T11 PM Developments in Bioremediation of Acid Mine Drainage Wastes
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 343-344

(GRO-1122-316718) PASSIVE TREATMENT OF ACID DRAINAGE WATERS DURING COLD WINTER MONTHS.

Groudev, S¹, Nicolova, M¹, Georgiev, P¹, Spasova, I¹, Diels, L², Tabak, H³, ¹ University of Mining and Geology, Sofia, Bulgaria² VITO, Mol, Belgium³ U.S. Environmental Protection Agency, Cincinnati, Ohio, USA

ABSTRACT- Acid drainage waters were treated under field conditions during different climatic seasons by means of different passive systems (natural and constructed wetlands, alkalizing drains, permeable reactive barriers and rock filters) used separately or in different combinations. The waters had pH in the range of about 2.5 - 3.5 and contained radionuclides (mainly uranium and radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt), 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 passive treatment of these waters was efficient but in most cases markedly depended on the temperature. The best results during the cold winter months were achieved by a multibarrier consisting of an alkalizing limestone drain and a unit for microbial dissimilatory sulphate reduction and sorption of pollutants on the dead plant biomass (plant compost, hay, straw) present in this unit. The multibarrier was located in a light building with an internal air temperature higher than 5 °C even during the coldest days. Under such conditions, the sorption of pollutants was essential and the activity of the sulphate-reducing bacteria and the other metabolically interdependent microorganisms was still quite good.

Key words: Acid