Comparative review of sediment properties from drainage canals

Abstract

Our paper presents a comparative review of the properties of sediments from drainage canals in Backa and Banat (two regions in northern Serbia). The drainage canals are important for agriculture and water management in the two regions. On the other hand, these canals are exposed to different point and non-point polluters. The resulting accumulation and increased concentration of undesirable substances in sediments may adversely impact the environment in the canals and their surroundings. Thirty-nine samples of canal sediments were collected in each region. The samples were analyzed for concentrations of macronutrients and heavy metals. The content of nutrients was on average 2 to 2.5 times higher in drainage canal sediments than in the arable soil around the canals. The average concentrations of heavy metals in the sediments were 38.84 and 53.75 mg·kg-1 for Pb; 2.79 and 7.55 mg·kg-1 for Cd; 52.09 and 42.72 mg·kg-1 for Ni; 28.73 and 698.36 mg·kg-1 for Cr; 40.76 and 13.54 mg·kg-1 for As; 60.32 and 52.33 mg·kg-1 for Cu; and 200.10 and 222.94 mg·kg-1 for Zn, for Backa and Banat, respectively. The sediments of studied canals were characterizied by high concentrations of heavy metals, in some of them several times exceeding the allowable maximum concentration. These canals were typically located near large urban areas, directly receiving untreated municipal and industrial waste waters in addition to drainage water. Judging by the number, type and intensity of pollution, the concentrations of nutrients and most of the analyzed heavy metals were higher in the canal sediments from Banat than those from Backa.