Comparison of sediment pollution in the rivers of the Hungarian Upper Tisza Region using non-destructive analytical techniques

Abstract

The rivers in the Hungarian Upper Tisza Region are frequently polluted mainly due to mining activities in the catchment area. At the beginning of 2000, two major mining accidents occurred in the Romanian part of the catchment area due to the failure of a tailings dam releasing huge amounts of cyanide and heavy metals to the rivers. Surface sediment as well as water samples were collected at six sites in the years 2000-2003, from the northeast-Hungarian section of the Tisza, Szamos and Túr rivers. The sediment pollution of the rivers was compared based on measurements of bulk material and selected single particles, in order to relate the observed compositions and chemical states of metals to the possible sources and weathering of pollution. Non-destructive X-ray analytical methods were applied in order to obtain different kinds of information from the same samples or particles. In order to identify the pollution sources, their magnitude and fate, complementary analyses were carried out. Heterogeneous particulate samples were analyzed from a large geographical territory and a 4-year time period. Individual particles were analyzed only from the "hot" samples that showed elevated concentrations of heavy metals. Particles that were classified as anthropogenic were finally analyzed to identify trace concentrations and chemical states of heavy metals.Although the Tisza river was affected by water pollution due to the two major mining accidents at the beginning of 2000, the concentration of heavy metals in sediments decreased to the mineral background level 1 year after the pollution event. In the tributaries Szamos and Túr, however, no significant decrease of the heavy metal concentrations was observed in the recent years, indicating a continuous pollution. Among the water suspended particles collected from river Túr, fibers of unknown origin were observed by electron microscopy; these particles were aluminosilicates enriched in Zn and Mn. Cd was also concentrated in this particle type. Zn in the sulfide form was observed by microbeam X-ray absorption near-edge structure analysis only in the samples collected from river Tisza in 2000, while this metal was connected to carbonates and silicates in the other samples. The dissolved Zn content of the river water and the chemical state of Zn in the fibers collected from river Túr indicate that the heavy metal pollution arrived to the Hungarian section originally mostly in the dissolved phase. The accidental heavy metal pollution of River Tisza, however, was in the form of microscopic metal sulfide particles.

Assessment of heavy metals in sediments from a typical catchment of the Yangtze River, China

“…To date, many researchers have conducted extensive surveys of heavy metal contamination in sediments (Meybeck et al 2007;Osán et al 2007). The results demonstrated that accumulation of heavy metals has occurred in sediments of different regions.…”

Tracing the Metal Pollution History of the Tisza River Through the Analysis of a Sediment Depth Profile

“…Together with the cyanide and heavy metal spill from Baia Mare in January 2000, it was recently the most serious environmental disaster in Tisza river (Laszlo et al 2000;WWF 2002). In other studies (Laszlo et al 2000;Fleit and Lakatos 2003;Osan et al 2002Osan et al , 2007, high concentrations of these elements were also noticed in 10-cm surface sediment layers of Tivadar village, as well as the upper Tisza, as indications of these newly arrived pollution events. For the peaks occurring at a depth of about 120 cm of the core, the most possible explanation is heavy runoff from historical metal exploitation.…”

“…The upper Tisza river, flowing through Hungary, has been subject to severe metal pollution due to mining activities and major industrial complexes in Romania, near the border of Romania and Hungary. Heavy floods, which occur regularly due to snow-melting and intensive precipitation, are a great potential risk of enhancing these metal pollutions by leaching of the mine tailing, which are stocked nearby the river banks, as well as spreading of the contamination outside the river bed and further downstream (Hamar and Sarkany-Kiss 1999, Osan et al 2002, 2007. The river has about 70 oxbow lakes, with surface areas larger than 5 ha, that are only connected to the main river during flooding events (Braun et al 2000).…”

Grazing angle X-ray fluorescence from periodic structures on silicon and silica surfaces

“…The TXRF technique is mainly used for micro-and trace-element analysis of evaporated solvents, aerosols and powders [27,28]. Another common application is the control of surfaces' contamination [29].…”