Water Quality of Medium Size Watercourse Under Baseflow Conditions: The Case Study of River Sutla in Croatia

Abstract

The study on medium size river Sutla in Croatia indicated considerable water contamination at specific sites during the baseflow period, probably associated to low flowrate (0.73-68.8 m 3 s -1 ), and consequently low dilution capacity of this river. Various aspects of contamination were observed: increased conductivity to 1,000 lS cm -1 , decreased dissolved oxygen level to 50%, 4-5°C increased water temperature, increased concentrations of several dissolved trace elements (e.g., maximal values of Li: 45.4 lg l -1 ; Rb: 10.4 lg l -1 ; Mo: 20

Accumulation of metals relevant for agricultural contamination in gills of European chub (Squalius cephalus)

“…3b). As seen from Table 1, five sampling sites differed in the level of metal contamination of the river water, and the lowest concentrations were found at site 1 (Hum na Sutli) for Li, Mg, Sr, Ba, V, Co and Mo; at site 4 (Klanjec) for Na, K, Rb, Cs and Ca and at site 5 (Drenje Brdovečko) for Mn and Fe (Dragun et al 2011). The highest water metal concentrations, on the other hand, were generally found at only one site, the site 2 (Donje Brezno), for all metals, except for Ba which was increased in the water at sites 2-5 compared to site 1.…”

“…It has a catchment area of 581 km 2 , and its water discharge in 2009 was in the range from 0.73 to 68.8 m 3 s −1 (Dragun et al 2011). This river is considered as moderately contaminated, and the known contamination sources refer to small industrial facility (glass factory), municipal wastewaters, agricultural runoff and thermal bath discharges (Dragun et al 2011). Fish were sampled at five locations, starting from the source of the Sutla River to its confluence with the Sava River.…”

“…1 and was previously published by Dragun et al (2012Dragun et al ( , 2013b. Detailed physicochemical and microbiological characterization of the river water quality at the selected sampling sites in September/October of 2009 was also previously published (Dragun et al 2011). The samples of surface river water for dissolved metal analysis were taken simultaneously with fish sampling and the measured concentrations of 14 elements discussed in this study, as well as the pH and dissolved oxygen values are presented in Table 1 (data were extracted from previously published detailed study on river water quality; Dragun et al 2011).…”

“…In small rural rivers across the world, which are vital for the life and economy of the areas they are flowing through, agricultural runoff is often the main source of water contamination, followed by small industrial facilities and municipal wastewater outlets. Although total waste input from such sources does not have to be immense, the fact that small watercourses also have small dilution capacity can lead to considerable water and sediment contamination (Dragun et al 2011). The example can be found in the Sutla River, a medium-size rural watercourse on the border of Croatia and Slovenia, which was proven as more contaminated compared with many major Responsible editor: Philippe Garrigues * Zrinka Dragun zdragun@irb.hr rivers under significant industrial impact, due to their higher water discharge and thus also higher dilution capacity (Dragun et al 2011).…”

“…Although total waste input from such sources does not have to be immense, the fact that small watercourses also have small dilution capacity can lead to considerable water and sediment contamination (Dragun et al 2011). The example can be found in the Sutla River, a medium-size rural watercourse on the border of Croatia and Slovenia, which was proven as more contaminated compared with many major Responsible editor: Philippe Garrigues * Zrinka Dragun zdragun@irb.hr rivers under significant industrial impact, due to their higher water discharge and thus also higher dilution capacity (Dragun et al 2011). In the Sutla River, a high number of metals were found in increased concentrations, and among them, it is important to point out metals which are characteristic for agricultural and municipal water contamination: Na and K, which are characteristic for sewage (Dautović 2006); Li, which is characteristic for thermal waters (Fiket et al 2007), as well as Ba, Co, K, Rb, Sr, and V, which can be found increased near the corn fields and cultivated land due to application of fertilizers (Senesi et al 1983;Vachirapatama et al 2002;Schrauzer 2004).…”