Having known the fact that on the territory of West-Backa region the only water used for water supply system is subterranean water, from different water layers, an assumption can be made that the waters also differ in their physical and chemical content. It is also assumed that these waters differ in their total iron content. The aim of this work is to test the significance of the difference between central water supply systems of West-Backa region (Sombor, Apatin, Kula and Odzaci) for the value of iron in drinking water, using the adequate statistics methods. The central water supply systems in Sombor, Apatin, and Kula are using water from the second water layer (60-75 m), while the water supply system in Odzaci is using deep artesian and subartesian waters (146-220 m). Sombor and Apatin have the raw water purification system and one of the goals is to decrease the concentration of total amount of iron in drinking water.

Due to very high concentration of organic matter there is a great need for alternative solutions for drinking water disinfection in the world. Chlorine dioxide has been successfully used for almost 50 years for disinfection and later for taste removal, odor control, color reduction and oxidation of inorganic compounds such as iron and manganese. An advantage of using chlorine dioxide instead of chlorine is that it does not directly react with organic matter and form halogenated byproducts when it is used for disinfection. THMs, such as CHBr3, ChCl3 etc, are considered as most dangerous for people health. In this article we are to represent the results got from raw water disinfection treatment with chlorine dioxide.

This study investigates removal efficiency of arsenic species from water on natural and modified sorbent materials. Selective removal of As(III) and As(V) from water was carried out with pure natural materials: bentonite, sepiolite, limonite, pyrolusite and zeolite. Materials most commonly used in water treatment, quartz sand and granular active carbon, were modified by iron coating in order to increase its sorption capacity. For the purpose of comparison, commercial material, granular ferry hydroxide (Everzit As), was investigated under the same conditions. The investigations were performed in batch experiments following the standard experimental methodology. Of all the tested natural materials zeolite exhibited significant sorption capacity: 100 microgram As(III, V)/g. Iron coating increased materials sorption capacity for at least 80%. Iron coated sand and iron coated activated carbon exhibited 340 and 430 microgram As(V)/g respectively.

The results of researches of the degree of metals (Fe and Cu) of accumulation in certain species aquatic macrophytes and their organs which sampled in three lakes near city Kragujevac are exposed in this study. The results show variability of the degree of accumation of Fe and Cu among species, their organs and researched localities, and capacity of some aquatic macrophytes species and their organs which accumulate high level of mentioned metals from aquatic environment. Results obtained in this reserches pointed important role of macrophytes vegetation in bioindication and phytoremediation, and ability for use for monitoring pollutants, in studies of quality aquatic ecosystems and their protection, repairing and revitalization.