Skip to main content

Science – Society – Technology

Table 2 Analysis of geothermal waters at the wellhead of the investigated facilities

From: Hydrochemical and operational parameters driving carbonate scale kinetics at geothermal facilities in the Bavarian Molasse Basin

Group Site TDS \(\hbox {CO}_2\) \(\hbox {HCO}_{3}^{-}\) \(\hbox {Ca}^{2+}\) \(\hbox {Mg}^{2+}\) Ca/Mg Scales
  Nr. (mg/L) (mmol/L) (mmol/L) (mmol/L) (mmol/L) (mmol/mmol)  
1 13 634 2.11 5.20 0.93 0.39 2.4  
1 15 680 2.00 5.90 0.96 0.45 2.1 Fe-sulf.
2 17 661 2.00 4.11 0.85 0.18 4.6 cc, Fe-sulf., Cu-sulf., apatite
2 8 656 4.79 4.23 0.42 0.09 4.5 cc, vat, Fe-sulf.
2 10 548 1.80 4.52 0.25 0.08 3.0 cc, Fe-sulf., Cu-sulf.
2 7 648 2.70 3.36 0.58 0.12 5.0 cc, Fe-sulf.
2 9 605 4.79 4.33 0.51 0.11 4.6 cc, Fe-sulf., Cu-sulf.
2 16 689 2.60 4.92 0.71 0.18 3.9  
3 5 917 4.41 5.08 1.09 0.25 4.4 cc
3 6 902 4.80 4.98 0.85 0.23 3.7 cc, Fe-sulf., Cu-sulf.
4 2 4844 3.91 7.24 3.57 1.29 2.8  
4 3a 1109 3.00 12.85 1.05 0.24 4.3 cc, Fe-sulf.
4 3b 2083 5.02 5.00 2.36 0.75 3.1 cc, Fe-sulf.
Group Site (\(\hbox {Na}^{+}+ \hbox {K}^{+}- \hbox {Cl}^{-})/\) \((\hbox {S}^{2-} + \hbox {HS}^{-})/\) pH* SI Water type Scales
  Nr. \(\hbox {HCO}_{3}^{-}\) (meq/meq) \(\hbox {SO}_4^{2-}\) (meq/L)   calcite*  
1 13 0.56 0.54 ** ** \(\hbox {Na}-\hbox {Ca}-\hbox {HCO}_{3}-\hbox {Cl}\)  
1 15 0.57 0.74 ** ** \(\hbox {Na}-\hbox {Ca}-\hbox {HCO}_{3}-\hbox {Cl}\) Fe-sulf.
2 17 0.61 0.58 6.75 0.30 \(\hbox {Na}-\hbox {Ca}-\hbox {HCO}_{3}-\hbox {Cl}\) cc, Fe-sulf., Cu-sulf., apatite
2 8 0.84 1.00 6.72 0.24 \(\hbox {Na}-\hbox {HCO}_{3}-\hbox {Cl}\) cc, vat, Fe-sulf.
2 10 0.92 0.66 ** ** \(\hbox {Na}-\hbox {HCO}_{3}-\hbox {Cl}\) cc, Fe-sulf., Cu-sulf.
2 7 0.70 0.99 6.66 0.22 \(\hbox {Na}-\hbox {HCO}_{3}-\hbox {Cl}\) cc, Fe-sulf.
2 9 0.69 0.76 6.69 0.20 \(\hbox {Na}-\hbox {HCO}_{3}-\hbox {Cl}\) cc, Fe-sulf., Cu-sulf.
2 16 0.67 0.61 6.73 0.17 \(\hbox {Na}-\hbox {HCO}_{3}-\hbox {Cl}\)  
3 5 0.59 2.06 6.42 0.23 \(\hbox {Na}-\hbox {Ca}-\hbox {HCO}_{3}-\hbox {Cl}\) cc, cc
3 6 0.44 1.89 ** ** \(\hbox {Na}-\hbox {Cl}-\hbox {HCO}_{3}\) cc, Fe-sulf., Cu-sulf.
4 2 0.82 8.11 ** ** Na-Cl  
4 3a 0.67 1.86 ** ** \(\hbox {Na}-\hbox {Cl}-\hbox {HCO}_{3}\) cc, Fe-sulf.,cc
4 3b 0.29 4.00 ** ** \(\hbox {Na}-\hbox {Cl}-\hbox {HCO}_{3}\) cc, Fe-sulf.,cc
  1. Total dissolved solids = TDS. * = calculated values. **No data for back-calculation. Four groups of geothermal waters can be distinguished: 1) low-saline dolomite in the northeast of Munich, 2) low-saline limestone southeast of Munich, 3) medium-saline limestone southeast of Munich, 4) high-saline gas-rich western Molasse Basin. Water type = according to Furtak & Langguth (1965)