In the years 2005-2010 concentrations of chlorides in the water flow Čaradice brook were evaluated. For their determination we used measuring method according to Mohr. Čaradice brook springs in the mountains of Pohronský Inovec in the southern foot of Drienka hill and it is the right tributary of the Hron River, into which mouth near the village Kozárovce. Samples of the water in longitudinal profile of the watercourse were carried out from six sampling sites, on a regular basis, in the second decade of the month. The places of taking samples were localized to include all real sources causing the pollution of watercourse. The average concentration of chlorides in the monitored period ranged from 12.52 (year 2010) to 28.01 (year 2007) mg dm-3 and for the whole period represented value of 20.54 mg dm-3. Depending on the time of sampling the lowest average concentrations for the whole monitored period in spring season were recorded, with a minimum average value in the month of March (13.93 mg dm-3). From that month occurs generally gradual increase in chloride concentration until the month of October, when we found the highest average concentration in the water flow throughout the period (23.35 mg dm-3). Effect of sampling sites on the chloride concentration in the water flow was as significant as the influence of the month. In the longitudinal profile of the watercourse, we recorded the tendency of its gradual increase in concentration from the first to the last sampling site. Low concentrations in first and second sampling site are likely related to the fact that the sampling sites were located near the natural ecosystems (forest ecosystem and agroecosystem of permanent grassland). The highest average concentration of chlorides during the entire monitored period was in sampling sites situated near the water reservoir, near village Kozárovce (25.11 mg dm-3) and near village Kozárovce (27.46 mg dm-3). Their most significant increase in the water flow near villages’ Čaradice and Kozárovce was recorded. It can be assumed that the increase in Cl- values in mentioned sampling sites is probably due to the fact that villages do not have drainage networks or wastewater treatment. In the regulation of the Government of the Slovak republic No. 269/2010 Coll. the recommended value for chlorides is 200 mg dm-3. Calculated values of 90-th percentile (P90) of this indicator in all sampling sites were lower than the recommended value of government regulations.

chlorides, Slovak Republic, water flow, water quality

Presentation: oral