Author/Editor		Kotnik, Jože; Horvat, Milena; Fajon, Vesna; Logar, Martina; Ogrinc, Nives
Title		Modeliranje hidrodinamike in transporta živega srebra v Velenjskem jezeru - 1. del: živo srebro v jezerski vodi
Translated title		Modelling of hydrodynamics and mercury transport in Lake Velenje - part 1: mercury in lake water
Type		članek
Source		Acta Hydrotech
Vol. and No.		Letnik 21, št. 35
Publication year		2003
Volume		str. 87-103
Language		slo
Abstract		Lake Velenje is located in one of the most polluted regions in Slovenia, the Šalek Valley. There are two major sources of pollution: the coal-fired thermal power plant in Šoštanj (ŠTPP) and the coal mine in Velenje. The aim of our study was to establish the transport and distribution of mercury in the Lake Velenje. In the past, dumping of coal ash directly into Lake Velenje and drainage water from the ash disposal site resulted in unique chemical characteristics of the lake water, such as very high pH (10-12) and high concentrations of heavy metals. The introduction of a closed cycle ash transport system in 1995 resulted in a very fast recovery of the lake water quality. With the aim of establishing recent sources of mercury in Lake Velenje, total mercury and methylmercury concentrations were measured in different environmental samples (lake inflows, outflow, rainwater, sediments, etc.). The results show that the major sources of mercury in Lake Velenje are lake inflows and wet deposition. Total mercury and methylmercury concentrations in the water column are very low (total mercury: 0.2-2.7 ng/L; methylmercury: 20-86 pg/L) and can be compared to other non-contaminated freshwater lakes. Total mercury and methylmercury concentrations were measured at the surface and at different depths to establish mercury cycling, its transport and chemical transformations, and for calibration and verification of a mathematical model for mercury cycling simulations in Lake Velenje, which is in detail described in Part 2. In Part 1 only short summary on lake water isotopic composition and Hg content is given. Data about isotopic composition of lake water are essential for validation and verification of the hydrodynamic model described in Part 2.
Descriptors		FRESH WATER WATER POLLUTANTS, CHEMICAL MERCURY METHYLMERCURY COMPOUNDS TEMPERATURE OXYGEN ISOTOPES HYDROGEN SEASONS