King's mine, Norway Parys mine, United Kingdom Cantareras, Spain Richmon mine, USA pH 2,7 2,5 2,7 0,5-1 Eh (mV) - 285 425 - Fetotal 171 650 1130 13-19 × 103 Fe2+ - 650 915 13-19 × 103 Cu 16 40 160 120-650 Zn 25 60 24 700-2600 Sulfate 668 1550 1190 20-100<103 Moderate Fe-oxidizers 1x103 1x103 <102 - Extreme Fe-oxidizers 6 × 104 3 × 103 1 × 105 - S-oxidizers <50 <102 <102 - Heterotrophic acidophiles 2 × 104 2 × 103 <102 -

Table 2: Physic-chemical characteristics of AMD from various sites worldwide and associated microbial populations (Cupper mine). All concentrations of metals and sulfate are shown in mg/L. Microbial counts are cells/ml and “-“ means that numbers are not determined [13].