Arsenic is inorganic spread out in nature. Toxicity of arsenic is different, depending on its form. However, current international and Serbian legislation in drinking water regulate maximum allowed concentration of 0.010 mg/l (of total arsenic), regardless of its form. Concentration of total arsenic in water of springs of mountain Avala (Serbia) is higher than 0.010 mg/l. This paper present determination of inorganic arsenic in drinking water of spring Sakinac (Avala), also determination which form is more represented, relation of As(III) and As(V) and implementation of legislation. We used stripping voltametry method and gain value of total arsenic-62.87 microgram/l, in which 3.97 microgram/l is As(III) and residue of 58.90 microgram/l is As(V). It is obvious that value of 62.87 microgram/l is higher than MAL, but the most abundant arsenic form is less toxic, so the question is whether the water from spring Sakinac can or cannot be used.

Groundwater from the middle Banat region (Serbia) which is used as a drinking water supply for Zrenjanin town contains a high amount of natural organic matter and a high content of arsenic. In this study a pilot-scale system was used to investigate the influence of different ozone doses (0.4-0.9 mg O3/mg DOC) during a pre-ozonation process on NOM removal by coagulation. Ferric chloride coagulant was chosen at a dose of 100 g/cubic meter, as a traditional coagulant which can also help in arsenic removal. The obtained results indicate that an ozone dose of 0.4 mg O3/mg DOC has the best influence on structural changes of NOM. The coagulation process with ferric chloride as coagulant had a significant influence on the arsenic content of the water, with the measured values in the water after coagulation in all three investigated treatment trains being below 10 microgram/l, which is the standard MCL in Serbian legislation.

Content of arsenic in groundwater form south Banat which are used for water supply of local population was determined. 228 wells were analyzed, and for arsenic determination was used atomic apsorption spectrometry - graphite furnace technique (Perkin Elmer Analyst 700). Arsenic is detected in concentrations over 10 microgram/l in several locations: Pancevo (water supply Filter Stanica, Gradska Suma, OB, and in part of water supply Sibnica), Kovin, Dubovac, Idvor, Veliki Gaj, Glogonj, Sefkerin and part of Sakule. The lowest concentrations of arsenic are detected in the territory of Deliblatska Pescara and municipalities of Vrsac and Bela Crkva.

Arsenic speciation can be very important in analysis of water, foodstuffs, and environmental samples, besides of total arsenic analysis. Hydride generation atomic absorption spectrometry can be used for speciation analysis based on different hydride generation condition. In our work, we studied effect of L-ascorbic acid like the reaction medium and the prereducing agent.

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.