This study was performed to investigate the efficiency of Fenton's process (FP) for removing natural organic matter, in particular the main disinfection by-products precursors. In order to determine the optimal reaction conditions of the process, the influence of pH, mixing speed and reaction time were investigated, as well as the influence of initial concentration and the molar ratio of Fe2+ and H2O2. The best results in terms of reducing the DOC content (by 82%) were achieved under pH 5, 30 rpm, reaction time of 15 min, Fe2+ concentration of 0.25 mM and a molar ratio of 1:10, and in terms of reducing trihalomethane and haloacetic acid precursors (by 98-99%) under a Fe2+ and H2O2 molar ratio of 1:20.

Quality of groundwater from aquifers used for water supply in the town of Zrenjanin, does not meet the drinking water quality requirements. Among the basic problems are the high content of natural organic matter and arsenic, but also sodium and boron. This paper presents one of possible alternative of technological solutions for drinking water preparation in Zrenjanin. Research has lasted three years. The paper presents a only an outline of the drinking water preparation processes.