The Dynamic Experiment on Treating Acid Mine Drainage with Iron Scrap and Sulfate Reducing Bacteria Using Biomass Materials as Carbon Source

The study is aimed at the problem of high content of Cr6+ Cr3+ and SO42- is high and low pH value in acid mine drainage (AMD). Moreover, treatment of AMD by sulfate reducing bacteria (SRB) requires the addition of carbon source, while the treating effectiveness is not good enough on its own. The sugarcane slag, the corn cob and the sunflower straw were selected as the SRB carbon source cooperating with iron scrap to construct the dynamic columns 1, 2 and 3. The mechanism of removing Cr6+, Cr3+, SO42- and H+ and the regularity of sustained release of carbon source and TFe release was studied in AMD. The removal efficiency of heavy metal ions, the ability of sustained release of carbon source, and the ability of adjusting acid by the three dynamic columns were compared. The result shows that the average removal rates of Cr6+, Cr3+ and SO42- in effluent of dynamic column 1, filled by sugarcane slag, iron scrap and SRB, were 96.9%, 67.1% and 54.3%. The average release of TFe and chemical oxygen demand (COD) were 4.4 and 287.3 mg/L. Its average pH was 6.98. Compared with the performance of dynamic columns 1, 2 and 3, dynamic column 1 performed best in removing Cr6+, Cr3+ and SO42- from AMD and controlling the release of COD and TFe, adjusting the pH of the solution. The study is of significance in treatment of AMD by taking for biomass materials as SRB carbon source in cooperation with iron scrap.