Zagar Dusan, Knap Ana, Warwick John J, Rajar Rudi, Horvat Milena, Cetina Matjaz
Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova 2, Ljubljana, Slovenia.
Sci Total Environ. 2006 Sep 1;368(1):149-63. doi: 10.1016/j.scitotenv.2005.09.068. Epub 2005 Oct 25.
In the town of Idrija, Slovenia, the world's second largest mercury mine was active for 500 years and about 37,000 tons of mercury has been lost in the environment. Mercury is still drained from soil, riverbed and floodplains and transported with the Idrijca and Soca Rivers to the Gulf of Trieste. A part of inorganic mercury is methylated either in the river system, or later in the coastal area, and, due to its bioaccumulation and biomagnification represents potential danger to human health. A 1-D aquatic model MeRiMod was used to simulate hydrodynamics and sediment transport in the river system from Idrija to the Soca River mouth. Transport of particle bound and dissolved mercury as well as potential net methylation of mercury in the river system was simulated. The simulation of an observed flood wave with 20-year recurrence period was performed in order to validate the model. Methylation was simulated at lower discharges, as higher methylation rates occur in such conditions. The measurement data and the MeRiMod model were also used to establish a historical mercury mass balance of the Idrijca and Soca Rivers catchment. Sediment core data from the Gulf of Trieste and the measured concentrations from floodplains were used to verify and calibrate the model. Simulations of different high discharges were performed as most of the transport of particulate mercury occurs within flood wave conditions. Compared to the measurements, the results of the model showed an agreement within an order of magnitude, for the transport of total mercury mostly within a factor of 4, and for the methylation within a factor of 5. However, proper trends of the phenomena were obtained by simulations. The combination of modelling and measurements has resulted in some interesting conclusions about the phenomenon of the transport and transformations of mercury in the observed river system.
在斯洛文尼亚的伊德里亚镇，世界第二大汞矿开采了500年，约3.7万吨汞流失到环境中。汞仍从土壤、河床和洪泛区排出，并通过伊德里亚河和索卡河输送到的里雅斯特湾。一部分无机汞在河流系统中或之后在沿海地区被甲基化，由于其生物累积和生物放大作用，对人类健康构成潜在威胁。使用一维水生模型MeRiMod来模拟从伊德里亚到索卡河河口的河流系统中的水动力和泥沙输运。模拟了河流系统中颗粒结合态汞和溶解态汞的输运以及汞的潜在净甲基化。为了验证该模型，对观测到的20年重现期洪水波进行了模拟。在较低流量下模拟甲基化，因为在这种条件下甲基化速率较高。测量数据和MeRiMod模型还用于建立伊德里亚河和索卡河流域的历史汞质量平衡。的里雅斯特湾的沉积物岩芯数据和洪泛区的测量浓度用于验证和校准模型。由于大部分颗粒汞的输运发生在洪水波条件下，因此进行了不同高流量的模拟。与测量结果相比，模型结果在数量级上显示出一致性，总汞输运大多在4倍以内，甲基化在5倍以内。然而，通过模拟获得了该现象的正确趋势。建模与测量相结合，得出了一些关于观测河流系统中汞的输运和转化现象的有趣结论。
