diffusion
advection
overlying
water
dc layer
Dissolution
Ca z~, HCO 3"
41
uboxic layer
Precipitation:
L
MnCO 3
~oxic layer
Precipitation:
L
FeCO~, metalmlfide, vivianite
diffusion
advection
co~ NO~
sedimentation
02 NO~ SO
organic
matter
C 0 2 , N ~
z, - 4 NO~
organic
matter
- "
PO~,Mn
MnO2
CO,, NH 2,
FeOOH
organic
IN:) ~ , Fe 2~ ,,4matter
HS"
SOy
methane
fermentation
sediments
C02
9 CH4, NIt ~
organic
PO~
matter
porew~er
sediments
Fig. 2.1. Schematic view of the early diagenetic processes
2. (CH20) I06(NH3) 16(H3PO4) + 236 MnO2 + 472 H +
--~ 236 Mn ~+ + 106 CO2 + 8 N2 + H3PO4 + 366.I-I20
A G ~ = -3090 kJ/molc
3. (CH20)106(NH3)16(H3PO4) + 94.4 HNO3
----> 106 CO2 + 55.2 N2 + H3PO4 + 177.2 H 2 0
A G ~ = -3030 kJ/mole
4. (CH20)106(NH3)16(H3PO4) + 424 FcOOH + 848 H +
----> 424 Fe 2+ + 106CO2 + 16 Nit 3 + H3PO4 + 742 H 2 0
A G ~ = -I 330 kJ/mole
5. (CH20) 106(NH3) 16(H3PO4) + 53 SO42"
106 CO2 + 16 NH3 + 53 S 2- + H3PO4 + 106 H 2 0
AG ~ = -380 kJ/mole