Changes of some sulphuric thermal water characteristics due to chlorination

Positive and negative effects of water chlorination and aeration were examined in samples of sulphuric thermal water from rehabilitation pools. Although chlorination considerably improved the microbiological quality of the water, it caused various negative physical and chemical changes. Aeration caused loss of hydrogen sulphide and production of colloidal sulphur (milky turbidity), whereas chlorination developed a yellowish-reddish-brown colouring depending on chlorine dosage, and also provoked the disappearance of sulphides. It is concluded that sulphuric thermal water should not be chlorinated because of elimination, through chlorination, of therapeutically active compounds causing organoleptic changes that are subject to complaints from patients.