title: Generation of polluted waters from mining wastes in a uranium deposit.
abstract: Dump consisting of 9500 tons of rich-in-pyrite mining wastes located in the uranium deposit Curilo, Western Bulgaria, was, after rainfall, an intensive source of acid drainage waters. These waters had a pH in the range of about 1.7-4.5 and contained radionuclides (uranium, radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt, iron, and manganese), arsenic and sulphates in concentrations usually much higher than the relevant permissible levels for waters intended for use in the agriculture and/or industry. The generation of these polluted waters was studied under real field conditions for a period of about seven years during different climatic seasons. It was found that the dump was inhabited by a diverse microflora in which some acidophilic chemolithotrophic bacteria were the prevalent microorganisms. The solubilization of the above-mentioned pollutants from the dump material was connected mainly with the oxidation of pyrite and other sulphide minerals by these bacteria. Their activity depended on some essential environmental factors such as temperature, pH, and water, oxygen and nutrient contents in the dump.
authors.affiliation: Department of Engineering Geoecology, University of Mining and Geology "St. Ivan Rilski", Studentski grad - Durvenitza, Sofia 1700, Bulgaria.
authors.forename: Stoyan N
authors.initials: SN
authors.lastname: Groudev
authors.forename: Irena I
authors.initials: II
authors.lastname: Spasova
authors.forename: Marina V
authors.initials: MV
authors.lastname: Nicolova
authors.forename: Plamen S
authors.initials: PS
authors.lastname: Georgiev
mesh_terms: D015258:Acid Rain; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D002031:Bulgaria; D004783:Environmental Microbiology; D004784:Environmental Monitoring; D007220:Industrial Waste / Q000032:analysis; D007501:Iron / Q000032:analysis / Q000378:metabolism; D019216:Metals, Heavy / Q000032:analysis; D008906:Mining; D011850:Radioactive Waste / Q000032:analysis; D012621:Seasons; D013440:Sulfides / Q000032:analysis / Q000378:metabolism; D014501:Uranium / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism; D014875:Water Pollutants, Radioactive / Q000032:analysis* / Q000378:metabolism; D014878:Water Pollution, Radioactive
chemical_list: D015258:Acid Rain; D007220:Industrial Waste; D019216:Metals, Heavy; D011850:Radioactive Waste; D013440:Sulfides; D014874:Water Pollutants, Chemical; D014875:Water Pollutants, Radioactive; C011342:pyrite; D014501:Uranium; D007501:Iron