Sulfates(SO₄²⁺) are salts of a sulfuric acid in which sulfate anion (SO42−) and a cation – mostly of metal, ocassionaly amonium cation NH4+ – are found.

Limits of the sulfates in drinkable water

Limit of the sulfates in drinkable water are set to 250 mg/l. See more details in the chart.

Quality class	very clean water	clean water	polluted water	highly polluted water	super highly polluted water
Content of the sulfates (mg/l)	up to 80	up to 150	up to 200	up to 300	above 300

Varieties of sulfates

Calcium sulphate, magnesium sulphate, barium sulphate, copper sulphate, ammonium sulphate, potassium sulphate, sodium sulphate, zinc sulphate.

Options to remove the sulfates from the water

• classical condensation of sulfates with the use of lime
• condensation with the use of barium salts
• by high-aluminius cements
• using aluminium and calcium ions
• classical ion exchange
• membrane processes

Effect of sulfates to human health

Sulfates can cause diarrhea (they function as a laxative), digestion problems, irritation to the digestive dystem and dehydratation.

When bacteria overpopulate, sulfates can reduce to a dangerous hydrogen sulfate.