Vorlesung 5 - Redox

Diagenetic sequence - Primary redox
reactions
Oxidation by dissolved Oxygen
(CH 2
O) 106
(NH 3
) 16
(H 3
PO 4
) + 138 O 2
-3190 kJ/mol
106 CO 2
+ 16 HNO 3
+ 122 H 2
O + H 3
PO 4
Oxidation by Manganese-Oxides
(CH 2 O) 106 (NH 3 ) 16 (H 3 PO 4 ) + 236 MnO 2
236 Mn 2+ + 106 CO 2 + 8 N 2 + 366 H 2 O + H 3 PO 4
-3090 kJ/mol
Oxidation by Nitrate
(CH 2 O) 106 (NH 3 ) 16 (H 3 PO 4 ) + 84.4 HNO 3
106 CO 2
+ 42.2 N 2
+ 16 NH 3
+ 148.4 H 2
O + H 3
PO 4
-2750 kJ/mol
Oxidation by Iron-Oxides
(CH 2
O) 106
(NH 3
) 16
(H 3
PO 4
) + 212 Fe 2
O 3
+ 848 H +
424 Fe 2+ + 106 CO 2
+ 16 NH 3
+ 530 H 2
O + H 3
PO 4
-1410 kJ/mol
Oxidation by Sulphate
(CH 2
O) 106
(NH 3
) 16
(H 3
PO 4
) + 53 SO 4
2-
-380 kJ/mol
106 CO 2
+ 16 NH 3
+ 53 S 2- + 106 H 2
O + H 3
PO 4
Methane Fermentation
(CH 2 O) 106 (NH 3 ) 16 (H 3 PO 4 ) 53 CO 2 + 53 CH4 + 16 NH 3 + H 3 PO 4
-350 kJ/mol