4. BAHAN ORGANIK SEDIMEN

[email protected]/2013
Accumulated Organic Content
Sinking velocity and travel time for spherical particles in
nonturbulent freshwater (after von Engelhardt
1973, Littke et al. 1997a)
Correlation between
marine organic
carbon
content and
sedimentation rate
sediments
deposited in normal openocean environments (field A),
upwelling high-productivity
areas (field A’) and anoxic
environments (field B)
Allochthonous Organic Matter
accumulate organic matter from
the (mainly planktonic) productivity in the
overlying water column
Autochto
nous
Organic
Matter
Alochtho
nous
• redeposition of marine sediments after
erosion
• turbidity current by which sediment is
suspended in the near-bottom water
column and then settles again
Turbidity currents may expose the organic
matter to an oxygen rich water mass causing
further degradation during resettling
The redeposited allochthonous sediment will
differ only very little in age from the underlying
autochthonous sediment
Organic Carbon
pore-water DOC
concentrations generally
increase with depth
In anoxic sediments :
sulfate reduction
dominates and benthic
macrofaunal processes
(i.e., bioturbation
and/or bioirrigation)
are insignificant
Pore-water DOC concentrations versus depth in bioturbated
and/or bioirigated
Organic Nitrogen
Organic Phosphorus
Dissolved Transport Index (DTI)
Rasio antara konsentrasi materi teruspensi dengan
transport totalnya
DTI 
elemen kimia terlarut
x100%
elemen kimia terlarut  elemen kimia teradsorpsi partikel
Makin tinggi DTI  makin besar komposisi elemen terlarut
Kapasitas Adsorbsi
Banyaknya zat terlarut yang teradsorpsi oleh setiap gram
adsorben pada keadaan jenuh
Kapasitas adsorpsi 
elemen kimia teradsorpsi partikel
100%
elemen kimia terlarut  elemen kimia teradsorpsi partikel
TUGAS
• Jelaskan fate bahan organik C, N, P di sedimen
(lengkapi dengan diagram/skema bila perlu)
• Bila ada data sbb, hitung nilai DTI dan kapasitas
adsorpsi. Jelaskan maknanya
St1
St2
St3
St4
Silikat
saring
St1
St2
St3
St4
N Kjendhal
17.96 14.425 5.595
5.391
saring
1.024
1.118
0.605
0.733
tdk
17.874 15.417 7.098
saring
5.888
tdk
saring
2.033
1.343
0.775
0.541
PO4
Total P
saring
0.157
0.188
0.097
0.081
saring
0.42
0.188
0.446
0.171
tdk
saring
0.02
0.853
0.109
0.026
tdk
saring
0.134
0.108
0.167
0.19