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Baeyens W. Dehandschutter B. Leermakers M. Bobrov V. A. Hus R. Baeyens-Volant D. 《Water, air, and soil pollution》2003,142(1-4):375-393
Natural geological Hg deposits control the Hg levels inthe upper Katun river. Very high levels of total Hg areobserved in the watercolumn (up to 20 ng L-1) and thesediments (up to 244 μg g-1) close to the depositarea, but almost normal levels (1.8 ng L-1 in the watercolumn and 0.14 μg g-1 in the sediments) are reached60 km downstream of that zone. In general, low dissolvedmethylmercury (MMHg) concentrations were found (0.04–0.05 ngL-1) due to unfavourable methylation conditions. The MMHgconcentrations in the sediments vary from 23.3 ng g-1, inthe vicinity of the geological Hg deposits, to 0.17 ng g-1 60 km downstream.Total Hg levels in Lake Teletskoye (a geological activearea) are slightly increased (1.1–1.8 ng L-1) compared toLake Baikal and fairly constant alover the Lake, suggestingmultiple sources. High mercury concentrations in springs andsoils coincide with high radon concentrations in the samecompartments as well as high soil exhalation fluxes. Theseresults in combination with the fact that Lake Teletskoye islocated in an active fault zone suggest that the Rn and Hgsources may be fault aligned spring waters and deep seatedgases escaping through open cracks. Methylmercuryconcentrations in the Lake (0.03–0.1 ng L-1) werecomparable to the concentrations found in Katun river butrelative to the total Hg burden this means a higher percentage. 相似文献
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V. M. Gavshin F. V. Sukhorukov V. A. Bobrov M. S. Melgunov L. V. Miroshnichenko J. Klerkx S. I. Kovalev P. A. Romashkin 《Water, air, and soil pollution》2004,154(1-4):71-83
In 1996, an abandoned uranium mine was re-discovered in the Djilubulak ephemeral stream valley on the southern shore of Issyk-Kul - one of the largest and most pristine lakes in the world. The tail storages from the past mining may pose a pollution hazard to the lake water and sediments. A chain of six protective pools interconnected by drain pipes descend from the abandoned mine and processing plant down the Djilubulak stream valley. To assess the effectiveness of these catch pools and the scale of pollution risk the investigation of tail storages composition was performed. As a result, three sources of anomalous radioactivity were discovered: 1. Natural brown coal with the mean total radioactivity value not exceeding 16 kBq kg-1, with U being in state of equilibrium with Ra. 2. Ashes depleted in U (relative to Ra) with the mean radioactivity reaching 49 kBq kg-1, mostly due to the Ra content. 3. Clay and silt from the artificial protective pools where U activity (up to 2—2.5 kBq kg-1) significantly exceeds that of Ra indicating recent process of U enrichment. Uranium in these pools is accompanied by very high contents of heavy metals such as Cu, Zn, Cd, Ni, Cr, and to a smaller degree Pb, Mo, Hg, Ag. From the upper catch pool to the lower ones the content of U and some heavy metals diminishes. Within the two lowest pools neither U nor heavy metal contents exceed background values (U < 0.1 kBq kg-1). It appears that the system of catch pools effectively protects Lake Issyk-Kul from inorganic pollutants at the present time. However, a flash flood or other catastrophic event could breach the catch pool dams and carry radioactive elements and heavy metals into the Djilubulak stream valley and the lake. 相似文献
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Eurasian Soil Science - Measuring soil moisture by the dielectric method is considered. It was revealed that the complex dielectric permeability (CDP) affects the readings of sensors using... 相似文献
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