Tham khảo tài liệu 'waste management 2009 part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Basic Concepts in Environmental Geochemistry of Sulfidic Mine-Waste Management 191 Fig. 6. Adsorption of oxyanions and bivalent cations to Fe III hydroxides. With decreasing pH the net surface charge becomes positive due to proton adsorption at the surface. Elements which are stable at acidic condition as oxyanions become preferentially adsorbed. The adsorption of metals stable as cations increases with pH due to the increasing negative surface charge of the adsorbent. The dashed curves have been calculated based on data from Dzombak and Morel 1990 from Stumm and Morgan 1996 . As mentioned in section Acidithiobacillus ferrooxidans has been known to play a key role in sulfide oxidation for 40 years Singer Stumm 1970 . These acidophilic chemolithotroph and autotroph bacteria derives cellular carbon from atmospheric CO2 fixation via the Calvin cycle and obtains energy from the oxidation of Fe II or reduced S compounds H2S HS- S S2O32- SO3- . This microbe is also reported to be a facultative H2-oxidizer and is capable of surviving under anaerobic conditions by utilizing reduced S compounds as an electron donor 192 Waste Management and Fe III as an electron sink Davis 1997 . Acidithiobacillus ferrooxidans is the longest known and most studied organism in acid mine drainage and mine waste environments. Nevertheless a diverse microbial population of metal-tolerant neutrophilic to acidophilic sulfide and sulfur-oxidizing Thiobacilli are known so far Johnson Hallberg 2003b Schippers et al. 1995 . Leptospirilum ferrooxidans seems to be the dominant genus in some acid environments as reported from Iron Mountain California Edwards et al. 1998 mine tailings Diaby et al. 2007 or leach piles Rawlings Johnson 2007 . Also heterotrophic bacteria green algae fungi yeasts mycoplasma and amoebae have all been reported from acid mine waters. Wichlacz Unz 1981 isolated 37 acidophilic heterotrophs from acid mine drainage. Davis 1997 reports the highest Acidithiobacillus .
