Groundwater in the area of eastern Croatia contains increased concentrations of organic
compounds, primarily natural organic matter (NOM). Organic compounds in water become a
problem in drinking water treatment, especially during water disinfection with chlorine, when harmful
disinfection by-products like trihalomethanes appear. Therefore, the removal of disinfection byproducts
(DBP) precursors gains high importance.
This paper deals with the efficiency of NOM removal from groundwater by the Fenton’s process and
its influence on trihalomethane formation potential (THMFP). In this research performance of Fenton
process at conditions close to conditions of natural groundwater was investigated. pH value was not
decreased under 4.5 and attempt was done to perform Fenton’s process at natural iron
concentration in groundwater of town Osijek area. Once optimized, process achieved about 50 %
removal of TOC (2.5 mM H2O2; 0.1 mM Fe2+; pH 4.5) and decrease of THMFP (A254/A203) for about
70 % (5 mM H2O2; 0.1 mM Fe2+; pH 4.5). Under adequate conditions Fenton process could be
successfully used for the removal of organic contaminants from groundwater.