Deposition of Heavy Metals on Sulphate Reducing Bacteria Bioreactor Treatment

Heavy metal sedimentation of acid mine waste (AMW) with sulphate reducing bacteria (SRB) isolated from estuary dam ecosystem sediment of Denpasar was studied in detail. Three isolates of SRB namely DPS 1703, DPS 1705 and DPS 1711 were selected. The bacterium was straight rods, motile, spore-forming and able to grow in simple or defined media. According to physiology and biochemical characterization, the isolates were identified as Desulfotomaculum orientis. The bacterium survived at pH 3 and showed abundant growth at pH 4.0 to 7.0. Reactor with SRB consortium was applied to precipitate heavy metal ions from acid mine waste. The experiment used compost as a simple organic matter source. Growth of SRB in the anaerobic reactor significantly reduced sulphate to sulfide (92.77 -94.52%) and increased the pH from 3 to 6.2-6.7. Soluble heavy metal ions reduced to the much less mobile or insoluble state. The efficiency achieved for Cd(II) was 85.45-90.00%, Pb(II) 95.10-97.95%, Mn(II) 99.79-99.89%, Zn(II) 99.87-99.90%, Cu(II) 99.23-99.43% and Fe(III) 99.93-99.96%.