygen is used up. The danger is particularly high in stagnant water and when there is no wind. In addition to the algae and plants, all other living creatures in the lake then die. The reason for this is that they can no longer breathe. For example, these are crabs and fish. Furthermore, since there is no longer any oxygen available to decompose the dead substance, incomplete decomposition now takes place. This creates a toxic and malodorous sludge. This often has a sulphurous smell.