Pollution Characteristics Of A Uranium Tailings Dam And Downstream River Environment Radioactivity

This paper selects a southern uranium mine tailings water environment as the research object, through field visits, sampling and indoor measurement, PHREEQC simulation calculation process, studied the groundwater, radioactive water chemical characteristics of surface water, water chemical composition, as well as radioactive correlation analysis of radionuclides uranium, the use of single-factor evaluation index, Nemerow index evaluation on water quality status and its pollution assessment, estimated ages suffered within dose, the conclusion that the irradiated residents of the collective dose and radionuclide dose contribution. Obtained results are as follows:(1) In water chemistry parameters and the types of water chemistry, the study area tailings discharge water and shallow groundwater and the river has a significant difference, indicating that the study area of shallow groundwater and river water is less affected by industrial discharges of water.(2) Study of shallow groundwater Radionuclides as the distance tailings farther downward trend, probably because of the release of tailings near bedrock and soil enrichment tailings in industrial waste water to migrate through leakage tailings from the sampling point closer; tailings downstream activity of radionuclides in the river along the flow direction of the downward trend, primarily by dilution in rivers radionuclide migration process.(3) Study of shallow groundwater radionuclide U with the chemical composition of the water was positively correlated, U and TDS(salinity) good correlation, indicating that the U and TDS in groundwater good symbiotic relationship; the study area the main surface water nuclide U good correlation with SO42-, SO42- main tailings is a major component in industrial waste water, the impact of the tailings surface water affected.(4) Regional Shallow Groundwater radionuclides U major presence in the form of UO2(OH)2 and UO2CO3, mainly in the form of nuclides Th is Th(OH)4, Th(OH)3+; radioactive water nuclide U major presence in the form of UO2(OH)2, UO2(CO3) 22-, mainly in the form of a nuclide Th Th(OH) 4.(5) The study area surrounding the tailings shallow groundwater and downstream rivers are contaminated radionuclide contamination rate of 100%. Shallow groundwater concentrations of radionuclides in line with WHO "Guidelines for Drinking Water Quality"; tailings downstream river H2 point of receiving industrial wastewater outfall downstream of the first point of the radionuclide concentrations in drinking water in line with China’s "Uranium mining and metallurgy and Radiation Protection regulations on environmental protection. "(6)Study area resident individual dose was in line with "Guidelines for Drinking Water Quality" 2004 the third edition of the World Health Organization’s recommended intake of water resulting effective dose reference levels(1 × 10-4Sv / a); regional water environment radionuclides in individual dose of all ages contribute sortable group for young children, adult, youth group; the whole area residents annual collective dose of 0.865 man· Sv / a, where children group in collective dose of 0.128 man · Sv / a, juvenile group was 0.242 man · Sv / a, 0.495 adult man · Sv / a, the largest contribution to the collective dose nuclides Th(approximately accounting for 47.5%), followed by Ra(approximately 42.1%), the minimum contribution rate of nuclides U(approximately 10.4%).