Chemistry and treatment of ground water in the Vojvodina

Due to the geological and hydrochemical characteristics, the majority of the ground waters in the Vojvodina possess an unusual chemistry. Mainly this concerns their high alkalinity, low hardness and high contents in natural organic matter. Moreover the concentrations of arsenic, boron, ammonia and methane are elevated in many waters. Arsenic is present in the inorganic species arsenate(III) and arsenate(V), which are toxic to humans. Complex and expensive technology is required for these types of waters to produce drinking water for the public supply. Amongst others, the treatment process would have to include flocculation with high dosages of chemicals and for some waters also reverse osmosis, resulting in waste water amounts of up to 30%. The latter is critical since the exploited aquifer recharges very slowly. The Tisza River is an alternative resource, especially in the case that bank filtrate extraction could be implemented.